Integrated process and Cu/Zn-based catalyst for synthesizing methanol utilizing CO2, generating electricity from hydrocarbon feedstock
The present disclosure provides an integrated process and a Cu/Zn-based catalyst system for synthesizing methanol from CO 2 and generating electricity from hydrocarbon feedstock. The process includes steps of gasifying hydrocarbon feedstock into syngas by using oxygen and using the produced syngas as a fuel in a power generation unit, reusing a first part of an exhaust stream of the power generation unit as a reactant in the gasification unit. Using a second part of the said exhaust stream as a reactant for methanol synthesis in a methanol reactor, wherein, the second part is treated to separate CO 2 and water, and CO 2 is used as the reactant for methanol synthesis. Operating an electrolyzer during non-peak hours to produce hydrogen, wherein, a required stoichiometric ratio of the produced hydrogen is transferred into the methanol reactor for methanol synthesis, wherein, a Cu/Zn-based catalyst system is used for methanol synthesis through a direct hydrogenation reaction of CO 2 .
1. An integrated process for synthesizing methanol from CO 2 and generating electricity from a hydrocarbon feedstock, wherein the process comprising the steps of:
(i) gasifying the hydrocarbon feedstock and oxygen inside a gasification unit to produce a syngas, wherein the syngas is used as a fuel for electrical power generation inside a power generation unit, wherein the power generation unit is configured to produce an exhaust stream, and wherein the exhaust stream comprises CO 2 and water;
(ii)reusing a first part of the exhaust stream of the power generation unit as a reactant in the gasification unit, wherein the first part of the exhaust stream comprises a fixed portion of CO 2 and water;
(iii) using a second part of the exhaust stream of the power generation unit as a reactant for methanol generation in a methanol reactor, wherein the second part of the exhaust stream is treated to separate CO 2 and water, and the separated CO 2 is used as the reactant for methanol synthesis;
(iv) operating an electrolyzer during non-peak hours to produce hydrogen and oxygen as a by-product, wherein a required stoichiometric ratio of the produced hydrogen is transferred into the methanol reactor for methanol synthesis, wherein a Cu/Zn-based catalyst system is used inside the methanol reactor for methanol synthesis through direct hydrogenation reaction of CO 2 ; and
(v)recovering and reusing oxygen by-product from the electrolyzer, wherein the oxygen by-product is used as a gasifying agent in the gasification unit and a combustion agent in the power generation unit.
2. The integrated process as claimed in claim 1 , wherein the Cu/Zn-based catalyst system is a heterogeneous catalyst of copper and zinc, and one or more metals selected from alumina, cerium, zirconium, and gallium.
3. The integrated process as claimed in claim 2 , wherein the Cu/Zn-based catalyst system results hydrogenation of CO 2 and provides per-pass conversion of CO 2 equal to or higher than 65.56% and methanol yield more than 12.37%.
4. The integrated process as claimed in claim 3 , wherein the methanol reactor has a temperature in a range of 200° C. to 320° C., a pressure in a range of 10 to 200 bar, a molar ratio of CO 2 :H 2 in a range of 1:2 to 1:10, and a gas hourly space velocity (GHSV) in a range of 2000 to 10000 per hour.
5. The integrated process as claimed in claim 4 , wherein the methanol reactor has the temperature in a range of 220° C. to 280° C., the pressure in a range of 40 to 60 bar, the molar ratio of CO 2 :H 2 in a range of 1:3 to 1:5, and the GHSV in a range of 4000 to 6000 per hour.
6. The integrated process as claimed in claim 1 , wherein the hydrocarbon feedstock is a biomass material, coal or petcoke.
7. The integrated process as claimed in claim 1 , wherein the CO 2 of the first part of the exhaust stream is converted into CO inside the gasification unit, and H 2 O works as a gasifying agent inside the gasification unit.
8. The integrated process as claimed in claim 1 , wherein the electrolyzer is operated by a portion of electrical power generated by the power generation unit.
9. The integrated process as claimed in claim 1 , wherein the methanol reactor is selected from a fixed-bed reactor, a down-flow reactor and a single pass configuration reactor.