Feasibility study for a vendor-neutral baseline concept for CCS, and methodology for flue gas characterization of heterogeneous flue gas at Kvitebjørn Varme

Background
Kvitebjørn Varme aims to capture approximately 100,000 tonnes of CO₂ from its waste incineration plant in Tromsø and transport it for permanent storage. The conditions for CCS (Carbon Capture and Storage) at KVAS differ significantly from similar projects due to:
• Being a small-scale facility, located far from both other point sources and permanent CO₂ storage sites
• Having access to the sea and the possibility to establish its own CO₂ export terminal
• Being located in the Arctic, which presents several weather- and climate-related challenges
• Lacking access to steam

Therefore, a feasibility study for CCS at KVAS is needed, based on these site-specific conditions.

The flue gas at KVAS originates from waste incineration across three incineration lines. The quality and composition of the flue gas vary depending on the waste content and whether one or more incineration lines are out of operation. There is no established standard for characterizing heterogeneous flue gas from waste incineration for CO₂ capture purposes. Several of the particles relevant to CO₂ capture are also not measured in the mandatory monitoring system for waste incineration. How technology providers interpret the flue gas characteristics may also affect the dimensioning and design of the capture plant and the pre-treatment steps for the flue gas.

Goal
The goal of the study has been to establish a techno-economic base concept for CCS at Kvitebjørn Varme using CESAR1 amine technology, and to develop a methodology for flue gas characterization of heterogeneous flue gas from waste incineration.

The techno-economic study of a base concept for CCS at KVAS provides a solid foundation for:
• Technology and concept selection
• Assessing necessary safety measures and permits
• Evaluating the impact on the energy system, flue gas, and emissions to air and water
• CAPEX and OPEX estimates
• Providing a basis for comparison with alternative solutions, such as capture technologies and transport options

The aim of establishing a methodology for flue gas characterization of heterogeneous flue gas is to:
• Reduce the risk of incorrect sizing and design of the CO₂ capture plant
• Reduce interface risks between the incineration plant, capture plant, and transport/storage operators in terms of emissions, CO₂ purity, and capture volume

Activities
Deliverable 1: Flue Gas Analyses and Methodology for Characterizing Heterogeneous Flue Gas
The flue gas has undergone a standard half-hour average analysis, where the gas quality and data basis have been assessed against expectations from technology providers. The flue gas has also been studied at minute-level resolution to evaluate measurement quality, variation during normal operation, and during the most common operational disturbances. The results are described in a separate report.

Deliverable 2: Technology and Energy Concept + Integration
The technical process steps in the base concept have been assessed and simulated using Promax and Thermoflex to gain an overview of energy demand, energy recovery potential, cooling requirements, chemical usage, and waste products from the capture process. This enables estimation of CAPEX, OPEX, and space and height requirements. This deliverable has been coordinated with a separate energy study conducted in parallel. The energy study has evaluated how energy integration and recovery solutions interact with the district heating system. Based on this comprehensive assessment of energy efficiency, an energy concept has been selected. The deliverable provides the basis for comparing different technical concepts and raises awareness of the Balance of Plant (BoP) requirements for the project. The results are summarized in a separate report.

Deliverable 3: Techno-Economic Assessment of CO₂ Capture at KVAS
This deliverable compiles the entire base concept, from flue gas to transport to permanent storage, in order to estimate CAPEX, OPEX, and establish a physical layout of the entire concept, including port facilities for CO₂ export. Transport costs for direct shipment of CO₂ from KVAS to permanent storage have been estimated based on various sailing distances and ship sizes. The base concept is compared with an alternative concept that is more cost-effective in terms of CAPEX and OPEX due to optimized ship size, sailing distance, and simpler integration with the incineration plant. The deliverable includes analyses of CO₂ leakage risk and air emissions. HAZID and project risks have been mapped, and mitigation measures have been proposed. The results are summarized in a separate report.

Deliverable 4: Updated Design Basis
The study has further developed a Design Basis based on the most cost-effective concept in accordance with the current maturity of the project. This is a living document that will be updated with, among other things, the complete flue gas characterization based on the methodology from Deliverable 1, as well as emission limits to air and water, etc.

