Advertisement

Biochar

pp 1–13 | Cite as

Past, present, and future of biochar

  • Wenfu ChenEmail author
  • Jun Meng
  • Xiaori Han
  • Yu Lan
  • Weiming Zhang
Review
  • 448 Downloads

Abstract

After entering the twenty-first century, biochar has become a focal point of multidisciplinary research because of its special characteristics, broad application, and promising development prospects. Basic and applied research on the application of biochar in the areas of agriculture, environment, and energy have increased dramatically in the face of food security, environmental pollution, and energy shortage. Although there are some disputes about biochar research, many studies have demonstrated the importance of biochar research from the perspective of scientific advancement and practical application. This paper briefly recalls the history of biochar application; introduces research progress on the basic characteristics of biochar and its associated production technologies; summarizes the research status and existing problems of biochar application in the areas of agriculture, environment, and energy; and analyzes the potential problems and development trends of biochar research in the future.

Keywords

Biochar Agricultural production Soil improvement Pollution abatement New energy 

1 The history of biochar

Biochar, a term that is both new and ancient, generally refers to the carbon-rich solid product when biomass is thermally decomposed under anoxic conditions (Lehmann et al. 2006). As a typical biochar precursor, charcoal has been closely related to human civilization since the Paleolithic era of slash and burn.

1.1 The long history of biochar application

In China, a large amount of black pottery mixed with charcoal was found in the relics unearthed from the Hemudu site more than 7000 years ago (Li 1996). To reduce the clay cohesion and increase the output of finished products, ancestors in Hemudu consciously mixed charcoal in the clay (Ma 2018). There are also records of the use of charcoal from the Shang and Zhou dynasties, which is a testimony to China’s entry into the Bronze Age and then into the Iron Age from an agricultural civilization. In 1971, charcoal was also found at the archeological site of the Mawangdui Tomb from the Han dynasty. Although the tomb owner was buried more than 2100 years ago, her body was still well-preserved when unearthed. The more than 5000 kg of a special charcoal, within the tomb is very likely to be the reason for the preservation of her body in the tomb (You 2012). Using charcoal for energy in ancient China was reflected in the poet of Bai Juyi in the Tang Dynasty. Since the modern civilization, the household application of carbon materials, from charcoal, coal, ink, dyes to preservatives, has become widespread, traditional industrial use of carbon such as electrodes, carbon black, and dynamo brushes, and carbon fiber, pyrolytic graphite and other new industrial carbon products, has also developed (Shui 2009; Yang et al. 2017; Han et al. 2019; Song et al. 2015; Cai et al. 2017).

1.2 Biochar for soil improvement

The Terra Preta in the Amazon Basin of South America is an example of applying biochar to the soil environment (Glaser et al. 2001). In the 1960s, a Dutch soil scientist, Wim Sombroek, discovered a soil rich in black matter in the Amazon basin of Brazil. The content of organic matter, nitrogen (N), phosphorus (P), potassium (K), and other plant nutritional elements were extremely high in this soil which is now called Terra Preta, meaning the black soil of the Indians (Tenenbaum 2009; Harder 2006; Marris 2006). By analyzing the soil components, archeologists found that it contained human-burned wood, ceramic carbon residue, crop residues, and bone residues from various animals including fish (Sombroek et al. 2002). The black carbon in charcoal is considered to be an important component of this black soil, which can exist in soil for 1000 years or longer (Young 1804). Its pore structure facilitates the accumulation of nutrients and beneficial microorganisms, and thus makes the soil more fertile and beneficial to plant growth (Cheng et al. 2008; Shindo 1991). Some archeologists believe that “the black soil from human activities” has unleashed a long-lasting mystery of how a large population of the Amazonian basin had access to adequate food supplies in barren jungle soils before Columbus discovered the New World (Petersen et al. 2001; Lehmann 2009).

1.3 The definition of biochar

Biochar has a long history of use by humans. With widespread attention and an increased understanding of biochar, more and more researchers are trying to unify the definition of biochar. In recent years, with continuously increasing demands for food security, environmental safety, and reduction in greenhouse gas emissions, biochar has gradually been linked to soil management, sustainable agricultural development, and carbon sequestration (Lehmann et al. 2006). In the book “Biochar for Environmental Management: Science and Technology”, Lehmann (2009) defined biochar as the carbon-rich product of biomass produced by “so-called” thermal decomposition of organic materials under conditions of anoxia or limited oxygen supply, and at relatively low temperatures (< 700 °C). Currently biochar’s main uses are for enhancement of soil fertility and for carbon sequestration. In 2013, the International Biochar Initiative (IBI) revised the definition of biochar, pointing out that biochar is a solid product obtained by thermochemical conversion of biomass under anoxic conditions, which can be used alone or as an additive to improve soil fertility, increase resource use efficiency, alleviate environmental pollution, and reduce greenhouse gas emissions. This concept focuses more on the differences between biochar and other carbon products in their application, and further highlights the role of biochar in agriculture and the environment (Fig. 1).
Fig. 1

Framework of biochar research

In China, Chen et al. (2013) advocated for the strategy of returning the carbonized straw to the field in 2006, and put forward the concept of “Straw Biochar Returning” with consideration of the whole industrial chain. In this strategy, biochar-based fertilizer or soil amendment are practical pathways for application of biochar in the environment; and biochar is more clearly defined as a carbon-rich solid product derived from agro-forestry biomass waste such as straw.

2 Structure, elemental composition, and physicochemical properties of biochar

The composition and structure of a substance determine its characteristic and application. Exploration of the structure and properties of biochar is a prerequisite and basis for all applied research. Comprehensive research has been conducted on this aspect, and some key progress has been made in further understanding biochar.

2.1 Structural characteristics of biochar

Biomass is transformed, through pyrolysis and carbonization, into carbon-rich microporous materials which have a well-developed porous structure and a high degree of aromatization (Lehmann and Joseph 2015; Chen et al. 2013). The properties of raw materials and carbonization technologies used for this process relate closely to the properties of biochar (Zhao et al. 2018). The structure of biochar products depends on the structure, inclusions, and cellulose and lignin content of the different biomasses (Lehmann 2007b). For example, the total nano-pore size of rice husk biochar is 2.1 cm3 g−1, which was 12.35 times larger than that of biochar produced from sludge (Ma et al. 2018). The carbonization temperature is also an important factor affecting the biochar structure. It is generally believed that as the carbonization temperature increases, the aromatic carbon structure and the nano-pore size of the biochar increase. However, when the temperature exceeds 700 °C, some microporous structures on the surface of biochar may be destroyed, and when the temperature exceeds 800 °C, the carbon skeleton structure of biochar will be unstable (Lian et al. 2011; Huang et al. 2014).

2.2 Elemental composition of biochar

The composition of biochar generally includes elements such as C, H, O, N, S, P, K, Ca, Mg, Na, and Si; of which C content is the highest (generally above 60%), followed by H and O. The mineral elements exist mainly in the ash (Yuan et al. 2011).

The C in biochar is mainly aromatic carbon, which is deposited in an irregular stack of stable aromatic rings (Lehmann and Joseph 2015). The types of carbon compounds mainly include fatty acids, alcohols, phenols, esters, and components similar to fulvic acid and humic acid. Relatively high levels of the last two components are found in fresh biochar, low temperature pyrolytic biochar, and livestock manure biochar (Bruun et al. 2012). Nitrogen is mainly present on the surface of biochar within a C–N heterocyclic structure, and the available N content is very low in biochar (Lehmann et al. 2006). The content of P in biochar is relatively low. The P availability varies greatly, and is negatively correlated with carbonization temperature. This variation may be impacted by the high pH value and phosphates containing Ca and Mg formed during the process of carbonization (Chan et al. 2007; Cao and Harris 2010). The contents of K, Ca, Mg, and Na are different in different kinds of biochar, with the highest contents in livestock manure biochar, followed by biochar from herbaceous plants and woody plants. Low-valence metal ions such as K and Na are more available than the high-valence metal ions such as Al, Ca, and Mg in biochar. In general, the elemental composition and activity of biochar are related to raw materials, conditions of carbonization process, and pH (Chan et al. 2007; Sadaka and Boateng 2009; Silber et al. 2010).

2.3 Physicochemical properties of biochar

2.3.1 pH

Biochar is generally alkaline, this is mainly related to the inorganic minerals such as carbonates and phosphates, and the ash formed during pyrolysis and carbonization (Yuan et al. 2011), and is also affected by factors such as raw materials and pyrolysis carbonization temperature (Lehmann 2007b). For example, the pH of leguminous biochar is higher than that of non-legume biochar, and under the same conditions of pyrolysis and carbonization, the pH of poultry manure biochar is greater than biochar from herbaceous plants, followed by woody plant biochar (Lehmann 2007a; Yuan et al. 2011). Under different pyrolysis and carbonization temperatures, the pH generally increases as the temperature rises due to the decomposition of acidic functional groups such as carboxyl and phenolic hydroxyl, and the volatilization of organic acids (Novak et al. 2009; Yuan et al. 2011; Chintala et al. 2014).

