Background/Objectives

To limit warming to 2°C or lower, all climate models necessitate CO₂ capture from power plants and industrial facilities, as well as negative carbon cycles via direct air or natural capture systems. Achieving this objective demands integrating carbon capture, utilization, storage (CCUS), and the associated transportation infrastructure on a multi-gigaton scale. The current focus in CCUS logistics centers on optimizing source-sink matching and pipeline infrastructures. While prevailing models utilize conventional optimization techniques rooted in graph theory and integer programming, these methods exhibit limitations, assuming a centralized, perfectly informed, rational design. To address this, our work developed a strategic model employing an agent-based simulation approach.

Approach/Activities

The model operates on data inputs, accommodating CO₂ supply and demand points, and offers versatility in transportation modes including waterways, rail, or pipelines. The primary aim is to assess how the United States can mitigate potential transportation constraints during the evolution of CCUS to a gigaton-scale system. This model represents an initial iteration of a strategic assessment tool, capable of simulating and scrutinizing the progression of the CCUS and associated transportation system from its present state toward an annual sequestration capacity of at least 1 gigaton of CO₂. Moreover, it lays the groundwork for a nationwide exploration of CCUS, providing estimations of carbon capture, transportation, utilization, and sequestration metrics by location, region, and transportation method. The modeling framework is adaptable and scalable, designed to emulate the intricacies and scale of the comprehensive CCUS system at an appropriate granularity. It incorporates the capacity to facilitate CO₂ movements via waterways, rail, or pipelines as deemed suitable, factoring in system evolution, distances, locations, and quantities. Additionally, the model can incorporate potential sites for future capture facilities, such as direct air capture or CO₂ utilization facilities, integrating considerations of facility expenses, transportation logistics, and sequestration alternatives.

Results/Lessons Learned

While a gigaton-scale CCUS system will eventually heavily depend on pipelines for transportation, the initial availability and expenses of pipelines may present obstacles for certain sources. Other viable modes like waterway, rail and potentially truck transport could offer cost-effective alternatives, especially for smaller initial capacities. Offshore sequestration via tanker ships could accommodate large volumes. This modeling initiative aims to showcase the potential roles of these alternative modes in assisting early adopters and facilitating the transition toward a nationwide pipeline infrastructure. The model's primary objective is to optimize CO₂ capture. Noteworthy features of the model include the ability to distribute revenue among supply agents (such as sources/capture sites) and demand agents (such as storage sites). Model outcomes encompass captured and sequestered CO₂ volumes, available but uncaptured CO₂, total revenue for supply and demand agents, and overall revenue.