Effects of Ammoniation Pretreatment at Low Moisture Content on Anaerobic Digestion Performance of Rice Straw

Abstract

The effect of ammonia pretreatment on the anaerobic digestion performance of rice straw was investigated. The rice straw was pretreated with four different moisture contents (30%, 50%, 70%, and 90%) and three concentrations of ammonia (2%, 4%, and 6%). The results showed that the anaerobic digestion achieved best performance for the rice straw pretreated by ammonia concentration of 4% and moisture content of 70%, and biogas yield achieved the highest value (396.92 mL·g -1 total solid), which was 21.9% higher than that of the untreated rice straw. Higher moisture was recommended as it could increase system stability, shorten anaerobic digestion time, and increase biogas production. The composition analyses indicated that ammonia pretreatment could effectively destroy the chemical structure of lignocellulose, and partially decompose cellulose, hemicellulose, and lignin. Cellulose and hemicellulose were converted by 79.2% and 63.2%, respectively, at optimal ammonia amount and moisture content. The ammonia pretreatment proved to be a simple and effective methods to improve the anaerobic digestion performance of rice straw.

Influence of moisture content of solid-state NaOH pretreatment and codigestion on methane production in the semi-dry anaerobic digestion of rose stalk

“…The R3 group, with 77% moisture content during pretreatment, obtained the highest methane yield, but its yield was not significantly higher than those of the R1 and R2 groups. An increase in biogas yield with the increment of moisture content was also observed in the ammonia pretreatment of rice straw with 2% ammonia content (w/w) (Yuan et al 2014). This phenomenon was ascribed to the increase in the alkali transfer rate and reaction extent, thereby resulting in a greater disruption of lignocellulosic structure, thus improving the digestibility of lignocellulosic biomass (Liang et al 2011;Yuan et al 2014).…”

“…Thus, Liang et al (2016) reported that 4% NaOH-treated rose stalk produced 44% higher yields than non-NaOH-treated biomass. The moisture content of pretreatment has a remarkable influence on pretreatment performance (Yuan et al 2014;Peces et al 2015). Moreover, the disruption of lignocellulosic structure and removal of chemical composition were affected by the moisture content during pretreatment, thereby changing the biogas production and process stability for anaerobic digestion of pretreated biomass (Yuan et al 2014).…”

“…The moisture content of pretreatment has a remarkable influence on pretreatment performance (Yuan et al 2014;Peces et al 2015). Moreover, the disruption of lignocellulosic structure and removal of chemical composition were affected by the moisture content during pretreatment, thereby changing the biogas production and process stability for anaerobic digestion of pretreated biomass (Yuan et al 2014). However, no systematic study on the influence of moisture content on the performance of solid-state pretreatment has been conducted yet.…”

Enhancing and upgrading biogas and biomethane production in anaerobic digestion: a comprehensive review

“…There are contrasting reports on the effect of chemical pretreatment techniques on the rate of feedstock hydrolysis during AD process. Yuan et al (2014) and Li et al (2015) have reported that the chemical pretreatment technique is a fast process, while Kumar and Sharma (2017), Gumisiriza et al (2017) and Amin et al (2017) reported that the technique is a slow process. This difference could be due to variations in their chemical pretreatment conditions.…”

Study on the Effect of Two-Phase Anaerobic Co-Digestion of Rice Straw and Rural Sludge on Hydrogen and Methane Production

“…Conversely, co-digestion can significantly improve gas production rates due to its advantages of balancing nutrients, diluting toxic substances, and improving microbial activity [14]. Hairong Yuan et al [15] explored the performance of the anaerobic co-digestion of sludge and wheat straw. The results of the study showed that the anaerobic digestion performance of sludge was affected by different C/N ratios, and the use of anaerobic co-digestion resulted in higher gas production than single sludge.…”