Stamatia Skoutida, Apostolos Malamakis, Dimitrios Geroliolios, Christos Karkanias, Lefteris Melas, Maria Batsioula, Georgios F. Banias
{"title":"The Latent Potential of Agricultural Residues in Circular Economy: Quantifying their Production Destined for Prospective Energy Generation Applications","authors":"Stamatia Skoutida, Apostolos Malamakis, Dimitrios Geroliolios, Christos Karkanias, Lefteris Melas, Maria Batsioula, Georgios F. Banias","doi":"10.1007/s12155-024-10814-8","DOIUrl":"10.1007/s12155-024-10814-8","url":null,"abstract":"<div><p>Residual biomass from agriculture is a highly promising resource for sustainable energy production. Its abundant generation and accurate estimation are essential for the development and implementation of efficient utilization strategies. However, the calculations proposed in the existing literature are often contradictory or exhibit impractically wide range. This study compiles residual biomass indices for cereal, oil, industrial, and arboreal crops. By evaluating and processing these indices, a refined set of modified indices is presented to enhance existing methodologies for calculating agricultural residues. The methodology establishes lower, average and upper bound scenarios for the residual biomass of selected crops and is applied to Greece to estimate its energy production potential. The findings suggest that Greece generates approximately 5.5 million tons of agricultural residues annually, ranging from 4.5 million tons (lower-bound) to 6.6 million tons (upper-bound). This biomass has the potential to produce 70,730 TJ of energy, corresponding to 8.4% of the country’s energy demands, with energy potential ranging between 55,644 and 82,635 TJ. The most noteworthy crops include olive trees, cotton, maize, vineyards and wheat since they account for 82% of the total estimated energy. Spatial analysis conducted at NUTS-2 and NUTS-3 levels highlights the Regions of Central Macedonia and Thessaly as having substantial potential for residual biomass to support energy conversion strategies.\u0000</p></div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"18 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Md. Sanowar Hossain, Showmitro Bhowmik, Mujahidul Islam Riad, Md. Golam Kibria, Barun K. Das, Sanjay Paul
{"title":"Performance Study of a Woody Downdraft Gasifier: Numerical Investigation and Experimental Validation","authors":"Md. Sanowar Hossain, Showmitro Bhowmik, Mujahidul Islam Riad, Md. Golam Kibria, Barun K. Das, Sanjay Paul","doi":"10.1007/s12155-024-10807-7","DOIUrl":"10.1007/s12155-024-10807-7","url":null,"abstract":"<div><p>Biomass gasification is an established and widely utilized renewable energy system. The research work aims to develop and construct a downdraft gasifier to investigate gasifier performance. The gasifier’s performance and cold gas efficiency were calculated for three volumetric airflow rates: 7.16 m<sup>3</sup>/h, 5.97 m<sup>3</sup>/h, and 4.78 m<sup>3</sup>/h. The efficiency was found maximum of 69.6% for an airflow rate of 7.16 m<sup>3</sup>/h. The oxidation zone and neck region of the gasifier reactor had the maximum recorded temperatures of 845 °C and 823 °C for <i>Swietenia macrophylla</i> (SM) and <i>Mangifera indica</i> (MI), respectively. A two-dimensional computational fluid dynamics (CFD) model for a downdraft gasifier was also developed using ANSYS/FLUENT software. The simulation results provided valuable insights into thermal characteristics and the gasification process taking place inside the gasifier. Taking into account the introduction of wood at a rate of 6.2 kg/h and the flow of air at a rate of 7.16 m<sup>3</sup>/h, predictions were made about the composition of syngas, and subsequently, validation of the model was conducted with experimental data. The simulation study visually represents the gasification process, illustrating the distribution of velocity and the contours of carbon monoxide, carbon dioxide, and hydrogen within the gasifier.</p></div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"18 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142811095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Semie Kim, Pyeong-Gon Jung, Young-Il Lim, Youn Kim, Youngdo Yang, Sang Tae Park
