Energy Crops and Methane: Process Optimization of Ca(OH)2 Assisted Thermal Pretreatment and Modeling of Methane Production

Abstract

Switchgrass earned its place globally as a significant energy crop by possessing essential properties such as being able to control erosion, low cost of production, biomass richness, and appeal for biofuel production. In this study, the impact of a Ca(OH)2-assisted thermal pretreatment process on the switchgrass variety Shawnee for methane fuel production was investigated. The Ca(OH)2-assisted thermal pretreatment process was optimized to enhance the methane production potential of switchgrass. Solid loading (3–7%), Ca(OH)2 concentration (0–2%), reaction temperature (50–100 °C), and reaction time (6–16 h) were selected as independent variables for the optimization. Methane production was obtained as 248.7 mL CH4 gVS−1 under the optimized pretreatment conditions. Specifically, a reaction temperature of 100 °C, a reaction time of 6 h, 0% Ca(OH)2, and 3% solid loading. Compared to raw switchgrass, methane production was enhanced by 14.5%. Additionally, the changes in surface properties and bond structure, along with the kinetic parameters from first order, cone, reaction curve, and modified Gompertz modeling revealed the importance of optimization.

Torrefaction of Willow in Batch Reactor and Co-Firing of Torrefied Willow with Coal

“…These insights enhance our understanding of the torrefaction process, offering valuable information for optimizing its industrial application. Over the past 15 years, there has been a growing utilization of biomass derived from agricultural crops, industrial waste, and wood industry waste as a fuel source in the energy industry [20,21]. Perennial plants are particularly suitable for energy production due to their long-term cultivation cycle [22,23], making willow an efficient energy species.…”

Emerging Strategies for Enhancing Propionate Conversion in Anaerobic Digestion: A Review

“…The anaerobic digestion process involves multistep complex biochemical reactions, which can be mainly divided into three stages (Figure 2): (i) the hydrolysis of complex polymers, (ii) the fermentation of hydrolytic products to short VFAs, formate, CO2, and Anaerobic digestion is widely used in the treatment of organic waste and organic wastewater [3][4][5]. According to the concentration of total solid (TS) feed content, anaerobic fermentation can be divided into wet anaerobic and dry anaerobic processes [6,7]; according to the use of fermentation tanks, this can be divided into continuously stirred tank reactors (CSTRs) [8], upflow anaerobic sludge beds (UASBs) [9], internal circulation (IC) [10], expanded granular sludge beds (EGSBs) [11], upflow solid reactors (USRs) [12], etc.…”