本研究以咖啡渣分別添加不同的環境友善添加劑(碳酸氫鈉及過氧化氫水溶液)，於培燒溫度(200-300 °C)下衍生的生物炭，其中碳酸氫鈉用於孔體積改質，而過氧化氫水溶液用於提升生物炭燃料特性。本文主要分析生物炭的燃料性質以評估其應用的潛力，並對製程進行最佳化，本文主要分為兩大部分，如下所述。
第一部分旨在添加碳酸氫鈉水溶液(NaHCO3)於培燒溫度下提高生物炭孔體積。該生物炭是咖啡渣在不同溫度（200-300 °C）、停滯時間（30-60分鐘）和碳酸氫鈉濃度（0-8.3 wt%）的狀態下所製成的。結果表明，生物炭的總孔體積隨溫度，停留時間或NaHCO3水溶液濃度的升高而增加，而堆積密度卻有相反的趨勢。添加8.3 wt％的NaHCO3溶液，在300°C的焙燒溫度下持續60分鐘所製成的造孔生物炭(300-TP-SCG)，其比表面積和總孔體積為42.050 m2∙g-1和0.1389cm3∙g-1，與未造孔生物炭(300-TCG)相比，分別提高了141％和76％。300-TP-SCG的接觸角（126°）和水活性（0.48 aw）顯示它易於儲存。300-TP-SCG的二氧化碳吸收能力為0.32 mmol·g-1，相較於300-TSCG提高了39％。燃料性質方面，300-TP-SCG具有較高的熱值（28.31 MJ∙kg-1）和較低的點火溫度（252 °C）。總體而言，300-TP-SCG是煤炭的潛在燃料替代品。本研究成功地在低溫下製造的中孔生物炭滿足「3E」，即能源（生物燃料），環境（生物廢料再利用固體廢物）和循環經濟（生物吸附劑）
在第二部分中，於咖啡渣中添加過氧化氫並透過培燒技術製成生物炭，以提升生物炭之燃料特性並減少環境汙染，同時藉由神經網路模型最佳化培燒溫度(200-300 °C)、滯留時間(30-60 min)及過氧化氫濃度(0-100 wt%)等三個參數，以得到最小的堆積密度(輕量化燃料)，結果顯示神經網路模型對具有高準確性及可靠度(R2 = 0.9994)。隨著溫度、持續時間或過氧化氫濃度的升高，生物炭熱值（HHV）升高，而堆密度卻呈現相反的趨勢。使用100 wt％的過氧化氫溶液（230-100％-TSCG）在230°C培燒30分鐘所製成的生物炭的熱值、點火溫度及堆積密度分別為27.00 MJ∙kg-1、292 °C和120 kg∙m-3。與未處理咖啡渣相比，熱值提高了29%。再者，其接觸角（126°），水活性（0.51 aw）和水分含量（7.69％）表明，它具有更高的抗生物降解性，因此可以保存更長的時間。總體而言，過氧化氫是咖啡渣固體燃料的綠色處理添加劑。本研究成功地生產出了在低溫下具有較高熱值和較低堆積密度的生物炭。綠色添加劑的開發可以有效減少環境污染物並將廢物提升為資源，並實現「3E」，即環境（無污染綠色添加劑），能源（生物燃料）和循環經濟（廢物利用）。另外，所生產的生物炭在生物吸附劑和土壤改良劑領域具有巨大潛力。

In this study, spent coffee grounds were added with different environmentally friendly additives (sodium bicarbonate and hydrogen peroxide aqueous solution), and the biochar was derived at the torrefaction temperature (200-300 °C). Sodium bicarbonate (NaHCO3) and hydrogen peroxide (H2O2) are used to upgrade the pore volume and intensify fuel properties of biochars, respectively. The fuel properties of biochar were analyzed to evaluate its potential application, and the process optimization was demonstrated. Consequently, the study was divided into two parts, as described below.