2.3.2 Specific surface area

The specific surface area of biochar is generally within the range of 1.5–500 m2 g−1 (Suliman et al. 2016; Li et al. 2018), and increases as pyrolysis temperature increases within a certain range (Al-Wabel et al. 2013). At relatively low temperatures volatiles, tars, and other products, from the thermal decomposition of biomass, fill the internal pore structure of biochar, and, therefore, reduce the specific surface area. As the temperature increases, these substances decompose into volatile gases and escape; reducing the pore size but increasing the number of pores in the Biochar, resulting in more microporous structures and larger specific surface areas (Bansal et al. 1988). However, the specific surface area of biochar will reach a plateau as temperature increases. When the temperature exceeds the critical value, the specific surface area decreases with increasing temperature, probably due to the destruction of microporous structure and the enlargement of micropores (Brown et al. 2006).

2.3.3 Surface functional groups

Biochar contains a large number of functional groups such as carboxyl, carbonyl and hydroxyl groups. Most of these functional groups are oxygen-containing or alkaline, these provide biochar with good absorption ability, hydrophilicity or hydrophobicity, buffering, and ion exchange capacity (Anton-Herrero et al. 2018). The number of functional groups on the surface of biochar is closely related to the carbonization temperature. As the carbonization temperature increases, the C–O bond, C–H bond, and O–H bond content in biochar decrease; the number of oxygen-containing functional groups such as hydroxyl and carboxyl and acid groups also decrease, while the number of alkaline groups increases. In total, the number and density of functional groups decrease as the carbonization temperature increases (Gul et al. 2015; Wang 2015).

2.3.4 Cation exchange capacity

Cation exchange capacity (CEC) of biochar is related to the biomass type and pyrolysis temperature (Suliman et al. 2016). In the carbonization process, some oxygen-containing functional groups such as hydroxyl, carboxyl and carbonyl are retained due to the incomplete decomposition of cellulose; increasing the biochar CEC (Lee et al. 2010). Moreover, as biochar ages, some functional groups on the surface can generate more oxygen-containing functional groups through oxidation reactions, which could increase the O/C ratio and CEC of the biochar (Clough and Condron 2010; Atkinsonc et al. 2010). Within a certain range, the biochar CEC decreases with increasing temperature (Kalinke et al. 2017), accompanied by the destruction of oxygen-containing functional groups, the reduction of the negative charge on the biochar surface, and the decrease in the O/C ratio (Lee et al. 2010; Suliman et al. 2017). On the other hand, the increase in temperature causes an increase in the content of alkali metals such as K, Ca, and Mg in biochar, which could lead to an increase in CEC (Chen et al. 2011; Kalinke et al. 2017).

2.3.5 Water-holding capacity

In general, as the temperature increases, the degree of aromatization and hydrophobicity of biochar is enhanced, the number of functional groups containing O and N is decreased, and the water-holding capacity of biochar declines (Shinogia and Kanri 2003; Moreno-Castilla 2004; Kinney et al. 2012). Studies have shown that the straw biochar prepared at 300 °C had a water-holding capacity of 13 × 10−4 ml m−2, however, when carbonization temperature was raised to 700 °C, it was reduced to 4.1 × 10−4 ml m−2 (Spokas 2010).

2.3.6 Stability

Biochar has a high degree of carboxylate esterification and aromatization structure, high C content, very low solubility, high boiling point, high stability, and strong resistance to physical, chemical, and biological decomposition (Hammes et al. 2008; Leng et al. 2019). These characteristics allow biochar to exist in the soil for thousands of years under natural environmental conditions (Sun et al. 2018).

3 Biochar and agriculture

3.1 Biochar and farmland management

The inherent structure and physicochemical properties of biochar have a direct or indirect impact on the soil micro-ecological environment by affecting soil bulk density, water content, porosity, cation exchange capacity and nutrient content (Chen et al. 2013). The abundant organic carbon and minerals in biochar are also beneficial for increasing soil organic carbon content (Zwieten et al. 2010; Lehmann et al. 2006; Steiner et al. 2008) and soil mineral content (Zwieten et al. 2010). Moreover, the high porosity in biochar also improves soil water holding capacity significantly (Glaser et al. 2002; Benjamin et al. 2019). Biochar’s alkaline nature supports its use as a soil amendment for acid soil and for improving soil nutrient availability (Novak et al. 2009; Masulili et al. 2010; Muhammad et al. 2018). This property also makes biochar an effective material for the ameliorating saline soil (Saifullah et al. 2018). Therefore, biochar can be used as a soil amendment because it can overcome or alleviate soil constraint factors, promote crop growth and development, suppress pathogen infestation, and reduce the absorption of harmful substances such as heavy metals and pesticides by plants (Beluri et al. 2018). Biochar can also be used as a carrier for slow/controlled-release fertilizers and microbial inoculants, which can be applied in producing biochar-based compound fertilizers, biochar-based organic fertilizers, biochar-based bio-fertilizers, etc., due to biochar’s ability in delaying the release of nutrients in the soil, reducing leaching and fixing losses, and improving nutrient utilization efficiency.

3.2 Improvement of crop yield by biochar application

The effects of biochar on crop yield depend largely on the amount of biochar applied and the soil types. Biochar has a positive effect on crop yield in general, and it is more effective when applied to low to medium fertility or degraded soil rather than to fertile or healthy soil (El-Naggar et al. 2019). Lehmann et al. (1999) applied biochar to soil at a rate of 68 t ha−1 and 135 t ha−1, and found that the biomass of rice and cowpea increased by 17% and 43%, respectively. Uzoma et al. (2011) applied biochar at a rate of 15 t ha−1 and 20 t ha−1 to the sandy soil where maize was grown and found that the crop yield was increased by 150% and 98%, respectively.

The positive effect of biochar on crop biomass and yield has been found to accumulate with time. Major et al. (2010b) conducted a multi-year experiment in a maize–soybean rotation system, and found that the maize yield was not increased in the 1st year when biochar was applied at 20 t ha−1. However, the yield was increased by 28%, 30%, and 140% compared to the control in the following 3 years, respectively. Field research conducted in the Amazon River basin in Brazil also showed that an 11 t ha−1 of biochar application increased the grain yield of rice and sorghum together by 75% after four growing seasons in 2 years (Steiner et al. 2007).

In addition to studies on the interaction between biochar and soil, the interaction between biochar and fertilizers has also attracted the interest of researchers (Yamato et al. 2006). In China, in particular, researchers have mixed biochar with fertilizers and invented biochar-based fertilizers, which increase crop yield significantly. For example, the biochar-based fertilizer specifically for peanut increased its yield by 13.5% due to extended functional duration of leaves; a biochar-based fertilizer developed specifically for maize increased its yield by 7.6–11.6% due to increased grain number and weight; and a biochar-based fertilizer designed for soybean increased its yield by 7.2% due to increased branch number, grain number per plant, and 100-grain weight (Cui and Chen 2008; Cui et al. 2008; Chen et al. 2008).

In summary, the effect of biochar on crop yield depends not only on biochar’s characteristic and function, but also on soil conditions and ways to apply biochar. Only by adapting to local conditions, and by knowing the soil constraint factors, can the advantages of biochar be fully used for farmland management.

3.3 Biochar and livestock/poultry/aquatic production

3.3.1 Biochar improves animal growth performance

Biochar can improve the digestion and metabolism of nutrients in animals, thereby improving animal growth performance. For example, an increase of biochar in the feed improved the protein levels in the muscles of Nile tilapia (Boonanuntanasarn et al. 2014); the application of 2% biochar in the feed significantly increased the specific growth rate of catfish and reduced ammonia nitrogen emissions (Quaiyum et al. 2014); application of bamboo charcoal significantly increased the specific growth rate, feed conversion efficiency, and protein efficacy ratio of flounder (Thu et al. 2010); a supplement of wheat straw bio-charcoal to fodder reduced the deposition of abdominal fat, lowered total cholesterol in serum and triglyceride levels, and to a certain extent, improved the growth performance of broilers (Fu et al. 2015). Similar results have also been found in turkeys (Majewska et al. 2009) and goats (Villalba et al. 2002).

3.3.2 Disease resistant and anti-bacterial effects of biochar

Biochar and its by-product wood vinegar have disease resistance and anti-bacterial effects. Dietary charcoal powder including wood vinegar, as a feed additive, improved the feed utilization efficiency of piglets (Mekbungwan et al. 2004), promoted piglet growth (Han et al. 2014), and increased the average daily weight gain of ducks (Ruttanavut et al. 2009).

