Effects of potassium on hydrothermal carbonization of sorghum bagasse

Abstract

Hydrothermal carbonization (HTC) reacts with biomass in water at a high temperature and pressure to produce hydrochar with a higher heating value (HHV) and lower ash content than dry torrefaction. The high potassium content in biomass can promote thermochemical conversion; however, it lowers the melting temperature of the ash, causing slugging and fouling. Therefore, this study, investigated the effect of potassium on the HTC of sorghum bagasse by comparing the removal of potassium by washing with the addition of K₂CO₃. Consequently, the ash content was the highest in the potassium-added hydrochar and was 3.81% at a reaction time of 2 h. Elemental analysis showed that the lower the potassium content, the higher the carbon content, and the hydrochar with potassium removed by water washing at a reaction time of 3 h had the highest carbon content at 68.3%. Fourier transform infrared spectrometer showed dehydration and decarboxylation reactions due to HTC, but no significant differences were observed between the potassium concentrations. The mass yield decreased with increasing potassium content, and was 27.2% for the potassium-added hydrochar after 3 h. This trend was more pronounced with increasing reaction temperature. On the other hand, HHV was not affected by the potassium content. Therefore, the energy yield was similar to the weight yield. Thermal gravimetry and derivative thermal gravimetry (TG-DTG) analysis showed that higher potassium tended to accelerate the decomposition of lignin and decrease the oxidation temperature.

Keywords

Hydrothermal carbonization / Potassium / Sorghum bagasse

References

[1] Abdel-Fattah TM, Mahmoud ME, Ahmed SB, Huff MD, Lee JW, Kumar S. Biochar from woody biomass for removing metal contaminants and carbon sequestration. J Ind Eng Chem, 2015, 22: 103-109.

[2] Acharya B, Dutta A, Minaret J. Review on comparative study of dry and wet torrefaction. Sustainable Energy Technol Assess, 2015, 12: 26-37.

[3] An H, McGinn PJ. Catalytic behavior of potassium containing compounds for diesel soot combustion. Appl Catal B, 2006, 62(1–2): 46-56.

[4] Bach QV, Tran KQ, Skreiberg Ø. Comparative study on the thermal degradation of dry-and wet-torrefied woods. Appl Energy, 2017, 185: 1051-1058.

[5] Bridgwater T. Biomass for energy. J Sci Food Agric, 2006, 86(12): 1755-1768.

[6] Cen K, Chen D, Wang J, Cai Y, Wang L. Effects of water washing and torrefaction pretreatments on corn stalk pyrolysis: combined study using TG-FTIR and a fixed bed reactor. Energy Fuels, 2016, 30(12): 10627-10634.

[7] Chen D, Mei J, Li H, Li Y, Lu M, Ma T, Ma Z. Combined pretreatment with torrefaction and washing using torrefaction liquid products to yield upgraded biomass and pyrolysis products. Biores Technol, 2017, 228: 62-68.

[8] Chen H, Tang Z, Liu B, Chen W, Hu J, Chen Y, Yang H. The new insight about mechanism of the influence of K₂CO₃ on cellulose pyrolysis. Fuel, 2021, 295: 120617.

[9] Correa CR, Hehr T, Voglhuber-Slavinsky A, Rauscher Y, Kruse A. Pyrolysis vs. hydrothermal carbonization: understanding the effect of biomass structural components and inorganic compounds on the char properties. J Anal Appl Pyrol, 2019, 140: 137-147.

[10] Deng L, Zhang T, Che D. Effect of water washing on fuel properties, pyrolysis and combustion characteristics, and ash fusibility of biomass. Fuel Process Technol, 2013, 106: 712-720.

[11] Diao R, Sun M, Huang Y, Zhu X. Synergistic effect of washing pretreatment and co-pyrolysis on physicochemical property evolution of biochar derived from bio-oil distillation residue and walnut shell. J Anal Appl Pyrol, 2021, 155: 105034.

[12] Du S, Yang H, Qian K, Wang X, Chen H. Fusion and transformation properties of the inorganic components in biomass ash. Fuel, 2014, 117: 1281-1287.

[13] Ferreira AF, Ribau JP, Costa M. A decision support method for biochars characterization from carbonization of grape pomace. Biomass Bioenergy, 2021, 145: 105946.

[14] González-Arias J, Sánchez ME, Martínez EJ, Covalski C, Alonso-Simón A, González R, Cara-Jiménez J. Hydrothermal carbonization of olive tree pruning as a sustainable way for improving biomass energy potential: effect of reaction parameters on fuel properties. Processes, 2020, 8(10): 1201.

[15] González-Arias J, Gómez X, González-Castaño M, Sánchez ME, Rosas JG, Cara-Jiménez J. Insights into the product quality and energy requirements for solid biofuel production: a comparison of hydrothermal carbonization, pyrolysis and torrefaction of olive tree pruning. Energy, 2022

[16] Hoekman SK, Broch A, Robbins C. Hydrothermal carbonization (HTC) of lignocellulosic biomass. Energy Fuels, 2011, 25(4): 1802-1810.

[17] Hwang H, Oh S, Cho TS, Choi IG, Choi JW. Fast pyrolysis of potassium impregnated poplar wood and characterization of its influence on the formation as well as properties of pyrolytic products. Biores Technol, 2013, 150: 359-366.

[18] Jones JM, Darvell LI, Bridgeman TG, Pourkashanian M, Williams A. An investigation of the thermal and catalytic behaviour of potassium in biomass combustion. Proc Combust Inst, 2007, 31(2): 1955-1963.

