Agricultural Biomass Research Articles

Adsorption of orange G using activated carbon derived from common reed (Phragmites australis) in Mekong Delta, Vietnam

Activated carbon (AC) fabrication using agricultural waste biomass has been considered economical and sustainable. In this study, common reed (Phragmites australis)-derived activated carbon (CRPa-AC) was prepared via two consecutive stages, including pyrolysis and activation using K2CO3 and employed as an absorbent for orange G (OG) removal. The CRPa-AC prepared at 1073 K and the K2CO3/char weigh ratio of 1.5 had the surface area = 549.7 m2/g and exhibited the removal efficiency of OG = 91.8%. The pseudo-second order kinetic and Langmuir isotherm models accurately described the adsorption of OG on the CRPa-AC. The maximum adsorption capacity of CRPa-AC (77.5 mg·g−1) surpassed that of other biomass-based AC previously published. Thermodynamic studies suggested that the OG adsorption on the CRPa-AC surface is endothermic. The good reusability of CRPa-AC after three regeneration cycles enabled its practical use in the OG removal. This study provided a typical example of converting waste into valuable material for wastewater treatment.

Quantitative Estimation and Comparative Assessment of Particle Morphological Features and Energy Requirement During Hammer Milling of Softwood Chips and Wheat Straw

Highlights Quantified particle size and shapes generated during hammer milling of softwood and wheat straw. Size reductions in length and width correlated with milling energy requirement. Assessed the validity of existing comminution laws for predicting milling energy requirement. Improved milling energy requirement prediction for softwood based on size reductions. Abstract. The valorization of agricultural and woody residues into higher quality fuels is an attractive pathway and can contribute to decarbonizing the energy system. One essential step for the conversion of these residues to fuels is comminution through commercial mills. This study aimed to investigate the effects of feedstock, input feed size, and milling screen size on particle size and shape, as well as to validate the reliability of existing comminution laws for predicting energy requirements during hammer milling of agricultural and wood biomass. Additionally, the study proposed a new empirical correlation for comminution energy prediction, taking two-dimensional size reduction descriptors into consideration. A machine vision-based image processing method was used to estimate particle size, particle size distribution (PSD), and particle shape factors. The aspect ratio of wheat straw particles was 1.3 to 1.5 times larger than softwood particles, suggesting they are more fibrous. The shapes generated during hammer milling were estimated, with rectangular shapes being predominant. The specific energy requirement (SER) estimated for the hammer milling of softwood chips and wheat straw at different mill screen sizes (4, 8, and 12 mm) was found to be in the range of 153.2–25.5 kJ kg-1 and 38.5–16.1 kJ kg-1, respectively. The validity of existing comminution laws to predict the SER during hammer milling of softwood and wheat straw was tested at a fixed feed rate of 45 kg hr-1, and an improvement in SER prediction for softwood was achieved by formulating a new empirical correlation factoring size reductions in length and width. Further, the correlation developed for the SER for wheat straw was found to lack statistical significance. The findings of this study can be applied to improve the effectiveness of the comminution process, a critical precursor to numerous thermochemical conversion methods used for transforming biomass residues into valuable fuels. Keywords: Bioenergy, Biomass comminution, Machine-vision image analysis, Particle shape, Particle size distribution, Specific energy consumption.

Graphitized mango seed as an effective 3D anode in batch and continuous mode microbial fuel cells for sustainable wastewater treatment and power generation.

Herein, we explored the utilization of graphitized mango seeds as 3D-packed anodes in microbial fuel cells (MFCs) powered by sewage wastewater. Mango seeds were graphitized at different temperatures (800 °C, 900 °C, 1000 °C, and 1100 °C) and their effectiveness as anodes was evaluated. Surface morphology analysis indicated that the proposed anode was characterized by layered branches and micro-sized deep holes, facilitating enhanced biofilm formation and microorganism attachment. Maximum power densities achieved in the MFCs utilizing the mango seed-packed anodes graphitized at 1100 °C and 1000 °C were 2170.8 ± 90 and 1350.6 ± 125 mW m-2, respectively. Furthermore, the weight of the graphitized seed anode demonstrated a positive correlation with the generated power density and cell potential. Specifically, MFCs fabricated with 9 g and 6 g anodes achieved maximum power densities of 2170.8 ± 90 and 1800.5 ± 40 mW m-2, respectively. A continuous mode air cathode MFC employing the proposed graphitized mango anode prepared at 1100 °C and operated at a flow rate of 2 L h-1 generated a stable current density of approximately 12 A m-2 after 15 hours of operation, maintaining its stability for 75 hours. Furthermore, a chemical oxygen demand (COD) removal efficiency of 85% was achieved in an assembled continuous mode MFC. Considering that the proposed MFC was driven by sewage wastewater without the addition of external microorganisms, atmospheric oxygen was used as the electron acceptor through an air cathode mode, agricultural biomass waste was employed for the preparation of the anode, and a higher power density was achieved (2170.8 mW m-2) compared to reported values; it is evident that the proposed graphitized mango seed anode exhibits high efficiency for application in MFCs.

