Final Sinks of Carbon Capture, Utilization and Storage (CCUS)

Dear Colleagues,

Carbon Capture, Utilization, and Storage (CCUS) is the most recent term (which began with CCS) used to refer to global efforts to curb the increasing concentration of carbon dioxide (CO₂) in the Earth's atmosphere. In less than five years, as of July 2019, the 5-year moving average recorded at the Mauna Loa Observatory, Hawaii, has risen from just under 400 ppm to over 411 ppm.

CCUS aims to reduce anthropogenic emissions of CO₂, typically by removing it from point sources, and in some cases even directly removing CO₂ from the atmosphere. Capture on its own does not suffice, so utilization or storage of CO₂ is necessary. Over the last two decades, many processes that convert CO₂ back into fuels, or into plastics, char, etc. have been developed and reported in scientific literature, with some of these recently reaching large-scale implementation. Likewise, many approaches to storing CO₂, in geological formations, such as carbonated minerals, in building materials, etc., are presently known and used.

The principles of sustainability, among its definitions, require that environmentally-friendly processes deliver long-term performance and security. This can be related to CCUS in terms of the idea of Final Sinks. We shall define a Final Sink as a sustainable Carbon Sink. This Topic seeks contributions from CCUS researchers and policy makers that can help to define and assess the Final Sinks of CCUS technologies. The following are suggested questions that we invite authors to address:

(a) What is/are the Final Sink(s) of CO₂, at relevant decade-to-century timescales, for your CCUS technology?

(b) Does your CCUS approach lead to an intermediate/temporary Sink, rather than a Final Sink? How can we ensure that CO₂ eventually ends up in a Final Sink, or for how long and what amount can it remain in an intermediate/temporary Sink?

(c) What can we learn about natural Carbon Sinks to design our CCUS technologies?

(d) Is the concept of a Final Sink compatible with the concept of a Circular Economy?

(e) What are the challenges of managing, monitoring and validating Final Sinks?

The editors encourage submissions of varied styles: original research articles, review papers, concept papers, short communications, technical notes, commentaries, and opinions.

Prof. Dr. Rafael Santos
Prof. Dr. Muhammad Salman
Prof. Dr. Lidija Siller
Topic Editors