[19] Keskinen R, Hyväluoma J, Sohlo L, Rasa K. Fertilizer and soil conditioner value of broiler manure biochars. Biochar, 2019, 1: 259-270.

[20] Khan SA, Hussain MZ, Prasad S, Banerjee UC. Prospects of biodiesel production from microalgae in India. Renew Sustain Energy Rev, 2009, 13(9): 2361-2372.

[21] Leng L, Zhang W, Leng S, Chen J, Yang L, Li H, Jiang S, Huang H. Bioenergy recovery from wastewater produced by hydrothermal processing biomass: Progress, challenges, and opportunities. Sci Total Environ, 2020, 748: 142383.

[22] Liaw SB, Wu H. Leaching characteristics of organic and inorganic matter from biomass by water: differences between batch and semi-continuous operations. Ind Eng Chem Res, 2013, 52: 4280-4289.

[23] Ma D, Zhang G, Zhao P, Chinnathan A, Shen Y, Yoshikawa K, Xu G. Hydrothermal treatment of antibiotic mycelial dreg: more understanding from fuel characteristics. Chem Eng J, 2015, 273: 147-155.

[24] Marcus Y. On transport properties of hot liquid and supercritical water and their relationship to the hydrogen bonding. Fluid Phase Equilib, 1999, 164(1): 131-142.

[25] PetroviĿ J, PerišiĿ N, MaksimoviĿ JD, MaksimoviĿ V, KragoviĿ M, StojanoviĿ M, LauševiĿ M, MihajloviĿ M. Hydrothermal conversion of grape pomace: Detailed characterization of obtained hydrochar and liquid phase. J Anal Appl Pyrol, 2016, 118: 267-277.

[26] Reza MT, Lynam JG, Uddin MH, Coronella CJ. Hydrothermal carbonization: fate of inorganics. Biomass Bioenerg, 2013, 49: 86-94.

[27] Reza MT, Wirth B, Lüder U, Werner M. Behavior of selected hydrolyzed and dehydrated products during hydrothermal carbonization of biomass. Biores Technol, 2014, 169: 352-361.

[28] Ruiz HA, Rodríguez-Jasso RM, Fernandes BD, Vicente AA, Teixeira JA. Hydrothermal processing, as an alternative for upgrading agriculture residues and marine biomass according to the biorefinery concept: a review. Renew Sustain Energy Rev, 2013, 21: 35-51.

[29] Rutkowski P. Pyrolysis of cellulose, xylan and lignin with the K₂CO₃ and ZnCl₂ addition for bio-oil production. Fuel Process Technol, 2011, 92(3): 517-522.

[30] Safar M, Lin BJ, Chen WH, Langauer D, Chang JS, Raclavska H, Pétrissans A, Rousset P, Pétrissans M. Catalytic effects of potassium on biomass pyrolysis, combustion and torrefaction. Appl Energy, 2019, 235: 346-355.

[31] Savage PE. Organic chemical reactions in supercritical water. Chem Rev, 1999

[32] Sermyagina E, Saari J, Kaikko J, Vakkilainen E. Hydrothermal carbonization of coniferous biomass: effect of process parameters on mass and energy yields. J Anal Appl Pyrol, 2015, 113: 551-556.

[33] Shen Y. Chars as carbonaceous adsorbents/catalysts for tar elimination during biomass pyrolysis or gasification. Renew Sustain Energy Rev, 2015, 43: 281-295.

[34] Van der Stelt MJC, Gerhauser H, Kiel JHA, Ptasinski KJ. Biomass upgrading by torrefaction for the production of biofuels: a review. Biomass Bioenerg, 2011, 35(9): 3748-3762.

[35] Wang T, Zhai Y, Zhu Y, Chuan P, Wang T, Xu B, Li C, Zeng G. Feedwater pH affects phosphorus transformation during hydrothermal carbonization of sewage sludge. Biores Technol, 2017, 245: 182-187.

[36] Wang T, Zhai Y, Zhu Y, Li C, Zeng G. A review of the hydrothermal carbonization of biomass waste for hydrochar formation: process conditions, fundamentals, and physicochemical properties. Renew Sustain Energy Rev, 2018, 90: 223-247.

[37] Wuebbles DJ, Jain AK. Concerns about climate change and the role of fossil fuel use. Fuel Process Technol, 2001, 71(1–3): 99-119.

[38] Xu Z, Guo Z, Xiao X, Zeng P, Xue Q. Effect of inorganic potassium compounds on the hydrothermal carbonization of Cd-contaminated rice straw for experimental-scale hydrochar. Biomass Bioenergy, 2019, 130: 105357.

[39] Yafei S, Zhang N, Zhang S. Catalytic pyrolysis of biomass with potassium compounds for Co-production of high-quality biofuels and porous carbons. Energy, 2020, 190: 116431.

[40] Zhang S, Dong Q, Zhang L, Xiong Y, Liu X, Zhu S. Effects of water washing and torrefaction pretreatments on rice husk pyrolysis by microwave heating. Biores Technol, 2015, 193: 442-448.

[41] Zhang S, Su Y, Xu D, Zhu S, Zhang H, Liu X. Assessment of hydrothermal carbonization and coupling washing with torrefaction of bamboo sawdust for biofuels production. Biores Technol, 2018, 258: 111-118.

[42] Zhang C, Li F, Ho SH, Chen WH, Duleeka SG, Pau LS. Oxidative torrefaction of microalga Nannochloropsis Oceanica activated by potassium carbonate for solid biofuel production. Environ Res, 2022, 212: 113389.