In the first part of this research, a novel approach for upgrading the pore volume of biochar at low temperatures using a green additive of sodium bicarbonate (NaHCO3) is developed in this study. The biochar was produced from spent coffee grounds (SCGs) torrefied at different temperatures (200-300 °C) with different residence times (30-60 min) and NaHCO3 concentrations (0-8.3 wt%). The results reveal that the total pore volume of biochar increases with rising temperature, residence time, or NaHCO3 aqueous solution concentration, whereas the bulk density has an opposite trend. The specific surface area and total pore volume of pore-forming SCG from 300 °C torrefaction for 60 min with an 8.3 wt% NaHCO3 solution (300-TP-SCG) are 42.050 m2∙g-1 and 0.1389 cm3∙g-1, accounting for the improvements of 141% and 76%, respectively, compared to the parent SCG. The contact angle (126°) and water activity (0.48 aw) of 300-TP-SCG reveal that it is easy to be stored. The CO2 uptake capacity of 300-TP-SCG is 0.32 mmol∙g-1, rendering a 39% improvement relative to 300-TSCG, namely, SCG torrefied at 300 °C for 60 min. 300-TP-SCG has higher HHV (28.31 MJ∙kg-1) and lower ignition temperature (252 °C). Overall, it indicates 300-TP-SCG is a potential fuel substitute for coal. This study has successfully produced mesoporous biochar at low temperatures to fulfill “3E”, namely, energy (biofuel), environment (biowaste reuse solid waste), and circular economy (bioadsorbent).
In second part, a green approach using hydrogen peroxide (H2O2) to intensify the fuel properties of spent coffee grounds (SCGs) through torrefaction is developed in this study to minimize environmental pollution. Meanwhile, a neural network (NN) is used to minimize bulk density at different combinations of operating conditions to show the accurate and reliable model of NN (R2=0.9994). The biochar produced from SCGs torrefied at temperatures of 200-300 °C, duration of 30-60 min, and H2O2 concentrations of 0-100 wt% is examined. The results reveal that the higher heating value (HHV) of biochar increases with rising temperature, duration, or H2O2 concentration, whereas the bulk density has an opposite trend. The HHV, ignition temperature, and bulk density of biochar from torrefaction at 230 °C for 30 min with a 100 wt% H2O2 solution (230-100%-TSCG) are 27.00 MJ∙kg-1, 292 °C, and 120 kg∙m-3, respectively. This HHV accounts for a 29% improvement compared to that of untorrefied SCG. The contact angle (126°), water activity (0.51 aw), and moisture content (7.69%) of the optimized biochar indicate that it has higher resistance against biodegradation, and thereby can be stored longer. Overall, H2O2 is a green treatment additive for SCGs solid fuel. This study has successfully produced biochar with greater HHV and low bulk density at low temperatures. The green additive development can effectively reduce environmental pollutants and upgrade wastes into resources, and achieve "3E", namely, environmental (non-polluting green additives), energy (biofuel), and circular economy (waste upgrade). In addition, the produced biochar has great potential in the fields of bioadsorbents and soil amendments.

[1]　　　Dong K, Dong X, Jiang Q. How renewable energy consumption lower global CO2 emissions? Evidence from countries with different income levels. The World Economy 2019;43(6):1665-98.
[2]　　　Shafiee S, Topal E. When will fossil fuel reserves be diminished? Energy Policy 2009;37(1):181-9.
[3]　　　Sun Y, Ouyang Y, Luo J, Cao H, Li X, Ma J, et al. Biomass-derived nitrogen self-doped porous activation carbon as an effective bifunctional electrocatalysts. Chinese Chemical Letters 2021;32(1):92-8.
[4]　　　Lam SS, Mahari WAW, Ok YS, Peng W, Chong CT, Ma NL, et al. Microwave vacuum pyrolysis of waste plastic and used cooking oil for simultaneous waste reduction and sustainable energy conversion: Recovery of cleaner liquid fuel and techno-economic analysis. Renewable and Sustainable Energy Reviews 2019;115:109359.
[5]　　　Malik P, Awasthi M, Sinha S. Biomass‐based gaseous fuel for hybrid renewable energy systems: An overview and future research opportunities. International Journal of Energy Research 2020;45(3):3464-94.
[6] 　　Ge S, Foong SY, Ma NL, Liew RK, Mahari WAW, Xia C, et al. Vacuum pyrolysis incorporating microwave heating and base mixture modification: An integrated approach to transform biowaste into eco-friendly bioenergy products. Renewable and Sustainable Energy Reviews 2020;127:109871.
