Biomass derived fuels are an essential alternative for heat and energy production, in order to minimise environmental impact, since they make no net contribution to the increase of CO2 emissions into the atmosphere. In certain countries, biofuels are also interesting since they are available as waste products from the agricultural or forestry industry. Unfortunately, combustion of biofuels often results in high emissions levels of pollutants such as NOx, CO and unburned hydrocarbons.
In gas turbines, catalytic combustion of biofuels has the potential to reduce emissions of these undesired species. The ULECAT project (Ultra Low Emissions CATalytic combustor) described in this paper is the first step of a program aiming at the development of an ultra-low emission gas turbine in the range of 1 to 5 MWe, able to run with both biomass-derived gases and liquid fuels. The objective of the project is to assess the feasibility of a dual fuel catalytic combustor.
Combustor design issues are investigated at full and part load conditions. For the comparison of combustor configuration, modelling provides a useful help for catalytic section design, in particular for the estimation of catalytic activity and wall temperature which strongly influence catalyst life time.
Catalyst development is one of the main topics of this project. It is mainly focused on high temperature catalyst durability and the reduction of NOx formation. This last point is of primary importance in biofuels combustion and certain catalysts have shown an important potential in reducing ammonia conversion into NOx in some operating conditions. Catalyst performances are evaluated at lab scale and also pilot scale in representative gas turbine combustor conditions with both Diesel fuel and biomass derived fuels.