Methanol synthesis using captured CO2 as raw material: Techno-economic and environmental assessment

Abstract

h i g h l i g h t sA carbon utilisation plant that synthesise methanol is simulated in CHEMCAD. The total amount of CO 2 demand is 1.46 t/t methanol . The CO 2 not-produced compared to a conventional plant is 0.54 t/t methanol . Production costs results too high for a financially attractive project. There is a net potential for CO 2 emissions reduction of 2.71 MtCO 2 /yr in Europe. g r a p h i c a l a b s t r a c t a b s t r a c t The purpose of this paper is to assess via techno-economic and environmental metrics the production of methanol (MeOH) using H 2 and captured CO 2 as raw materials. It evaluates the potential of this type of carbon capture and utilisation (CCU) plant on (i) the net reduction of CO 2 emissions and (ii) the cost of production, in comparison with the conventional synthesis process of MeOH Europe. Process flow modelling is used to estimate the operational performance and the total purchased equipment cost; the flowsheet is implemented in CHEMCAD, and the obtained mass and energy flows are utilised as input to calculate the selected key performance indicators (KPIs). CO 2 -based metrics are used to assess the environmental impact. The evaluated MeOH plant produces 440 ktMeOH/yr, and its configuration is the result of a heat integration process. Its specific capital cost is lower than for conventional plants. However, raw materials prices, i.e. H 2 and captured CO 2 , do not allow such a project to be financially viable. In order to make the CCU plant financially attractive, the price of MeOH should increase in a factor of almost 2, or H 2 costs should decrease almost 2.5 times, or CO 2 should have a value of around 222 €/t, under the assumptions of this work. The MeOH CCU-plant studied can utilise about 21.5% of the CO 2 emissions of a pulverised coal (PC) power plant that produces 550 MW net of electricity. The net CO 2 emissions savings represent 8% of the emissions of the PC plant (mainly due to the avoidance of consuming fossil fuels as in the conventional MeOH synthesis process). The results demonstrate that there is a net but small potential for CO 2 emissions reduction; assuming that such CCU plants are constructed in http://dx.Europe to meet the MeOH demand growth and the quantities that are currently imported, the net CO 2 emissions reduction could be of 2.71 MtCO 2 /yr.

RETRACTED: Techno-Economic Comparison of Onshore and Offshore Underground Coal Gasification End-Product Competitiveness

“…Usually, methanol is produced by means of the Fischer-Tropsch process, where CO and 2H 2 react to CH 3 OH [16]. However, in the present study we follow methanol production by direct hydrogenation of CO 2 with H 2 , since CO contained in the UCG synthesis gas is considered to be consumed for internal power supply.…”

“…Deducting a waste CO 2 mass flow of 0.58 kg/s purged during the methanol synthesis process as well as inseparable CO 2 components remaining in the flue gas after Selexol capture (1.3 kg CO 2 /s), 92% of CO 2 produced throughout the entire UCG-MeOH production chain (23.7 kg CO 2 /s) is utilised. Consequently, carbon capture and its subsequent utilisation represents a new economy for CO 2 , since captured CO 2 has not to be handeled as waste product but can be used as raw material for other processes [16]. In the underlying study, costs for CO 2 capture and utilisation (CCU) that arise in line with methanol synthesis are not charged separately.…”

“…Gross generation amounts up to 285 MW, ensuring energy supply for compressors as well as the separation of air and CO 2 . Following the model setup presented by Perez et al [16], methanol production amounts up to 426 kt per year. The amount of produced ammonia was determined to 310 kt per year, representing an average Polish ammonia plant size [17].…”

“…Hereby, existing gasoline distribution and storage infrastructure like pipelines, road tankers and filling stations would require little modification to operate with methanol. Besides, methanol can function as storage for hydrogen or as a feedstock to synthesise olefins [16,[48][49][50].…”

“…Thermodynamic process simulations to analyse mass and energy flows are implemented using the DWSIM software tool [21], whereby applied boundary conditions and subsequent model validation closely follow the reference process [16,51]. In summary, methanol synthesis consists of the following process steps: after CO 2 pressure is increased from 1 bar up to 23.2 bar, H 2 (30 bar, 25 • C) and CO 2 (23.2 bar, 28 • C) feeds are mixed, compressed to 76.4 bar and heated in a heat exchanger to 210 • C before the methanol synthesis reactor inlet.…”