The adsorption of toxic substances by biochar is thought to improve disease resistance and promote the healthy growth of animals. Kana et al. (2010) reported that dietary plant charcoal from Canarium schweinfurthii Engl. seed and maize cob alleviated the decline in average daily feed intake and intestinal-specific weight of broiler chickens caused by aflatoxin B1 toxicosis. Watarai and Tana (2005) found that the carriage of Salmonella enterica serovar enteritidis was eliminated in domestic fowls and the damage to its intestine was reduced by feeding activated charcoal from bark containing wood vinegar. Besides, adding 1% biochar including wood vinegar in feed improved the immunologic function and anti-stress ability of piglets (Han et al. 2014). Moreover, biochar can purify aquaculture water (Qi et al. 2012) and wastewater of aquaculture (Wu et al. 2010), contributing to the healthy development of animal husbandry.

4 Biochar and environment

Biochar has become a focus of soil environmental research as a result of its potential for increasing soil carbon sinks, reducing greenhouse gas emissions, remediating contaminated soils and alleviating the pressure of straw burning.

4.1 Carbon sequestration and emission reduction

The carbon framework of biochar is stable and difficult to decompose, and it can be immobilized by soil and transformed directly to carbon sinks in the soil (Cao and Pawłowski 2013). Biochar has a profound impact on the transformation processes of carbon and nitrogen in the soil. The application of biochar reduces soil CO2 emissions due to a negative priming effect (Zimmerman et al. 2011; Chintala et al. 2014; Cross and Sohi 2011; Major et al. 2010a; Steinbeiss et al. 2009; Sagrilo et al. 2015) and N2O emissions are reduced significantly through various mechanisms (Jia et al. 2012; Renner 2007; Cayuela et al. 2014). These mechanisms include that (1) the proportion of N2O transformation to N2 during denitrification is changed due to the change of pH (Sun et al. 2014); (2) the abundance of soil microbes is changed (Zhu et al. 2017), in particular, the increase in the growth and activity of microorganisms involved in denitrification (Bruun et al. 2011); (3) the adsorption ability of soil to NH4+ or NO3 is improved (Kettunen and Saarnio 2013; Van Zwieten et al. 2010; Case et al. 2012); (4) soil aeration is enhanced and the denitrification rate is reduced (Rogovska et al. 2011; Augustenborg et al. 2011). In general, biochar demonstrates a significant effect on soil N cycle, although the effects are not exactly the same across various studies due to the differences in soil characteristics, management practices, and application methods (Clough et al. 2010; Wang et al. 2012; Quin et al. 2014). In a rice cropping system, biochar reduced soil CH4 emissions significantly (Feng et al. 2012) and increased soil net absorption of CH4 (Khan et al. 2013). However, other studies showed that biochar increased soil CH4 emissions (Zhang et al. 2010), which was probably because biochar provided a substrate for methanogens (Zhang et al. 2013) or inhibited the activity of methane oxidizing bacteria (Spokas and Reicosky 2009).

4.2 Contamination control

Contamination control using biochar has been researched for a long time (Shaheen et al. 2019). Biochar mainly affects the bioavailability of heavy metals in the soil through adsorption; the adsorption includes both chemisorption and physisorption. Biochar is highly aromatized and highly porous (Yang et al. 2019; Zhang et al. 2019a, b). When heavy metal ions are close to the benzene ring, the electron cloud of benzene ring can be polarized and produce a weak electrostatic effect, which leads to physisorption (Gomez-Eyles and Ghosh 2018). Biochar accomplishes chemisorption of heavy metals by surface functional groups (Xia et al. 2019). Besides, biochar is more alkaline and can significantly increase soil pH, which indirectly reduces the bioavailability of heavy metals (Huang et al. 2018a, b). In addition, biochar can alter soil moisture condition and aeration, and affect soil redox potential, thereby changing the toxicity of some charge-sensitive toxic heavy metals such as cadmium (Bogusz et al. 2017). It is noteworthy that the passivating function of biochar on bioavailability is not effective on all heavy metals.

Biochar can also adsorb various organic pollutants such as polycyclic aromatic hydrocarbons, polychlorinated biphenyls, naphthalenes, and phenols; and affects the transport and fate of pollutants (He et al. 2018). The adsorption mechanism of biochar on organic pollutants mainly includes partitioning, surface adsorption, pore retention, and microscopic adsorption (Huang et al. 2018a, b), but the adsorption process is usually governed by the combination of several mechanisms. Carbonaceous materials, degree of aromatization, elemental composition, pH, pore structure, surface chemistry, etc., of biochar plays important roles in its ability to adsorb organic pollutants (Chen et al. 2019), which leads to complex adsorption mechanisms when different kinds of biochar adsorbs various organic pollutants with different characteristics. At present, most biochar studies focusing on the mechanism of adsorption of organic pollutants are at a qualitative level; while quantitative research on structure–activity relationship is gradually being carried out (Chiou et al. 2015). However, the mechanism of reducing the bioavailability of organic pollutants by biochar is still difficult to quantify in the soil environment since it involves complex microbial metabolic processes (Zhu et al. 2017).

Currently, there is a lack of in situ or long-term and multi-year experiments studying the roles of biochar in inorganic or organic pollution remediation, and there is no successful case of applying biochar and related products for remediation practice on a large scale. Therefore, the research on the mechanism of environmental remediation of biochar will remain a hot topic for a long time, and biochar modification or combination with other remediation methods may be an ideal strategy for accelerating the applied research of biochar.

5 Biochar and energy

5.1 Carbonized bio-coal

The use of charcoal as a high-quality energy source is quite common even after the emergence of coal and oil. Biochar has desirable fuel properties, exhibiting comparable H/C and O/C ratios and calorific value to coal (Abdullah and Wu 2009). Physicochemical properties and combustion characteristics of biochar largely depend on the biomass feedstocks and carbonization processes. Zhao et al. (2014) evaluated the flammability of 34 biochar samples although they were not defined as flammable materials and reported that 71% of the fast pyrolysis biochar samples had a higher burning distance, while no burning distance was observed for 80% of slow pyrolysis biochar samples. Given this, they indicated that volatile content played an essential role in determining the flammability of biochar. Functional group type and biochar surface area also impacted on the ability of biochar to react with oxygen. Several studies showed that compared with clean and pulverized coal, higher calorific value and similar combustion properties of biochar could be obtained through optimizing the pyrolysis process and increasing the specific surface area by reducing particle size, respectively (Wijayanta et al. 2014; Jiang et al. 2018). Increasing evidence from studies on mixed combustion of biochar and coal revealed that biochar could effectively reduce the ignition and burnout temperatures of fuel mixtures and improve their conversion efficiency and combustion characteristics (Mi 2018; Wang et al. 2018; Toptas et al. 2015). This demonstrated that biochar could be used for co-combustion of fire coal for large boilers in the future.

Biochar molding has been proposed to be a practical energy strategy to improve volumetric energy density of powdered biochar and reduce the formation of particulates during combustion. Chen et al. (2011) developed “carbonized bio-coal” to replace fossil fuels in China’s rural energy upgrading process. This new type of coal could be widely adopted by small households for energy supply and by large-scale central heating systems, as it is environment-friendly and has superior combustion performance, Compressed biochar with shapes shows superior combustion properties (Zhu et al. 2018). It should be pointed out that moisture content, molding pressure, holding time of pressure, and type of adhesion agents significantly affected the breaking strength, dimensional stability, and combustion characteristics of compressed biochar (Chen et al. 2016; Bazargan et al. 2014).

5.2 Biochar slurry

A bio-oil/biochar slurry (also known as bio-slurry) is a new fuel product of suspending fine biochar particles in pyrolysis bio-oil (Wu et al. 2010). This product can help overcome some constraints in biomass utilization including high transportation costs, poor grindability, and mismatched fuel properties when it is co-processed with coal. Kichatov et al. (2018) reported that overall burning rate of foamed emulsions was increased significantly when biochar microparticles were added. In addition, technologies to produce hydrogen-rich syngas by steam gasification of bio-slurry (Sui et al. 2015; Chen et al. 2015) or by steam/CO2 gasification of biochar have been developed (Jia et al. 2018; Kraisornkachit et al. 2018). Raw materials, particle size, and catalysts are becoming key research topics for the development of the technology for producing hydrogen-rich syngas by steam gasification of bio-slurry.

5.3 Energy storage materials

Direct carbon solid oxide fuel cell (DC-SOFC) is an all-solid-state device that directly converts chemical energy of carbon fuel into electrical energy. It is feasible to use raw biochar as a fuel in direct carbon fuel cells (DCFC) or hybrid carbon fuel cells (HCFC) (Jafri et al. 2018; Kacprzak et al. 2016). Biochar as an electrode or catalyst has a promising prospect in microbial fuel cells (Deng et al. 2018; Huggins et al. 2016). In addition, biochar has shown great potential as an electrode material used directly or indirectly for the production of electrochemical energy storage devices such as supercapacitors (SC) and lithium ion batteries (LIB) (Caguiat et al. 2018; Liu et al. 2017; Gao et al. 2017; Guo et al. 2015).

