Towards Sustainable Oxalic Acid from CO₂ and Biomass

Abstract

To quickly and drastically reduce CO2 emissions and meet our ambitions of a circular future, we need to develop carbon capture and storage (CCS) and carbon capture and utilization (CCU) to deal with the CO2 that we produce. While we have many alternatives to replace fossil feedstocks for energy generation, for materials such as plastics we need carbon. The ultimate circular carbon feedstock would be CO2. A promising route is the electrochemical reduction of CO2 to formic acid derivatives that can subsequently be converted into oxalic acid. Oxalic acid is a potential new platform chemical for material production as useful monomers such as glycolic acid can be derived from it. This work is part of the European Horizon 2020 project “Ocean” in which all these steps are developed. This Review aims to highlight new developments in oxalic acid production processes with a focus on CO2‐based routes. All available processes are critically assessed and compared on criteria including overall process efficiency and triple bottom line sustainability.

Sustainable polyesters via direct functionalization of lignocellulosic sugars

“…In this case, 84% of the calculated GWP of DMGX was associated with the production of glyoxylic acid. If glyoxylic acid was instead sourced from CO2, which may soon be feasible as its precursor, oxalic acid, is already being produced from captured CO2 at pilot scale (25), DMGX production was estimated to have 80% lower associated emissions as compared to terephthalic acid (GWP of 0.4 kg CO2 equivalent per kg DMGX). This could be further reduced to 5 % of terephthalic acid's GWP if agricultural residues were used for heat production as opposed to natural gas, which is typical in a biorefinery.…”

“…Cellulose and hemicellulose are more abundant, can be grown on marginal lands, and their simple sugars are projected to be far less expensive and more sustainable as compared to their edible counterparts (7,8). However, their industrial use has been limited by the high cost of their saccharification and subsequent fermentation, and the lack of mature integrated lignocellulosic conversion processes that can valorize the non-polysaccharide fractions of the plant, which notably include lignin (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) wt/wt% of lignocellulosic biomass). Promising bioplastics from non-carbohydrate plant fractions such as plant oils (9) or lignin (10) are emerging, but they are inherently limited by lower natural abundancesor, in the case of lignin, the lack of mature upgrading technologies which makes achieving cost-competitiveness even more challenging than with sugars.…”

A State‐of‐the‐Art Update on Integrated CO2 Capture and Electrochemical Conversion Systems

“…Carbon Capture and Utilization (CCU) technologies have been postulated as one of the most promising strategies to relieve the increase in the concentration of CO 2 present in the atmosphere and introduce sustainable carbon cycles by using CO 2 directly from the air or flue gasses as a substrate in the chemical industry [1–6] . In this way, the CO 2 , which is mostly released from energy production or industrial processes, can be converted back to fuels (like syngas or alcohols) [7,8] or chemical synthesis precursors (such as formic acid, carbon monoxide or oxalic acid) [9–12] . However, capturing, storing and releasing the CO 2 to the chemical reactor is expensive and logistically cumbersome [13,14] .…”

“…[1][2][3][4][5][6] In this way, the CO 2 , which is mostly released from energy production or industrial processes, can be converted back to fuels (like syngas or alcohols) [7,8] or chemical synthesis precursors (such as formic acid, carbon monoxide or oxalic acid). [9][10][11][12] However, capturing, storing and releasing the CO 2 to the chemical reactor is expensive and logistically cumbersome. [13,14] Therefore, integrating the capture and the conversion steps is crucial to decrease the costs and make the process efficient, and thus industrially attractive.…”

Stepping Stones in CO2 Utilization: Optimizing the Formate to Oxalate Coupling Reaction Using Response Surface Modeling

“… 9 , 10 CO 2 -based chemicals such as oxalic acid will become new platform chemicals for a wide range of downstream products such as monoethylene glycol (MEG), glycolic acid, and glyoxylic acid that all can be obtained from oxalic acid in various sustainable routes. 26 , 30 …”