Influence of the Conditions of Alkaline Pretreatment of Vegetable Raw Material before Hydrolysis in a Rotor Pulsation Device on the Cellulose Conversion

Introduction. The growing global energy demand, limited fossil fuel resources, and increasing greenhouse gasemissions highlight the need for expanded use of renewable energy sources, particularly biomass.Problem Statement. A significant drawback in the production of bioethanol is its high cost, primarily due tothe presence of hemicellulose and lignin.Purpose. This study aims to determine the effect of treating an alkaline suspension of wheat straw in a rotary pulsation device on the degree of cellulose conversion during enzymatic hydrolysis, a critical step in the productionof fuel ethanol.Materials and Methods. The raw material is pre-crushed wheat straw. The experiments have been conductedwith the use of a rotary pulsation device in an experimental plant.Results. It has been found that the combined physical effects of the discrete pulse energy input method andreduced straw particle size significantly increase the lignin extraction, from 40.0% at an average particle size of2—1 mm to 62.0% at an average particle size of 0.4—0.1 mm. Additionally, the treatment of an alkaline suspension of wheat straw at 90 оC for one hour, at alkali concentrations ranging from 1 to 4% (wt./wt.), results in anincrease in the cellulose conversion during enzymatic hydrolysis from 38% to 65.8%. Additionally, a corresponding decrease in the lignin content, from 17.1% to 3.16% has been reported.Conclusions. Increasing alkali concentration during the alkaline pretreatment of wheat straw using the discrete-pulse energy input method in a rotary pulsation device enhances the rate of cellulose conversion duringsubsequent enzymatic hydrolysis.