Industrial Carbon Capture from a Cement Facility Using the Cryocap^TM FG Process

The US Department of Energy (DOE), through its Office of Fossil Energy and Carbon Management (FECM) has funded several Front-End Engineering and Design (FEED) studies for retrofitting existing industries with carbon capture technology. These comprehensive studies are publicly available on the US DOE Office of Scientific and Technical Information (OSTI) website as part of the knowledge sharing requirements associated with the funding. 

This study is our effort to help stakeholders quickly understand the key findings in lengthy reports highlighting methodologies, and unique design aspects that could shape future carbon capture plant designs.  Our objective is to highlight the most relevant sections of each study. 

Overview

This FEED study examines adding a carbon capture facility to an existing cement plant. This was conducted by the University of Illinois, in collaboration with Holcim US Cement, Air Liquide Engineering and Construction, Visage Energy Clean Energy Consulting and Kiewit Corporation. The host facility for this study is the Holcim Cement plant located in Ste. Genevieve County, Missouri, USA. The cement plant uses coal and petroleum coke as the primary fuels for energy supply. This study focused on capturing 95% of the CO₂ from the combined emissions coming from the main kiln stack and coal mill stack using Air Liquide’s cryogenic carbon capture technology known as Cryocap^TM Flue Gas (FG).

FEED study link: Industrial Carbon Capture from a Cement Facility Using the Cryocap™ FG Process   

Total CO2 Captured: 3.9 MM tonnes/yr 

Total As-Spent CAPEX ($MM USD in 2023): $1,450-$1,890 (the cost estimate provided is dependent on several factors such as project contingency levels, engineering, procurement and construction fee, capital expenditure premium for inclusion of a zero-liquid discharge system, etc.)

Objective

This summary highlights the unique design and planning aspects from this FEED study which include:

• Use of Air Liquide’s Cryocap^TM FG Process
• Selection of two trains for carbon capture and compression
• Design of a zero-liquid discharge system to minimize water consumption and liquid waste streams
• Feasibility of modularization and transport logistics
• Findings from techno-economic analysis
• Summary of life cycle analysis

What is it:

Cryocap^TM FG is a cryogenic carbon capture process with a Technology Readiness Level (TRL) of 6+, meaning it has been successfully demonstrated in a simulated environment (to learn more about TRL, click here). This capture system utilizes a pressure swing adsorption (PSA) unit to increase the concentration of the CO₂ in the flue gas stream, making it easier to separate the CO₂ when it enters the cryogenic system. In the cryogenic system, the CO₂ is separated from the flue gases and purified using a low-temperature distillation process. This process has been demonstrated in a variety of industrial applications, including cement production, steam methane reforming, and fluid catalytic cracking. 

Models have been used since 2006 to simulate and design several Air Liquide pilot and industrial-scale CO₂ capture and liquefaction plants, including the Port-Jérôme Cryocap^TM H2 plant in France, which has been in operation since 2015. In fact, a strong correlation was observed when comparing outputs from this FEED study to the operational data from these pilot and commercial plants.

In this study:

Based on the flue gas composition from the cement plant, Cryocap^TM FG was selected as the most suitable cryogenic technology within the Cryocap^TM portfolio. Air Liquide’s proprietary software, along with modeling equations and parameters, was used to simulate the full-scale performance of the technology. Historical data from the cement plant’s most common operating mode was used to optimize the Cryocap^TM FG system for CO₂ capture. 

Compared to traditional amine-based systems, Cryocap^TM FG offers several advantages such as lower chemical consumption, no degradation products, and potentially lower energy penalties. The table below summarizes additional key features of the technology.

Additional information:

This study highlights that carbon capture and storage (CCS) is vital for decarbonizing the cement industry. Unlike other industries, where the substitution of carbon-based feedstock for renewable energy may be enough to offset CO₂ emissions, this is not the case for cement production. This is because approximately 70% of CO₂ emissions are from the calcination of limestone (CaCO₃), which is a critical stage of producing cement.  During calcination, CaCO₃ is heated to high temperatures (i.e. above 1,400°C) in the kiln to form quicklime (i.e. calcium oxide), which releases CO₂ emissions. Limestone and other raw materials are used to produce clinker, a key component that allows cement to harden when mixed with water to form concrete. To learn more about CO₂ emissions sources, unique challenges, and decarbonization strategies for the cement industry and other industries, refer to CO₂ Emission Sources Across Major Industries.

