Biomass Valorization Under Methane Environment

Abstract

Biomass Valorization Under Methane Environment IntroductionEnergy consumption continues to increase, while the use of unrenewable energy resources such as fossil fuels brings a myriad of problems such as energy crises, environment pollution, greenhouse gas accumulation, deglaciation, and ecosystem destruction [1]. Therefore, developing renewable energy resources is of great urgency. Biomass refers to faunal and floral materials used for energy generation or the production of a range of chemicals, which can be regarded as a renewable substituent of conventional resources. Biomass also covers a variety of agricultural and domestic waste materials such as wheat straw, corn cobs, manure, and household garbage [2]. Therefore, the utilization of biomass not only compensates the shortage of energy supply but also converts various intractable wastes into valuable products, namely, turning "trash" into "treasure" [3]. As a result, corresponding studies are critical for environment protection and sustainable development.Current biomass utilization techniques include biological conversion, gasification, liquefaction, pyrolysis, and hydrodeoxygenation [4]. Corresponding research of these pathways provides solutions for using biomass effectively, while several intrinsic drawbacks are still hard to overcome. Biological processes (Fig. 7.1) are often operated at mild conditions, and the selectivity towards valuable products is often favorable. However, the product yield and efficiency are still undesirable, leading to high operational cost and low profitability of the whole process [5]. Gasification (Fig. 7.2) is less costly and can handle biomass with high water content, but the operation temperature is relatively high, and the product distribution is hard to control, resulting in extra energy consumption and greenhouse gas emissions [6]. Liquefaction (Fig. 7.3) occurs at much milder temperatures and produces more liquid products, while a solvent is usually needed, and the intricacy and high cost limit its practical applications [7]. Pyrolysis (Fig. 7.4) also adopts relatively mild reaction temperatures and pressures. In this process, gas, liquid, and solid