6 Equipment and technologies for biochar production

Technologies for biochar production generally include pyrolytic carbonization, gasified carbonization, hydrothermal carbonization, flash carbonization, and baking carbonization (Zhang et al. 2019a, b; Meyer et al. 2011). In pyrolytic carbonization, biomass is decomposed at high temperatures of 300–900 °C (generally < 700 °C) in the absence of oxygen or with limited oxygen supply (Lehmann and Joseph 2015). In this process, the proportion of the end products, in the form of gas, liquid and solid is relatively balanced. Gasified carbonization is a process in which a gasification reaction occurs at high temperature (> 700 °C) and under a controlled supply of oxidant (oxygen, air, steam or a mixture of these gases) to produce a gaseous mixture with minor amounts of liquid and solid products. Biochar produced by gasified carbonization has a higher degree of aromatization compared with pyrolytic carbonization (Zhang et al. 2019a, b; Meyer et al. 2011). Hydrothermal carbonization is an approach to produce biochar–water slurry mixture by suspending the biomass in high-pressure water at a lower temperature (150–375 °C) for several hours. Biochar obtained by hydrothermal carbonization is mainly composed of alkane structures that have low stability (Zhang et al. 2019a, b; Weber and Quicker 2018). Flash carbonization is generally carried out at a reaction temperature of 300–600 °C for no more than 30 min, with mainly gaseous and solid products as output (Wade et al. 2006). Baking carbonization, also known as mild pyrolysis, is used to manipulate biomass by thermochemical treatment with a low heating rate of less than 50 °C min−1 at a lower temperature (200–300 °C) and under anoxic or anaerobic conditions (Kambo and Dutta 2015; Fan et al. 2018).

Clearly, biochar provides substantial environmental, social, and economical benefits. However, it is difficult to evaluate advantages and disadvantages of various technologies of biochar production because of data unavailability. Among the above-mentioned biochar production systems, pyrolytic and gasified carbonization have the highest economic feasibility and technological maturity (Meyer et al. 2011), and thus are becoming the dominant technologies for biochar production. Furthermore, pyrolytic carbonization has attracted more attention because of its potential for climate change mitigation.

There are many types of processes and equipment for biomass pyrolytic carbonization (Cong et al. 2015; Meng and Meng 2016). They can be classified into external heating, internal heating, and self-ignition based on heat source; batch-type and continuous processing systems based on continuity of operation mode; and slow, normal speed, and fast pyrolysis carbonization based on heat transfer rate. Among them, slow pyrolysis carbonization is a traditional processing system with a low heating rate and a solid residence time ranging from hours to days, which is mainly used to produce charcoal. The solid residence time generally lasts 5–30 min in normal speed pyrolysis carbonization, which produces relatively balanced products in the forms of gas, liquid, and solid. Fast pyrolysis carbonization has a high heating rate, resulting in heating raw materials of fine-particle biomass (1–2 mm) up to 400–700 °C in a short time. Notably, this processing system with the target product of bio-oil requires the moisture content of the raw material to be below 10% and has a short gas residence time (< 5 s).

Presently, equipment for normal speed pyrolysis carbonization has been widely employed for commercial production of biochar. To a certain extent, polygeneration is achieved for biochar production. The following are some polygeneration systems.

6.1 Co-production for biochar and heat

A pilot-scale rotary kiln continuously producing 600 kg of biochar per hour has been established in Henan and Guizhou provinces of China. This kiln starts working with the heat of natural gas and is maintained with syngas from biomass pyrolysis in situ. Syngas is burnt without intermediate purification, and no bio-liquid is left. Besides a self-maintainable pyrolysis process, the heat can be used for drying biochar-based fertilizer. This equipment is fed with small sized biomass with good flow ability, such as peanut shell and rice husk, or other biomass pretreated into similar size.

6.2 Co-production for biochar, bio-liquid, and heat

Rotary and batch kilns can produce bio-liquid as a by-product with added syngas purifier. Typically, a water cooling module is used in different forms. It is worth noting that the bio-liquid can substitute for water after a solid–liquid separation during the pyrolysis production.

A semi-closed sub-high-temperature anoxic carbonization furnace is effective in co-production for biochar, bio-liquid, and heat. Unlike external heating process, this equipment relies on internal heating or so-called smoldering to maintain the pyrolysis process. In some companies in Liaoning and Jilin province of China, a similar semi-closed kiln is widely applied on the account of its high compatibility with a raw material that has low flow ability, such as roughly pretreated corn stalk. Spare heat could be used for drying the material and for residential heating. Bio-liquid could be used to quench the biochar or serve as a component in biochar-based fertilizer.

6.3 Co-production for biochar, bio-liquid, heat, and electricity

In Anhui, Hubei, Hebei and some other provinces of China, a semi-closed biochar kiln of 0.5–3 MW internal combustion generator was widely adopted to make biochar from rice husk or apricot stone. Theoretically, steam turbine generator can lower purification requirement and can be easily maintained, but no application for straw biochar has been reported.

Generally, in addition to small-scale equipment developed for barbeque char, the prices of large-scale biochar kilns vary from 0.6 to 6 million RMB (a Chinese currency) corresponding to the capacity of biochar production ranging from 3 to 14 tons per day.

7 Outlook

From a historical point of view, biochar has been closely related to human civilization since the Paleolithic era of slash and burn. Compared with the practical use of biochar, the biochar research is really just in its infancy. Even though enormous progress has been achieved in biochar research since the beginning of the twenty-first century, there are still many questions to be answered. For example, no standard has been established for the description of biochar’s basic characteristics. Moreover, most of the research has focused only on determining the impacts of the raw material and carbonization process on the properties of the biochar. Methodology is limited in determining the quality, quantity, and microscopic conformation of biochar in the soil. The effects of biochar on soil, crops, and environment were studied mainly in short-term and simulated experiments but not in long-term field experiments. To date, no major breakthrough has been achieved in the research areas of biochar amendment and biochar-based fertilizers.

In view of the above problems, it is necessary to advance the development of biomass carbonization technology and modern equipment; to improve carbonization efficiency, quality of the biochar product, and the utilization of by-products to reduce production costs. It is also necessary to strengthen the basic research of biochar in the areas of agriculture and environment and innovated research of biochar in the areas of soil management, crop production, carbon sequestration and emission reduction, pollution control, and discovery of new materials. In line with that research, environmental risk assessments and cumulative feedback effects of biochar application need to be completed. To make it available, traceable, and controllable a standard system for biochar research protocol, biochar production technology, and biochar products needs to be established and a standardized management system needs to be applied across the whole biochar industry chain.

Nature gives humanity an environment in which people live and multiply. However, the excessive consumption on natural resources and environmental destruction associated with human activities have already posed a burden on sustainability of the natural environment, which forces humans to bear the punishment from nature. Biochar is closely related to agriculture, environment and sustainable development. The beautiful vision of harmony between people and natural environment can be realized in the process of promoting “carbon to biochar” transition. Therefore, for the future of human survival, sustainable and healthy development of society, it is our responsibility to explore the future of biochar by strengthening the research and development of biochar.

Notes

Acknowledgements

This work was supported by the Earmarked Fund for Modern Agro-industry Technology Research System, China (Project No. CARS-01-46), the National Key Research and Development Program, China (Project No. 2017YFD0200800), the Innovative Talents Promotion Plan of Ministry of Science and Technology, China (No. 2017RA2211) and the Project of Promoting Talents in Liaoning Province, China (XLYC1802094). We thank Kim McGrouther for her constructive comments on the manuscript.

