Carbon-dioxide-to-methanol intensification with supersonic separators: Extra-carbonated natural gas purification via carbon capture and utilization.

A novel carbon-capture-and-utilization route from extra-carbonated natural gas using low-cost/low-carbon chloralkali hydrogen is disclosed. Methanol and methane-rich gas are produced without direct carbon emissions and also with low indirect emissions assuming the local electricity-matrix as 87% non-emitting. Carbon dioxide removed from raw natural gas via cryogenic extractive distillation with methanol entrainer, feeds a new Carbon-Dioxide-to-Methanol hydrogenation route intensified by supersonic separators with liquid water injection for greater methanol conversion per pass in the synthesis-loop and greater methanol recovery in the separation system. Intensified Carbon-Dioxide-to-Methanol is designed economically optimizing water/methanol injection-ratios and maximum Mach numbers of supersonic separators. Extra-carbonated natural gas processing coupled to intensified Carbon-Dioxide-to-Methanol is techno-economically assessed, demonstrating that supersonic intensification entails 2% greater methanol production, 11% less power consumption and 7.5% greater net value comparatively to non-intensified counterpart. The intensified process removes 99.2% of CO 2 from extra-carbonated gas and was analyzed at two methanol scales [8021. 5 t/d , 1692. 3 t/d ] giving, respectively, [9.5, 41.5] payback-years, and [2896.4MMUSD, 41.37MMUSD] net values (60years). A critical feasibility factor is low-cost/low-carbon by-product hydrogen from chloralkali industries, for which the break-even prices were respectively evaluated for the two scales as [685USD/t H2 , 358USD/t H2 ]. A third, better and safer, option is to couple intensified Carbon-Dioxide-to-Methanol to large-scale Carbon-Dioxide-to-Enhanced-Oil-Recovery providing hedging against insufficient offer of low-cost/low-carbon hydrogen while practically keeping the project net value (60years) despite twofold investment. [Display omitted] • Supersonic separator with H 2 O injection intensifies CO 2 -to-Methanol process. • New carbon-capture-&-utilization from 72%CO 2 natural gas using CO 2 -to-Methanol. • Economic viability depends on low-price/low-carbon H 2 as chloralkali by-product. • Intensified CO 2 -to-Methanol financially enables 72%CO 2 natural gas processing. • CO 2 capture via cryogenic CH 3 OH extractive distillation with refrigeration-cascade. [ABSTRACT FROM AUTHOR]