Journal of Energy Bioscience 2024, Vol.15, No.5, 326-336 http://bioscipublisher.com/index.php/jeb 327 feedstock. The significance of this research lies in its potential to inform future research directions and policy decisions, ultimately contributing to the development of sustainable biofuel production systems. 2 Switchgrass as a Feedstock for Cellulosic Ethanol 2.1 Biological and agronomic characteristics Switchgrass (Panicum virgatum L.) is a C4, warm-season, perennial native grass that has been strongly recommended as an ideal biofuel feedstock due to its high productivity and broad adaptability to various environmental conditions (Kim et al., 2020). It can be cultivated in both lowland and upland regions, depending on local soil and environmental conditions, making it suitable for diverse geographical areas (Gu and Wylie, 2017). Additionally, switchgrass has a deep root system that enhances its resilience to drought and other environmental stresses, contributing to its adaptability and sustainability as a bioenergy crop (Li et al., 2022). Switchgrass has demonstrated significant biomass yield potential, with field trials showing annual yields ranging from 5.2 to 11.1 Mg/ha (Schmer et al., 2008). The yield can be influenced by factors such as nitrogen fertilization, which has been shown to increase aboveground biomass yield by 1.2 times compared to unfertilized controls (Li et al., 2022). Moreover, genetic improvements and optimized agronomic practices can further enhance biomass yields, making switchgrass a highly productive feedstock for cellulosic ethanol production (Fu et al., 2011; Yan et al., 2018). 2.2 Environmental benefits Switchgrass cultivation has been shown to improve soil health by enhancing soil carbon and nitrogen content and maintaining microbial diversity and activity (Li et al., 2022). The deep root system of switchgrass helps in reducing soil erosion and improving soil structure, which contributes to better soil health and sustainability (Gu and Wylie, 2017). Additionally, switchgrass can be grown on marginal lands, which helps in preventing soil degradation and promoting soil conservation (Wullschleger et al., 2010). Switchgrass has a high potential for carbon sequestration, which can significantly reduce greenhouse gas emissions. Studies have shown that cellulosic ethanol derived from switchgrass can result in greenhouse gas emissions that are 94% lower than those from gasoline (Schmer et al., 2008). The deep root system of switchgrass also contributes to long-term carbon storage in the soil, further enhancing its environmental benefits (Keshwani and Cheng, 2009). 2.3 Economic viability The cost of cultivating and harvesting switchgrass is relatively low compared to other bioenergy crops, primarily due to its low requirements for agricultural inputs such as fertilizers and pesticides (Keshwani and Cheng, 2009). Field trials have shown that switchgrass can be managed with minimal inputs while still achieving high biomass yields, making it an economically viable option for biofuel production (Schmer et al., 2008). Additionally, advancements in genetic modification and agronomic practices can further reduce cultivation costs and improve biomass yield (Fu et al., 2011; Yan et al., 2018). The market for cellulosic ethanol is growing, driven by increasing demand for renewable energy sources and government policies promoting biofuels. Switchgrass, with its high biomass yield and low input requirements, is well-positioned to capitalize on these market trends (Weijde et al., 2013). Economic analyses have shown that switchgrass can produce 540% more renewable energy than the nonrenewable energy consumed in its production, highlighting its profitability as a bioenergy crop (Schmer et al., 2008). Furthermore, the development of value-added products from switchgrass, such as bio-oil and fiber composites, can enhance its market potential and profitability (Keshwani and Cheng, 2009). 3 Technical Processes in Switchgrass-Based Cellulosic Ethanol Production 3.1 Pretreatment methods Pretreatment is a crucial step in the conversion of switchgrass to cellulosic ethanol, as it helps to break down the complex structure of lignocellulosic biomass, making the cellulose more accessible for enzymatic hydrolysis.
RkJQdWJsaXNoZXIy MjQ4ODYzMg==