To Integrate or Not to Integrate—Techno-Economic and Life Cycle Assessment of CO₂ Capture and Conversion to Methyl Formate Using Methanol

Abstract

Utilizing CO 2 to produce value-added chemicals can save environmental and economic impacts. However, these savings are reduced by the cost of CO 2 supply when CO 2 has to be captured from dilute sources. To reduce the cost of CO 2 supply, the combination of CO 2 capture and utilization has been suggested in a single integrated CO 2 capture and utilization (ICCU) process. Although integration is intuitively appealing, a rigorous assessment of the savings by integration is missing. In this work, we evaluate if integration indeed increases savings, by comparing a utilization process without integration to a novel ICCU process. In the novel ICCU process, methanol absorbs CO 2 from raw natural gas, before the mixture of CO 2 and methanol is hydrogenated to methyl formate. We show that the novel ICCU process saves up to 46% of the electricity demand, which results in savings of up to 8 and 7% in the cost and the greenhouse gas emissions of the utilities, respectively. However, these savings are only enabled when raw natural gas with 30 mol % CO 2 is employed; with lower CO 2 concentrations, integration can even increase the cost and emissions of CCU. From the obtained results, we derive an indicator to assess the savings potential of ICCU processes. Finally, life cycle assessment reveals that CO 2 -based methyl formate has the potential to reduce both the global warming impact and the depletion of fossil resources compared to methyl formate produced from fossil sources.

Life Cycle Assessment for the Design of Chemical Processes, Products, and Supply Chains

“…Still, LCA for process selection has been applied for important problems such as the selection of feedstocks (74), catalysts (75), products (76,77), and process routes (78,79). Major interest in comparing process alternatives arises from the assessment of novel process designs to conventional processes, e.g., recently in the area of bio-based production of chemicals (80) or carbon capture and utilization (27).…”

Methylformate from CO2: an integrated process combining catalytic hydrogenation and reactive distillation

“…A very recent life cycle assessment indicates that the generation of MF from CO 2 would reduce the global warming impact by 16% as compared with the fossil-based production even when using raw materials and energy from fossil sources. 34 Depending on the concentration of CO 2 in the feed, it is advantageous to integrate the carbon capture reference process Rectisol® (CO 2 adsorption in cold methanol) 35 with the carbon utilization step (up to 46% saving of the electricity demand) realizing an Integrated Carbon Capture und Utilization process (ICCU). Mandatory conditions to achieve the integration is on the one side the use of the same solvent in both processes, i.e.…”

“…methanol, and on the other side to develop an efficient immobilized catalyst system. 34 In the present paper, we address and fulfill these preconditions for the realization of an ICCU process to produce methylformate (MF) from CO 2 and H 2 . We demonstrate that combining catalytic hydrogenation of CO 2 with reactive distillation provides a strategy to effectively balance these seemingly contradicting requirements in a fully integrated two-step process for production of MF from CO 2 , H 2 and MeOH.…”

Economics of CO2 Utilization: A Critical Analysis

“…Many reviews and papers have discussed the costs and techno-economic feasibility of CO 2 utilization routes, a selection (not exhaustive) of which is the following: Centi and Perathoner (2010), Quadrelli et al (2011), Aresta et al (2013), Centi et al (2013), Barbato et al (2014), Centi and Perathoner (2014), Perathoner and Centi (2014), Laumb et al (2013), Ampelli et al (2015), Dimitriou et al (2015), Pérez-Fortes et al (2016), Naims (2016), Navarrete et al (2017), Ordomsky et al (2017), Senftle and Carter, (2017), Zheng et al (2017), Iaquaniello et al (2018), Koytsoumpa et al (2018), González-Garay et al (2019a), Hepburn et al (2019), Jens et al (2019), , Grim et al (2020), Meunier et al (2020), Mustafa et al (2020), , and Zimmermann et al (2020). Although the conclusions are often contradictory, it is commonly suggested that there still exist large barriers for the implementation and deployment of CCU.…”