{"title":"Economic and Environmental Analyses of Biodiesel Production Processes From Unused Low-grade Oil","authors":"Semie Kim, Pyeong-Gon Jung, Young-Il Lim, Youn Kim, Youngdo Yang, Sang Tae Park","doi":"10.1007/s12155-024-10805-9","DOIUrl":"10.1007/s12155-024-10805-9","url":null,"abstract":"<div><p>Two two-step transesterification processes are presented for biodiesel (BD) production from 300 t/d unused low-grade oil (LGO) with 24.5 wt% of free fatty acid (FFA). Acid-catalyzed (case 1) and enzymatic (case 2) esterifications were used for FFA reduction. The FFA in LGO was converted into fatty acid methyl esters (FAME) by H<sub>2</sub>SO<sub>4</sub>-catalyzed esterification (case 1) or transformed into sodium salts (soap) via a neutralization reaction with NaOH (case 2). In case 2, FFA was separated from soap and transformed into monoesters via enzymatic esterification. The two de-acidification processes decreased the FFA content of LGO to 0.5 wt%, enabling the production of 294 t-BD/d through subsequent alkali-catalyzed transesterification. Case 2, using an enzyme, was proposed to reduce the concentration of H<sub>2</sub>SO<sub>4</sub>, resulting in less corrosion to downstream equipment. The total production cost of case 2 ($62 million/y) was 32% higher than that of case 1 ($47 million/y) because of the greater consumption of CH<sub>3</sub>OH, H<sub>2</sub>SO<sub>4</sub>, NaOH, and enzyme during FFA reduction. The total capital investment for case 2 ($41 million) exceeded that of case 1 ($31 million). Consequently, the minimum fuel selling price of case 2 (0.58 $/kg-BD) is higher than that of case 1 (0.42 $/kg-BD). The net CO<sub>2</sub> emissions reduction of the produced BD is 2.47 kg-CO<sub>2</sub>/kg-BD for case 1 and 2.34 kg-CO<sub>2</sub>/kg-BD for case 2. Given the variability in the acidity and composition of the feedstocks, future studies should include comparative economic and environmental analyses of various raw materials.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"18 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142798299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kanit Manatura, Supaporn Klinkesorn, Benjapon Chalermsinsuwan, Namfon Samsalee, Sutthipoj Wongrerkdee, Kitipong Jaojaruek, Adisak Pattiya, Jun Li
{"title":"Multi-objective Optimization of Pelletized Coffee Silver Skin in Flue Gas Torrefaction for Producing Premium Solid Fuel","authors":"Kanit Manatura, Supaporn Klinkesorn, Benjapon Chalermsinsuwan, Namfon Samsalee, Sutthipoj Wongrerkdee, Kitipong Jaojaruek, Adisak Pattiya, Jun Li","doi":"10.1007/s12155-024-10808-6","DOIUrl":"10.1007/s12155-024-10808-6","url":null,"abstract":"<div><p>Coffee silver skin, an organic residue from coffee production, demonstrates low solid fuel characteristics such as low bulk density and heating value, necessitating enhancements for solid fuel applications. Torrefaction in a flue gas environment (5% O<sub>2</sub>, 15% CO<sub>2</sub>, and a balance of N<sub>2</sub>, v/v) is more energy-efficient than inert torrefaction, using recovered flue gas to improve fuel quality and process efficiency. Three input factors were assessed: temperature (200, 250, and 300 °C), residence time (30, 45, and 60 min), and gas media (N<sub>2</sub> and flue gas). Four performance metrics were evaluated: energy yield, upgrading energy index, specific energy consumption, and energy-mass co-benefit. Temperature significantly influenced most outcomes, except for energy-mass co-benefit, which was medium-dependent. Optimal torrefaction conditions achieving maximum energy yield (71.48%) and energy-mass co-benefit (5.30%) were identified at 200 °C for 30 min with flue gas. The torrefied material’s properties include moisture content, volatile matter, fixed carbon, and ash content of 3.03%, 69.24%, 27.04%, and 1.01%, respectively. Furthermore, the hydrophobicity of pelletized coffee silver skin notably increased under flue gas conditions, evident by a contact angle greater than 100°, indicating that flue gas torrefaction is a feasible approach for producing high-grade solid fuel.</p></div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"18 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hernán Darío Zamora Zamora, Caroline de Freitas, Daniel Pasquini, Fernando Masarin, Michel Brienzo