[7]　　　Limousy L, Jeguirim M, Labbe S, Balay F, Fossard E. Performance and emissions characteristics of compressed spent coffee ground/wood chip logs in a residential stove. Energy for Sustainable Development 2015;28:52-9.
[8]　　　Atelge MR, Atabani AE, Abut S, Kaya M, Eskicioglu C, Semaan G, et al. Anaerobic co-digestion of oil-extracted spent coffee grounds with various wastes: Experimental and kinetic modeling studies. Bioresour Technol 2020;322:124470.
[9]　　　Blinová L, Sirotiak M, Bartošová A, Soldán M. Review Utilization of Waste From Coffee Production. Research Papers Faculty of Materials Science and Technology Slovak University of Technology 2017;25:91-101.
[10] 　　Ｄa Silva Correia IK, Santos PF, Santana CS, Neris JB, Luzardo FHM, Velasco FG. Application of coconut shell, banana peel, spent coffee grounds, eucalyptus bark, piassava (Attalea funifera) and water hyacinth (Eichornia crassipes) in the adsorption of Pb2+ and Ni2+ ions in water. Journal of Environmental Chemical Engineering 2018;6(2):2319-34.
[11] 　　Khataee A, Kayan B, Kalderis D, Karimi A, Akay S, Konsolakis M. Ultrasound-assisted removal of Acid Red 17 using nanosized Fe3O4-loaded coffee waste hydrochar. Ultrason Sonochem 2017;35(Pt A):72-80.
[12]　　 Kang SB, Oh HY, Kim JJ, Choi KS. Characteristics of spent coffee ground as a fuel and combustion test in a small boiler (6.5 kW). Renewable Energy 2017;113:1208-14.
[13] 　　Kwon EE, Yi H, Jeon YJ. Sequential co-production of biodiesel and bioethanol with spent coffee grounds. Bioresour Technol 2013;136:475-80.
[14]　　 Mussatto SI, Machado EMS, Carneiro LM, Teixeira JA. Sugars metabolism and ethanol production by different yeast strains from coffee industry wastes hydrolysates. Applied Energy 2012;92:763-8.
[15] 　　Murthy PS, Madhava Naidu M. Sustainable management of coffee industry by-products and value addition—A review. Resources, Conservation and Recycling 2012;66:45-58.
[16]　　 Shin J, Kwak J, Lee YG, Kim S, Choi M, Bae S, et al. Competitive adsorption of pharmaceuticals in lake water and wastewater effluent by pristine and NaOH-activated biochars from spent coffee wastes: Contribution of hydrophobic and pi-pi interactions. Environ Pollut 2020;270:116244.
[17] 　　Chakrabarti A, Kaur H, Savio J, Rudramurthy SM, Patel A, Shastri P, et al. Epidemiology and clinical outcomes of invasive mould infections in Indian intensive care units (FISF study). J Crit Care 2019;51:64-70.
[18] 　　Du C, Li B, Yu W. Indoor mould exposure: Characteristics, influences and corresponding associations with built environment—A review. Journal of Building Engineering 2021;35.
[19] 　　Kirbiyik Ç. Modification of biomass-derived activated carbon with magnetic α-Fe2O3 nanoparticles for CO2 and CH4 adsorption. Turkish Journal of Chemistry 2019;43:687-704.
[20] 　　Soares B, Gama N, Freire CSR, Barros-Timmons A, Brandão I, Silva R, et al. Spent coffee grounds as a renewable source for ecopolyols production. Journal of Chemical Technology & Biotechnology 2015;90(8):1480-8.
[21]　　 Frealle E, Reboux G, Le Rouzic O, Bautin N, Willemin MC, Pichavant M, et al. Impact of domestic mould exposure on Aspergillus biomarkers and lung function in patients with chronic obstructive pulmonary disease. Environ Res 2021;195:110850.
[22] 　　Das S, Sarkar PK, Mahapatra S. Single particle combustion studies of coal/biomass fuel mixtures. Energy 2021;217.
[23] 　　Lee HW, Lee H, Kim Y-M, Park R-s, Park Y-K. Recent application of biochar on the catalytic biorefinery and environmental processes. Chinese Chemical Letters 2019;30(12):2147-50.
