Patent ID: 8829059

Claim:
A methanol synthesis loop production process comprising the following steps: (a) providing a source of syngas, wherein the syngas has a composition parameter R 1 , where R 1 >2; (b) performing a methanol synthesis reaction to react the syngas to produce methanol; (c) performing a condensation step to recover methanol; (d) withdrawing a purge stream from the condensation step to limit the concentration of inerts and excess hydrogen; (e) withdrawing non-condensed methanol synthesis loop syngas from the condensation step; (f) performing a sweep-based membrane separation step comprising, (i) providing a membrane having a feed side and a permeate side, where the membrane exhibits a selectivity to carbon dioxide over hydrogen, (ii) passing a carbon dioxide-containing gas across the feed side, (iii) passing at least a portion of the methanol synthesis loop syngas as a sweep stream across the permeate side, (iv) withdrawing from the feed side a carbon dioxide-depleted residue stream, (v) withdrawing from the permeate side a carbon dioxide-enriched permeate stream; (g) compressing the permeate stream; and (h) passing the compressed permeate stream to the methanol synthesis reaction.