Envitec Biogas and Ohra Energie to complete CNG filling station in Thuringia

EnviTec Biogas will implement its innovative gas upgrading technology as a single-stage process for the first time, the company announced on 7 March.
The flagship project will see the Lower Saxony-based firm work with Ohra Energie to enhance the transition to sustainable transport.
The project encompasses a single-stage gas upgrading plant that is operated with just five SEPURAN® Green Membranes. The purified methane is then fed directly to the CNG filling station. The remaining residual gas stream, consisting of methane and CO2, known as the ‘permeate’, is used thermally. This additional heat can be deployed for heating the digester or used in dairy cattle operations.
“Since all of the gas is used as clean energy, no methane slip is discharged into the atmosphere,” said Volkmar Braune, chief technical officer at Ohra Energie. The raw gas is sourced from an existing 400 kW biogas plant run by Agra GmbH Frohndorf/Orlishausen in Sömmerda.
The shared project was initiated following the completion of a feasibility study on the regional generation and use of biogas as a fuel (‘RUM’ – regional, environmentally friendly and mobile).
“We completed the groundwork back in September 2021 in Fröttstädt, and the project will now be completed with the implementation of a small-scale biogas upgrading plant featuring direct integration with a CNG/biogas filling station,” Braune continued. “We received funding from Thüringer Aufbaubank for both the feasibility study and the demonstration project. Without this support, a pilot project of this kind would simply have been economically impractical.”
“We developed this innovative approach together with our customer,” added Jürgen Tenbrink, chief technical officer at EnviTec Biogas and responsible for project research.
Focus on plant sustainability
The second step in the joint project plan is an integrated CNG compressor and storage unit, including a dual fuel pump, for a filling station located in the Frohndorf district of Sömmerda.
Apart from cooler, fuel pump and card payment point, all of the components are housed in a single container.
“Although we kept the size of the container as a 45-foot unit, we’ve redesigned the interior from scratch compared with our conventional, three-stage EnviThan process,” explained Stefan Laumann, head of the gas upgrading department at EnviTec Anlagenbau GmbH & Co. KG.
This is the first time that EnviTec Biogas has sourced the CNG compressor, cylinder bundle storage, fuel pump and gas upgrading screw compressor from one provider, which also minimises service costs.
Laumann stated: “We also want our customers to be able to benefit from our long-standing cooperation with BAUER.”
He continued:  “Thanks to this CNG filling station, we will soon have filled yet another gap on the map of CNG filling stations in Germany.”
Currently, more than 760 CNG filling stations are usable across Germany, of which roughly 80% (660) offer bio-CNG. In Thuringia, only about 25 CNG filling stations have been completed to date.