[24] 　　Chen W-H. Torrefaction. Pretreatment of Biomass. 2015, p. 173-92.
[25] 　　Tun MM, Raclavska H, Juchelkova D, Ruzickova J, Safar M, Strbova K, et al. Spent coffee ground as renewable energy source: Evaluation of the drying processes. J Environ Manage 2020;275:111204.
[26] 　　Chen W-H, Lin B-J, Lin Y-Y, Chu Y-S, Ubando AT, Show PL, et al. Progress in biomass torrefaction: Principles, applications and challenges. Progress in Energy and Combustion Science 2021;82.
[27]　　 Arriola E, Chen W-H, Chih Y-K, De Luna MD, Show PL. Impact of post-torrefaction process on biochar formation from wood pellets and self-heating phenomena for production safety. Energy 2020;207.
[28]　　 Adeleke AA, Odusote JK, Ikubanni PP, Lasode OA, Malathi M, Paswan D. Essential basics on biomass torrefaction, densification and utilization. International Journal of Energy Research 2020;45(2):1375-95.
[29]　　 Yaashikaa PR, Kumar PS, Varjani S, Saravanan A. A critical review on the biochar production techniques, characterization, stability and applications for circular bioeconomy. Biotechnol Rep (Amst) 2020;28:e00570.
[30] Xiang W, Zhang X, Chen J, Zou W, He F, Hu X, et al. Biochar technology in wastewater treatment: A critical review. Chemosphere 2020;252:126539.
[31] 　　Quan C, Su R, Gao N. Preparation of activated biomass carbon from pine sawdust for supercapacitor and CO2 capture. International Journal of Energy Research 2020;44(6):4335-51.
[32] 　　Sermyagina E, Mendoza Martinez CL, Nikku M, Vakkilainen E. Spent coffee grounds and tea leaf residues: Characterization, evaluation of thermal reactivity and recovery of high-value compounds. Biomass and Bioenergy 2021;150.
[33] 　　Lee XJ, Ong HC, Gao W, Ok YS, Chen W-H, Goh BHH, et al. Solid biofuel production from spent coffee ground wastes: Process optimisation, characterisation and kinetic studies. Fuel 2021;292.
[34]　 Mayson S, Williams ID. Applying a circular economy approach to valorize spent coffee grounds. Resources, Conservation and Recycling 2021;172.
[35]　　 Lee J-C, Kim H-J, Kim H-W, Lim H. Iron-impregnated spent coffee ground biochar for enhanced degradation of methylene blue during cold plasma application. Journal of Industrial and Engineering Chemistry 2021;98:383-8.
[36] 　　Dalhat MA, Mu’azu ND, Essa MH. Generalized decay and artificial neural network models for fixed-Bed phenolic compounds adsorption onto activated date palm biochar. Journal of Environmental Chemical Engineering 2020.
[37] 　　Albalasmeh A, Gharaibeh MA, Mohawesh O, Alajlouni M, Quzaih M, Masad M, et al. Characterization and Artificial Neural Networks Modelling of methylene blue adsorption of biochar derived from agricultural residues: Effect of biomass type, pyrolysis temperature, particle size. Journal of Saudi Chemical Society 2020;24(11):811-23.
[38] 　　Arumugasamy SK, Selvarajoo A, Tariq MA. Artificial neural networks modelling: Gasification behaviour of palm fibre biochar. Materials Science for Energy Technologies 2020;3:868-78.
[39]　　 Bi H, Wang C, Jiang X, Jiang C, Bao L, Lin Q. Investigation of sewage sludge and peanut shells co‐combustion using thermogravimetric analysis and artificial neural network. International Journal of Energy Research 2020;45(3):3852-69.
[40]　　 Oginni O, Yakaboylu GA, Singh K, Sabolsky EM, Unal-Tosun G, Jaisi D, et al. Phosphorus adsorption behaviors of MgO modified biochars derived from waste woody biomass resources. Journal of Environmental Chemical Engineering 2020;8(2):103723.
[41] 　　Hu B, Huang Q, Bourtsalas ACT, Ali M, Chi Y, Yan J. Effect of Chlorine on the Structure and Reactivity of Char Derived from Solid Waste. Energy & Fuels 2017;31(7):7606-16.