Cassava cultivation; current and potential use of agroindustrial co–products

<abstract> <p>Cassava (<italic>Manihot esculenta</italic> Crantz) has garnered global attention due to its importance as a crucial raw material for ethanol and other derivative production. Nonetheless, its agroindustry generates a substantial amount of residues. We examined the potential utilization of co–products from both agricultural and industrial sectors concerning starch extraction processes. A total of 319 million tons of fresh cassava roots are globally produced, yielding up to 55% of agricultural co–products during harvesting. For every ton of starch extracted, 2.5 tons of bagasse, along with 100 to 300 kg of peel per ton of fresh processed cassava, and 17.4 m<sup>3</sup> of residual liquid tributaries are generated. Consequently, both solid agricultural biomass and solid/liquid residues could be directed towards cogenerating bioenergy such as bioethanol, biobutanol, biodiesel, bio–oil, charcoal, and other bioproducts. In conclusion, the conversion of cassava agroindustrial co–products into food and non–food products with high added value could be promoted, thus fostering a circular economy to enhance profitability, sustainability, and crop promotion.</p> </abstract>

Rice husk valorisation by in situ grown MoS2 nanoflowers: a dual-action catalyst for pollutant dye remediation and microbial decontamination.

Rice husk (RH) is a common agricultural waste generated during the rice milling process; however, a major portion is either burned or disposed of in landfills, posing significant environmental risks. In this study, RH waste was transformed into bio-based catalysts via delignification cum in situ growth of MoS2 (DRH-MoS2) for efficient pollutant dye removal and microbial decontamination. The developed DRH-MoS2 exhibits nanoflower-like structures with a 2H-MoS2 phase and a narrow band gap of 1.37 eV, which showed strong evidence of photocatalytic activity. With the presence of abundant hydroxyl functionality, delignified rice husk (DRH) exhibits a malachite green (MG) dye adsorption capacity of 88 mg g-1. However, in situ growth of MoS2 nanosheets on DRH enhances MG degradation to 181 mg g-1 under dark conditions and 550 mg g-1 in the presence of light. Mechanistic insights reveal a synergistic adsorption-cum-degradation phenomenon, amplified by generation of reactive oxygen species during photodegradation which was confirmed from radical scavenging activity. Interestingly, DRH-MoS2 demonstrates potent antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) with sustained photodegradation efficiency (>80%) over three cycles. The present work reports a cost-effective and scalable strategy for environmental remediation of real wastewater which usually contains both dye pollutants as well as microbes using abundantly available renewable resources such as sunlight and agricultural biomass wastes.

Leucaena interspecific hybrid 'KX4-Hawaii' as a source of agricultural biomass in a water-scarce small island developing state.

Leucaena leucocephala is a useful multipurpose tree species for agroforestry systems, but traditional seeded cultivars often become weedy and invasive. A seedless hybrid cultivar, 'KX4-Hawaii', offers a potential solution to this problem. However, relevant agronomic information and information on the performance of 'KX4-Hawaii' under varying growth conditions is required. The goal of this research was to evaluate 'KX4-Hawaii' as a source of agricultural biomass in Barbados, a small island developing state with limited arable land. 'KX4-Hawaii' air layers were imported into Barbados to create stock trees. Air layering was used to create propagation material and a field study was established with a 'KX4-Hawaii' hedgerow planted as a field border. Three plant spacings (50, 75, and 100 cm) were evaluated and data on the growth and biomass yields of the trees were collected at 4-month intervals. Precipitation data were used to investigate climatic effects on 'KX4-Hawaii' productivity. 'KX4-Hawaii' was successfully propagated via air layers and could be planted directly in the field with irrigation. All recorded growth and biomass yields were correlated with precipitation. However, the woody (lignified stems and branches) biomass was more responsive to precipitation than the green (leaves and green tender stems) biomass and made up a large fraction of the total biomass produced. 'KX4-Hawaii' was productive even under drought conditions and biomass yields per meter of hedgerow increased with closer spacings. Of the tested spacing treatments, 75 cm was optimum for a 4-month pruning interval under the conditions seen in Barbados as it produced similar yields to the 50 cm spacing treatment but would require less propagation material.

