EUBCE 2024 - Alejandra LENIS - Optimizing Biogas Desulfurization: Anoxic Biotrickling Filtration with Agricultural Digestate for Enhanced Sulfur Removal Efficiency

Optimizing Biogas Desulfurization: Anoxic Biotrickling Filtration with Agricultural Digestate for Enhanced Sulfur Removal Efficiency

Short Introductive summary

The testing and systematic investigation of the biologically oxidative desulfurization of biogas in a pilot-scale biotrickling filter (BTF) under anoxic conditions was conducted. The innovation of the process lies on the utilization of an alternative oxidative path of H2S, using nitrate (NO3-) or nitrate (NO2-) rather than oxygen from air, which is conventionally used. This approach allows a cleaner biogas purification that doesn`t result in degrading of biogas quality due to contamination with oxygen and nitrogen, which also contributes to a more efficient upgrading of biogas to biomethane, since no elimination of O2 and N2 is needed. Another innovation that is also of environmental relevance is the usage of digestate as both inoculum and washing liquid in the BTF. During the second part of the research, an additional process unit was studied. In this unit, the ammonia (NH4+) contained naturally in the digestate was nitrified before being used as a washing liquid. This additional process unit utilizes the bacteria present in the digestate to convert NH4+ into NO3- or NO2- by aerating the process unit. This means that only digestate was used as inoculum and nutrient solution.

A. Lenis, RWTH Aachen, GERMANY
K. Ooms, RWTH Aachen, GERMANY
J. Pinnekamp, RWTH Aachen, GERMANY
J. Gonzalez-Cortes, University of Cadiz, SPAIN
M. Ramirez, University of Cadiz, SPAIN