[42]　　 Su Y, Liu L, Zhang S, Xu D, Du H, Cheng Y, et al. A green route for pyrolysis poly-generation of typical high ash biomass, rice husk: Effects on simultaneous production of carbonic oxide-rich syngas, phenol-abundant bio-oil, high-adsorption porous carbon and amorphous silicon dioxide. Bioresour Technol 2020;295:122243.
[43] 　　Nguyen V-T, Nguyen T-B, Huang CP, Chen C-W, Bui X-T, Dong C-D. Alkaline modified biochar derived from spent coffee ground for removal of tetracycline from aqueous solutions. Journal of Water Process Engineering 2021;40.
[44]　　 Zhang S, Su Y, Zhu S, Zhang H, Zhang Q. Effects of pretreatment and FeCl3 preload of rice husk on synthesis of magnetic carbon composites by pyrolysis for supercapacitor application. Journal of Analytical and Applied Pyrolysis 2018;135:22-31.
[45]　　 Dai L, Zeng Z, Tian X, Jiang L, Yu Z, Wu Q, et al. Microwave-assisted catalytic pyrolysis of torrefied corn cob for phenol-rich bio-oil production over Fe modified bio-char catalyst. Journal of Analytical and Applied Pyrolysis 2019;143.
[46] 　　Cheng H, Sun Y, Wang X, Zou S, Ye G, Huang H, et al. Hierarchical porous carbon fabricated from cellulose-degrading fungus modified rice husks: Ultrahigh surface area and impressive improvement in toluene adsorption. J Hazard Mater 2020;392:122298.
[47]　　 Tian W, Zhang H, Sun H, Suvorova A, Saunders M, Tade M, et al. Heteroatom (N or N-S)-Doping Induced Layered and Honeycomb Microstructures of Porous Carbons for CO2Capture and Energy Applications. Advanced Functional Materials 2016;26(47):8651-61.
[48] 　　Shin J, Lee YG, Lee SH, Kim S, Ochir D, Park Y, et al. Single and competitive adsorptions of micropollutants using pristine and alkali-modified biochars from spent coffee grounds. J Hazard Mater 2020;400:123102.
[49] 　　Chai L, Saffron CM, Yang Y, Zhang Z, Munro RW, Kriegel RM. Integration of decentralized torrefaction with centralized catalytic pyrolysis to produce green aromatics from coffee grounds. Bioresour Technol 2016;201:287-92.
[50] 　　Konnerth P, Jung D, Straten JW, Raffelt K, Kruse A. Metal oxide-doped activated carbons from bakery waste and coffee grounds for application in supercapacitors. Materials Science for Energy Technologies 2021;4:69-80.
[51] 　　Nguyen VT, Nguyen TB, Chen CW, Hung CM, Vo TD, Chang JH, et al. Influence of pyrolysis temperature on polycyclic aromatic hydrocarbons production and tetracycline adsorption behavior of biochar derived from spent coffee ground. Bioresour Technol 2019;284:197-203.
[52]　　 Nakason K, Khemthong P, Kraithong W, Chukaew P, Panyapinyopol B, Kitkaew D, et al. Upgrading properties of biochar fuel derived from cassava rhizome via torrefaction: Effect of sweeping gas atmospheres and its economic feasibility. Case Studies in Thermal Engineering 2021;23.
[53] 　　Torquato LDM, Crnkovic PM, Ribeiro CA, Crespi MS. New approach for proximate analysis by thermogravimetry using CO2 atmosphere. Journal of Thermal Analysis and Calorimetry 2016;128(1):1-14.
[54]　　 Zhang C, Ho S-H, Chen W-H, Xie Y, Liu Z, Chang J-S. Torrefaction performance and energy usage of biomass wastes and their correlations with torrefaction severity index. Applied Energy 2018;220:598-604.
[55] 　　Pala M, Kantarli IC, Buyukisik HB, Yanik J. Hydrothermal carbonization and torrefaction of grape pomace: a comparative evaluation. Bioresour Technol 2014;161:255-62.
[56] 　　Yue Y, Singh H, Singh B, Mani S. Torrefaction of sorghum biomass to improve fuel properties. Bioresour Technol 2017;232:372-9.