Valorizacija otpadne poljoprivredne biomase kao goriva za održivu proizvodnju energije kosagorevanjem

Waste agricultural biomass, like the crop residue, is an abundant indigenous renewable energy source in Serbia. As such, the agricultural residue might be utilized for sustainable power production. Direct co-combustion of biomass with coal/lignite offers a viable option to remove this kind of waste and, in the same time, to use its energy potential, mitigate harmful emissions and retrofit existing coal-fired power plants cost-effectively. However, there are serious issues regarding the waste management and the co-firing process itself, yet to be solved. The main aim of this paper is to present benefits and challenges of co-firing the waste agricultural biomass, as a promising technology for biomass valorization and decarbonization in energy, focusing the agricultural residues energy potential, as well as characteristics, preparation and efficient utilization of the biomass as an alternative fuel in power sector.

A critical review on the production and upgradation of sustainable biocrude from hydrothermal liquefaction of Canadian-grown agricultural biomass

Oxygenated biocrude produced from hydrothermal liquefaction is of great interest as it originated from renewable feedstocks.

Experimental Study on Two-Phase (Solid-Liquid) Flows of Ground Wheat Straw in Inclined Pipes

Highlights Knife milled wheat straw-water slurry flow through inclined pipes at various inclinations is experimentally studied. Slurry concentration and pipe inclination affect the onset velocity of drag reduction and the percentage of drag reduction. The critical mass concentration of maximum drag reduction is a vital function of velocity and is independent of the pipe angle. Downhill wheat straw slurry flows exhibit the most significant reduction in drag and the smallest onset velocities. Wheat straw slurry flows moving uphill exhibit nonmonotonic variations in onset velocity and drag reduction. Abstract. Long-distance pipeline hydro-transport of lignocellulosic biomass for industrial-scale biofuel production at levels comparable to conventional oil refineries presents an economically and logistically viable alternative to fossil fuels. There is very limited understanding on the behavior of the transportation of agricultural biomass slurries in an inclined pipeline. This research is focused on a laboratory-scale investigation of 6.4 mm nominal particle length (d50 = 4.85 mm) knife-milled wheat straw-water suspensions' uphill and downhill flows for a range of pipe inclination and saturated mass concentrations. The range of pipe inclination and saturated mass concentration was -7° to +21° and 5%-30%, respectively. The inclined test section was 29 m long with a 50 mm inside diameter of a closed pipeline loop. The accuracy of the measurements was verified by calibrating the inclined pipe section with fine sand (d50 = 0.103 mm)-aqueous slurries and comparing the results with established correlations. Most wheat straw-aqueous suspensions in the inclined flows showed the characteristics of the plug flow and the transition flow regions together for saturated mass concentration, Cm = 5%-30% and the entire flow range (0.5-4.7 m s-1), with a clear dependence of both the onset velocity of drag reduction (vOD) and drag reduction (%DR) on the pipe inclination as well as the slurry concentration and the critical concentration of maximum drag reduction (Cm)cr on a specific range of suspension velocity. Because of the accelerating effect of gravity, downhill slurry flows had the lowest vOD and the highest %DR at every Cm and pipe inclination with a maximum drag reduction of 25.53% at vm = 4.5 m s-1 and Cm = 25%. Uphill flows demonstrated some nonmonotonic changes in vOD and %DR, which need more experimental data for us to reach a firm conclusion. The research outcomes could help design and operate a long-distance integrated pipeline network for biomass transportation to produce biofuels on a large scale. Keywords: Biomass transport, Drag reduction, Flow regions, Frictional pressure drop, Pipe inclination, Wheat straw slurry.

The Energy Potential of Agricultural Biomass in the European Union

The objective of this study is to conduct a quantitative assessment of the theoretical potential of agricultural biomass in EU countries for energy production. It explores various biomass sources, such as agricultural residues, animal husbandry by-products, and energy crops. Using data, the study examines the potential biomass across different EU countries, emphasizing the disparities due to diverse agricultural practices. The analysis underscores the need for customized biomass strategies in each Member State, tailored to their specific agricultural conditions. The study identifies biomass as a vital energy source for the EU's energy independence and reducing fossil fuel reliance. It also highlights the necessity for future research on improving biomass conversion technologies and policy development for integrating agricultural biomass into the energy framework, considering the unique aspects of each country's agricultural sector.

