Treatment of Waste Paper Using Ultrasound and Sodium Hydroxide for Bioethanol Production

Osama F Saeed,Shatha Muallah,Rafid Abdulkareem

doi:10.24126/jobrc.2018.12.1.555

Abstract

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.

Highlights

‫ت‬ٛ‫ انًخهفبث انٕرق‬،‫ت‬ٛ‫ الايٕاج فٕق انصٕح‬،ٕ٘ٛ‫ثبَٕل انح‬ٚ‫ الا‬:‫انكهًبث انذانت‬ Introduction Increasing energy costs together with increasing concerns about global warming related to CO2 emissions and the decrease of landfill locations for disposal of solid waste resulted in increasing interest in alternative, low and non-carbon based energy sources [1,2,3,4]
Waste paper could be used as an excellent source for bioethanol production; it is abundant, low cost with high amount of cellulose and does not require energy-intense thermophysical or severe strong acid pretreatments prior to enzymatic hydrolysis generally used in hydrolysis of lignocellulose substrates [3,7]
Bioethanol derived from biomass is the only liquid transportation fuel that does not contribute to the greenhouse gas e ffect, it yields zero net CO2 output into the atmosphere because after burning of bioethanol, the released CO2 is recycled back into plant material because plants use CO2 to synthesize cellulose during photosynthesis

Summary

Introduction

‫ت‬ٛ‫ انًخهفبث انٕرق‬،‫ت‬ٛ‫ الايٕاج فٕق انصٕح‬،ٕ٘ٛ‫ثبَٕل انح‬ٚ‫ الا‬:‫انكهًبث انذانت‬ Introduction Increasing energy costs together with increasing concerns about global warming related to CO2 emissions and the decrease of landfill locations for disposal of solid waste resulted in increasing interest in alternative, low and non-carbon based energy sources [1,2,3,4]. Waste paper could be used as an excellent source for bioethanol production; it is abundant, low cost with high amount of cellulose and does not require energy-intense thermophysical or severe strong acid pretreatments prior to enzymatic hydrolysis generally used in hydrolysis of lignocellulose substrates [3,7]. Ultrasonic helps in enhancing the mass transfer rates due to the generation of turbulence and sound streaming which enhance delignification process by increased penetration of solvent into substrate [17] In this sense, ultrasonic can be successfully used to develop the pretreatment process by reducing the structural rigidity of lignocellulosic biomass and by reducing the mass -transfer resistances, which can lead to enhanced hydrolysis step, increased product yield with reduced processin g time and enzyme consumption, based on these features, the main objective of this study was to determine the optimum conditions for waste paper treatment using ultrasound and sodium hydroxide

Objectives

Methods

Results