The design of modern Low Heating Value (LHV) fuel combustion devices, such as gas turbine combustors, relies heavily on numerical simulations. In addition, numerical predictions are always validated by experimental tests. In this work, an experimental facility was built. The fuel input power of the combustor was 300 kW. Such facility requires a gas flow of typically 0.06 kg/s, so a syngas production at a reasonable cost was required to undertake tests under real working conditions.
Within this work, an inexpensive and flexible syngas generator has been designed, produced and tested. The main idea was to use cheap available gas fuels and to crack it in order to obtain the syngas. Such conversion is heavily used in oil refineries and called “Steam Reforming”. Propane is used as a fuel and is cracked on a commercial steam reforming catalyst. To ensure the wanted ratio of C/H and C/O in the final product, CO2, H2O and air were added to the fuel gas. Catalytic cracking is needed as propane cracking kinetics are low at wanted operation temperatures, namely 900 to 1100 K. Care is taken to avoid carbon formation in the gasification device which may cause decomposition of the stainless steel reactor vessel.
The gasification device was used to feed a 300kW combustor at 2.8 bar pressure. The device was successfully integrated into a test rig and used for a burner study. The obtained composition was quite close to a typical gasified biomass composition. A wide range of different compositions has also been explored. Hydrocarbon concentration range was investigated from 3 vol% up to 16 vol% (Methane equivalent). The CO2 concentration varied between 13 vol% and 20 vol%. The syngas temperature was kept at an interval between 900 and 1100 K. The device provided 0.06 kg/s of a 3 to 5 MJ/kg heating value fuel. The operating costs of the gasification device were found about one tenth of the bottled gas price.