Bioethanol production by syngas fermentation from pyrolysis gas using mixed culture: Heat-pretreatment effect

Abstract

In recent years, the production of bioethanol from synthesis gas offers a common solution to the increasing levels of air pollution and the need for renewable energy sources. Synthesis gas is the combination of gases such as CO, CO2, N-2, H-2, NOx, which can form air pollution and can be used in the production of bioethanol by metabolizing these gases by Clostiridium species. Bioethanol is one of the most important biofuels because of the advantage of direct use by blending with gasoline. Pyrolysis and biochar production is an important alternative to expensive pretreatment methods used in waste and lignocellulosic raw materials in bioethanol production. In this study the wastes were converted into biochar by pyrolysis and the waste gas is collected to produce bioethanol which is an integrated and energy intensive approach. The use of mixed culture in the production of ethanol from pyrolysis gas instead of pure Clostiridium species is also important in terms of reducing costs. In this study, by using the the waste gas released during biochar production from fruit and vegetable wastes ethanol produced by syngas fermentation using heat pretreated mixed culture. While the positive effect of heat pretreatment was observed in the mixed culture, the amount of pyrolysis gas to be fed to the reactors was optimized and the highest ethanol production was observed in 5 and 10 mL pyrolysis gas feedings as 5 g/L.