Strategies of pretreatment of feedstocks for optimized bioethanol production: distinct and integrated approaches

Akanksha Shukla; Deepak Kumar; Madhuri Girdhar; Anil Kumar; Abhineet Goyal; Tabarak Malik; Anand Mohan

doi:10.1186/s13068-023-02295-2

Strategies of pretreatment of feedstocks for optimized bioethanol production: distinct and integrated approaches

Biotechnol Biofuels Bioprod. 2023 Mar 13;16(1):44. doi: 10.1186/s13068-023-02295-2.

Authors

Akanksha Shukla¹, Deepak Kumar², Madhuri Girdhar¹, Anil Kumar³, Abhineet Goyal⁴, Tabarak Malik⁵, Anand Mohan⁶

Affiliations

¹ School of Bioengineering and Biosciences, Lovely Professional University, Phagwara, 144411, India.
² School of Chemical Engineering and Physical Sciences, Lovely Professional University, Phagwara, 144411, India.
³ Gene Regulation Laboratory, National Institute of Immunology, New Delhi, 110067, India.
⁴ SAGE School of Science, SAGE University Bhopal, Sahara Bypass Road Katara Hills, Extension, Bhopal, Madhya Pradesh, 462022, India.
⁵ Department of Biomedical Sciences, Institute of Health, Jimma University, Jimma, Ethiopia. malikitrc@gmail.com.
⁶ School of Bioengineering and Biosciences, Lovely Professional University, Phagwara, 144411, India. anandmohan77@gmail.com.

Abstract

Bioethanol is recognized as a valuable substitute for renewable energy sources to meet the fuel and energy demand of the nation, considered an environmentally friendly resource obtained from agricultural residues such as sugarcane bagasse, rice straw, husk, wheat straw and corn stover. The energy demand is sustained using lignocellulosic biomass to produce bioethanol. Lignocellulosic biomass (LCBs) is the point of attention in replacing the dependence on fossil fuels. The recalcitrant structure of the lignocellulosic biomass is disrupted using effective pretreatment techniques that separate complex interlinked structures among cellulose, hemicellulose, and lignin. Pretreatment of biomass involves various physical, chemical, biological, and physiochemical protocols which are of importance, dependent upon their individual or combined dissolution effect. Physical pretreatment involves a reduction in the size of the biomass using mechanical, extrusion, irradiation, and sonification methods while chemical pretreatment involves the breaking of various bonds present in the LCB structure. This can be obtained by using an acidic, alkaline, ionic liquid, and organosolvent methods. Biological pretreatment is considered an environment-friendly and safe process involving various bacterial and fungal microorganisms. Distinct pretreatment methods, when combined and utilized in synchronization lead to more effective disruption of LCB, making biomass more accessible for further processing. These could be utilized in terms of their effectiveness for a particular type of cellulosic fiber and are namely steam explosion, liquid hot water, ammonia fibre explosion, CO₂ explosion, and wet air oxidation methods. The present review encircles various distinct and integrated pretreatment processes developed till now and their advancement according to the current trend and future aspects to make lignocellulosic biomass available for further hydrolysis and fermentation.

Keywords: Bioethanol; Biofuels; Biological pretreatment; Chemical pretreatment; Lignocellulosic structure; Physical pretreatment.

Publication types

Review