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This study investigated the effect of the anaerobic co-digestion of duck waste and alkali-pretreated groundnut shells at mesophilic temperature for methane yield optimization and waste management. Co-digestion of duck waste and alkali-pretreated groundnut shells was carried out using 100, 75: 25, 50: 50, 25: 75, and 100% duck waste: alkali-pretreated groundnut shells in a laboratory-batch digester at mesophilic temperature. The results indicated that anaerobic co-digestion of duck waste and alkali-pretreated groundnut shells is possible since no negative influence was observed during the joint digestion. It was observed that co-digestion released higher methane yield compared to mono-digestion. The optimum cumulative methane yield of 290 mL CH4 g/ VSadded was recorded from a 75: 25% ratio of duck waste: alkali-pretreated groundnut shells. This mixing ratio improved methane yield by 38%. This study confirms that the anaerobic co-digestion of duck waste and alkalipretreated groundnut shells can produce low-carbon fuel and economical waste management to maintain a sustainable environment.

Development of alternative energy is needed to solve the energy problem, including bioethanol. Banana pseudo-stem is a lignocellulose material that can used to produce bioethanol. Banana pseudo-stem has 28.83% cellulose and 19.39% lignin. The amount of lignin will reduce by pretreatment process. Variations of pretreatment methods by autoclaving of banana-pseudo stem in a steam, 0.5N, 1N, 1.5N, 2N NaOH solutions for 90 minutes were employed. Then the preteated samples were further enzymatic hydrolysed for 24, 48, 72 hours. The fermentation method of simultaneous saccharification and fermentation (SSF) was applied using cellulase enzyme and yeast of Saccharomyces cerevisiae for 120 hours. The variation of the pretreatment process by increasing of NaOH concentration solutions led to decreased the lignin content while increased in cellulose content. The lowest lignin content was 11.44% and the highest cellulose was 51.66%. The highest sugar content was 29.8 g/L (at pretreatment 2N NaOH solution, 72 hours hydrolysis). The highest bioethanol amount (4.32 g/L) was produced from pretreated banana stem using 2N NaOH solution.

The palm oil industry is currently growing rapidly and generating large amounts of biomass waste that is not utilized properly. Palm empty fruit bunch (PEFB), by product of palm oil industry is considered as a promising alternative and renewable energy source that can be converted to a liquid product by pyrolysis process. In this work, pyrolysis of PEFB was studied to produce bio-oil. Pyrolysis experiments were carried out in a bench scale tubular furnace reactor. The effects of pyrolysis temperatures (400–600 °C) at heating rate of 10 °C/min to optimize the pyrolysis process for maximum liquid yield were investigated. The characteristics of bio-oil were analyzed using FTIR and GC–MS. The results showed that the maximum bio-oil yield was 44.5 wt. % of the product at 450 °C. The bio-oil products were mainly composed of acids, aldehydes, ketones, alcohols, phenols, and oligomers. The chemical characterization showed that the bio-oil obtained from PEFB may be potentially valuable as a fuel and chemical feedstock.