Results
Flue Gas Quality and Methodology for Flue Gas Characterization
A methodology for flue gas characterization and a measurement program have been developed to supplement CEMS and mandatory third-party measurements, enabling a more precise and comprehensive description of the flue gas composition and its variation. The methodology establishes criteria for filtering minute-resolution values that may misrepresent the flue gas composition during normal operation due to system auto-calibrations and desynchronization between component measurements and normalization parameters, especially following operational disturbances.
This filtering affects the 1st and 99th percentiles for most variables used in the design and sizing of the capture plant. The composition and dynamics of the flue gas during common operational disturbances have also been mapped. Based on this, a set of system signals has been identified that can be used to activate flue gas bypass. These signals ensure that bypass is only triggered when it is likely that the flue gas will be significantly disturbed for an extended period. This prevents frequent interruptions to the capture plant while protecting it from prolonged exposure to abnormal flue gas, which could lead to corrosion and solvent degradation.

It should not be necessary to introduce continuous measurements of additional components beyond those already monitored via CEMS. Other parameters relevant to the design of the CO₂ capture plant can be measured by expanding the scope of mandatory third-party measurement campaigns to include more components. To better understand seasonal variation, these campaigns can be conducted more frequently than currently required. The measurement program specifies what should be measured, which methods to use, the measurement period and frequency, and the importance of each component in relation to CO₂ capture planning.

The most problematic aspect of the current flue gas is the high NOx level. The plant currently uses SNCR for NOx reduction, but further upstream reduction is recommended. This would improve solvent hygiene, result in cleaner CO₂, and make it easier to meet air quality standards. The capture process removes both CO₂ and water from the flue gas and lowers its temperature before release. Without NOx reduction to compensate for these changes, meeting NO₂ air quality limits may be challenging—mainly due to high background NO₂ concentrations from traffic and the area’s steep topography, which limits dispersion to the west.

Technology and Energy Concept
The capture plant initially requires approximately 120 GWh of heat and electricity, and around 170 GWh of cooling (amine-based). Through effective energy integration with the waste incineration and district heating systems, the heat and electricity demand can be reduced by 90 GWh, with a corresponding reduction in cooling needs.
OPEX for the capture plant has been estimated based on energy demand, chemical consumption, waste handling, and maintenance/staffing.

Techno-Economic Feasibility Study
The greatest uncertainty in the project relates to OPEX for CO₂ transport and storage. Results show that the key to minimizing transport costs is to use optimized ships that collect CO₂ frequently. This reduces the need for intermediate storage capacity, which is a major cost driver.

The base concept can reduce costs by approximately 30% through optimized layout and ship size.
The location introduces weather-related risk elements that must be addressed. Low temperatures require heat tracing and good insulation of equipment and piping, and care must be taken to avoid ice formation on surrounding surfaces. Heavy snowfall over short periods may hinder evacuation, so extensive use of heated surfaces is recommended. Collision protection for CO₂ ships and equipment exposed to vehicle traffic is also advised, in addition to general safety measures applicable to all CCS projects.

Further Work
The feasibility study has established a base concept for CCS at KVAS and identified measures to reduce risk and cost in the project. KVAS has received funding approval from Climit for a follow-up study that will build on the results of the base concept.

The next steps based on this study include:
• Implementation of the flue gas measurement program in the next phase. Once the data foundation is in place, a flue gas characterization will be carried out according to the methodology from this study. The characterization will be incorporated into the Design Basis.
• Assessment of the best method to reduce NOx upstream of the capture plant. The results will be included in the Design Basis. This will reduce risks related to CO₂ purity, emissions, maintenance, chemical usage, and equipment wear.
• Further development of the base concept to reduce CAPEX and OPEX through cost-saving measures.
• Further assessment of BoP (Balance of Plant) elements, emission limits, and safety-related mitigation measures identified in this project. These will be included in the Design Basis with clearly defined battery limits.
• Assessment of the Carbon Dioxide Removal (CDR) potential through LCA (Life Cycle Assessment) of the further developed base concept.
• Pre-FEED (Front-End Engineering Design) with a technology provider.

Publications
The results will not be published, but we are open to sharing them upon request.