References

  1. Abdullah H, Wu HW (2009) Biochar as a fuel: 1. Properties and grindability of biochars produced from the pyrolysis of mallee wood under slow-heating conditions. Energy Fuels 23(8):4174–4181CrossRefGoogle Scholar
  2. Al-Wabel MI, Al-Omran A, El-Nagger AH, Nadeem M, Usman AR (2013) Pyrolysis temperature induced changes in characteristics and chemical composition of biochar produced from conocarpus wastes. Bioresour Technol 131(3):374–379CrossRefGoogle Scholar
  3. Anton-Herrero R, Garciadelgado C, Alonsoizquierdo M, Garciarodriguez G, Cuevas J, Eymar E (2018) Comparative adsorption of tetracyclines on biochars and stevensite: looking for the most effective adsorbent. Appl Clay Sci 160:162–172CrossRefGoogle Scholar
  4. Atkinsonc J, Fitzgerald JD, Hipps NA (2010) Potential mechanisms for achieving agricultural benefits from biochar application to temperate soils: a review. Plant Soil 337:1–18CrossRefGoogle Scholar
  5. Augustenborg CA, Hepp S, Kammann C, Hagan D, Schmidt O, Müller C (2011) Biochar and earthworms effects on soil nitrous oxide and carbon dioxide emissions. J Environ Qual 41:1203–1209CrossRefGoogle Scholar
  6. Bansal RC, Donnet JB, Stoeckli F (1988) Active carbon. Marcel Dekker, New York, p 158Google Scholar
  7. Bazargan A, Rough SL, McKay G (2014) Compaction of palm kernel shell biochars for application as solid fuel. Biomass Bioenergy 70:489–497CrossRefGoogle Scholar
  8. Beluri K, Pullagurala VLR, Bojeong K, Sang SL, Sudhir KP, Ki-Hyun K (2018) Benefits and limitations of biochar amendment in agricultural soils: a review. J Environ Manag 227:146–154CrossRefGoogle Scholar
  9. Benjamin MCF, Stefano MLM, Monica G, Mark S, Johnson SW (2019) Lyon Improving agricultural water use efficiency with biochar—a synthesis of biochar effects on water storage and fluxes across scales. Sci Total Environ 657:853–862CrossRefGoogle Scholar
  10. Bogusz A, Nowak K, Stefaniuk M, Dobrowolski R, Oleszczuk P (2017) Synthesis of biochar from residues after biogas production with respect to cadmium and nickel removal from wastewater. J Environ Manag 201:268–276CrossRefGoogle Scholar
  11. Boonanuntanasarn S, Khaomek P, Pitaksong T, Yang LH (2014) The effects of the supplementation of activated charcoal on the growth, health status and fillet composition-odor of Nile tilapia (Oreochromis niloticus) before harvesting. Aquac Int 4:1417–1436CrossRefGoogle Scholar
  12. Brown RA, Kercher AK, Nguyen TH, Nagle DC, Ball WP (2006) Production and characterization of synthetic wood chars for use as surrogates for natural sorbents. Org Geochem 37(3):321–333CrossRefGoogle Scholar
  13. Bruun EW, Müller-Stöver D, Ambus P, Hauggaard-Nielsen H (2011) Application of biochar to soil and N2O emissions: potential effects of blending fast-pyrolysis biochar with anaerobically digested slurry. Eur J Soil Sci 62:581–589CrossRefGoogle Scholar
  14. Bruun EW, Ambus P, Egsgaard H, Hauggaardnielsen H (2012) Effects of slow and fast pyrolysis biochar on soil C and N turnover dynamics. Soil Biol Biochem 46:73–79CrossRefGoogle Scholar
  15. Caguiat JN, Gabriel A, Sally G, Krigstin Donald W, Kirk CQJ (2018) Dependence of supercapacitor performance on macro-structure of monolithic biochar electrodes. Biomass Bioenergy 118:126–132CrossRefGoogle Scholar
  16. Cai L, Xu J, Huang J, Xu H, Xu F, Liang Y, Fu R, Wu D (2017) Structure control of powdery carbon aerogels and their use in high-voltage aqueous supercapacitors. New Carbon Mater 32(06):550–556Google Scholar
  17. Cao XD, Harris W (2010) Properties of dairy-manure-derived biochar pertinent to its potential use in remediation. Biores Technol 101:5222–5228CrossRefGoogle Scholar
  18. Cao Y, Pawłowski A (2013) Life cycle assessment of two emerging sewage sludge-to-energy systems: evaluating energy and greenhouse gas emissions implications. Bioresour Technol 127:81–91CrossRefGoogle Scholar
  19. Case SDC, McNamara NP, Reay DS, Whitaker J (2012) The effect of biochar addition on N2O and CO2 emissions from a sandy loam soil—the role of aeration. Soil Biol Biochem 51:125–134CrossRefGoogle Scholar
  20. Cayuela ML, Van Zwieten L, Singh BP, Jeffery S, Roig A, Sánchez-Monedero MA (2014) Biochar’s role in mitigating soil nitrous oxide emissions: a review and meta-analysis. Agric Ecosyst Environ 191:5–16CrossRefGoogle Scholar
  21. Chan KY, Zwieten LV, Meszaros I, Downie A, Joseph S (2007) Agronomic values of greenwaste biochar as a soil amendment. Aust J Soil Res 45:629–634CrossRefGoogle Scholar
  22. Chen B, Zhou D, Zhu L (2008) Transitional adsorption and partition of nonpolar and polar aromatic contaminants by biochars of pine needles with different pyrolytic temperatures. Environ Sci Technol 42(14):5137–5143CrossRefGoogle Scholar
  23. Chen BL, Chen ZM, Lv SF (2011) A novel magnetic biochar efficiently sorbs organic pollutants and phosphate. Biores Technol 102(2):716–723CrossRefGoogle Scholar
  24. Chen WF, Zhang WM, Meng J (2013) Advances and prospects in research of biochar utilization in agriculture. Sci Agric Sin 46(16):3324–3333Google Scholar
  25. Chen G, Yao J, Liu J, Yan B, Shan R (2015) Biomass to hydrogen-rich syngas via catalytic steam gasification of bio-oil/biochar slurry. Biores Technol 198:108–114CrossRefGoogle Scholar
  26. Chen TY, Meng J, Xin MJ, Zhang Q, Song YQ, Ren WT, Jiang X (2016) Compaction behavior of biochar from corn stalk. J Shenyang Agric Univ 47(06):728–733Google Scholar
  27. Chen Y, Jiang Z, Wu D, Wang H, Li J, Bi M, Zhang Y (2019) Development of a novel bio-organic fertilizer for the removal of atrazine in soil. J Environ Manag 233:553–560CrossRefGoogle Scholar
  28. Cheng CH, Lehmann J, Thies JE, Burton SD (2008) Stability of black carbon in soils across a climatic gradient’. J Geophys Res 113:G02027Google Scholar
  29. Chintala R, Mollinedo J, Schumacher TE, Malo DD, Julson J (2014) Effect of biochar on chemical properties of acidic soil. Arch Agron Soil Sci 60(3):393–404CrossRefGoogle Scholar
  30. Chiou CT, Cheng JZ, Hung WN, Chen BL, Lin TF (2015) Resolution of adsorption and partition components of organic compounds on black carbons. Environ Sci Technol 49:9116–9123CrossRefGoogle Scholar
  31. Clough TJ, Condron LM (2010) Biochar and the nitrogen cycle: introduction. J Environ Qual 39:1218–1223CrossRefGoogle Scholar
  32. Clough TJ, Bertram JE, Ray JL, Condron LM, O’Callaghan M, Sherlock RR, Wells NS (2010) Unweathered wood biochar impact on nitrous oxide emissions from a bovine-urine-amended pasture soil. Soil Biol Biochem 74:852–860Google Scholar
  33. Cong HB, Zhao LX, Yao ZL, Meng HB, Li M (2015) Research status of biomass carbonization technical equipment and proposals for its development in China. J China Agric Univ 20(02):21–26Google Scholar
  34. Cross A, Sohi SP (2011) The priming potential of biochar products in relation to labile carbon contents and soil organic matter status. Soil Biol Biochem 43(10):2127–2134CrossRefGoogle Scholar
  35. Cui YF, Chen WF (2008) Preliminary study of environment-friendly and biochar-based slow release fertilizer application effect on soybean and peanut. Liaoning Agric Sci 4:41–43Google Scholar
  36. Cui YF, Zeng YQ, Chen WF (2008) Applying effect of pellet active carbon and slow-release fertilizer on maize. Liaoning Agric Sci 3:5–8Google Scholar
  37. Deng LF, Dong G, Cai XX, Tang JH, Yuan HR (2018) Biochar derived from the inner membrane of passion fruit as cathode catalyst of microbial fuel cells in neutral solution. J Fuel Chem Technol 46(01):120–128Google Scholar
  38. El-Naggar A, Sang SL, Jorg R, Muhammad F, Songe Hocheol, Ajit KS, Andrew RZ, Mahtab A, Sabry MS, Yong SO (2019) Biochar application to low fertility soils: a review of current status, and future prospects. Geoderma 337:536–554CrossRefGoogle Scholar
  39. Fan F, Yang Z, Li H, Shi Z, Kan H (2018) Preparation and properties of hydrochars from macadamia nut shell via hydrothermal carbonization. R Soc Open Sci 5(10):1–10CrossRefGoogle Scholar
