Performance evaluation of chemically recuperated gas turbines (CRGT) power plants fuelled by di-methyl-ether (DME)

This paper reports a performance analysis on CRGT power plants fuelled by DME, which is a potentially attractive fuel for gas turbines. The study also includes a performance comparison of simple cycle gas turbines fuelled by natural gas, DME and methanol. The study shows that, owing to the exhaust heat recovery carried out through DME pre-heating and vaporization before combustion, the efficiency of the DME fuelled turbine improves by about 1 point, without any significant change in power output. Thermochemical recuperation in DME fuelled turbines allows to achieve a significant performance improvement. For the highest water/DME molar ratio allowed by the minimum temperature difference here assumed, the power output of the CRGT plant is 44% higher than that of the reference plant, with a corresponding 54% efficiency (versus 41% of the reference unit) and a 8%decrease of the specific CO2 emissions.