What is it:

Single-train and multi-train systems are both viable options for capture projects. An evaluation of the costs and benefits of each system is often necessary to determine the best option for a project.

In this study:

Two identical Cryocap^TM process trains operating in parallel were selected in this study, with each train receiving 50% of the total incoming flue gas. Each train consists of pre-treatment, a flue gas compressor, cooling and dryers, PSA, tail gas compressor, distillation unit, and CO₂ product compressor.

Additional information:

This FEED report did not explain the rationale behind selecting a two-train configuration over a single train system; however this arrangement is expected to enhance the projects operational flexibility and reliability. By incorporating redundancy in the configuration, the capture system can remain in continuous operation even if one train is offline for any repairs, maintenance, or unexpected issues. This minimizes the risk of a full system shutdown and supports uninterrupted capture.  

What is it:

A zero liquid discharge (ZLD) system is a wastewater treatment design in which all water from industrial processes is recovered and reused, leaving behind only solid waste. The primary goals are to eliminate liquid waste discharge into the environment and minimize water consumption. The use of a ZLD system is driven by environmental regulations, water scarcity concerns, and the high costs associated with liquid waste disposal.

In this study:

A ZLD system was selected to convert wastewater streams into reusable water, eliminating the need for wastewater disposal and the associated permitting requirements. This design decision addressed concerns about scaling risks in the cooling water system and the need to minimize freshwater consumption. 

As part of this FEED study, various cooling strategies were assessed, beginning with the development of a site-wide water balance, and resulting in the selection of evaporative cooling. Following analysis of onsite well water and river water, it was determined that river water was acceptable for cooling water makeup. The integration of the ZLD system further supports Holcim’s sustainability goals of minimizing freshwater usage and reducing environmental impact by recycling process water and eliminating liquid effluent discharge.  

Since ZLD changes the overall water management approach, Holcim’s existing National Pollutant Discharge Elimination System permit will need to be updated to reflect these changes. 

 Additional information:

The dewatered waste from the ZLD system is identified as the project’s main waste stream, with another source of waste material identified as the spent filter media used in the PSA system. The methods for handling, storing, and disposing of the waste depends on the waste test results. Based on preliminary estimates, no hazardous waste permits are expected to be required for the capture plant’s operation. 

What is it:

Large scale projects typically require onsite construction of sizable equipment and facilities to be built from ground up, a process that is often complex and subject to various challenges. Modularization is a construction strategy, that designs prefabricated sections (modules) that are typically built off-site and then transported to the site location for assembly. Modular construction helps to reduce higher cost field labor requirements, improve schedule certainty, enhance safety, and increase quality control. This modular approach is commonly used for process skids, structural platforms and preassembled pipe racks. 

In this study:

This FEED study determined that the selected site was well suited for offsite modularization as well as the use of roll-on/roll-off (RORO) heavy haul transportation by ship or barge. RORO transportation systems allow equipment to be loaded and unloaded without cranes. This approach minimizes lifting, thereby reducing the risk of damaging equipment during transport and construction. 

For transport and delivery efficiency, the site selected for the capture plant has direct access to both highways and barge transport via the Mississippi river. Although, some sections of the access roads connecting the site to the barge port would need to be widened to accommodate oversized loads during construction.  

Additional information:

Considerations for modularization include complex configurations and site challenges. Modular construction is especially advantageous in regions where skilled labour availability is limited or where site congestion and weather risks could delay construction. To mitigate risks associated with the design and manufacturing of large modules, this modularization strategy would be defined at the beginning of FEED when considering constructability, maximum shipping windows and manufacturer’s capabilities.  

Transport logistics play a pivotal role in construction planning as the site’s access constraints, such as highways, barge availability and clearance restrictions will impact the delivery of this strategy. RORO transportation methods are especially useful, allowing heavy equipment and prefabricated modules to be loaded and unloaded without cranes. These logistics directly influence a project’s cost, schedule, and feasibility.

What is it:

A techno-economic analysis (TEA) combines engineering principles with economic modelling to estimate a project’s costs and potential revenue. Its primary goal is to assess the commercial viability of a technology while also identifying key factors that can impact a project’s profitability, enabling more informed decision-making from the start. 

CCS projects typically benchmark performance and cost using both project-specific data and standardized reference cases, such as those developed by the National Energy Technology Laboratory (NETL). NETL cases provide a consistent framework for comparing technologies and projects, and they are widely used in other industry and government-funded studies. 