Sustainable conversion of agricultural biomass waste into electrode materials with enhanced energy density for aqueous zinc-ion hybrid capacitors

Herein, we demonstrate the facile, economic and highly scalable conversion of (N, O and Fe)-self-doped heteroatom Solanum melongena (SM) biomass into highly electro-active carbon material for symmetric supercapacitor and zinc-ion hybrid capacitor (ZIHC) applications. The SM is ubiquous agri-bio-waste that inherently possess electro-active constituents and upon conversion resulted in high surface area, self-doped heteroatoms (N, O and Fe) through one step pyrolysis. A synergetic combination of N, O and Fe co-doping and relatively high-surface-area features that offers widespread interfacial active sites for charge storage and fast kinetics of electrochemical reactions in both supercapacitor and battery-type capacitor to maximize energy and power output. The symmetric supercapacitor is fabricated using 6 M KOH, delivering high specific capacitance of 154.64 F/g at 0.1 A/g current density. Long cycling performance of device exhibits 99 % retention over 50,000 charge and discharge cycles at 10 A/g. While SM carbon as the cathode in zinc ion hybrid capacitor (ZIHC) endows excellent Zn2+ ion storage capacity with 2 M ZnSO4·7H2O as electrolyte. The ZIHC delivered an excellent specific capacitance of 313.08 F/g, a substantial energy density output of 141.35 W h/kg and a power density of 6935.38 W/kg. In addition, ZIHC exhibited better cyclic stability with 1.92 % loss over 20,000 charge and discharge cycles at 4 A/g. The ZIHC device delivered excellent output in wearable devices and in lightning the LED (25.04 min). This study provides ubiquitous agri-waste-derived carbon that can be outstanding electrode material in energy storage devices owing to their hierarchal pore configuration, graphitization degree and self-doping of heteroatoms.

Biogas and biohydrogen for net zero cooking and transportation in Bhutan

Agricultural biomass is a promising renewable energy material for Bhutan to support net zero transition of its cooking and transport sectors. In this study, crop residue and animal manure biomass-based biogas and biohydrogen potential of Bhutan are assessed at district and regional levels using a spatial framework. Existing energy demand of the cooking and transport sectors and associated greenhouse gases (GHGs) emissions are also estimated spatially. To analyze the net zero transition potential in the cooking and transport sectors, current energy situations of the sectors are compared with biogas-based cooking and biohydrogen-based transportation. It is observed that, annual biogas potential of Bhutan is 105 million cubic meter (mcm), equivalent to 2091 tera joule (TJ) energy. The potential is higher than the current cooking energy demand of 1230 TJ. At individual district level, 16 out of 20 districts can 100 % substitute LPG and firewood with biogas to support net zero transition of the cooking sector. Estimated annual GHGs emissions from the cooking sector are 102,089 t CO2eq. Transitioning to biogas-based cooking would provide significant GHGs emissions savings benefits for Bhutan. For example, annual emissions savings of 93,443 t CO2eq could be achieved through crop residue biogas-based cooking. Similarly, estimated biohydrogen potential (111 mcm, equivalent to 1194 TJ) can meet 35 % of current transportation energy demand (3353 TJ) of Bhutan. Full realization of the biohydrogen potential (1194 TJ) could provide annually 27,187 t CO2eq emissions savings in the transport sector of Bhutan. The findings of the present research could be useful for net zero transition of cooking and transport sectors of Bhutan. Thus, by leveraging the potential of biogas and biohydrogen, Bhutan can accelerate net zero transition and circular growth.

Effects of Fe3+ on Hydrothermal Humification of Agricultural Biomass.

Hydrothermal humification technology for the preparation of artificial humic matters provides a new strategy, greatly promoting the natural maturation process. Iron, as a common metal, is widely used in the conversion of waste biomass; however, the influence of Fe3+ on hydrothermal humification remains unknown. In this study, FeCl3 is used to catalyze the hydrothermal humification of corn straw, and the influence of Fe3+ on the hydrothermal humification is explored by a series of characterization techniques. Results show that Fe3+ as the catalyst can promote the decomposition of corn straw, shorten the reaction time from 24 h to 6 h, and increase the yield from 6.77 % to 14.08 %. However, artificial humic acid (A-HA) obtained from Fe3+ -catalysis hydrothermal humification contains more unstable carbon and low amount of aromatics, resulting in a significantly decreased stability of the artificial humic acid. These results provide theoretical guidance for regulating the structure and properties of artificial humic acid to meet various maintenance needs.

