Upgrading of high moisture low rank coal to hydrogen and methane
The C2H upgrade project developed a new process for upgrading high moisture low rank brown coals yielding two valuable products: - a H2-rich fuel gas which can be used for high efficient power generation in a combined cycle or as a natural gas substitute; - a pre-calcined feed for a cement clinker kiln consisting of CaO, CaSO4 and coal ash. The C2H upgrade process consists of two core reactors: (i) a steam gasifer with in situ CO2 capture by CaO, and (ii) a sorbent regenerator with the possibility to produce a separate CO2 stream. The project evaluated the necessary aspects of process... development. Characterisation of coals and CaO-based sorbents: A European geological survey produced suitable locations for a C2H plant. A methodology for evaluation of calcium-based sorbents was developed. Pilot scale gasification: Testing on three different reactor types was successfully completed (ABFB, PBFB, Rotary Kiln). A H2-rich (>85 vol. %) and CO2-lean gas with low tar content (< 2 g/Nm3) was generated. Two continuous C2H pilot plants were designed for small-scale applications and large-scale power generation. IGCC simulation: The C2H-based IGCC plant has a net electric efficiency of 45.0 %. With CO2 capture, the base efficiency decreases to 37.5 %. Utilisation of the pre-calcined feed in a cement plant yields savings in fuel (66 %) and CO2 emissions (88 %). Life-cycle analysis: The C2H-based IGCC process is economically competitive compared with conventional IGCC systems, especially for CO2 capture: the specific investment cost is estimated at < 1 500 €/kWe and the CO2 mitigation cost is < 20 €/ tonne CO2 avoided.