{"title":"Enhanced Fractionation of Guava Seed Cake Using Alkali-Catalyzed Ethanol Organosolv Pretreatment","authors":"Hernán Darío Zamora Zamora, Caroline de Freitas, Daniel Pasquini, Fernando Masarin, Michel Brienzo","doi":"10.1007/s12155-024-10813-9","DOIUrl":"10.1007/s12155-024-10813-9","url":null,"abstract":"<div><p>This study presents the performance of NaOH-catalized ethanolic organosolv pretreatment on guava seed cake (waste industrially generated after oil extraction process of guava seed) aiming to extract hemicellulose and lignin. The pretreatment assessment also included cellulose conversion to glucose by enzymatic hydrolysis. The pretreatment used NaOH 10 and 60% (m/m), temperatures of 120 and 170 °C, and ethanolic aqueous solution concentrations of 30 and 70%. NaOH concentration was the most significant factor in the extraction yield of hemicelluloses, and the temperature was the most significant in the lignin extraction and cellulose conversion to glucose. At 170 °C, ethanolic aqueous solution concentration of 30%, and NaOH concentration of 60%, the highest yield of extracted hemicellulose was 97.3%. The maximum extraction of lignin (45%) was reached at 170 °C, ethanol aqueous solution concentration of 70%, and NaOH concentration of 60%. The best cellulose conversion to glucose (50.3%) was obtained with material pretreated at 170 °C, ethanol aqueous solution concentration of 30%, and NaOH concentration of 60%. The extracted hemicelluloses presented low molecular weight (14.7–59.3 kDa), and, according to qualitative chemical analysis, the extracted hemicelluloses and lignin showed great correspondence with the commercial ones.</p></div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"18 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jude A. Okolie, Keon Moradi, Brooke E. Rogachuk, Bala Nagaraju Narra, Chukwuma C. Ogbaga, Patrick U. Okoye, Adekunle A. Adeleke
{"title":"Data-Driven Framework for the Techno-Economic Assessment of Sustainable Aviation Fuel from Pyrolysis","authors":"Jude A. Okolie, Keon Moradi, Brooke E. Rogachuk, Bala Nagaraju Narra, Chukwuma C. Ogbaga, Patrick U. Okoye, Adekunle A. Adeleke","doi":"10.1007/s12155-024-10803-x","DOIUrl":"10.1007/s12155-024-10803-x","url":null,"abstract":"<div><p>The aviation sector plays a vital role in global transportation, economic growth, and social integration. However, its rapid expansion has led to increased emissions. Sustainable aviation fuel (SAF) provides a promising solution by offering a clean-burning, renewable alternative to conventional jet fuel. SAF can be produced through various processes and feedstocks, significantly reducing the aviation industry’s environmental footprint. Fast pyrolysis (FP) presents a cost-effective and scalable approach for SAF production due to its low-cost feedstocks, rapid reaction times, and simpler technology. However, estimating the economic viability of FP for SAF production is complex and labor-intensive, requiring detailed process models and numerous assumptions. Furthermore, determining the relationship between feedstock properties and the minimum selling price (MSP) of the fuel can be challenging. To address these challenges, this study developed a data-driven framework for the preliminary estimation of SAF's MSP from FP. Synthetic data was generated using Generative Adversarial Networks (GAN) and Variational Autoencoders (VAE), and hyperparameter optimization was performed using Grid Search to enhance model accuracy and predictions. Five surrogate models were evaluated: linear regression, gradient boost regression (GBR), random forest (RF), extreme boost regression (XGBoost), and elastic net. Among these, GBR and RF showed the most promise, based on metrics such as <i>R</i><sup>2</sup>, RMSE, and MAE for both original and synthetic datasets. Specifically, GBR achieved a Train <i>R</i><sup>2</sup> of 0.9999 and a Test <i>R</i><sup>2</sup> of 0.9277, while RF recorded Train and Test <i>R</i><sup>2</sup> scores of 0.9789 and 0.9255, respectively. The use of data from the VAE further improved model accuracy. Additionally, a publicly accessible graphical user interface was developed, enabling researchers to estimate the MSP of SAF based on biomass properties, plant capacity, and location.