Integrating low-temperature methanol synthesis and CO2 sequestration technologies: application to IGCC plants

Coupling a low-temperature once-through methanol synthesis process with CO2 separation technology would provide an option for integrated gasification combined cycle (IGCC) power plants to address the CO2 mitigation issue and also create the capability to utilize methanol as a peak-shaving fuel. Data are presented that show that several nickel complexes activated by alkoxide bases catalyze facile synthesis of methanol from synthesis gas (primarily a mixture of CO and H2) in homogeneous liquid phase under mild conditions of temperature (<150 °C) and pressure (<5 MPa). Under these mild conditions, batch-mode productivity of up to 20 g mol MeOH/l cat. h is achieved and more importantly, per pass gas conversion and methanol selectivity exceed 90 and 95%, respectively. The overall synthesis gas to methanol process has built-in waste-minimization and minimum by-product formation features and thus achieves CO2 mitigation. The potential of this low-temperature methanol synthesis approach is considered in light of the recent advances in CO2 sequestration technologies. A successful development of this technology may also provide an atom-economical pathway to transport remote natural gas in the form of methanol, a liquid energy-carrier.