SNG test rig

The SNG pilot plant is used to investigate the production of synthetic natural gas (SNG) from biomass. The overall system consists of a fluidized bed gasifier, as well as a gas cleaning and methanation facility wherein the product gas is treated and processed.

The gasifier is an allothermal fluidized bed gasifier that uses superheated steam as a gasifying agent for biomass at about 850 °C and at pressures up to 5 bar. Wood pellets are fed in as fuel which is introduced into the reformer from the top. After leaving the reformer, the product gas flows through a sintered metal filter in which the temperature is around 850 °C. Here the separation of soot particles and discharged bed material takes place. Various aspects of the hot gas cleaning can be examined. After separation of the gas particles, part of the gas stream flows through successive SNG reactors for processing and cleaning of the product gas:

  • Tar reactor (Ni-catalyzed tar reforming / decomposition, 900 °C)
  • Chlorine adsorber (Adsorbent filling, 350 °C)
  • Sulfur adsorber (Adsorbent filling, 350 °C)
  • Methanation reactor (cooled Ni-catalyzed reaction, 300 °C )
  • Condenser

After the product gas is purified in the first three reactors - from impurities such as tar, chlorine and sulfur compounds - the product gas enters the methanation reactor. This reactor is designed for the removal of heat, released during the exothermic reaction, which is carried out through a double fixed bed tubular reactor with oil cooling. Subsequently the gas is purified through condensation of water in order to produce  the desired raw-SNG.

There is a variety of measuring devices, which provide continuous monitoring of key operating parameters such as pressure, temperature and flow rate of the entire system.Also, the facility is well equipped in order to study the gas composition. This includes the determination of water content in the gas, the main gas components and trace elements (such as hydrogen sulfide and tar compounds).

The aim is to study the behavior of the catalysts and their influence on the reactions in long-term experiments (100 hrs). To achieve this, the test rig is provided with a PLC controller that continuously records all measurements and enables automated operation.

Technical Data:

Fuel capacity 5 kWth
Max. pressure 5 bar
Max. temperature 900 °C
Size 1.2 x 0.8 x 3.8 m


Contact Person: Felix Fischer