[57]　　 Zheng W-T, Huang K, Dai S. Solvothermal and template-free synthesis of N-Functionalized mesoporous polymer for amine impregnation and CO2 adsorption. Microporous and Mesoporous Materials 2019;290:109653.
[58] 　　Chen W-H, Tu Y-J, Sheen H-K. Disruption of sugarcane bagasse lignocellulosic structure by means of dilute sulfuric acid pretreatment with microwave-assisted heating. Applied Energy 2011;88(8):2726-34.
[59]　　 Schikora PF, Godfrey MR. Efficacy of end-user neural network and data mining software for predicting complex system performance. International Journal of Production Economics 2003;84(3):231-53.
[60] 　　Alhassan MA, Ababneh AN, Betoush NA. Optimum Prediction of the Transfer Length of Strands Based on Artificial Neural Networks. Procedia Manufacturing 2020;44:505-12.
[61]　　 Lin X, Kong L, Cai H, Zhang Q, Bi D, Yi W. Effects of alkali and alkaline earth metals on the co-pyrolysis of cellulose and high density polyethylene using TGA and Py-GC/MS. Fuel Processing Technology 2019;191:71-8.
[62] 　　Chen W-H, Lu K-M, Lee W-J, Liu S-H, Lin T-C. Non-oxidative and oxidative torrefaction characterization andSEM observations of fibrous and ligneous biomass. Applied Energy 2014;114:104-13.
[63]　　 Tian W, Zhang H, Duan X, Sun H, Tade MO, Ang HM, et al. Nitrogen- and Sulfur-Codoped Hierarchically Porous Carbon for Adsorptive and Oxidative Removal of Pharmaceutical Contaminants. ACS Appl Mater Interfaces 2016;8(11):7184-93.
[64] 　　Poletto M, Zattera AJ, Forte MM, Santana RM. Thermal decomposition of wood: influence of wood components and cellulose crystallite size. Bioresour Technol 2012;109:148-53.
[65]　　 Bishnoi A, Kumar S, Joshi N. Wide-Angle X-ray Diffraction (WXRD). Microscopy Methods in Nanomaterials Characterization. 2017, p. 313-37.
[66] 　　Gebert J, Rachor I, Bodrossy L. Composition and activity of methane oxidizing communities in landfill covers. Twelfth International Waste Management and Landfill Symposium. 2009.
[67] 　　Collard F-X, Blin J. A review on pyrolysis of biomass constituents: Mechanisms and composition of the products obtained from the conversion of cellulose, hemicelluloses and lignin. Renewable and Sustainable Energy Reviews 2014;38:594-608.
[68] 　　Chen W-H, Peng J, Bi XT. A state-of-the-art review of biomass torrefaction, densification and applications. Renewable and Sustainable Energy Reviews 2015;44:847-66.
[69] 　　Bach QV, Chen WH, Chu YS, Skreiberg O. Predictions of biochar yield and elemental composition during torrefaction of forest residues. Bioresour Technol 2016;215:239-46.
[70] 　　Alothman Z. A Review: Fundamental Aspects of Silicate Mesoporous Materials. Materials 2012;5(12):2874-902.
[71] 　　Ma Y, Cao X, Feng X, Ma Y, Zou H. Fabrication of super-hydrophobic film from PMMA with intrinsic water contact angle below 90°. Polymer 2007;48(26):7455-60.
[72] 　　Chen W-H, Lin B-J, Colin B, Chang J-S, Pétrissans A, Bi X, et al. Hygroscopic transformation of woody biomass torrefaction for carbon storage. Applied Energy 2018;231:768-76.
[73] 　　Krause MC, Moitinho AC, Ferreira LFR, Souza RLd. Production and Characterization of the Bio-Oil Obtained by the Fast Pyrolysis of Spent Coffee Grounds of the Soluble Coffee Industry. Journal of the Brazilian Chemical Society 2019;30:1608-15.
[74] 　　Vuk AŠ, Ješe R, Orel B, Dražiˇ G. The effect of surface hydroxyl groups on the adsorption properties of nanocrystalline TiO2 films. INTERNATIONAL JOURNAL OF PHOTOENERGY 2005;Vol. 07:164-8.
[75] 　　Kubovsky I, Kacikova D, Kacik F. Structural Changes of Oak Wood Main Components Caused by Thermal Modification. Polymers (Basel) 2020;12(2).