</p></div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"18 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s12155-024-10803-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Microwave-Heated Pretreatment of Corncob, Giant Juncao Grass, and Hemp Using Choline Derivatives with Glycerol","authors":"Sanphawat Phromphithak, Tossapon Katongtung, Patiroop Pholchan, Nakorn Tippayawong","doi":"10.1007/s12155-024-10810-y","DOIUrl":"10.1007/s12155-024-10810-y","url":null,"abstract":"<div><p>Lignocellulosic biomass has diverse applications in bioenergy, biochemical, and biomaterial production. Enhancing these processes through pretreatment to obtain cellulose-rich material (CRM) using low transition temperature mixtures (LTTMs) is crucial. This study explores the impact of biomass type, LTTMs type, and heating methods on biomass pretreatment. Choline derivatives combined with glycerol were used for pretreatment of corncob, giant Juncao grass, and inflorescence hemp. Microwave irradiation heating was compared to conventional heating at 90 °C and 150 °C, with residence times of 5 and 10 min. The study demonstrated efficient breakdown of lignocellulosic structures to obtain CRMs. Corncob showed high-efficiency pretreatment with a 153% increase in cellulose content and 27% lignin removal. Pretreatment with LTTMs effectively increased cellulose content and delignification. The impact of different choline derivatives (ChCl, ChOAc, ChOH) was evident, with extraction efficiency influenced by anion type in the order OH<sup>−</sup> > OAc<sup>−</sup> > Cl<sup>−</sup>. The ChOH pretreatment increased cellulose content by 157% and lignin removal by 56%. Microwave-assisted heating surpassed conventional heating in lignocellulosic fractionation, achieving higher cellulose content and effective lignin removal. Microwave heating increased cellulose content by 343% and lignin removal by 82% at 150 °C, which was three times more than conventional heating, with a reaction time of 10 min compared to 720 min. Temperature and residence time were critical in lignin removal. The process allowed for the preservation of hemicellulose at lower temperatures or its extraction at higher temperatures.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"18 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142737348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maria Cecilia D. Salangsang, Mutsumi Sekine, Shin-ichi Akizuki, Pranshu Bhatia, Tatsuki Toda
{"title":"pH Adjustment Alleviates Ammonia Inhibition of Cell Proliferation During a Short Resting Period in Semi-continuous Anaerobic Digestion of Food Waste","authors":"Maria Cecilia D. Salangsang, Mutsumi Sekine, Shin-ichi Akizuki, Pranshu Bhatia, Tatsuki Toda","doi":"10.1007/s12155-024-10804-w","DOIUrl":"10.1007/s12155-024-10804-w","url":null,"abstract":"<div><p>During the anaerobic digestion (AD) of food waste, the deliberate secession of substrate rapidly increases the microbial cell population, which can reach a maximum in 2–3 d. During short-term resting (STR), an increase in free NH<sub>3</sub> due to an increase in pH is a key inhibitor of cell proliferation; therefore, cell growth would be further promoted if free NH<sub>3</sub> was reduced. To explore adopting an STR technique to increase microbial cells in the AD of organic waste, we attempted to reduce free NH<sub>3</sub> by controlling the pH in the reactors. Two semi-continuously treated reactors were fed with food waste at a loading rate of 3.0 g-VS/L/d for 40 days and then the feeding was stopped in both reactors until day 47. One of the reactors was maintained at pH 7.37 ± 0.03, whereas pH was not controlled in the other. During STR, the cell density in the pH-controlled condition reached a maximum of 7.48 × 10<sup>10</sup> cells/mL, which was twice as high as that before STR, and 1.7-times higher than that in the non-pH-controlled condition. These results demonstrated that mitigating NH<sub>3</sub> using pH can affect cell proliferation during STR.