Overview
The objective of the study was to explore the status and potential of the modular construction of CO2 capture plant, targeted at accelerating the deployment of carbon capture, utilisation and storage (CCUS) in the power and industry sectors.
For this study, modular construction, prefabrication or off-site construction was defined as “a process in which a component is prefabricated off-site and is then transported as a completed component to the required location for integration with the plant”.
Compared to on-site or ‘stick-built’ construction, there are several reported advantages of construction in a more controlled environment, e.g., it can be less prone to delays, can reduce labour costs, can provide uniform quality and optimised performance, can eliminate interference from inclement weather and, with access to superior tools and methods, can reduce overall build time.
A downside might be that modular carbon capture units are often, by nature, mass manufactured and regular in design and may require a degree of adaptation for a particular application, whereas on-site construction can present a more ‘customised’ design tailored precisely to the situation required.
Key Findings
- A wide range of companies possess commercial and near-commercial experience in modular carbon capture plant design and supply, including major engineering firms, modular plant suppliers and process technology providers.
- There is a diverse portfolio of proven modular designs for capturing up to 100,000 t CO2/a across multiple industrial sources. Twelve leading suppliers were identified as ready to deliver modular capture projects using proven technologies and established execution capabilities.
Technological Progress and Innovation
- Technical innovation is reducing capture and transport costs, improving efficiency, and increasing technology readiness levels (TRLs).
- Collaboration between process licensors, engineering companies and plant suppliers is optimising cost-effective and standardised modular capture designs.
- New capture technologies that use fewer equipment items and alternative energy sources are particularly suited to smaller-scale[1], modular implementation.
Application Focus and Process Suitability
- While traditional CCUS efforts have focused on large-scale flue gas emissions, capture from high-CO₂-content streams (e.g. cement, steel blast furnaces, and blue hydrogen) could offer lower specific costs and is now a major focus for modular deployment.
- Modular suppliers are adapting and refining proven process technologies to meet the specific requirements of these concentrated CO₂ sources.
Process Efficiency and Energy Integration
- Capture technologies that produce CO₂ at elevated pressure can reduce compression costs. Advances in solvent-based, physical solvent, and cryogenic systems are enabling such efficiencies in modular configurations.
- Electrifying the capture plant can promote technologies other than “conventional” solvent-based. These innovations are particularly viable at small scales and are helping modular systems overcome traditional economies-of-scale constraints.
Standardisation and Design Flexibility
- Standardised modular designs shorten engineering, procurement, and fabrication timelines without compromising quality or safety.
- Leading suppliers already have standardised plant configurations, supply capability, and experience in modular delivery.
- While most suppliers can tailor designs to client requirements, such modifications can increase cost and delivery time. Early clarity on specifications and deviations is therefore essential during project definition.
Project Configuration and Execution
- Suppliers standardise module sizes to suit road and rail transport. For larger capture capacities, multiple processing “trains” are operated in parallel, or in some cases, larger modules enable a single-train configuration.
- Project execution strategies should determine the optimal number and configuration of capture trains in coordination with the selected supplier.
Cost Estimation and Project Definition
- Accurate cost estimation requires a clearly defined scope covering supplier scope, balance-of-plant, utilities, installation and construction.
- Indicative module prices are useful for preliminary screening but are insufficient for final investment decision (FID) without detailed engineering and project definition since gas composition, required capture, utilities availability and cost, and the ease or not of installation all have an impact on cost.
Deployment Timescales and Project Delivery
- Smaller-scale modular projects are easier to define, cost and deliver, allowing for faster project approvals and reliable quotations.
- Small larger-scale projects may benefit from modularisation, but it may not follow that duplication of smaller-scale modules is a better way to proceed for larger-scale projects. Some larger-scale projects can benefit from a degree of modularisation, such as dressed columns.
- With proper definition and permitting, beneficial operation can be achieved within approximately three years from project initiation.
Strategic Benefits of Modularisation
- As every capture project will differ, decisions on modularisation are best made on a case-by-case basis.
- Modularisation should be optimised across all capture project types and sizes. Multiple-train configurations, pre-assembled columns and vessels, and modular pipe-racks can significantly shorten construction time and reduce project risk.
- Modular supply simplifies site activities, enhances safety, reduces waste and offers clear environmental benefits.
- Except where labour costs are exceptionally low and site productivity is high, modular construction should be considered the default approach for carbon capture plant deployment, especially for smaller industrial sites and distributed power generation (large-scale projects can also benefit from a degree of modularisation).
[1] For this study, “small-to-medium scale” was broadly considered as being carbon emissions of the order of 100,000 tonnes per annum or less. Carbon capture solutions at capacities as low as 10,000 tonnes per annum were considered.