  40. Feng Y, Xu Y, Yu Y, Xie Z, Lin X (2012) Mechanisms of biochar decreasing methane emission from Chinese soils. Soil Biol Biochem 46:80–88CrossRefGoogle Scholar
  41. Fu PP, Dong J, Li LQ, Zhang YS, Pan GX, Zhang XH, Zheng JF, Zheng JW, Liu XY, Wang JF, Yu XY (2015) Effects of wheat straw bio-charcoal supplement to fodder on growth, slaughter performance and lipid metabolism of broilers. J Chin Cereals Oils Assoc 6:88–93Google Scholar
  42. Gao Z, Zhang Y, Song N, Li X (2017) Biomass-derived renewable carbon materials for electrochemical energy storage. Mater Res Lett 5(2):69–88CrossRefGoogle Scholar
  43. Glaser B, Haumaier L, Guggenberger G, Zech W (2001) The ‘Terra Preta’ phenomenon: a model for sustainable agriculture in the humid tropics. Naturwissenschaften 88:37–41CrossRefGoogle Scholar
  44. Glaser B, Lehmann J, Zech W (2002) Ameliorating physical and chemical properties of highly weathered soils in the tropics with charcoal—a review. Biol Fertil Soils 35(4):219–230CrossRefGoogle Scholar
  45. Gomez-Eyles JL, Ghosh U (2018) Enhanced biochars can match activated carbon performance in sediments with high native bioavailability and low final porewater PCB concentrations. Chemosphere 203:179–187CrossRefGoogle Scholar
  46. Gul S, Whalen JK, Thomas BW, Sachdeva V, Hongyuan D (2015) Physico-chemical properties and microbial responses in biochar-amended soils: mechanisms and future directions. Agric Ecosyst Environ 206(1):46–59CrossRefGoogle Scholar
  47. Guo J, Zhang J, Jiang F, Zhao S, Su Q, Du G (2015) Microporous carbon nanosheets derived from corncobs for lithium–sulfur batteries. Electrochim Acta 176:853–860CrossRefGoogle Scholar
  48. Hammes K, Torn MS, Lapenas AG, Schmidt MWI (2008) Centennial black carbon turnover observed in a Russian steppe soil. Biogeosciences 5(5):1339–1350CrossRefGoogle Scholar
  49. Han J, Zhang F, Du LB, Chen WF, Meng J (2014) Effects of dietary biochar including vinegar liquid on growth performance and peripheral blood characteristics of piglets. Mod J Anim Husb Vet Med 10:17–20Google Scholar
  50. Han Q, Zhou Z, Chen L (2019) Interface properties study of graphene reinforced carbon fiber and epoxy resin composites. Knitt Ind 01:1–3Google Scholar
  51. Harder B (2006) Smoldered-Earth policy: created by ancient Amazonia natives, fertile, dark soils retain abundant carbon. Sci News 169:133CrossRefGoogle Scholar
  52. He L, Fan S, Müller K, Wang H, Che L, Xu S, Song Z, Yuan G, Rinklebe J, Tsang DCW, Ok YS, Bolan N (2018) Comparative analysis biochar and compost-induced degradation of di-(2-ethylhexyl) phthalate in soils. Sci Total Environ 625:987–993CrossRefGoogle Scholar
  53. Huang H, Wang YX, Tang JC, Zhu WY (2014) Properties of maize stalk biochar produced under different pyrolysis temperatures and its sorption capability to naphthalene. Environ Sci 35(5):1884Google Scholar
  54. Huang P, Ge C, Feng D, Yu H, Luo J, Li J, Strong PJ, Sarmah AK, Bolan NS, Wang H (2018a) Effects of metal ions and pH on ofloxacin sorption to cassava residue-derived biochar. Sci Total Environ 616–617:1384–1391CrossRefGoogle Scholar
  55. Huang S, Bao J, Shan M, Qin H, Wang H, Yu X, Chen J, Xu Q (2018b) Dynamic changes of polychlorinated biphenyls (PCBs) degradation and adsorption to biochar as affected by soil organic carbon content. Chemosphere 211:120–127CrossRefGoogle Scholar
  56. Huggins TM, Latorre A, Biffinger JC, Ren ZJ (2016) Biochar based microbial fuel cell for enhanced wastewater treatment and nutrient recovery. Sustainability (Switzerland) 8(2):169CrossRefGoogle Scholar
  57. Jafri N, Wong WY, Doshi V, Yoon LW, Cheah KH (2018) A review on production and characterization of biochars for application in direct carbon fuel cells. Process Saf Environ Prot 118:152–166CrossRefGoogle Scholar
  58. Jia J, Li B, Chen Z, Xie Z, Xiong Z (2012) Effects of biochar application on vegetable production and emissions of N2O and CH4. Soil Sci Plant Nutr 58(4):503–509CrossRefGoogle Scholar
  59. Jia S, Ying H, Xu W, Sun YJ, Yin H, Sun N (2018) Steam gasification of bio-char for hydrogen-rich syngas. Chem Ind Eng Prog 04:1402–1407Google Scholar
  60. Jiang KM, Cheng CG, Ran M, Lu YG, Wu QL (2018) Preparation of a biochar with a high calorific value from chestnut shells. New Carbon Mater 33(2):183–187CrossRefGoogle Scholar
  61. Kacprzak A, Kobyłecki R, Włodarczyk R, Bis Z (2016) Efficiency of non-optimized direct carbon fuel cell with molten alkaline electrolyte fueled by carbonized biomass. J Power Sources 321:233–240CrossRefGoogle Scholar
  62. Kalinke C, Oliveira PRD, Oliveira GAD, Mangrich AS, Marcolinojunior LH, Bergamini MF (2017) Activated biochar: preparation, characterization and electroanalytical application in an alternative strategy of nickel determination. Anal Chim Acta 983:103–111CrossRefGoogle Scholar
  63. Kambo HS, Dutta A (2015) Comparative evaluation of torrefaction and hydrothermal carbonization of lignocellulosic biomass for the production of solid biofuel. Energy Convers Manag 105:746–755CrossRefGoogle Scholar
  64. Kana JR, Teguia A, Tchoumboue J (2010) Effect of dietary plant charcoal from Canarium schweinfurthii Engl and maize cob on aflatoxin B1 toxicosis in broiler chickens. Adv Anim Biosci 4:462–463CrossRefGoogle Scholar
  65. Kettunen R, Saarnio S (2013) Biochar can restrict N2O emissions and the risk of nitrogen leaching from an agricultural soil during the freeze–thaw period. Agric Food Sci 22:373–379CrossRefGoogle Scholar
  66. Khan S, Chao C, Waqas M, Arp HPH, Zhu YG (2013) Sewage sludge biochar influence upon rice (Oryza sativa L) yield, metal bioaccumulation and greenhouse gas emissions from acidic paddy soil. Environ Sci Technol 47:8624–8632CrossRefGoogle Scholar
  67. Kichatov B, Korshunov A, Kiverin A (2018) Combustion of the foamed emulsion containing biochar microparticles. Fuel 228:164–174CrossRefGoogle Scholar
  68. Kinney TJ, Masiello CA, Dugan B, Hockaday WC, Dean MR, Zygourakis K, Barnes RT (2012) Hydrologic properties of biochars produced at different temperatures. Biomass Bioenergy 41:34–43CrossRefGoogle Scholar
  69. Kraisornkachit P, Vivanpatarakij S, Powell J, Assabumrungrat S (2018) Experimental study of dual fixed bed biochar-catalytic gasification with simultaneous feed of O2-steam-CO2 for synthesis gas or hydrogen production. Int J Hydrog Energy 43(32):14974–14986CrossRefGoogle Scholar
  70. Lee JW, Kidder M, Evans BR (2010) Characterization of biochars produced from cornstovers for soil amendment. Environ Sci Technol 44(20):7970–7974CrossRefGoogle Scholar
  71. Lehmann J (2007a) A handful of carbon. Nature 447:143–144CrossRefGoogle Scholar
  72. Lehmann J (2007b) Bio-energy in the black. Front Ecol Environ 5(7):381–387CrossRefGoogle Scholar
  73. Lehmann J (2009) Terra preta Nova—where to from here? In: Woods WI, Teixeira WG, Lehmann J, Steiner C, WinklerPrins A (eds) Terra Preta Nova: a tribute to Wim Sombroek. Springer, Berlin, pp 473–486Google Scholar
  74. Lehmann J, Joseph S (2015) Biochar Environ Manag Sci Technol Implement, 2nd edn. Routledge, LondonCrossRefGoogle Scholar
  75. Lehmann J, Weigl D, Peter I, Droppelmann K, Gebauer G, Goldbach H, Zech W (1999) Nutrient interactions of alley-cropped Sorghum bicolor and Acacia saligna in a run off irrigation system in Northern Kenya. Plant Soil 210:249–262CrossRefGoogle Scholar
  76. Lehmann J, Gaunt J, Rondon M (2006) Bio-char sequestration in terrestrial ecosystems—a review. Mitig Adapt Strat Glob Change 11:403–427CrossRefGoogle Scholar
  77. Leng LJ, Huang HJ, Li H, Li J, Zhou WG (2019) Biochar stability assessment methods: a review. Sci Total Environ 647:210–222CrossRefGoogle Scholar
  78. Li J (1996) Exploration of Hemudu pottery culture. Jingdezhen’s Ceram 03:36–40Google Scholar
