Treatment of waste paper using ultrasound and sodium hydroxide for bioethanol production

Abstract EN

Bioethanol produced from lignocellulose feedstock is a renewable substitute to declining fossil fuels.

Pretreatment using ultrasound assisted alkaline was investigated to enhance the enzyme digestibility of waste paper.

The pretreatment was conducted over a wide range of conditions including waste paper concentrations of 1-5%, reaction time of 10-30 min and temperatures of 30-70°C.

The optimum conditions were 4 % substrate loading with 25 min treatment time at 60°C where maximum reducing sugar obtained was 1.89 g/L.

Hydrolysis process was conducted with a crude cellulolytic enzymes produced by Cellulomonas uda (PTCC 1259).The maximum amount of sugar released and hydrolysis efficiency were 20.92 g/L and 78.4 %, respectively.

Sugars released from waste paper were fermented into bioethanol with Saccharomyces cerevisiae.

The maximum concentration of bioethanol estimated was 9.5 g/L after 48h of cultivation, the yield and volumetric productivity were 0.454 g/g glucose and 0.2g bioethanol/ L h.

respectively.

This study of ultrasound and sodium hydroxide treatment may be (we think) it will be a promising technique to develop bioethanol production from waste paper.