Biogas synthesis from leather industry solid waste in Pakistan

Abstract

About 80% of raw material of the leather industry ends up in waste, which poses a great problem for waste management. During the current study, economical and ecofriendly techniques for conversion of tannery waste into biogas were evaluated. Fats, shavings and dried sludge showed 50%, 65% and 61% organic content and 68%, 45% and 9.6% moisture content, respectively. Dried sludge, pre-tanning waste (fats and shavings) and manure were digested either alone or in different combinations through amber glass bottles. The temperature was maintained from 32ºC to 35ºC by insulating digesters with sand at pH 6.8 to 7.5. The maximum amount of biogas (1623±26.1 ml/kg) was observed by digesting equal proportions of manure and dried sludge. The results depicted that 473±9.19 ml of biogas was biosynthesized from 1kg of sample comprising 25% pre-tanning waste and 75% manure.