  79. Li JM, Cao LR, Yuan Y, Wang RP, Wen YZ, Man JY (2018) Comparative study for microcystin-LR sorption onto biochars produced from various plant- and animal-wastes at different pyrolysis temperatures: influencing mechanisms of biochar properties. Bioresour Technol 247:794–803CrossRefGoogle Scholar
  80. Lian F, Huang F, Chen W, Xing BS, Zhu LY (2011) Sorption of apolar and polar and polar organic contaminants by waste tire rubber and its chars in single- and bi-solute systems. Environ Pollut 159(4):850CrossRefGoogle Scholar
  81. Liu S, Wang L, Zheng C, Chen Q, Feng M, Yu Y (2017) Cost-effective asymmetric supercapacitors based on nickel cobalt oxide nanoarrays and biowaste-derived porous carbon electrodes. ACS Sustain Chem Eng 5(11):9903–9913CrossRefGoogle Scholar
  82. Ma Y (2018) Study and research on the pottery block of Hemudu five-leaf grain. World Antiq 05:46–49Google Scholar
  83. Ma C, Feng X, Ding YJ, Zhang XH, Cheng K, Pan GX (2018) Nano-pore distribution of biochar and soil aggregates revealed with the technology of nuclear magnet. Chin J Soil Sci 49(3):582–587Google Scholar
  84. Majewska T, Mikulski D, Siwik T (2009) Silica grit, charcoal and hardwood ash in turkey nutrition. J Elementol 3:489–500Google Scholar
  85. Major J, Lehmann J, Rondon M, Goodale C (2010a) Fate of soil-applied black carbon: downward migration leaching and soil respiration. Glob Chang Biol 16:1366–1379CrossRefGoogle Scholar
  86. Major J, Rondon M, Molina D, Riha SJ, Lehmann J (2010b) Maize yield and nutrition during 4 years after biochar application to a Colombian savanna oxisol. Plant Soil 333:117–128CrossRefGoogle Scholar
  87. Marris E (2006) Black is the new green. Nature 442:624–626CrossRefGoogle Scholar
  88. Masulili A, Utomo WH, Syechfani MS (2010) Rice husk biochar for rice based cropping system in acid soil 1. The characteristics of rice husk biochar and its influence on the properties of acid sulfate soils and rice growth in west Kalimantan, Indonesia. J Agric Sci 2(1):39–47Google Scholar
  89. Mekbungwan A, Yamauchi K, Sakaida T (2004) Intestinal villus histological alterations in piglets fed dietary charcoal powder including wood vinegar compound liquid. Anat Histol Embryol 1:11–16CrossRefGoogle Scholar
  90. Meng FB, Meng J (2016) Review of biomass carbonization technology. Biomass Chem Eng 50(06):61–66Google Scholar
  91. Meyer S, Glaser B, Quicker P (2011) Technical, economical, and climate-related aspects of biochar production technologies: a literature review. Environ Sci Technol 45(22):9473–9483CrossRefGoogle Scholar
  92. Mi MX (2018) Study on co-combustion kinetics and pollutant emission characteristics of phoenix tree’s leaves and their biochar with coal. Hefei University of Technology, HefeiGoogle Scholar
  93. Moreno-Castilla C (2004) Adsorption of organic molecules from aqueous solutions on carbon materials. Carbon 42:83–94CrossRefGoogle Scholar
  94. Muhammad S, Lukas VZ, Saqib B, Aneela Y, Avelino N, Muhammad AC, Kashif AK, Umeed A, Muhammad SR, Mirza AM, Ronggui H (2018) A concise review of biochar application to agricultural soils to improve soil conditions and fight pollution. J Environ Manag 228:429–440CrossRefGoogle Scholar
  95. Novak JM, Busscher WJ, Laird DL (2009) Impact of biochar amendment on fertility of a southeastern coastal plain soil. Soil Sci 174(2):105–112CrossRefGoogle Scholar
  96. Petersen JB, Neves E, Heckenberger MJ (2001) Gift from the past: Terra Preta and prehistoric Amerindian occupation in Amazonia. In: McEwan C, Barreto C, Neves E (eds) Unknown Amazonia. British Museum Press, London, pp 86–105Google Scholar
  97. Qi WR, Cheng XY, Chen ZR, Sun GQ, Zhang WB (2012) Preliminary study on purification effect of bamboo charcoal on aquaculture water. J Zhejiang For Sci Technol 1:16–20Google Scholar
  98. Quaiyum MA, Jahan R, Jahan N, Akhter T, Islam MS (2014) Effects of bamboo charcoal added feed on reduction of ammonia and growth of Pangasius hypophthalmus. J Aquac Res Dev 5:6Google Scholar
  99. Quin PR, Cowie AL, Flavel RJ, Macdonald LM, Morris SG, Singh BP, Young IM, Van Zwieten L (2014) Oil mallee biochar improves soil structural properties—a study with X-ray micro-CT. Agric Ecosyst Environ 191:142–149CrossRefGoogle Scholar
  100. Renner R (2007) Rethinking biochar. Environ Sci Technol 41(17):5932–5933CrossRefGoogle Scholar
  101. Rogovska N, Lair D, Cruse R (2011) Impact of biochar on manure carbon stabilization and greenhouse gas emissions. Soil Biol Biochem 75:871–879Google Scholar
  102. Ruttanavut J, Yamauchi K, Goto H, Erikawa T (2009) Effects of dietary bamboo charcoal powder including vinegar liquid on growth performance and histological intestinal change in Aigamo ducks. Int J Poult Sci 3:229–236Google Scholar
  103. Sadaka S, Boateng AA (2009) Pyrolysis and bio-oil. Cooperative Extension Service, University of Arkansas, US Department of Agriculture and County Governments Cooperating, Arkansas, pp 1–6Google Scholar
  104. Sagrilo E, Jeffery S, Hoffland E, Kuyper TW (2015) Emission of CO2 from biochar-amended soils and implications for soil organic carbon. Glob Change Biol Bioenergy 7:1294–1304CrossRefGoogle Scholar
  105. Saifullah Saad D, Asif N, Zed R, Ravi N (2018) Biochar application for the remediation of salt-affected soils: challenges and opportunities. Sci Total Environ 625:320–335CrossRefGoogle Scholar
  106. Shaheen SM, Niazi NK, Hassan NEE, Bibi I, Wang H, Tsang DCW, Ok YS, Bolan N, Rinklebe J (2019) Wood-based biochar for the removal of potentially toxic elements in water and wastewater: a critical review. Int Mater Rev 64(4):216–247.  https://doi.org/10.1080/09506608.2018.1473096 CrossRefGoogle Scholar
  107. Shindo H (1991) Elementary composition, humus composition, and decomposition in soil of charred grassland plants. Soil Sci Plant Nutr 37:651–657CrossRefGoogle Scholar
  108. Shinogia Y, Kanri Y (2003) Pyrolysis of plant, animal and human waste: physical and chemical characterization of the pyrolytic products. Biores Technol 90:241–247CrossRefGoogle Scholar
  109. Shui Y (2009) Azo-dye adsorption of active carbon, charcoal, modified sludge. Beijing Jiaotong University, BeijingGoogle Scholar
  110. Silber A, Levkovitch I, Graber ER (2010) pH-dependent mineral release and surface properties of cornstraw biochar: agronomic implications. Environ Sci Technol 44:9318–9323CrossRefGoogle Scholar
  111. Sombroek W, Kern D, Rodriques T, da S Cravo M, Jarbas TC, Woods W, Glaser B (2002) ‘Terra Preta and Terra Mulata: pre-Columbian Amazon kitchen middens and agricultural fields, their sustainability and their replication. In: Proceedings of the 17th World Congress of Soil Science, Thailand, Paper no 1935Google Scholar
  112. Song J, Huang B, Yuan Q, Liu X, Yang W (2015) Suitable charcoal loadings improving heat-resistance and mechanical properties of epoxy resins composites. Trans Chin Soc Agric Eng (Trans CSAE) 31(14):309–314.  https://doi.org/10.11975/j.issn.1002-6819.2015.14.043 CrossRefGoogle Scholar
  113. Spokas KA (2010) Review of the stability of biochar in soils: predictability of O:C molar ratios. Carbon Manag 1(2):289–303CrossRefGoogle Scholar
  114. Spokas KA, Reicosky DC (2009) Impact of sixteen different biochars on soil greenhouse gas production. Ann Environ Sci 3:179–193Google Scholar
  115. Steinbeiss S, Gleixner G, Antonietti M (2009) Effect of biochar amendment on soil carbon balance and soil microbial activity. Soil Biol Biochem 41:1301–1310CrossRefGoogle Scholar
  116. Steiner C, Teixeira WG, Lehmann J, Nehls T, Macêdo JLV, Blum WEH, Zech W (2007) Long term effects of manure, charcoal, and mineral: fertilization on crop production and fertility on a highly weathered central Amazonian upland soil. Plant Soil 291:275–290CrossRefGoogle Scholar
  117. Steiner C, Glaser B, Teixeira WG, Lehmann J, Blum WEH, Zech W (2008) Nitrogen retention and plant uptake on a highly weathered central Amazonian Ferralsol amended with compost and charcoal. J Plant Nutr Soil Sci 171(6):893–899CrossRefGoogle Scholar
