Lessons Learned from Carbon Capture Kickstart  | Part 4: Waste, secondary emissions, transport and storage, and execution challenges

Carbon Capture Kickstart Introduction 

In 2022, the Government of Alberta, through Emissions Reduction Alberta (ERA), launched the Carbon Capture Kickstart (CCK) program – a CAD $40 million investment supporting Front-End Engineering Design (FEED) studies for 11 large-scale carbon capture projects across the province. 
 
In our Lessons Learned from 11 Industrial CCS FEED Studies report, developed in partnership with ERA, we share key findings from the CCK program. To help you navigate the report, this blog series will walk through each of the key technical and operational insights from the FEED studies.  

Part 4:  Waste, secondary emissions, transport and storage, and execution challenges 

In this blog, we highlight the lessons learned about solid and liquid waste, secondary emissions, CO₂ transport and storage, and execution. 

Solid & Liquid Waste 

Carbon capture and storage (CCS) facilities produce both solid and liquid waste that vary by type, volume and options for disposal/recycling. This part of the CCS process increases operating costs and impacts the technical, environmental and regulatory aspects involved in these projects.  
 
In an amine-based CCS plant, solid waste mainly consists of spent activated carbon, filters, and desiccants, which are components used to purify amine solutions and reduce moisture and contaminants in the treated flue gas. Solid waste can also accumulate during the thermal amine reclaiming process, which purifies the amine solution by removing degradation products based on their boiling points. Additionally, liquid waste can be made up of condensed water recovered during cooling and dehydration, spent amine solution, and liquid waste from the thermal reclaimer. For each of these wastes, management strategies include treatment, reuse or safe disposal. 
 
For capture technologies using solid sorbents and cryogenic processes, the primary source of solid waste is spent adsorbents and filters used for contaminant removal. Meanwhile, liquid waste from these processes includes condensed water recovered from cooling and dehydration. 
 
Understanding the sources and composition of waste is critical to develop an effective waste management strategy. Some facility waste streams may contain sensitive or hazardous materials that require careful management and confidentiality protections, such as requiring third-party waste management vendors to sign non-disclosure agreements (NDA). Additional administrative responsibilities, including the preparation of hazard information safety sheets and disposal certificates (for both environmental considerations and legal verification of NDA compliance), may also result in increased costs and potential delays. 

Key learnings include: 

• A wide range of liquid waste stream volumes were identified by the CCK participants, from 41-8,000 tonnes/year. Although preliminary, these results highlight that site-specific factors can strongly influence waste quantities.
• Management strategies exist for handling waste, however some effluents require careful environmental consideration for disposal. Treatment and reuse where possible, provide a pathway to reduce environmental impacts. 

For more detail go to Section 4.7. 

Secondary emissions 

CCS facilities are designed to remove large amounts of CO₂ from flue gas. Amine-based carbon capture provides the additional benefit of significantly reducing emissions of other flue gas impurities such as sulfur oxides (SOx), nitrogen oxides (NOx), and particulate matter.  
 
This is because amine-based capture plants typically require flue gas pretreatment to remove impurities to prevent amine degradation and interference with the capture process. The pretreatment of flue gas to remove these impurities is also crucial for minimizing the release of secondary emissions. Secondary emissions are other emissions that may form due to the chemical processes involved in carbon capture, and can include amines and their nitrosamines and nitramines, as well as compounds like aldehydes, amides, ketones, and ammonia. To learn about the present status of environmental and regulatory requirements for potential secondary emissions produced by amine-based CCS systems, click here. 

Key learnings: 

• Liquid amine-based CCS plants produce secondary emissions that must be characterized. Understanding the interactions between flue gas components, amine reactivity and operating conditions is useful for understanding secondary emission profiles. Well-designed pilot testing can help identify potential secondary emissions.
• All sectors identified amines and aldehydes as potential secondary emissions. Material production and the oil and gas sectors also named ammonia, nitrosamines, NOx, SOx, volatile organic compounds, carbon monoxide, and particulate matter as other possible emissions. The new secondary emissions formed due to the carbon capture process are:
  • Amines: May be emitted as aerosols
  • Aldehydes: Typically formed from the oxidative degradation of monoethanolamine and have been detected in the gas phase in the absorber
  • Ammonia: A by-product of many carbon capture solvents, requiring monitoring for operational and environmental purposes
  • Nitrosamines: Formed through direct emissions and amine emissions, which can lead to the formation of nitrosamines in the atmosphere by reactions with nitrogen dioxide  

For more detail go to Section 4.8. 

CO₂ Transportation & Storage 

Once CO₂ is captured from a facility, it needs to be safely and reliably transported for storage or utilization. At early planning stages, capture projects need to understand their options for transportation and storage, as each piece affects the design, economics and timing of a project. Transportation can be via rail, truck or pipeline – each with its own advantages and considerations.  
 
Read Getting to Final Investment Decisions Series Part 2: Know your CO₂ Storage and Transportation Options 
 
The FEED studies evaluated transportation distances up to 400 kilometres and consistently identified saline aquifers as the storage type.  

Key learnings: 

• Proponents evaluated geological storage only. This approach can accommodate higher CO₂ volumes compared to current utilization technologies, is readily available in Alberta, and eligible for Canada’s CCUS investment tax credit.
• CO₂ product specifications influence capture-facility design. Pipeline safety and storage requirements are critical factors that determine CO₂ product specifications. This is an emerging topic as many of the sequestration hub and pipeline projects that will ultimately define these specifications are still in the engineering phase. 

For more detail go to Section 4.9. 

Execution 

CCK participants identified several execution-related challenges when progressing their carbon capture and storage initiatives. These challenges exist because these large-scale projects require significant amounts of specialized, large equipment, which increases complexity in sourcing, transportation, and construction.  

Key learnings: 

• Lack of access to tidewater creates a geographic disadvantage. Alberta does not have access to tidewater for shipping. This could increase transportation costs for equipment and may limit equipment sizes.
• Supply chain constraints pose a significant risk. Large-scale projects happening in the same timeframe may amplify supply chain challenges. For example, CO₂ compressors can be difficult to source in certain size ranges.
• Proponents are adopting different execution strategies. Some companies are aiming to modularize by pre-fabricating equipment offsite for later assembly onsite, while others are combining both shop and field construction approaches. Rectangular structures are being considered where sections are fabricated offsite, shipped, and then assembled on site. 
• Post start-up operation and maintenance must be factored into design. Participants noted concerns about coordinating maintenance and turnaround activities between upstream processes and capture facilities post-startup. 

For more detail go to Section 4.10. 

These FEED study phases reveal that success lies in developing waste-handling pathways, gaining deeper insight into secondary emissions and planning for transportation and storage at early planning stages.  
 
Examining execution-related challenges raises important considerations for moving CCS projects along.  
 
Together, these insights position projects to make informed decisions, strengthening the path to final investment decision, and large-scale CCS development. 
 
Note: The lessons learned in this report are as of July 2024. While the studies were initially intended to be complete by end of 2024, the majority will now be completed by end of 2025. At the time of completion, all projects will publish final public reports summarizing FEED outcomes. Final metrics, including costs and emissions reductions, will be collected, analyzed, and disseminated.