[76]　 Benavente V, Fullana A. Torrefaction of olive mill waste. Biomass and Bioenergy 2015;73:186-94.
[77]　　 Bora MM, Gogoi P, Deka DC, Kakati DK. Synthesis and characterization of yellow oleander (Thevetia peruviana) seed oil-based alkyd resin. Industrial Crops and Products 2014;52:721-8.
[78] 　　Ozbekova Z, Kulmyrzaev A. Study of moisture content and water activity of rice using fluorescence spectroscopy and multivariate analysis. Spectrochim Acta A Mol Biomol Spectrosc 2019;223:117357.
[79]　　 Gustavo VBC, Anthony JF, Jr. , Shelly JS, Theodore PL. Water Activity in Foods: Fundamentals and Applications. Second ed.; 2020.
[80]　　 Song T, Liao J-m, Xiao J, Shen L-h. Effect of micropore and mesopore structure on CO2 adsorption by activated carbons from biomass. New Carbon Materials 2015;30(2):156-66.
[81] 　　Kim M-J, Choi SW, Kim H, Mun S, Lee KB. Simple synthesis of spent coffee ground-based microporous carbons using K2CO3 as an activation agent and their application to CO2 capture. Chemical Engineering Journal 2020;397.
[82] 　　Chen W-H, Wang C-W, Ong HC, Show PL, Hsieh T-H. Torrefaction, pyrolysis and two-stage thermodegradation of hemicellulose, cellulose and lignin. Fuel 2019;258.
[83]　　 Long J, Xu Y, Wang T, Yuan Z, Shu R, Zhang Q, et al. Efficient base-catalyzed decomposition and in situ hydrogenolysis process for lignin depolymerization and char elimination. Applied Energy 2015;141:70-9.
[84]　　 Newkirk AE, Aliferis I. Drying and Decomposition of Sodium Carbonate. Analyitcal chemistry 1958:982-4.
[85] 　　Sabil KM, Aziz MA, Lal B, Uemura Y. Synthetic indicator on the severity of torrefaction of oil palm biomass residues through mass loss measurement. Applied Energy 2013;111:821-6.
[86] 　　Cao W, Li J, Martí-Rosselló T, Zhang X. Experimental study on the ignition characteristics of cellulose, hemicellulose, lignin and their mixtures. Journal of the Energy Institute 2019;92(5):1303-12.
[87] 　　Lu J-J, Chen W-H. Investigation on the ignition and burnout temperatures of bamboo and sugarcane bagasse by thermogravimetric analysis. Applied Energy 2015;160:49-57.
[88] 　　Restuccia F, Mašek O, Hadden RM, Rein G. Quantifying self-heating ignition of biochar as a function of feedstock and the pyrolysis reactor temperature. Fuel 2019;236:201-13.
[89] 　　Yu Z, Xueqing Z, Wen Y, Haihui X, Sherong H, Yu S. Pore structure and its impact on susceptibility to coal spontaneous combustion based on multiscale and multifractal analysis. Sci Rep 2020;10(1):7125.
[90] 　　Cai J, Wang S, Kuang C, Tang X. Insight into the kinetic analysis of catalytic combustion for biomass after alkaline metals loaded pretreatment. Fuel 2017;203:501-13.
[91] 　　P. Pranda KP, V. Hlavacek. Combustion of fly-ash carbon Part I. TGrDTA study of ignition temperature. Fuel Processing Technology 1999:211-21.
[92]　　 Chen W-H, Lu K-M, Lee W-J, Liu S-H, Lin T-C. Non-oxidative and oxidative torrefaction characterization and SEM observations of fibrous and ligneous biomass. Applied Energy 2014;114:104-13.
[93] 　　Zhang C, Ho S-H, Chen W-H, Fu Y, Chang J-S, Bi X. Oxidative torrefaction of biomass nutshells: Evaluations of energy efficiency as well as biochar transportation and storage. Applied Energy 2019;235:428-41.
[94]　　 Ronsse F, Nachenius RW, Prins W. Carbonization of Biomass. Recent Advances in Thermo-Chemical Conversion of Biomass. 2015, p. 293-324.
[95] 　　Pudasainee D, Kurian V, Gupta R. Coal. Future Energy. 2020, p. 21-48.
