The carbon footprint of the carbon feedstock CO₂

Abstract

This paper reviews methodological approaches for determining the carbon footprint of captured CO2 as carbon feedstock, and shows why some approaches lead to suboptimal choices of CO2 sources and that increased consistency in life cycle assessment (LCA) studies on CCU is needed.

Sustainability footprints of a renewable carbon transition for the petrochemical sector within planetary boundaries

“…Following recommendations for LCA studies on CCU, the CO 2 captured at power plants is treated as a co-product, i.e., a technical flow of CO 2 feedstock, and its embodied impacts are quantified via economic allocation. 81 Similarly, the economic allocation was applied to allocate the inputs (raw materials and utility consumption) and outputs (emissions and wastes) of the MTO and MTA processes among their co-products, as recommended in the literature 82,83 and shown in Equation 3:…”

Life Cycle Assessment of Direct Air Carbon Capture and Storage with Low-Carbon Energy Sources

“…We identify no multi-functionality of our DACCS system, since the main purpose is to remove CO 2 from the atmosphere in a permanent way. Hence, allocation or system expansion is not required 27 .…”

“…This is, however, not always the case and the presentation of the GHG removal performance of DAC(CS) as one single number can be misleading (e.g. by Müller et al 27…”

Spiers Memorial Lecture: CO2 utilization: why, why now, and how?

“…7,9,146,147 Depending on the source of the CO 2 , the associated carbon footprint of capture and post-processing will vary substantially. 148 Continued efforts will develop enhanced sorbents and processes that will capture more CO 2 per specic amount of sorbent, that are more stable, and that require less energy for desorption. [149][150][151][152][153][154][155] The present amount of captured CO 2 is on the order of 77 million tons a year, and only a small fraction of that is used in CDU processes.…”