In addition, TEA considers how external financial mechanisms can affect a project’s feasibility. Public policies such as grants, low-interest loans, loan guarantees, increased carbon capture tax credits, and inflation-indexed credit values are all factors that could significantly influence project economics.

In this study:

A TEA was conducted as part of this FEED study. Key findings are provided below.

Technology Comparison:

• Unlike an amine-based system that uses natural gas for solvent regeneration, Cryocap^TM FG does not burn hydrocarbons. This results in a lower cost of CO₂ avoided for Cryocap^TM FG.

Major Cost Drivers: 

• Cost of Capture: Influenced by annualized capital expenditure (CAPEX) and electricity consumption from the cryogenic process.
• Total Plant Cost: Driven primarily by Outside Battery Limit (OSBL) systems, especially the river water intake structure and the ZLD system.

Sensitivity Analysis:

• Most influential parameters on cost of capture:
  • Amount of CO₂ captured
  • Total plant cost
  • After-tax weighted average cost of capital
• OSBL costs were found to be more sensitive than inside battery limit costs in affecting cost of capture

Opportunities for Cost Reduction:

• CAPEX related to OSBL systems
• Engineering and construction management
• Home office fees
• Process and project contingencies

Additional information:

Beyond technical and economic feasibility, the project also evaluated environmental and regional impacts. The deployment of carbon capture technology is expected to benefit surrounding communities through job creation, reduced emissions, and provide long-term economic revitalization, particularly in disadvantaged areas.

What is it:

Life Cycle Analysis (LCA) evaluates the environmental impact of a product or process across its entire lifecycle, from raw material extraction to final use and disposal. While carbon capture technologies are used to reduce CO₂ emissions, they still require a substantial amount of energy to operate. LCA is essential to determine the net reduction of greenhouse gas emissions, specifically CO₂, by accounting for the technology’s energy use across the entire value chain. This approach helps determine the overall effectiveness of the selected technology, while also highlighting any associated trade-offs. 

In this study:

The LCA evaluation included the operation of the carbon capture plant, transportation, and storage of captured CO₂, providing a complete inventory of the project’s environmental impacts. Using this data, the environmental impact of cement production with and without CCS was estimated using the TRACI 2.1 (NETL) method, as referenced here: Carbon Dioxide Utilization Life Cycle Analysis Guidance for the U.S. DOE Office of Fossil Energy and Carbon Management, NETL, January 2022.

As part of the capture system design, a flue gas pre-treatment process is included in the design to remove impurities such as sulfur oxides (SO_X) and nitrogen oxides (NO_X). This step not only protects the facility’s capture process integrity, preventing interference from contaminants but also contributes to reducing the environmental impact of the overall system. By removing pollutants before capture, the process minimizes additional emissions and supports cleaner operations, all of which were reflected in the LCA results.

This technology has two key differences from traditional amine-based systems. It does not rely on significant fuel consumption, and it does not use chemical solvents that are prone to degradation. Instead, it is powered primarily by electricity. As a result, the calculated emissions from the capture plant are primarily influenced by the energy mix of the grid at the time of project implementation. The CO₂ capture and compression processes have high electricity needs. The host site’s strategy was to procure renewable electricity to power the carbon capture system. As a result, the LCA values were calculated based on a renewable energy mix, reflecting the site’s intent to minimize indirect emissions from electricity consumption. 

Compared to baseline cement production, the addition of a CCS plant resulted in either significant reductions or minimal effects across most environmental impact categories defined in the NETL guidance. These categories include global warming potential, acidification, eutrophication, smog formation, and others. The most notable trade-off identified was increased water consumption, primarily due to cooling tower makeup water required for CCS operations. To mitigate this, the project includes ZLD system which is designed to eliminate effluent streams and minimize overall water usage, helping to balance environmental impacts.  

Additional information:

To ensure the long-term success and accountability of the carbon capture system, projects typically include provisions for ongoing monitoring and verification of the captured and stored CO₂. This is a critical component not only for regulatory compliance, but also for maintaining transparency and public trust. Monitoring systems will track the quantity and quality of CO₂ captured, transported, and stored, helping to validate environmental performance over time. These efforts align with best practices in CCS deployment and support the broader goal of ensuring that the environmental benefits of the technology are sustained throughout the project lifecycle.