Waste Valorisation

7Bioconversion of Processing Waste from Agro‐Food Industries to Bioethanol: Creating a Sustainable and Circular Economy

Deepak Kumar¹and Vijay Singh²

¹Department of Chemical Engineering, State University of New York College of Environmental Science and Forestry, Syracuse, NY, USA

²Agricultural and Biological Engineering Department, University of Illinois at Urbana‐Champaign, Urbana, IL, USA

7.1 Introduction

Increasing energy demand, limited fossil‐fuel reserves, and environmental concerns associated with production and use of fossil fuels necessitate the identification of alternative renewable and green energy resources. In 2018, the United States consumed a record high of 101.3 quadrillion Btu of energy. About a third of the total energy used in the US is consumed only in the transportation sector, and 92% of this is derived from petroleum (70% of total petroleum use) (EIA 2019). Bioethanol, a liquid fuel produced from the fermentation of sugars, is considered as the most promising renewable transportation fuel. Ethanol can be blended with gasoline at low concentrations, such as E10 (10% ethanol v/v), and used in the existing gasoline vehicles, or at high concentrations, such as E85 (85% ethanol v/v), to use in modified vehicles, also known as “flexible fuel vehicles.” Ethanol has a high blending octane rating (a measure of its ability to resist “knocking” in the engine) of 114, which increases the octane rating of E10 mix to 87, compared with the octane rating of 84 for regular ...