Expected increase in energy demand worldwide, local and global limitation of high quality fossil fuel resources and emission of gasses with climatic relevance resulting from the utilization of fossil fuels represent the main challenges for future sustainable energy supply. Therefore, future systems for a sustainable, i.e. stable energy supply will be characterized by increased use of renewable, volatile energy sources (wind, solar) combined with utilization of low-grade fossil and biogenic fuels. The worldwide available low-grade fuels (e.g. coal with high ash content, biomass, waste based fuels, oil sands, oil shale) feature high heterogeneity, low calorific value and high content of inert material and trace species. In order to be utilized in highly efficient energy conversion processes with high fuel- / load- and product-flexibility, these fuels must be converted to high quality, process adapted chemical energy carriers.
Entrained flow gasification at high pressure is a very promising process for conversion of low-grade fuels to a high quality fuel (syngas). The low quality feedstock can be fed as pulverized solid fuel or as a highly viscous liquid, which may contain a high content of solid material (suspension fuel, slurry). The oxygen-blown gasification process, which is a partial oxidation of hydrocarbons with oxygen and steam, is operated at high temperatures (typically about 1700 K) and high pressure (up to 80 bars), yielding a tar-free synthesis gas which can be converted to basic chemicals (e.g. methanol), to liquid fuels (e.g. gasoline) or can be fired in a gas turbine of a combined cycle power plant (CCP) to produce electricity at very high efficiency (above 60%). This so called poly-generation gives maximum operational flexibility combined with fuel-flexibility and high energetic efficiency. As the gasification reactor is operated at high pressure, the produced synthesis gas can be fed to subsequent process steps without further compression, which is of major relevance for the energetic efficiency of the total conversion process. The production of chemicals, which can also be used as storable chemical energy carriers with high specific enthalpy content, allows for the compensation of fluctuating power supply from Renewable Energy Sources, RES. In addition, CO2 can be removed from the almost nitrogen-free syngas (pre-combustion CCS) with a much higher efficiency as compared to post-combustion CO2-removal from utility boilers.
All these features make high pressure entrained flow gasification of low-grade solid / suspension fuels with oxygen a very strong tool for efficient and sustainable energy conversion and supply for the medium- and long-term future in Europe and world-wide.
The major scientific challenge of the project is the mathematical modelling and experimental validation of the reacting multi-phase system of fuel droplet and particle with gas phase at high temperature and pressure in the entrained flow gasification process. Combining the competences of the partners of the HVIGasTech is a unique approach and chance to successfully elaborate a know-ledge based numerical simulation tool for the design and scale-up of a technical entrained flow gasifier.