Improving biomethane yield by strengthening acidification of maize stover in two-phase anaerobic digestion

Huan Tong,Baoyu Zhou,Akiber Chufo Wachemo,Xiujin Li,Chunmei Liu,Xiaoyu Zuo

doi:10.25165/j.ijabe.20201304.4654

Abstract

Improving biomethane yield by strengthening acidification of maize stover in two-phase anaerobic digestion

Highlights

Maize crop is one of the highly produced cereals in China; averagely 2.2×108 t of maize stover are produced in 2016[1]
The results showed that the maximum Volatile fatty acids (VFAs) production (g Total Solids (TS) of maize stover (MS)) was obtained in experiment No.5, while the highest acetic acid content and acetic plus butyric acid content were obtained in experiment No
The two optimal conditions of the orthogonal acidification experiment and validation test were used for single-phase and two-phase Anaerobic digestion (AD) to determine the optimal conditions for producing biomethane. 3.2 Single phase and two-phase AD 3.2.1 Biomethane production performance

Summary

Introduction

Maize crop is one of the highly produced cereals in China; averagely 2.2×108 t of maize stover are produced in 2016[1]. Anaerobic digestion (AD) could generate sustainable bioenergy while reducing and stabilizing solid degradable organic wastes[5]; as a result, crop stover could represent a good substrate for renewable energy production by AD[6,7]. Two-phase AD separates acidification and methanation, thereby providing a suitable metabolic environment for both acidogenic and methanogenic bacteria[8], which could increase the system stability and improve the biogas yield[9,10,11,12]. The two-phase AD of unscreened dairy manure at a sludge retention time (SRT)/hydraulic retention time (HRT) of 10 d (2 d acidogenic and 8 d methanogenic) for AD resulted in 50% and 67% higher biogas production at organic loading rates (OLRs) of 5 g VS/(L·d) and 6 g VS/(L·d), respectively, relative to that of the single-phase configuration with an SRT/HRT of 20 d[14]. Few studies have focused on acidification and two-phase AD of MS; the reports on batch acidification combined with continuously stirred tank reactor (CSTR) methanation of two-phase AD are insufficient

Objectives

Methods

Results

Conclusion