Hydrochar-derived fuels from waste walnut shell through hydrothermal carbonization: characterization and effect of processing parameters

  • Mohadese Naderi
  • Masoud Vesali-NasehEmail author
Original Article


The raw walnut shell was converted to hydrochar fuel through hydrothermal carbonization. The structural, morphological, and compositional analyses were carried out using Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric and basic elemental analyses. The effect of the processing parameters including reaction temperature, residence time, and water:biomass ratio on the hydrothermal treatment was studied. The selected hydrochar has been produced at the optimized condition of T = 250 °C, t = 5 h, and water:biomass ratio = 6.0 mL/g. The H:C and O:C atomic ratios decreased from 1.51 and 0.73 to 0.91 and 0.26 for walnut shell and the selected hydrochar, respectively. The elemental reduction occurred through the carbonization process, which mainly includes dehydration, decarboxylation, and depolymerization reactions in liquid phase. The higher heating value increased from 18.85 for walnut shell to 27.95 for the selected hydrochar. The obtained walnut shell–based hydrochar presents a relatively homogenized structure consisting of microspherical particles with a mean diameter of 6 μm. This lignin-like material with high carbon content and low ash content shows high thermal stability. These promising results are relevant to the development of hydrochar products from waste biomass for fuel applications.


Walnut shell Biomass Hydrothermal Hydrochar Solid fuel 



  1. 1.
    Basso D, Patuzzi F, Castello D, Baratieri M, Rada EC, Weiss-Hortala E, Fiori L (2016) Agro-industrial waste to solid biofuel through hydrothermal carbonization. Waste Manag 47:114–121. CrossRefGoogle Scholar
  2. 2.
    Ahmad AA, Zawawi NA, Kasim FH, Inayat A, Khasri A (2016) Assessing the gasification performance of biomass: a review on biomass gasification process conditions, optimization and economic evaluation. Renew Sust Energ Rev 53:1333–1347. CrossRefGoogle Scholar
  3. 3.
    Sevilla M, Maciá-Agulló JA, Fuertes AB (2011) Hydrothermal carbonization of biomass as a route for the sequestration of CO2: chemical and structural properties of the carbonized products. Biomass Bioenergy 35:3152–3159. CrossRefGoogle Scholar
  4. 4.
    Weldekidan H, Strezov V, Town G (2018) Review of solar energy for biofuel extraction. Renew Sust Energ Rev 88:184–192. CrossRefGoogle Scholar
  5. 5.
    Kruse A, Funke A, Titirici MM (2013) Hydrothermal conversion of biomass to fuels and energetic materials. Curr Opin Chem Biol 17:515–521. CrossRefGoogle Scholar
  6. 6.
    Oh TH, Hasanuzzaman MD, Selvaraj J, Teo SC, Chua SC (2018) Energy policy and alternative energy in Malaysia: issues and challenges for sustainable growth – an update. Renew Sust Energ Rev 81:3021–3031. CrossRefGoogle Scholar
  7. 7.
    Dong X, Guo S, Wang H, Wang Z, Gao X (2019) Physicochemical characteristics and FTIR-derived structural parameters of hydrochar produced by hydrothermal carbonisation of pea pod (Pisum sativum Linn) waste. Biomass Conv Bioref 9:531–540. CrossRefGoogle Scholar
  8. 8.
    Kang K, Azargohar R, Dalai AK, Wang H (2016) Hydrogen production from lignin, cellulose and waste biomass via supercritical water gasification: catalyst activity and process optimization study. Energy Convers Manag 117:528–537. CrossRefGoogle Scholar
  9. 9.
    Toprak A (2019) Production and characterization of microporous activated carbon from cherry laurel (Prunus laurocrasus L.) stone: application of H2 and CH4 adsorption. Biomass Conv Bioref.
  10. 10.
