Modelling full-scale implementation of CCUS at large wood chip fuelled CHP plant in Denmark
The Danish Skærbæk CHP feeds heat into one of Denmark’s largest district heating systems, serving the towns of Vejle, Kolding, Fredericia and Middelfart. Today, the Skærbæk CHP plant delivers about 50% of the heat demand of the towns. The remaining heat demand is covered mainly by surplus heat from the local refinery and heat from the waste incineration plant in Kolding. Incidental peak demand is provided by peak load boilers based on oil or natural gas. The Skærbæk plant today uses approximately 550 thousand tonnes of wood chips per year.
In this case study report the consequences of investment in Carbon Capture, Utilisation and Storage (CCUS) technology at the Skærbæk plant are analysed, based on three scenarios for a future 2035 situation:
- Business as usual (BAU). The setup is a continuation of the current operation. The Skærbæk Power Station has the option to produce heat and electricity, either in combined generation or a separate generation. The other heat production units in the district heating system are assumed to continue operation with the same capacity as today.
- This scenario set involved a CO2-capture system (CC-plant), aiming to capture and store CO2 deriving from the woodchip boiler for potential future storage (S). the report described two subversions of this scenario: one capturing of a fixed annual amount of CO2 (CCS fixed); the other considered optimization of the sales of CO2, based on an assumed CO2 market price (CCS Market).
- CCUS. The 3rd scenario included the option of CO2-utilisation (U0 on top of the CCS installation. All or part of the CO2 can be directed to an electricity-powered methanol production facility with hydrogen provided by a large electrolyser. The methanol production capacity is dsegined to match the CO2-production from the biomass boilers at full capacity for 4,500 full-load hours, resulting in an assumed fixed amount of methanol produced over the year. A variant in the scenario is to operate the biomass boilers for more full load hours to provide more heat and power, allowing the possibility to also capture CO2 for sales at an assumed market price.
The report conludes that the modelling showed that:
- In The Business as Usal Scenario the operating hours of the plant increase compared to current operation, leading to increased heat production and the plant becoming more competitive.
- In the Carbon Capture and Storage Scenariob the operating hours are further increased, with even more dssitrict heating generation, plartyl originating from the surplus heat of the Carbon Capture facility.
- In the CCUS-scenaro a significant shift is observed in the denymics of net electricity prpduction: from positive to negateve on overage over the year. District heating is fuerther increased compared to the other scenarios, enabling the plant to cover almiast all the district heating demand in the area it supplies.
- Hydrogen production is optimised for period when the electricity valuer is low, while dsitrict heating demand proves significant in winter months only.
More case studies on Biomass combustion and CO2-capture
- Full-scale Waste-to-Energy CCS in Norway. read more
- Overview of CCU Technology Types Assessment Study for 1.5 Math Biomass District Heating Plant in Ottawa, Ontario. read more
About the BECCUS Project
Task 32 (Biomass Combustion) has delivered this case study report as part of the strategic (inter task) Bio Energy Carbon Capture, Utilisation and Storage (BECCUS) project aiming at the cross-sector and cross-country learning of implementing BECCUS systems at existing or new biomass energy facilities.
Within IEA Bioenergy TCP the topic of Bioenergy Carbon Capture, Usage and Storage is investigated with the involvement of many working Groups (Tasks), in an integral project of strategic relevance. In the years 2019-2021 the ‘Deployment of BECCUS value chains’-project was executed to understand the opportunities for, and obstacles to, deployment of BECCUs in different sectors. The project focused on determining factors for successful deployment, such as technology readiness levels, business model validities and designs of policy and regulatory framework.
In the second phase, the ‘BECCUS 2’-project is more diverse in scope, with stronger emphasis on cross-sector and cross-country learning about the implementation of BECCUS projects , using different energy conversion processes. The project also explores the effects of integrating BECCUSS facilities and systems within the overall energy system and, last but not least assesses the important differences between utilisation of captured carbon and storage of capture carbon.
Read more about Inter-task project BECCUS.