Efficient Degradation of Ciprofloxacin in Water over Copper-Loaded Biochar Using an Enhanced Non-Radical Pathway.

The development of an efficient catalyst with excellent performance using agricultural biomass waste as raw materials is highly desirable for practical water pollution control. Herein, nano-sized, metal-decorated biochar was successfully synthesized with in situ chemical deposition at room temperature. The optimized BC-Cu (1:4) composite exhibited excellent peroxymonosulfate (PMS) activation performance due to the enhanced non-radical pathway. The as-prepared BC-Cu (1:4) composite displays a superior 99.99% removal rate for ciprofloxacin degradation (initial concentration 20 mg·L-1) within 40 min. In addition, BC-Cu (1:4) has superior acid-base adaptability (3.98~11.95) and anti-anion interference ability. The trapping experiments and identification of reactive oxidative radicals confirmed the crucial role of enhanced singlet oxygen for ciprofloxacin degradation via a BC-Cu (1:4)/PMS system. This work provides a new idea for developing highly active, low-cost, non-radical catalysts for efficient antibiotic removal.

Application of persulfate-assisted graphitic carbon, derived through pyrolysis of waste biomass, driven by visible light, for the removal of tetracycline from water: Mechanisms and performance influencing parameters

Sulfate radical based advanced oxidation process by using carbon-based materials has attracted widespread attention for removal of emerging contaminants in water. This paper reports the study on the efficacy of visible light activated persulfate (PS) – graphitic carbon (GC) system for the removal of tetracycline (TC) from water . Here GCs from residual agricultural biomass were synthesized via a facile and chemical-free pyrolysis route, and their characteristics were analyzed under varying thermal conditions, viz. temperature (550–950 °C) and heating rate (2.5–10 °C min−1). The GCs at high pyrolysis temperatures (> 700 °C) revealed graphitic and condensed aromatic carbon networks with enhanced textural properties, facilitating electron-mediated reactions through interconnected morphology. The methodology is derived from the research that shows certain pyrolysis derived carbon products are known to have transient photocurrent response, indicating semiconductor properties. Here, the visible light-driven GC/PS (950 °C, 5 °C min−1) system resulted in high TC removal efficiency of 91.23% within 180 min compared to other PS/GCs prepred under different conditions. The mass spectroscopy data shows that the GC/PS system successfully degraded TC into simpler products and achieved the highest mineralization efficiency of about 65.43 ± 3.62%. The radical scavenging experiments revealed that 1O2 and •OH were the dominant reactive oxygen species suppressing degradation of TC by 13% and 9%, respectively. It can be surmised that both radical and non-radical pathways facilitate TC degradation via dehydration, demethylation and oxidation of aromatic rings- due to both catalytic and physico-chemical properties of GC/PS .

BIOMASS SUPPLY CHAIN OPTIMIZATION FOR RICE INDUSTRY IN PERLIS REGION

The efficient utilization of agricultural biomass holds significant promise in addressing energy and sustainability challenges. This study focuses on the optimization of the rice biomass supply chain in the Perlis region, aiming to enhance the resource utilization and minimize environmental impact. The abundance of rice residues generated after harvesting presents an opportunity to create a sustainable energy source while managing agricultural waste. This research encompasses a comprehensive analysis of the entire rice biomass supply chain, from residue collection at farms to the final biomass conversion process. Geographic information systems are employed to assess rice cultivation patterns and estimate potential biomass yield. Mathematical models are utilized to design an integrated supply chain network that considers collection, transportation, storage, and biomass conversion. Key factors influencing the supply chain are identified, including transportation costs, storage infrastructure, seasonal variations in biomass availability, and technological feasibility of conversion processes. Environmental implications are also evaluated, considering emissions reduction through the displacement of fossil fuels. The outcomes of this study contribute to the establishment of an efficient and sustainable rice biomass supply chain in the Perlis region. The developed optimization framework can serve as a blueprint for similar agricultural biomass utilization initiatives in other regions. The research not only addresses the technical aspects of biomass supply chain management but also considers the broader economic, social, and environmental implications, paving the way for a more resilient and resource-efficient agricultural sector.