    Park DK, Kim SD, Lee SH, Lee JG (2010) Co-pyrolysis characteristics of sawdust and coal blend in TGA and a fixed bed reactor. Bioresour Technol 101:6151–6156. CrossRefGoogle Scholar
  11. 11.
    Bassyouni M, Waheed u, Hasan S, Abdel-Aziz MH, Abdel-hamid SMS, Naveed S, Hussain A, Ani FN (2014) Date palm waste gasification in downdraft gasifier and simulation using ASPEN HYSYS. Energy Convers Manag 88:693–699. CrossRefGoogle Scholar
  12. 12.
    Ledesma B, Olivares-Marín M, Álvarez-Murillo A, Roman S, Nabais JMV (2018) Method for promoting in-situ hydrochar porosity in hydrothermal carbonization of almond shells with air activation. J Supercrit Fluid 138:187–192. CrossRefGoogle Scholar
  13. 13.
    Queirós CSGP, Cardoso S, Lourenço A, Ferreira J, Miranda I, Lourenço MJV (2019) Characterization of walnut, almond, and pine nut shells regarding chemical composition and extract composition. Biomass Conv Bioref.
  14. 14.
    Molino A, Chianese S, Musmarra D (2015) Biomass gasification technology: the state of the art overview. J Energy Chem 25:10–25. CrossRefGoogle Scholar
  15. 15.
    Kambo HS, Dutta A (2015) A comparative review of biochar and hydrochar in terms of production, physico-chemical properties and applications. Renew Sust Energ Rev 45:359–378. CrossRefGoogle Scholar
  16. 16.
    Li H, Wang S, Yuan X, Xi Y, Huang Z, Tan M, Li C (2018) The effects of temperature and color value on hydrochars’ properties in hydrothermal carbonization. Bioresour Technol 249:574–581. CrossRefGoogle Scholar
  17. 17.
    Lam SS, Liew RK, Lim XY, Ani FN, Jusoh A (2016) Fruit waste as feedstock for recovery by pyrolysis technique. Int Biodeterior Biodegradation 113:325–333. CrossRefGoogle Scholar
  18. 18.
    Durak H (2019) Characterization of products obtained from hydrothermal liquefaction of biomass (Anchusa azurea) compared to other thermochemical conversion methods. Biomass Conv Bioref 9:459–470. CrossRefGoogle Scholar
  19. 19.
    Zaini IN, Novianti S, Nurdiawati A, Irhamna AR, Aziz M, Yoshikawa K (2017) Investigation of the physical characteristics of washed hydrochar pellets made from empty fruit bunch. Fuel Process Technol 160:109–120. CrossRefGoogle Scholar
  20. 20.
    Funke A, Ziegler F (2010) Hydrothermal carbonization of biomass: a summary and discussion of chemical mechanisms for process engineering. Biofuels Bioprod Biorefin 4:160–177. CrossRefGoogle Scholar
  21. 21.
    Zhu X, Liu Y, Qian F, Zhou C, Zhang S, Chen J (2015) Role of hydrochar properties on the porosity of hydrochar-based porous carbon for their sustainable application. ACS Sustain Chem Eng 3:833–840. CrossRefGoogle Scholar
  22. 22.
    Röhrdanz M, Rebling T, Ohlert J, Jasper J, Greve T, Buchwald R, Frieling PV, Wark M (2016) Hydrothermal carbonization of biomass from landscape management-influence of process parameters on soil properties of hydrochars. J Environ Manag 173:72–78. CrossRefGoogle Scholar
  23. 23.
    Arnold S, Moss K, Henkel M, Hausmann R (2017) Biotechnological perspectives of pyrolysis oil for a bio-based economy. Trends Biotechnol 35:925–936. CrossRefGoogle Scholar
  24. 24.
    Kar Y (2011) Co-pyrolysis of walnut shell and tar sand in a fixed-bed reactor. Bioresour Technol 102:9800–9805. CrossRefGoogle Scholar
  25. 25.
    Ding D, Zhao Y, Yang S, Shi W, Zhang Z, Lei Z, Yang Y (2013) Adsorption of cesium from aqueous solution using agricultural residue-walnut shell: equilibrium, kinetic and thermodynamic modeling studies. Water Res 47:2563–2571. CrossRefGoogle Scholar
  26. 26.
    Liu J, Liu B, Wang C, Huang Z, Hu L, Ke X, Liu L, Shi Z, Guo Z (2017) Walnut shell derived activated carbon: synthesis and its application in the sulfur cathode for lithiumesulfur batteries. J Alloy Compd 718:373–378. CrossRefGoogle Scholar
