Insights and Commentaries
Partial CO2 capture and the CO2stCap project
15th October 2015
The CO2stCap project is a new four–year research project aiming to reduce the cost of industrial carbon dioxide (CO2) capture processes. In this Insight, Ragnhild Skagestad and Hans Aksel Haugen of Tel–Tek discuss the wider research project and one of its primary themes - partial CO2 capture.
A rule of thumb in carbon capture and storage (CCS) has been that the capture rate should be at 85 per cent or more. Even though from a technical perspective it is relatively straight forward in many cases to achieve such high rates (for instance when applied to power generation), in other industries such high capture rates would imply excess cost. The reasons for the higher costs are often linked to the fact that in process industries, access to energy for CO2 capture is a limiting factor.
In the recently approved project titled Cutting Cost of CO2 Capture in Process Industry (CO2stCap for short), partial CO2 capture as a way to achieve significant cost reductions will be explored. As a result of the project, Tel–Tek’s much used cost estimation tool will be brought from an Excel platform to a database platform while also being updated and calibrated towards industry data.
The CO2stCap project
Recently, Tel–Tek and Telemark University College hosted the kick–off meeting for the CO2stCap project, a four year project with funding from the Norwegian CLIMIT–Demo programme via Gassnova, Energimyndigheten in Sweden (Swedish Energy Agency) and participating industry and research partners. Two PhD candidates are going to be financed through CO2stCap. Including in–kind contributions the total project budget is 25 million Norwegian Krone (NOK), or approximately 2.7 million Euros at current exchange rates.
The main focus of the study is on partial CO2 capture and techno–economic analyses and cost estimation. As the term implies, with partial CO2 capture the aim is not to capture as close to 100% of the CO2 as possible, but rather to find a technical–economic optimum of capture based on process and plant specifics.
The concept of partial CO2 capture has been advocated previously although with focus on power generation; see the work by MIT (2009) and the IEA Greenhouse Gas Programme (2009). The IEA report points to the fact that multiple capture units will be needed on large power plants, and defines the concept of partial CO2 capture as one of two options:
- Capturing a relatively low fraction of CO2 in each power generation unit
- Capturing a high (eg ≥85%) fraction of CO2 in one or more power generation units and not capturing CO2 at the other units
A third option, not mentioned by IEA Greenhouse Gas Programme, may be to utilise partial capture through a time varying capture rate to consider the spot price of energy, for example differences between night operation and day.
Reduced cost capture for process industries
The project will investigate where and how partial CO2 capture may be applied cost efficiently to emission intensive industry, focusing on cement, pulp and paper, steel and ferroalloys. The project will take into account the fact that individual plants may have several scattered CO2–sources of varying quality and also that the possibilities for heat supply differ between plants. Also, the possibility to capture from bio–energy will be looked into. In fact, for instance at Norcem’s Brevik plant, a substantial part of energy–derived CO2 emissions originate from biomass-based fuels.
The project will further investigate if targeting the most suitable CO2 sources at individual sites could drastically reduce the cost of CO2 capture. As indicated, to base capture on the amount of waste heat resources available at a plant, is one way of performing partial CO2 capture. In process industry, utilisation of waste heat energy may reduce the need for additional energy supply, or even eliminate the need completely.
Our working hypothesis is that cost reductions of at least 20% should be possible to achieve through implementing partial capture including associated technological optimisation. Even if waste heat amounts are limited on a given site, capture cost may be reduced. The overall aim is therefore to suggest a cost effective carbon capture strategy for future CCS systems considering utilisation of waste heat and intermittent power generation, a more efficient use of biomass resources, different capture technologies and optimisation, as well as changed market conditions.
An improved methodology
Cost estimations will be based on the tool developed by Nils H. Eldrup, but during the project this tool will be further improved. In CO2stCap, the tool will be used to identify and verify potentials for cost reduction when applying different options for implementation of partial CO2 capture. The tool will be transferred from an Excel based platform to a database platform. Importantly, the project will focus strongly on developing an updated, calibrated and validated tool for technical–economic analyses and cost estimation of CO2 capture technologies in different industries. This will be facilitated through the close cooperation between the research institutions and the partner industrial companies. Such development will introduce process data from industries that are both new with regard to the technical economic model (steel, pulp/paper) while also being large CO2 emitters on a European and global scale.
Tel–Tek is the lead project partner with Ragnhild Skagestad as project leader. Industry partners are:
- SSAB EMEA AB
- Elkem AS
- Norcem Brevik AS
- AGA Gas AB
- Global CCS Institute
- IEA Environmental Projects Ltd. (IEAEPL) represented by IEA Greenhouse Gas R&D Programme
Research partners are:
- Telemark University College
- Chalmers tekniska högskola AB in Gothenburg
- Swerea MEFOS in Umeå
- Innventia in Stockholm