Production of Ethanol From Agro-Industrial Wastes: I. Pretreatment of Raw Materials for Using in Fermentation Processing.

Abstract

This study aimed to utilize of the agro-industrial wastes as a cheap materials for the production raw material for using in fermentation processing, at the same time eliminates environmental impact of open burning of waste. Conditions for acid hydrolysis of waste, to produce hydrolysate containing invert sugar were study. In this respect, milled rice straw, cotton stalks and beet pulp were subjected to pretreatment using diluted acid solution at high temperature to enable production of the maximum amount of fermentable sugars from acid hydrolysis. The effects of various operating variables including pretreatment temperature, pretreatment time of reaction, the concentration of acid, the solid-to-liquid ratio and soaking time on the degree of lignin removal and liberation of reducing sugar. Acid pretreatment was carried out with H2SO4 at 1-5% (w/v) concentrations at 121°C and Solid: liquid ratio ranged from 1:5 to 1:25(W/V) for time ranging from 20 to 120 min. The results reveal that, there was a significant differences among the three by-products. The optimal reaction conditions, which resulted in an acid hydrolysis, were (1:20) (w/v) solid to liquid ratio; 121˚C hydrolysis temperature; 4% (w/v) acid concentration, 90min reaction time and presoaked for 36 hours.

Production of Ethanol From Agro-Industrial Wastes: Ii - Optimizing Variables for Ethanol Production From Rice Straw and Beet Pulp Hydrolyzates.

“…The whole waste was dried at 80˚C to a constant weight, then milled in kitchen blender to give powder (80 mesh), which was used for further investigation. Acid pretreatment was carried out according to Ammar and Elsanat, (2014) as follow: The milled rice straw and beet pulp were soaked in 4% (w/v) H 2 SO 4 (Solid: liquid ratio 1:20 w/v) for 36 h, then autoclaved at 121°C for 90 min. to form a slurry.…”

Ethanol production from vineplant waste hydrolysate sugars by native yeast strains

“…Lignocellulosic biomass, the most abundant, readily available, renewable organic material and source of energy on Earth, is composed mainly of lignin and carbohydrate polymers (cellulose and hemicellulose) (Ho et al 2014). However, due to structural heterogeneity and chemical complexity, it is resistant to bioconversion (Hahn-Hägerdal et al 2006;Ammar and Elsanat 2014;Saini et al 2015).…”

“…Therefore, some studies have focused on the selection of microbial strains that are capable of producing comparatively high yields of bioethanol at low costs. This can be achieved by fermenting both pentose and hexose sugars, of which lignocellulosic biomass is comprised (Hahn-Hägerdal et al 2006;Navarro et al 2010;Ammar and Elsanat 2014;Saini et al 2015;Kumar et al 2016). The conversion of carbohydrates to ethanol via yeasts, most commonly employing Saccharomyces cerevisiae, has been done for generations.…”