Aksaray İli Tarımsal Biyokütle Enerji Eşdeğer Potansiyeli

Renewable energy sources are alternative fuel types that are environmentally friendly, healthy and can be used continuously as a solution to the harmful effects of fossil fuels on the environment and the problem of depletion of these fuels. Biomass, which is the residue of agricultural activity or a direct agricultural product, can be converted into a modern energy carrier by biochemical or thermochemical processes. Biomass energy of agricultural origin is an important renewable energy source such as wind, solar, geothermal energy types.
 
 Within the scope of this study, the agricultural biomass energy equivalent potential for the province of Aksaray was determined for the years 2011-2020, and the data determined for the aforementioned province were compared with the values reached in the Central Anatolia region and Turkey. Agricultural Biomass resources were examined under five main headings: Fruits - beverage - spice plants, Vegetables, Cereals - other herbal products, Clover and Sugar Beet. The energy equivalent potentials of these sources were determined in MW. In the conclusion part of the study, the average agricultural biomass energy equivalent of Aksaray province was determined as 39,027 MW in total for the five main topics. Also, the energy equivalents of Aksaray province determined in the last ten years were evaluated among themselves under each heading. In addition to all these, the same agricultural biomass energy calculation processes in Aksaray province were applied to Central Anatolia and Turkey as well, and small, medium, and large-scale evaluations were made on the table. In the light of the obtained values, it was concluded that Turkey's agricultural activities were not adversely affected by the negative effects of the pandemic process.

Layer formation on quartz bed particles during fast pyrolysis of grass

Commercial fast pyrolysis technologies use bed materials, normally natural sand mainly consisting of quartz, acting as circulating heat carrier materials. Nowadays, the commercial conversion of biomass into fast pyrolysis bio-oil (FPBO) is still using ash-lean woody residues as a feedstock since the application of more abundant and possibly cheaper ash-rich agricultural biomass is currently at a significantly lower technology readiness level (TRL). To promote FPBO production from ash-rich biomass, the ash-related issues during the operation process need to be further studied. In the present investigation, the characteristics and formation process of layers formed on quartz bed particles, collected from a bench-scale fast pyrolysis unit based on the rotating cone technology, were studied. Two grass residues, representative of typical Si-K-rich agricultural biomass fuels, were used as feedstocks. Quartz bed particles at different sampling times from startup with fresh bed particles were collected. Scanning Electron Microscopy/Energy-Dispersive Spectroscopy (SEM/EDS) was employed to characterize the layer properties. Bed particle layers exhibited an uneven and discontinuous distribution on the quartz surface. This distribution over bed particles, as well as layer thickness, increased with the operational time. The dominating elements contained in layers were Si, K, Ca, and Cl (excluding O), which resembled that of individual bed ash particles found in the bed samples. In addition, the interpretation of the results was supported by thermodynamic equilibrium calculations. The findings suggest that the process of layer formation was governed by the direct adhesion of non-melted bed ash particles during the fast pyrolysis of grass.

Biogas Production from Palm Oil Mill Effluent at Low pH

The palm oil industry in Malaysia has aided our economy, but with any thriving industry comes the baggage of industrial waste. This paper focuses on palm oil mill effluent (POME), a waste product formed by palm oil milling operations. The objective of this paper is to evaluate the ability of POME to generate biogas through acid and heat pre-treatment methods. The feasibility of producing biogas at pH levels lower than 5 was investigated. The inoculum is effective microbe 1 (EM1), and the substrate is a liquid POME. Hydrochloric and phosphoric acid were used in this study, and the effect of low initial pH on biogas generation was investigated. The results show that POME alone produced the highest biogas volume (20.1 Nml). However, POME incubated with activated EM1 inoculant at low pH (3.74) generated consistent biogas during 57.75 hours of digestion. In conclusion, the EM1 is a good source of inoculum for POME treatment at low pH, with no pre-treatment required. The pre-treatment methods proposed in this study could have opened new doors for bio-renewable energy research, particularly in agricultural biomass, since substrate pre-treatment can enhance biogas production.

Optimized Extraction of Glycosylated Flavonoids from Pepper (Capsicum annuum L.) Agricultural Biomass Residues through Ultrasonic Pulse-Assisted Natural Deep Eutectic Solvents

Optimized Extraction of Glycosylated Flavonoids from Pepper (<i>Capsicum annuum</i> L.) Agricultural Biomass Residues through Ultrasonic Pulse-Assisted Natural Deep Eutectic Solvents