The Renewable Resource Centre (RRC), located in the poultry unit of the Teaching and Research Farm, University of Ibadan, Nigeria (Fig. 1), was established in the year 2013. The center started with a few viable technologies developed in the Department of Environmental Health Sciences of the University which were scaled up in the field at several locations nationwide. The techniques are now proven to be viable to exploit commercially. The RRC has several sections, which are shown in Fig. 2:
A building with training facilities to train up to 30 trainees, a storeroom, a research exhibition area (TECH park) to display environmental health research outputs, a caretaker’s restroom, two toilets for visitors, a well-equipped mushroom spawn production area, and a small lounge where a visitor can sit and relax.
Biogas digesters to generate biogas from poultry piggery and cattle wastes for lighting and compression into cylinders.
A mushroom cultivation hut with thatched roof and bamboos, and accessories to produce on a large scale.
Liquid fertilizer production from biogas-spent slurry.
Permanent kiln for smokeless charcoal/biochar production.
Charcoal Kiln (a design adopted from Kenyan/Ethiopian technology) to produce charcoal within 24 h from fallen and cut trees.
Home composter for low-scale production of compost at house and farm unit.
Portable refuse-derived fuel unit.
A demonstration plot land set aside opposite the biogas section for demonstrating some of the products for agricultural production. Here, various field-based experiments are carried out.
Rainwater harvesting for ensuring the availability of water all year round with elementary and useful technology.
It is expected that the RRC will become a center of attraction for people to get trained on “Waste to Wealth” and “Waste to Energy” technologies. The center will benefit Nigerian communities as well as other developing economies through “Town and Gown” meet.
Activities and Climate Change Adaptive Technologies at Various Sections of the Center
Training Hall: About 30 people can comfortably sit and receive training. The room is equipped with two air conditioners, a PowerPoint projection, and a cupboard to display some standard books for the trainees to use. The target training participants include interested individuals, small and big scale farmers, members of cooperative society, students, and retirees (Fig. 3a).
Biogas Generation and Compression
There are two types of biogas digesters: One is 8 m3 capacity, flexible, and a product of PVC which can expand as the gas is generated (Fig. 4a). This kind of digester is suitable for larger families or establishments that need more gas for consumption. The other is a unique floating dome variety; the capacity can vary from 1 to 10 m3 or more, built from readily available water storage tanks from the local markets. They are affordable for households and have the potential for promotion at community levels to individual families. The biogas plants are designed to use dairy waste, poultry waste, piggery waste, or food waste from kitchens. Available end products from this section are biogas lamp, biogas compressor, biogas- multipurpose electricity generator, space heater, cooking stoves, and liquid and solid fertilizers produced from an effluent treatment filtration tank (Fig. 4b). The lamp is suitable for lighting an area without greenhouse gas emissions while the biogas cleaning unit is used to increase the percentage of methane. There is a kit that can be fixed to a household petrol-driven generator so that it can be adjusted to use petrol, natural gas, or biogas. The biosolids obtained after proper filtration are made into a very rich organic fertilizer that is used for mushroom cultivation (Fig. 4c) and raising crops at the demonstration plot (Fig. 4d). Besides, the space heater is used for warming young chickens in the poultry pens. At the same time, biogas fuel conversion kits and the portable cylinder are being tested to run vehicles, including cars, motorcycles, and tricycle, on biogas production from organic waste
A mushroom hut was built using materials ideal to maintain the required low temperature and humidity. In this hut, mushrooms will be grown from waste materials such as spent slurry, sawdust, etc. Also, bottles of spun (mushroom seedlings) of various tasty varieties are produced for household cultivation.
Wood Charcoal Kiln
A lot of trees fall due to heavy breeze and storms, and they are moved out by needy people for cooking purposes in an environmentally unfriendly manner that exacerbates climate change effects. A modern kiln available at the center can convert wood and cutoff trees to quality charcoal good commercial value (Fig. 5f). The furnace eliminates the traditional rural practice of digging holes all around and burning the wood openly, thus releasing greenhouse gases. In a 48-h cycle, 15–25 bags of charcoal are produced. Apart from a brick-made kiln for wood charcoal, there is another metal type (Fig. 5d) that converts light putrescible wastes to smokeless charcoal that is very popular in most of the western countries. By definition, when the charcoal is burned, no smoke is generated in the kitchen. This technology converts agroforestry residues: grass clippings, fallen leaves, maize stalks, lawn mowing, paper, sawdust, and other wastes from farms to biochar useful for farm input, wastewater treatment domestic cooking (Chang et al. 2011), warming house during cold weather, septic tank treatment, and others. The end product is in the form of charcoal powder (biochar) which is pelletized using a hand-operated extruder after some binder is added. Rejects and dust in the wood charcoal kiln are charged with treated effluent from the biogas digesters to produce nutrient-rich biochar that is sold to farmers as cheap fertilizer. The center also provides biocide-embedded smokeless charcoal for malarial control and energy for domestic cooking, at the same time (Fig. 5e). In the charcoal production process, a lot of heat is lost to the environment. The technology incorporated piped water into the furnace, whereby the temperature can be used to produce hot water. The poultry on the farm uses a lot of hot water, and it is a benefit.
