Integration of membrane filtration in two-stage anaerobic digestion system: Specific methane yield potentials of hydrolysate and permeate

Padma Priya Ravi; Wolfgang Merkle; Marc Tuczinski; Florencia Saravia; Harald Horn; Andreas Lemmer

doi:10.1016/j.biortech.2018.12.043

Integration of membrane filtration in two-stage anaerobic digestion system: Specific methane yield potentials of hydrolysate and permeate

Bioresour Technol. 2019 Mar:275:138-144. doi: 10.1016/j.biortech.2018.12.043. Epub 2018 Dec 15.

Authors

Padma Priya Ravi¹, Wolfgang Merkle¹, Marc Tuczinski², Florencia Saravia³, Harald Horn⁴, Andreas Lemmer¹

Affiliations

¹ University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy, Garbenstraße 9, 70599 Stuttgart, Germany.
² DVGW - Research Center at the Engler-Bunte-Institute of Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe, Germany.
³ Karlsruhe Institute of Technology (KIT), Engler-Bunte-Institute, Engler-Bunte-Ring 1, 76131 Karlsruhe, Germany.
⁴ DVGW - Research Center at the Engler-Bunte-Institute of Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe, Germany; Karlsruhe Institute of Technology (KIT), Engler-Bunte-Institute, Engler-Bunte-Ring 1, 76131 Karlsruhe, Germany.

PMID: 30580235
DOI: 10.1016/j.biortech.2018.12.043

Abstract

Two-stage biogas systems consisting of a CSTR-acidification reactor (AR) and an anaerobic filter (AF) were frequently described for microbial conversion of food and agricultural wastes to biogas. The aim of this study is to investigate the integration of a membrane filtration step in two-stage systems to remove inert particles from hydrolysate produced in AR in order to increase the efficiency of the subsequent AF. Hydrolysates from vegetable waste (VW) and grass/maize silage (G/M) were treated in cross-flow ceramic membrane filtration system (pore size 0.2 µm). Organic acids were extracted efficiently through filtration of hydrolysate. For both the substrates, membrane permeability was stable and high (46.6-49.3 L m^-2 h^-1 bar^-1). Filtration process effectively improved the specific methane yield of permeate by 40% (VW) and 24.5% (G/M) compared to hydrolysate. It could be shown that, the filtration-step increased hydrolysate's degradability, which lead to higher conversion efficiency in the following AF.

Keywords: Ceramic membrane filtration; Membrane permeability; Permeate; Specific methane yields; Two-stage anaerobic digestion.

MeSH terms

Anaerobiosis
Biofuels
Bioreactors
Filtration
Methane / biosynthesis*
Poaceae / metabolism
Silage
Zea mays / metabolism

Substances

Biofuels
Methane