Produção de Hidrogênio a partir do Hidrolisado da Palha da Soja

Abstract

Aiming at sustainable development, given the awareness that the planet has finite resources and the damage caused by pollution, we seek alternative energy sources that can compete and/or replace the use of fossil fuels. Hydrogen is an option because its obtaining by fermentation from biomass characterizes it as energy from renewable sources. For hydrogen production by fermentation, the hydrolyzate of soybean (Glycine max) crop residues, soybean straw, mechanically (milled) and chemical (dilute sulfuric acid (H2SO4)) at room temperature was used as substrate. Factorial design 23 was performed to evaluate the effect of solids loading (5 and 10% m/v), sulfuric acid concentration (1.0 and 4.0% v/v) and contact (30 and 60 min) in the biomass pretreatment stage in the biological hydrogen production. The experimental procedure was carried out in 15-day batch reactors maintained at mesophilic temperature (35±1°C) using a 120 rpm shaker rotary incubator, inoculated with UASB reactor sludge and initially pH 7.70. The chosen contact time range and dilute sulfuric acid concentration were not significant in the soybean straw pretreatment at room temperature, but the solids concentration did, so that increasing the amount of solids resulted in a higher quantification of total carbohydrates. Already in the biological production of hydrogen all parameters were significant. It was possible to obtain hydrogen of 89 mL of H2/g of dry biomass, under milder pretreatment conditions (with 1% v/v diluted acid, contact time of 30 minutes and solids concentration of 5,0% w/v).