The influence of the temperature regime on the formation of methane in a two‐phase anaerobic digestion process

Abstract

The influence of different temperature levels on the formation of methane in a two‐phase anaerobic digestion process using rye silage and barley straw as feedstocks was investigated in this study. This process comprised a leach‐bed reactor (LBR), a reservoir for leachate from the LBR, and a separate downstream fixed‐film anaerobic filter (AF), with immobilized micro biocoenosises. The degree of degradation of the volatile solids was similar in both studies and was almost equal at 75 Ma.‐%VS. When both reactor phases were operated at thermophilic conditions, the main substrate turnover was observed in the LBR (58% of the total methane yield, with an average methane content of 41 Vol.‐%). Only the excess of organic fraction in the process‐liquid was transformed in the AF (42% of the total methane yield, with an average methane content of 74 Vol.‐%). When the parts of the reactor system operated at different temperature regimes, thermophilic hydrolysis/acidogenesis phase and mesophilic methanization, a separation of carbon dioxide and methane production, was observed. A total methane yield of 88%, with an average methane content of 85 Vol.‐%, was formed in the AF. The generated biogas with high methane concentrations is suitable for feeding the purified biomethane into the natural gas grid. Furthermore, it can be used as fuel for cars and tractors.

Impact of process temperature and organic loading rate on cellulolytic / hydrolytic biofilm microbiomes during biomethanation of ryegrass silage revealed by genome-centered metagenomics and metatranscriptomics

“…For each reactor system and for each process temperature, two replicates were conducted in parallel, denominated further as biological replicates. Further process details were as previously published by [3].…”

“…To digest crop biomass as sole substrate and at high organic loading rates (OLRs), specially designed biogas reactors are advantageous such as staged degradation step ('phase') separated reactor systems consisting of a cellulolysis / hydrolysis fermenter and a downstream methanogenesis reactor. Compared to single phase reactors, these two-stage two-phase reactors possess several advantages, for example, the more stable operation (under particular process conditions) combined with higher bioenergy yields [2][3][4][5][6].…”

DNA and RNA Extraction and Quantitative Real-Time PCR-Based Assays for Biogas Biocenoses in an Interlaboratory Comparison

“…Partner A operated two mesophilic (37 °C) and two thermophilic (55 °C) two-stage two-phase biogas fermenter systems. The principle of the reactor set up was described in detail by Schönberg and Linke [ 20 ]. Each system consisted of one hydrolysis reactor (HR), one percolate (process fluid) storage tank and one anaerobic filter compartment.…”

Effect of a Profound Feedstock Change on the Structure and Performance of Biogas Microbiomes

“…The pH value was measured prior to feeding. The contents of total solids (TS), volatile solids (VS), volatile fatty acids (VFA, acetic, propionic, (i)-butyric, (i)-valeric, and caproic acids), total Kjeldahl nitrogen (TKN), and total ammonium nitrogen (TAN) were analyzed according to Schönberg and Linke [24].…”