</p></div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"18 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142714272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fungus-Yeast Tri-culture System for In Situ Cellulase Production, Biodetoxification, and Bioethanol Production Using Rice Straw with Cyclic Shifting of Temperature Strategy","authors":"Suraj K. Panda, Soumen K. Maiti","doi":"10.1007/s12155-024-10806-8","DOIUrl":"10.1007/s12155-024-10806-8","url":null,"abstract":"<div><p>The current study employs a tri-culture system, involving <i>Trichoderma reesei</i> and <i>Penicillium janthinellum</i> for cellulase production followed by the utilization of <i>Saccharomyces cerevisiae</i> for bioethanol production using pretreated rice straw as substrate. The fungal co-culture resulted in the production of maximum cellulase enzyme with the following activities: FPase, 1.09 IU/mL; CMCase, 24.47 IU/mL; beta-glucosidase, 4.74 IU/mL; and xylanase, 36.74 IU/mL respectively. Furthermore, the current work also represents a lesser studied aspect, concomitant biodetoxification, and cellulase production. Both <i>T. reesei</i> and <i>P. janthinellum</i> were able to metabolize the acid pretreatment by-products such as formic acid, acetic acid, HMF, and furfural. By implementing a cyclic shifting of temperature strategy, a maximum bioethanol titer of 17.05 g/L with a productivity of 0.405 g/(L × h) was achieved using the tri-culture system. This represents a 3.7-fold improvement compared to the SSF process conducted at the mutual optimum incubation temperature of 37 °C. This study presents a scope for a one-step process for fungal cellulase production and biodetoxification of the lignocellulose pretreated hydrolysate to avail an inhibitor-free medium for subsequent yeast co-culture for bioethanol production.</p></div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"18 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s12155-024-10806-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142694800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gowthami D., R. K. Sharma, M. Khalid, Muhammad Yusri Ismail
{"title":"Enhancing Surface Properties of Circular Carbon Biochar Derived from Spent Coffee Beans Through ZnCl2/KOH Activation","authors":"Gowthami D., R. K. Sharma, M. Khalid, Muhammad Yusri Ismail","doi":"10.1007/s12155-024-10809-5","DOIUrl":"10.1007/s12155-024-10809-5","url":null,"abstract":"<div><p>In this work, biochar was synthesized by carbonizing spent coffee grounds by conducting oxygen-limited pyrolysis in a muffle furnace. Six varieties of biochar have been synthesized at 550 ℃ and 750 ℃ with a ramp rate of 10 ℃/min and carbonization time of 120 min. Acid- and alkali-activated biochars were produced by carbonizing the activated biomass at 550 ℃ and 750 ℃. ZnCl<sub>2</sub> and KOH were used as activating agents for acid and alkali activation, respectively. All the synthesized biochar yield was recorded as 40–60 wt% of the biomass weight. BET surface area increased significantly after activation and the values varied between 1.01 and 720.52 m<sup>2</sup>/g. The process of chemical activation has resulted in increased BET surface area in comparison with the pristine biochar. Other characterizations include FESEM analysis, elemental analysis through EDX, FTIR, UV–visible spectroscopy, XRD analysis, TGA, and Raman spectroscopy. Raman spectra and UV–visible spectra of activated samples revealed a higher graphitic quality and absorbance, respectively, whereas XRD analysis demonstrated the changes in structural phases. Activated carbon based on spent coffee grounds has displayed higher thermal stability and better surface chemistry than pristine biochar, enabling its application in various domains that foster circular economy.</p></div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"18 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142694801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}