Evaluation and modelling of methane production from corn stover pretreated with various physicochemical techniques

Abstract

Lignocellulosic by-products from agricultural crops represent an important raw material for anaerobic digestion and clean renewable, which is a key component of the circular economy. Lignocellulose is recalcitrant to biodegradation and pretreatments are required to increase methane yield during anaerobic digestion. In this work, the efficacy of different physicochemical pretreatments was compared using corn stover biomass as substrate. Anaerobic digestion of untreated and pretreated corn stover was performed in batch mode at mesophilic temperature (38°C) and organic matter solubilization of pretreated substrates was also investigated. The highest organic matter solubilization occurred in autoclave pretreatment (soluble chemical oxygen demand = 5630 ± 42 mg O2 L−1). However, the highest methane yield was obtained using alkaline pretreatment (367 ± 35 mL CH4 g−1 VSadded). Alkaline pretreatment increased methane yield by 43.3% compared to untreated control (256 ± 15 mL CH4 g−1 VSadded). Two mathematical models (i.e. first-order kinetics and transfer function) were utilized to fit the experimental data with the aim of assessing anaerobic biodegradation and to obtain the kinetic constants in all cases studied. Both models adequately fit the experimental results. The kinetic constant, k, of the first-order model increased by 92.8% when stover was pretreated with sulphuric acid compared with control. The transfer function model revealed that the maximum methane production rate, Rm, was obtained for the sulphuric acid treatment, which was 63.5% higher compared to control.

A Review on Potential Biofuel Yields from Cover Crops

“…However, there are only a few studies on AD of cover crop biomass, mainly cereal rye. The results are included in Table 5 and are comparable to corn stover biomethane yield, which is typically in the range of 250-350 L-CH 4 /kg-VS (volatile solids), depending on the pretreatment and operation conditions [84]. Pretreatment and continuous stirring improved the biomethane yields.…”

Catch and Cover Crops’ Use in the Energy Sector via Conversion into Biogas—Potential Benefits and Disadvantages

“…The methane potential was between 229 and 450 m 3 Mg −1 VS, and its highest values were obtained in the case of a mixture of rapeseed and winter vetch (399-415 m 3 Mg −1 VS), and oilseed radish (368-450 m 3 Mg −1 VS) cultivated in one of the locations tested in the study (Holstebro), while the lowest values were obtained in the case of white mustard (239-252 m 3 Mg −1 VS), regardless of the location of the crops. The biomethane potential of the raw biomass of CCCs usually does not differ from the potential of raw corn biomass, which is 256 ± 15 m 3 Mg −1 VS [129].…”

Optimization of Biomethane Yield of Xyris capensis Grass Using Oxidative Pretreatment

“…The main reasons that make lignocellulose feedstocks acceptable are their high biogas production potential and fertilizer production and they require low energy input [8]. Lignocellulose from agricultural residues and energy grasses represents vital feedstock for clean energy through anaerobic digestion, which is also a crucial component of the circular economy [9]. Lignocellulose feedstocks are made up of cellulose, hemicellulose, and lignin that are firmly attached.…”