Process Advantages of Direct CO2 to Methanol Synthesis

Abstract

Developing a laboratory scale or pilot scale chemical process into industrial scale is not trivial. The direct conversion of CO2 to methanol, and concomitant production of hydrogen from water electrolysis on large scale, are no exception. However, when successful, there are certain benefits to this process over the conventional process for producing methanol, both economic and environmental. In this article, we highlight some aspects that are unique to the process of converting pure CO2 to methanol. Starting from pure CO2 and a separate pure source of H2, rather than a mixture of CO, CO2, and H2 as is the case with syngas, simplifies the chemistry, and therefore also changes the reaction and purification processes from conventional methanol producing industrial plants. At the core of the advantages is that the reaction impurities are essentially limited to only water and dissolved CO2 in the crude methanol. In this paper we focus on several aspects of the process that direct conversion of CO2 to methanol enjoys over existing methods from conventional syngas. In particular, we discuss processes for removing CO2 from a methanol synthesis intermediate product stream by way of a stripper unit in an overhead stream of a distillation column, as well as aspects of a split tower design for the distillation column with an integrated vapo-condenser and optionally also featuring mechanical vapor re-compression. Lastly, we highlight some differences in reactor design for the present system over those used in conventional plants.

Exploitation of the far-offshore wind energy resource by fleets of energy ships. Part A. Energy ship design and performance

“…The direct process is currently used in the George Olah power-to-methanol plant, which can produce 4,000 tonne per annum (Marlin et al, 2018). The process was modeled in (Machado et al, 2014).…”

“…Results show that the power consumption is 0.93 kWh per kg of methanol, and CO 2 consumption is approximately 1.38 kg per kg of methanol. According to (Marlin et al, 2018) and (Anicic et al, 2014), the direct methanol synthesis process is more energy-efficient than the two-step process. Moreover, according to (Anicic et al, 2014), the production cost is comparable in the two processes.…”

“…Several demonstration projects have shown the technical feasibility of such approaches, e.g. Jupiter 1000 in France, BMWi in Germany, SOLETAIR in Finland (Vazquez et al, 2018), George Olah PtL plant in Iceland (Marlin et al, 2018), among others. However, the main challenge faced by PtX products from renewable energy-based plants is cost competitiveness.…”

Methanol Production via CO2 Hydrogenation: Sensitivity Analysis and Simulation—Based Optimization

“…Recently, the production of methanol from direct CO 2 hydrogenation is of interest (Samimi et al, 2017;Marlin et al, 2018). The process has potential to mitigate the CO 2 emission to the atmosphere.…”

“…The process has potential to mitigate the CO 2 emission to the atmosphere. The methanol production from direct CO 2 (using pure sources of CO 2 and H 2 ) has several advantages over the conventional process-it results in significantly less byproducts, and requires less energy in product purification (Marlin et al, 2018). However, the methanol production cost via direct CO 2 hydrogenation is 2-2.5 times higher than the cost of conventional process (Atsonics et al, 2015).…”