According to Ana et al. (2013), global warming and its consequences on climate are among the problems posed by overdependence on fossil oil reserves. These drawbacks require exploring alternative energy sources such as biofuels that are environmentally friendly and renewable. Meanwhile, Bouros and Samiou (2001), Da Costa et al. (2004), and (Karve 2006) have earlier linked gaseous emissions from wood charcoal fires especially in an indoor environment to the incidence of many respiratory illnesses. The use of smokeless charcoal can reduce indoor air pollution, diseases, and gross environmental problems, arising from solid waste mismanagement while creating access to business opportunities for women and disadvantaged
For managing healthcare wastes, a recommended method is incineration operated at 1200 °C (Fig. 5b). However, none of the incinerators utilized in developing countries meets that requirement as they generally produce temperatures below 600 °C. World Bank tried to promote an incubator designed in the UK (De Montfort). Even this model is not able to maintain such an extreme temperature. Through locally developed and improved technology, the center designed an incinerator that uses heat generated from syngas. The heat is injected back into the incineration chamber to increase its temperature to around 800–1000 °C. The unit can also be used to handle pyrolysis of scrap tires and some types of e-waste which is an emerging global environmental health importance, as these wastes have become one of the fastest-growing waste types in the world (Sharma et al. 2012). The available end products in this section are carbon black and black oil that are generated from the smoke that might contribute to global warming as well as metal scrap salvaged from scrap tires. The distinctiveness of the plant is that: the unit is entirely covered to reduce the emission of GHGs, heat produced during the operation, in form of syngas, is used to replenish the furnace temperature, and the smoke generated is converted to diesel after some treatment. The unit can be operated safely at any convenient place since there is no pollution of the environment. Additionally, materials used in constructing the unit are locally available while the unit powers itself to treat hazardous wastes, hospital waste, and agricultural wastes
Refuse Derived Fuel (RDF) Plant
This compartment uses small wood chips (paper or any dry waste) and charcoal which on heating produce a black oil and, on further heating, produce a gas (syngas). This gas can be stored in a bag or cylinder and may be used to run a household generator to produce electricity, similar to biogas. The gas can also be used directly such as biogas for cooking at the household or institutional level. In this section, the end products are syngas and charcoal that emit very little smoke. This new innovative technology (Fig. 5a) has been developed to generate syngas from all types of combustible solid wastes and use the gas to run generators for electricity. In addition to health safety and environmental protection, this technology will be of great benefit to the rural and peri-urban populations who may want to develop small or medium scale entrepreneurship with low investment and very little skills. It does not need electricity or any sophisticated mechanical devices.
Gasification- and pyrolysis-related processes are usually confused with one another. Zhou et al. (2008) identified the major difference between the two methods as the gasification occurs in the presence of oxygen. On the other hand, pyrolysis does not require oxygen or air during its process. However, gases and liquids produced in the pyrolysis and gasification processes have high contents of carbon monoxide (CO) and hydrogen gas (H2) that can be a good source of syngas. The syngas is used for the production of methanol and ethanol or H2 used in fuel cells (Baumlin et al. 2006). For example, gases with the main benefit of pyrolysis is that it offers clean heat, which is needed to develop cooking technology with lower indoor pollution by smoke than is typically generated during the burning of biomass (Bailis et al. 2005). Also, the by-product
is smokeless briquette charcoal, because, during carbonization, its smoke disappears
This unit was designed for low-scale production of compost at houses and farm units (Fig. 5c).
The RRC is intended to be operated on a sustainable basis through various sources of revenue generation, including the following:
Consultancies and turnkey projects for public and government bodies on the technologies developed at the center (fertilizer, biogas, charcoal, smokeless charcoal, etc.)
Sale of products such as charcoal, biogas kits, mushrooms, maggots, liquid and solid organic fertilizers, black oil, carbon black, and organically grown produce from the demonstration plot
“Science Tourism” and education visits of schools, and the public
Assisting researchers through the use of locally fabricated equipment
Training programs (short-term) and hands-on training
Donors and philanthropists
University support for innovative researches and grants
Hospital waste management services
Compression of gas into cylinders for domestic