  118. Sui H, Wang X, Chen H (2015) Rheological behavior and steam gasification of bio-slurry. In: Yan J, Shamim T, Chou SK, Li H (eds) Energy Procedia, vol 75, pp 220–225, ElsevierGoogle Scholar
  119. Suliman W, Harsh JB, Abulail NI, Fortuna A, Dallmeyer I, Garciaperez M (2016) Influence of feedstock source and pyrolysis temperature on biochar bulk and surface properties. Biomass Bioenergy 84:37–48CrossRefGoogle Scholar
  120. Suliman W, Harsh JB, Fortuna A, Garciaperez M, Abulail NI (2017) Quantitative effects of biochar oxidation and pyrolysis temperature on the transport of pathogenic and nonpathogenic Escherichia coli in biochar-amended sand columns. Environ Sci Technol 51:5071–5081CrossRefGoogle Scholar
  121. Sun YN, Gao B, Yao Y, Fang J, Zhang M, Zhou Y, Chen H, Yang L-Y (2014) Effects of feedstock type, production method, and pyrolysis temperature on biochar and hydrochar properties. Chem Eng J 240:574–578CrossRefGoogle Scholar
  122. Sun X, Han XG, Ping F, Zhang L, Zhang KS, Chen M, Wu WX (2018) Effect of rice straw biochar on nitrous oxide emissions from paddy soils under elevated CO2 and temperature. Sci Total Environ 628:629–1009Google Scholar
  123. Tenenbaum D (2009) Biochar: carbon mitigation from the ground up. Environ Health Perspect 117(2):70–73CrossRefGoogle Scholar
  124. Thu M, Koshio S, Ishikawa M, Yokoyama S (2010) Effects of supplementation of dietary bamboo charcoal on growth performance and body composition of juvenile Japanese flounder, Paralichthys olivaceus. J World Aquac Soc 2:255–262CrossRefGoogle Scholar
  125. Toptas A, Yildirim Y, Duman G, Yanik J (2015) Combustion behavior of different kinds of torrefied biomass and their blends with lignite. Biores Technol 177:328–336CrossRefGoogle Scholar
  126. Uzoma KC, Inoue M, Andry H, Fujimaki H, Zahoor A, Nishihara E (2011) Effect of cow manure biochar on maize productivity under sandy soil condition. Soil Use Manag 27(2):205–212CrossRefGoogle Scholar
  127. Van Zwieten L, Kimber S, Morris S, Chan KY, Downie A, Rust J, Joseph S, Cowie A (2010) Effects of biochar from slow pyrolysis of papermill waste on agronomic performance and soil fertility. Plant Soil 327(1):235–246CrossRefGoogle Scholar
  128. Villalba JJ, Provenza FD, Banner RE (2002) Influence of macronutrients and activated charcoal on intake of sagebrush by sheep and goats. J Anim Sci 8:2099–2109Google Scholar
  129. Wade SR, Nunoura T, Antal MJ (2006) Studies of the flash carbonization process. 2. Violent ignition behavior of pressurized packed beds of biomass: a factorial study. Ind Eng Chem Res 45(10):3512–3519CrossRefGoogle Scholar
  130. Wang H (2015) Removal of Pb(II), Cu(II), and Cd(II) from aqueous solutions by biochar derived from KMnO4 treated hickory wood. Biores Technol 197(9):356–362CrossRefGoogle Scholar
  131. Wang J, Pan X, Liu Y, Zhang S, Xiong Z (2012) Effects of biochar amendment in two soils on greenhouse gas emissions and crop production. Plant Soil 360:287–298CrossRefGoogle Scholar
  132. Wang P, Wang G, Zhang J, Lee JY, Li Y, Wang C (2018) Co-combustion characteristics and kinetic study of anthracite coal and palm kernel shell char. Appl Therm Eng 143:736–745CrossRefGoogle Scholar
  133. Watarai S, Tana S (2005) Eliminating the carriage of Salmonella enterica serovar Enteritidis in domestic fowls by feeding activated charcoal from bark containing wood vinegar liquid (Nekka-Rich). Poult Sci 4:515–521CrossRefGoogle Scholar
  134. Weber K, Quicker P (2018) Properties of biochar. Fuel 217:240–261CrossRefGoogle Scholar
  135. Wijayanta AT, Alam MS, Nakaso K, Fukai J, Kunitomo K, Shimizu M (2014) Combustibility of biochar injected into the raceway of a blast furnace. Fuel Process Technol 117:53–59CrossRefGoogle Scholar
  136. Wu RJ, Chen QS, Cai YY, Lu R, Huang J (2010) Purification of pig farm wastewater using carbon-based treatment Agent- K. Fujian J Agric Sci 4:496–502Google Scholar
  137. Xia SP, Song ZL, Jeyakumar P, Shaheen SM, Rinklebe J, Ok YS, Bolan N, Wang H (2019) A critical review on bioremediation technologies for Cr(VI)-contaminated soils and wastewater. Crit Rev Environ Sci Technol.  https://doi.org/10.1080/10643389.2018.1564526 CrossRefGoogle Scholar
  138. Yamato M, Okimori Y, Wibowo IF, Anshori S, Ogawa M (2006) Effects of the application of charred bark of Acacia mangium on the yield of maize, cowpea and peanut, and soil chemical properties in South Sumatra, Indonesia. Soil Sci Plant Nutr 52:489–495CrossRefGoogle Scholar
  139. Yang N, Hu D, Cao B, Chen Y, Li D, Chen D (2017) Preparation of three-dimensional hierarchical porous carbon microspheres for use as a cathode material in lithium–air batteries. New Carbon Mater 32(06):564–571Google Scholar
  140. Yang X, Wan Y, Zheng Y, He F, Yu Z, Huang J, Wang H, Ok YS, Jiang Y, Gao B (2019) Surface functional groups of carbon-based adsorbents and their roles in the removal of heavy metals from aqueous solutions: a critical review. Chem Eng J 366:608–621CrossRefGoogle Scholar
  141. You Z (2012) On the legend of the ancient Mawangdui corpse and the continuation of the key preservation techniques. Hunan Provincial Museum, Hunan, pp 91–96Google Scholar
  142. Young A (1804) The farmer’s calendar. Richard Philips, LondonGoogle Scholar
  143. Yuan JH, Xu RK, Zhang H (2011) The forms of alkalis in the biochar produced from crop residues at different temperature. Biores Technol 102:3488–3497CrossRefGoogle Scholar
  144. Zhang A, Cui L, Pan G, Li L, Hussain Q, Zhang X, Zheng J, Crowley D (2010) Effect of biochar amendment on yield and methane and nitrous oxide emissions from a rice paddy from Tai Lake plain, China. Agric Ecosyst Environ 139:469–475CrossRefGoogle Scholar
  145. Zhang A, Bian R, Hussain Q, Li L, Pan G, Zheng J, Zhang X, Zheng J (2013) Change in net global warming potential of rice-wheat cropping system with biochar soil amendment in a rice paddy from China. Agric Ecosyst Environ 173:37–45CrossRefGoogle Scholar
  146. Zhang J, Zhang J, Wang M, Wu S, Wang H, Niazi NK, Man YB, Christie P, Shan S, Wong MH (2019a) Effect of tobacco stem-derived biochar on soil metal immobilization and the cultivation of tobacco plant. J Soils Sediments.  https://doi.org/10.1007/s11368-018-02226-x CrossRefGoogle Scholar
  147. Zhang Z, Zhu Z, Shen B, Liu L (2019b) Insights into biochar and hydrochar production and applications: a review. Energy 171:581–598CrossRefGoogle Scholar
  148. Zhao MY, Enders A, Lehmann J (2014) Short- and long-term flammability of biochars. Biomass Bioenergy 69:183–191CrossRefGoogle Scholar
  149. Zhao B, Oconnor D, Zhang JL, Peng TY, Shen ZT, Tsang DCW, Hou D (2018) Effect of pyrolysis temperature, heating rate, and residence time on rapeseed stem derived biochar. J Clean 174:977–987CrossRefGoogle Scholar
  150. Zhu XM, Chen BL, Zhu LZ, Xing BS (2017) Effects and mechanisms of biochar-microbe interactions in soil improvement and pollution remediation: a review. Environ Pollut 227:98–115CrossRefGoogle Scholar
  151. Zhu DC, Hu Q, He T, Yang HP, Wang XH, Chen HP (2018) Integrate quality upgrading study of biomass through pyrolysis and densification. Acta Energ Solaris Sin 39(07):1938–1945Google Scholar
  152. Zimmerman AR, Gao B, Ahn MY (2011) Positive and negative carbon mineralization priming effects among a variety of biochar-amended soils. Soil Biol Biochem 43:1169–1179CrossRefGoogle Scholar
  153. Zwieten LV, Kimber S, Morris S, Chan KY, Downie A, Rust J, Joseph S, Cowie A (2010) Effects of biochar from slow pyrolysis of papermill waste on agronomic performance and soil fertility. Plant Soil 327(1/2):235–246CrossRefGoogle Scholar

Copyright information

© Shenyang Agricultural University 2019

Authors and Affiliations

  • Wenfu Chen
    • 1
    Email author
  • Jun Meng
    • 1
  • Xiaori Han
    • 1
  • Yu Lan
    • 1
  • Weiming Zhang
    • 1
  1. 1.Biochar Engineering and Technology Research CenterShenyang Agricultural UniversityShenyangPeople’s Republic of China

Personalised recommendations