Corn straw has potential as a biofuel, and is generated in large amounts globally. However, this potential remains underutilized, and torrefaction is one of the processes that can be implemented to improve the energy grade of this biomass. In this study, three process parameters (temperature, heating rate, residence time) were investigated using a response surface method to optimize the torrefaction process of corn straw. At 242.26 ℃, a 60 min residence time, and 6.28 ℃/min heating rate, the mass yield and higher heating value (HHV) reached their maximum values. Temperature was the most important factor influencing torrefaction, followed by residence time and then heating rate. The gas and liquid by-products were measured by mass spectrometry and mass spectrometry-gas chromatography, and the heat demand of torrefaction was measured by thermogravimetric analysis-differential scanning calorimetry. The HHV of the by-products changed little before 240 ℃ but increased considerably as the temperature further increased. The HHV at 242 ℃ was 1,273 kJ/kg. When the heat loss was 50%, 242 ℃ was the critical point of energy balance, and after that the torrefaction process was energy self-sufficient. These findings provide data to support the establishment of semi-industrial or industrial corn straw torrefaction devices.

Torrefaction Biomass Energy Response Surface Method Corn Straw Energy Balance

Manzano-Agugliaro F, Alcayde A, Montoya FG, Zapata-Sierra A, Gil C, Energy Rev., 18, 134 (2013)
Bui HH, Tran KQ, Chen WH, Bioresour. Technol., 199, 362 (2016)
Trubetskaya A, Leahy JJ, Yazhenskikh E, Müller M, Layden P, Johnson R, Ståhl K, Monaghan RFD, Energy, 171, 853 (2019)
Wannapeera J, Worasuwannarak N, J. Anal. Appl. Pyrolysis, 96, 173 (2012)
Moayedi H, Aghel B, Abdullahi MM, Nguyen H, Rashid A, J. Clean Prod., 237, 117851 (2019)
Sheldon RA, Green Chem., 16, 95 (2014)
Naik SN, Goud VV, Rout PK, Dalai AK, Renew. Sust. Energ. Rev., 14, 578 (2010)
Park J, Meng J, Lim KH, Rojas OJ, Park S, J. Anal. Appl. Pyrolysis, 100, 199 (2013)
Deng J, Wang G, Kuang J, Zhang Y, Luo Y, J. Anal. Appl. Pyrolysis, 86, 331 (2009)
Basu P, Sadhukhan AK, Gupta P, Rao S, Dhungana A, Acharya B, Bioresour. Technol., 159, 215 (2014)
Tran KQ, Luo X, Seisenbaeva G, Jirjis R, Appl. Energy, 112, 539 (2013)
Chen WH, Lu KM, Tsai CM, Appl. Energy, 100, 318 (2012)
Chen WH, Hsu HC, Lu KM, Lee WJ, Lin TC, Energy, 36, 3012 (2011)
Nunes LJR, Matias JCO, Catalão JPS, Energy Rev., 40, 153 (2014)
Chen WH, Kuo PC, Energy, 36, 803 (2011)
Chen WH, Liu SH, Juang TT, Tsai CM, Zhuang YQ, Appl. Energy, 160, 829 (2015)
Pawlak-Kruczek H, Krochmalny K, Mościcki K, Zgóra J, Czerep M, Ostrycharczyk M, Niedźwiecki L, Inżynieria i ochrona środowiska, 20, 457 (2017)
Sulaiman MH, Uemura Y, Azizan MT, Procedia Eng., 148, 573 (2016)
Chiou BS, Valenzuela-Medina D, Bilbao-Sainz C, Klamczynski AK, Avena-Bustillos RJ, Milczarek RR, Du WX, Glenn GM, Orts WJ, Bioresour. Technol., 177, 58 (2015)
Li H, Liu X, Legros R, Bi XT, Lim CJ, Sokhansanj S, Appl. Energy, 93, 680 (2012)
Liu Y, Rokni E, Yang R, Ren X, Sun R, Levendis YA, Fuel, 285, 119044 (2021)
Zhang S, Su Y, Xiong Y, Zhang H, Fuel, 262, 116667 (2020)
Kutlu O, Kocar G, Int. J. Energy Res., 42, 4746 (2018)
Singh S, Chakraborty JP, Mondal MK, Energy, 186, 115865 (2019)
Granados DA, Velásquez HI, Chejne F, Energy, 74, 181 (2014)
Bates RB, Ghoniem AF, Bioresour. Technol., 134, 331 (2013)
Dos Reis Ferreira RA, Da Silva Meireles C, Assunção RMN, Soares RR, J. Therm. Anal. Calorim., 132, 1535 (2018)
Singh RK, Jena K, Chakraborty JP, Sarkar A, Int. J. Hydrog. Energy, 45, 18922 (2020)
Ohliger A, Förster M, Kneer R, Fuel, 104, 607 (2013)
Medic D, Darr M, Shah A, Potter B, Zimmerman J, Fuel, 91, 147 (2012)
Bergman P, Boersma AR (2005)
Mohadesi M, Aghel B, Maleki M, Ansari A, Fuel, 273, 117736 (2020)
Aghel B, Mohadesi M, Sahraei S, Chem. Eng. Technol., 41, 598 (2018)
Aghel B, Mohadesi M, Ansari A, Maleki M, Renew. Energy, 142, 207 (2019)
Arteaga-Pérez LE, Segura C, Bustamante-García V, Cápiro O, Jiménez R, Energy, 93, 1731 (2015)
Chang S, Zhao Z, Zheng A, He F, Huang Z, Li H, Energy Fuels, 26, 7009 (2012)
Arteaga-Pérez LE, Grandón H, Flores M, Segura C, Kelley SS, Bioresour. Technol., 238, 194 (2017)
Wang GJ, Luo YH, Jian D, Kuang JH, Zhang YL, Chin. Sci. Bull., 56, 1442 (2011)
Williams PT, Nugranad N, Energy, 25, 493 (2000)
Irfan M, Chen Q, Yue Y, Pang R, Lin Q, Zhao X, Chen H, Bioresour. Technol., 211, 457 (2016)
Wannapeera J, Fungtammasan B, Worasuwannarak N, J. Anal. Appl. Pyrolysis, 92, 99 (2011)
Esteves BM, Pereira HM, Bioresources, 4, 370 (2009)
Esteves B, Marques AV, Domingos I, Pereira H, Wood Sci. Technol., 42, 369 (2008)
Gonzalez-Pena MM, Hale M, Holzforschung, 63, 385 (2009)
Melkior T, Barthomeuf C, Bardet M, Fuel, 187, 250 (2017)
Pelaez-Samaniego MR, Yadama V, Lowell E, Espinoza- Herrera R, Wood Sci. Technol., 47, 1285 (2013)
Peng JH, Bi XT, Sokhansanj S, Lim CJ, Fuel, 111, 411 (2013)
Da Silva CMS, Carneiro ADCO, Vital BR, Figueiró CG, Fialho LDF, de Magalhães MA, Carvalho AG, Candido WL, Renew. Sust. Energ. Rev., 82, 2426 (2018)
Ribeiro J, Godina R, Matias J, Nunes L, Sustain, 10, 2323 (2018)
Milosavljevic I, Oja V, Suuberg EM, Ind. Eng. Chem. Res., 35, 653 (1996)
Gallego LJ, Cardona S, Martínez E, Rios LA, Waste and Biomass Valorization, 11, 2273 (2020)