  27. 27.
    Gao P, Zhou Y, Meng F, Zhang Y, Liu Z, Zhang W, Xue G (2016) Preparation and characterization of hydrochar from waste eucalyptus bark by hydrothermal carbonization. Energy 97:238–245. CrossRefGoogle Scholar
  28. 28.
    Nizamuddin S, Baloch HA, Griffin GJ, Mubarak NM, Bhutto AW, Abro R, Mazari SA, Ali BS (2017) An overview of effect of process parameters on hydrothermal carbonization of biomass. Renew Sust Energ Rev 73:1289–1299. CrossRefGoogle Scholar
  29. 29.
    Donar YO, Çağlar E, Sınağ A (2016) Preparation and characterization of agricultural waste biomass based hydrochars. Fuel 183:66–72. CrossRefGoogle Scholar
  30. 30.
    Liu Z, Quek A, Hoekman SK, Balasubramanian R (2013) Production of solid biochar fuel from waste biomass by hydrothermal carbonization. Fuel 103:943–949. CrossRefGoogle Scholar
  31. 31.
    Sabio E, Alvarez-Murillo A, Roman S, Ledesma B (2016) Conversion of tomato-peel waste into solid fuel by hydrothermal carbonization: influence of the processing variables. Waste Manag 47:122–132. CrossRefGoogle Scholar
  32. 32.
    Fang J, Gao B, Chen J, Zimmerman AR (2015) Hydrochars derived from plant biomass under various conditions: characterization and potential applications and impacts. J Chem Eng 267:253–259. CrossRefGoogle Scholar
  33. 33.
    Jain A, Balasubramanian R, Srinivasan MP (2016) Hydrothermal conversion of biomass waste to activated carbon with high porosity: a review. J Chem Eng 283:789–805. CrossRefGoogle Scholar
  34. 34.
    Vesali-Naseh M, Khodadadi AA, Mortazavi Y, Pourfayaz F, Alizadeh O, Maghrebi M (2010) Fast and clean functionalization of carbon nanotubes by dielectric barrier discharge plasma in air compared to acid treatment. Carbon 48:1369–1379. CrossRefGoogle Scholar
  35. 35.
    Xu Q, Qian Q, Quek A, Ai N, Zeng G, Wang J (2013) Hydrothermal carbonization of macroalgae and the effects of experimental parameters on the properties of hydrochars. ACS Sustain Chem Eng 1:1092–1101. CrossRefGoogle Scholar
  36. 36.
    Ahmad M, Lee SS, Dou X, Mohan D, Sung JK, Yang JE, Ok YS (2012) Effects of pyrolysis temperature on soybean stover- and peanut shell-derived biochar properties and TCE adsorption in water. Bioresour Technol 118:536–544. CrossRefGoogle Scholar
  37. 37.
    Pavia DL, Lampman GM, Kriz GS, Vyvyan JA (2008) Introduction to spectroscopy. Cengage LearningGoogle Scholar
  38. 38.
    Gao Y, Wang X, Wang J, Li X, Cheng J, Yang H, Chen H (2013) Effect of residence time on chemical and structural properties of hydrochar obtained by hydrothermal carbonization of water hyacinth. Energy 58:376–383. CrossRefGoogle Scholar
  39. 39.
    Harini K, Chandra Mohan C, Ramya K, Karthikeyan S, Sukumar M (2018) Effect of Punica granatum peel extracts on antimicrobial properties in walnut shell cellulose reinforced bio-thermoplastic starch films from cashew nut shells. Carbohydr Polym 184:231–242. CrossRefGoogle Scholar
  40. 40.
    Srinivasan NK, Su MC, Sutherland JW, Michael JV (2005) Reflected shock tube studies of high-temperature rate constants for OH + CH4 → CH3 + H2O and CH3 + NO2 → CH3O + NO. J Phys Chem A 109:1857–1863. CrossRefGoogle Scholar
  41. 41.
    Zhang DH, Light JC (1996) Quantum state-to-state reaction probabilities for the H+H2O→H2+OH reaction in six dimensions. J Chem Phys 105:1291–1294. CrossRefGoogle Scholar
  42. 42.
    Sevilla M, Fuertes AB (2009) Chemical and structural properties of carbonaceous products obtained by hydrothermal carbonization of saccharides. Chem Eur J 15:4195–4203. CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Chemical EngineeringHamedan University of TechnologyHamedanIran

Personalised recommendations