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The rapidly declining fossil fuels are no longer able to meet the ever-increasing energy demand. Moreover, they are considered responsible for greenhouse gas (GHG) emission, contributing to the global warming. On the other hand, organic wastes, such as kitchen waste (KW) and poultry manure (PM), represent considerable pollution threat to the environment, if not properly managed. Therefore, anaerobic co-digestion of KW and PM could be a sustainable way of producing clean and renewable energy in the form of biogas while minimizing environmental impact. In this study, the anaerobic co-digestion of KW with PM was studied to assess the rate of cumulative biogas (CBG) production and methane percentage in four digester setups (D1, D2, D3, and D4) operated in batch mode. Each digester setup consisted of five parallelly connected laboratory-scale digesters having a capacity of 1 L each. The digester setups were fed with KW and PM at ratios of 1:0 (D1), 1:1 (D2), 2:1 (D3), and 3:1 (D4) at a constant loading rate of 300 mg/L with 50 gm cow manure (CM) as inoculum and were studied at both room temperature (28 °C) and mesophilic temperature (37 °C) over 24 days. The co-digestion of KW with PM demonstrated a synergistic effect which was evidenced by a 16% and 74% increase in CBG production and methane content, respectively, in D2 over D1. The D3 with 66.7% KW and 33.3% PM produced the highest CBG and methane percentage (396 ± 8 mL and 36%) at room temperature. At mesophilic condition, all the digesters showed better performance, and the highest CBG (920 ± 11 mL) and methane content (48%) were observed in D3. The study suggests that co-digestion of KW and PM at mesophilic condition might be a promising way to increase the production of biogas with better methane composition by ensuring nutrient balance, buffering capacity, and stability of the digester. [ABSTRACT FROM AUTHOR]

In the present study, a co-culture of yeast (Lipomyces starkeyi) and bacterium (Bacillus cereus) was used to optimize lipid accumulation capability and simultaneous treatment of wastewater using palm oil mill effluent (POME) as a carbon source. The influence of process parameters (i.e., inoculum composition, pH, temperature, and time) on the lipid accumulation and the chemical oxygen demand (COD) removal were optimized using design of experiments (DoE) as a statistical tool. The DoE results suggested that the maximum lipid accumulation of 2.95 g/L and COD removal efficiency of 86.54% could be obtained while the inoculum composition, pH, temperature, and incubation time were 50:50, 6.50, 32.5 °C, and 90 h, respectively. The predicted results were very close to the experimental results (< 5% deviation); hence, the proposed model could be useful to predict the lipid accumulation and COD removal performance of a yeast and bacteria co-culture. [ABSTRACT FROM AUTHOR]

The purpose of this research is to evaluate the intent of empty fruit bunches of palm oil (EFBpalm oil) to catalytic gasification of wood produced charcoal (Woodcharcoal) in order to notify the large-scale application of Woodcharcoal as a possible gasification feedstock. In this study, co-catalyst of bismuth oxide (Bi2O3) was also used to obtain syngas. The raw samples were characterized by proximate and ultimate analyses, X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) analyses. The produced syngas was analyzed by online portable gas analyzer and gas chromatography-thermal conductivity detector (GC-TCD). The syngas composition of H2 increased from 3.91 to 4.70% (increased 20.20%), CO increased from 5.73 to 6.30% (increased 10.53%), whereas CO2 decreased from 20.60 to 12.67% (decreased 38.50%) and CH4 concentration increased insignificantly from 0.35 to 0.37% (increased 5.7%) which was happened due to the use of WoodCharcoal and Bi2O3 with EFBpalm oil during gasification. According to the findings, carbon is abundant in WoodCharcoal, which may considerably boost the gasification reactivity with Bi2O3. The yield of syngas (H2 and CO) increased when WoodCharcoal and Bi2O3 were used instead of single EFBppo gasification, indicating that catalyst (WoodCharcoal) and co-catalyst (Bi2O3) have a high potential for thermal decomposition and dehydrogenation of volatile matter. Therefore, catalytic gasification of empty palm fruit bunches will be the prospective energy sources for the production of syngas with the utilization of WoodCharcoal and Bi2O3. [ABSTRACT FROM AUTHOR]

This study is aimed to apply dry anaerobic digestion (DAD) for methane (CH4) enriched biogas production from unsorted organic municipal solid waste (MSW). Cumulative biogas production was monitored for 35 days of operation in batch digesters at fixed feedstock to inoculum (F/I) ratio 2. Anaerobic sludge (AS) and cow manure (CM) were used as inoculum in single and mixed modes. Several process parameters such as inoculum flow pattern (single layer, multilayer, and spiral), digestion temperature (25 to 40 °C), inoculation modes (single and mixed mode), and inoculation proportion (AS:CM = 1:1, 1:2, 1:3, and 2:1) were investigated to determine the optimum DAD conditions to maximize the CH4 laden biogas yield. The study of inoculum flow pattern showed that digester with multilayer inoculum configuration generated the maximum 555 mL cumulative biogas with the production rate of 195 mL/day (at 25 °C). Biogas production rate and cumulative biogas production were found to increase with a rise in temperature and the maximum values of 380 mL/day and 1515 mL respectively were observed at 37 °C. The mixed mode of inoculation containing AS and CM augmented the biogas yield at previously optimized conditions. Final results showed that digester with multilayer inoculum flow pattern at 37 °C produced 1850 mL cumulative biogas with 1256.58 mL CH4/kg volatile solid (VS) when the mixed inoculum was used at the AS:CM—1:2 ratio. Biogas production with this significant amount of CH4 justifies the use of the DAD process for energy (biogas) generation from widely available biomass feedstock (MSW), offering various advantages to the environment. [ABSTRACT FROM AUTHOR]