Comparative analysis of strong and weak acid pretreatment methods under pressurized and non-pressurized conditions for agro-industrial waste of apple pulp

Abstract

It is well known that energy-related emissions have been increasing the global warming and pushing the climate change. In the face of this situation biomass-based biofuels, which is a kind of renewable energy source, are great alternatives instead of fossil derivative fuels. Moreover, biomass can be found easily and widely, which makes it an economical alternative. Biological conversation rate of the biomass to the biofuel is insufficient because of the molecular structure of the biomass. Pretreatment is required to increase the bioavailability of the biomass as the raw material. In this study, weak and strong acid pretreatments are studied under pressurized and non-pressurized conditions for apple pulp as biomass, which is an agro-industrial residue coming from industrial plants. Box-Behnken statistical design is used to determine the optimum level of some factors as time, chemical dose, and raw material dose. While the maximum total sugar concentration was found to be 23.71 g/L with sulfuric acid pretreatment, the reduced sugar concentration under pressurized conditions with strong acid pretreatment was found as 17.00 g/L.