Reducing carbon footprint in cities: Natural gas-based energy generation with zero CO2 emission

Abstract

This work proposes a novel zero–CO2–emission energy system to meet thermal and electrical energy needs of the cities without emitting CO2 while using natural gas as a primary energy source. Since the system uses available technologies, it is envisioned as a part of transition towards net-zero sustainable economy. At the core of the system is production of hydrogen via pyrolysis of methane which has recently achieved technological maturity of industrial scale production. Natural gas combustion in a combined heat and power (CHP) unit produces electrical and thermal energy required by the city and by the energy system itself. CO2 produced by CHP is captured via MEA absorption and converted to methanol via synthesis with hydrogen while also producing carbon black. We consider different carbon reduction scenarios, urbanization levels, system operation conditions, operational costs, capital costs, and energy and material prices in evaluating the system. If such systems are deployed worldwide, subject to produced methanol being equal to the current demand (111 Million ton/yr), they would eliminate 44 Million t/yr CO2 emissions from existing methanol plants and 160 Millon t/yr CO2 emissions from standalone energy systems that provide heating and cooling for 40 Million people.