[96] 　　Barbanera M, Muguerza IF. Effect of the temperature on the spent coffee grounds torrefaction process in a continuous pilot-scale reactor. Fuel 2020;262.
[97] 　　Ho SH, Zhang C, Chen WH, Shen Y, Chang JS. Characterization of biomass waste torrefaction under conventional and microwave heating. Bioresour Technol 2018;264:7-16.
[98] 　　Ho MC, Ong VZ, Wu TY. Potential use of alkaline hydrogen peroxide in lignocellulosic biomass pretreatment and valorization – A review. Renewable and Sustainable Energy Reviews 2019;112:75-86.
[99] 　　Li X, Lu Z, Chen J, Chen X, Jiang Y, Jian J, et al. Effect of oxidative torrefaction on high temperature combustion process of wood sphere. Fuel 2021;286.
[100] Gan YY, Chen W-H, Ong HC, Lin Y-Y, Sheen H-K, Chang J-S, et al. Effect of wet torrefaction on pyrolysis kinetics and conversion of microalgae carbohydrates, proteins, and lipids. Energy Conversion and Management 2021;227.
[101] Ahmad MB, Soomro U, Muqeet M, Ahmed Z. Adsorption of Indigo Carmine dye onto the surface-modified adsorbent prepared from municipal waste and simulation using deep neural network. J Hazard Mater 2020:124433.
[102] Gong M, Yang J, Zhang J, Zhu H, Tong T. Physical–chemical properties of aged asphalt rejuvenated by bio-oil derived from biodiesel residue. Construction and Building Materials 2016;105:35-45.
[103] Padma Ishwarya S, Nisha P. Foaming agents from spent coffee grounds: A mechanistic understanding of the modes of foaming and the role of coffee oil as antifoam. Food Hydrocolloids 2021;112.
[104] Lin B-J, Chen W-H, Budzianowski WM, Hsieh C-T, Lin P-H. Emulsification analysis of bio-oil and diesel under various combinations of emulsifiers. Applied Energy 2016;178:746-57.
[105] Patel JP, Parsania PH. Characterization, testing, and reinforcing materials of biodegradable composites. Biodegradable and Biocompatible Polymer Composites. 2018, p. 55-79.
[106] Kaaya AN, Kyamuhangi W. Drying Maize Using Biomass-Heated Natural Convection Dryer Improves Grain Quality During Storage. Journal of Applied Sciences 2010;10(11):967-74.
[107] Wu K-T, Tsai C-J, Chen C-S, Chen H-W. The characteristics of torrefied microalgae. Applied Energy 2012;100:52-7.
[108] SÁMano Delgado E, Martinez-Flores HE, Garnica-Romo MG, Aranda-Sanchez JI, Sosa-Aguirre CR, De JesÚS CortÉS-Penagos C, et al. Optimization of Solar Dryer for the Dehydration of Fruits and Vegetables. Journal of Food Processing and Preservation 2013;37(5):489-95.
[109] Tun MM, Juchelková D. Estimation of greenhouse gas emissions: An alternative approach to waste management for reducing the environmental impacts in Myanmar. Environmental Engineering Research 2018;24(4):618-29.
[110] Gustavo V. Barbosa-Canovas, Anthony J. Forntana J, Shelly J. Schmidt, lABUZA TP. Water activity in Foods : Fundamentals and APpplications. 2020.
[111] Gan YY, Chen W-H, Ong HC, Sheen H-K, Chang J-S, Hsieh T-H, et al. Effects of dry and wet torrefaction pretreatment on microalgae pyrolysis analyzed by TG-FTIR and double-shot Py-GC/MS. Energy 2020;210.
[112] Basu S, Debnath AK. Main Equipment. Power Plant Instrumentation and Control Handbook. 2019, p. 41-147.
[113] Martín-Lara MA, Ronda A, Zamora MC, Calero M. Torrefaction of olive tree pruning: Effect of operating conditions on solid product properties. Fuel 2017;202:109-17.
[114] Gan YY, Ong HC, Show PL, Ling TC, Chen W-H, Yu KL, et al. Torrefaction of microalgal biochar as potential coal fuel and application as bio-adsorbent. Energy Conversion and Management 2018;165:152-62