1

Introduction

1.1 STUDY CONTEXT

To meet climate goals and limit the harmful effects of global warming, countries around the world are aiming to reach net-zero greenhouse gas (GHG) emissions across their economies by midcentury. Along this path toward net-zero emissions by 2050, the United States has set an intermediate goal of a 50–52 percent reduction in GHG emissions below 2005 levels by 2030 (DOS and EOP 2021), which aligns with the Paris Agreement target of limiting global warming to 1.5°C. Achieving net zero requires eliminating most emissions of carbon dioxide (CO₂) and other GHGs,¹ primarily via decarbonizing electricity generation, improving energy efficiency, and electrifying end uses (e.g., vehicles, buildings, industrial processes) where possible (DOS and EOP 2021; NASEM 2021). These actions, enabled by advances in low-carbon energy technologies and electrification, will significantly reduce the use of fossil fuels and resulting CO₂ emissions to the atmosphere. This report responds to a request from Congress to examine the role of carbon utilization in a net-zero emissions future.

While net GHG emissions to the atmosphere must end to achieve climate targets, carbon flows—particularly those related to embedded carbon in products—cannot be eliminated completely. As discussed in Chapter 2, global yearly materials flows are about 100 gigatonnes (Gt), including about 40 Gt of carbon-based materials, with about 15 Gt of that being fossil-derived carbon materials. Carbon-based products, including human-made chemicals, fuels, and materials, are central to global and national economies today, and many will remain important in a net-zero future. Historically, carbon-based products have been made from petroleum, natural gas, coal. The modern chemical industry was built to transform carbon-based molecules distilled from petroleum into a variety of products using inexpensive fossil fuel–derived heat. Most of these products are short-lived, and at end of life, become CO₂ via combustion or decay processes. When the carbon was fossil in origin, as is true for the vast majority of fuels, chemicals, and polymers produced today, then material end of life results in fossil CO₂ emissions to the atmosphere. To achieve net zero, these linear carbon flows from fossil feedstock to CO₂ in the atmosphere will need to shift to circular flows such that no new carbon enters the system, and instead any carbon emitted is

___________________

¹ The warming effects of CO₂ and other GHGs differ depending on their atmospheric lifetime and ability to absorb energy. These effects can be quantified and compared using Global Warming Potential (GWP), a measure of how much energy 1 ton of a GHG absorbs over a given amount of time (often 100 years) compared to the energy absorbed by 1 ton of CO₂ over the same amount of time (EPA 2024a).

captured and reused or stored. In a circular system, petroleum feedstocks will be largely unavailable² owing to their contribution to GHG emissions, and instead feedstocks will include biological material, recycled wastes, and CO₂. Using biological, recycled, or CO₂ feedstocks enable circularity by allowing carbon wastes, such as CO₂ from product degradation, to be incorporated into new products. The choice of sustainable carbon sources depends on many factors, including product composition and lifetime, feedstock cost, access to infrastructure, and regulatory and policy environment. To accommodate new feedstocks, the landscape of chemical and material products and processes is likely to change. Some carbon-based chemicals and materials will decline in use as zero-carbon alternatives become prominent (e.g., fuels replaced by electrification). Other carbon-based chemicals and materials are likely to increase in use because their relative value will increase (e.g., methanol or carbon monoxide as a more important intermediate for chemical synthesis, or carbon fibers as a replacement for higher-emitting materials in construction and manufacturing).

In addition to eliminating most sources of GHG emissions, long-term removal of CO₂ from the atmosphere will likely be needed to reach safe levels of GHGs for a stable climate. This removal could occur by geologic sequestration of CO₂ captured from the air or bodies of water or by incorporating captured CO₂ into long-lived products, especially those deployed at large (gigatonne) scales worldwide, such as concrete and aggregates. Such long-lived products additionally could contribute to emissions reductions by displacing heavily emitting processes like those used for producing conventional building materials.

The net-zero transition will require substantial amounts of critical minerals and materials to deploy clean energy technologies at scale. For example, lithium, cobalt, nickel, and graphite are used in batteries for electric vehicles and energy storage; silicon, copper, and silver are used in conventional photovoltaics; and copper, zinc, and rare earth elements (primarily neodymium) are used in wind turbines (IEA 2022). Currently, the United States imports the majority of minerals deemed “critical” by the U.S. Geological Survey (USGS): in 2022, imports comprised over 50 percent of demand for 43 critical minerals, with 12 of those being 100 percent imported (USGS 2023). Opportunities exist to extract some of these minerals from coal wastes, which could help to establish domestic supply chains while at the same time cleaning up legacy waste sites. The carbon constituents of coal waste can also be considered as a net-zero emissions feedstock for long-lived products, as explored in Chapter 9.

Expanding upon the committee’s first report (NASEM 2023, summarized in Section 1.5), this report examines in greater depth the role of CO₂ utilization in a net-zero future, where CO₂ flows to the atmosphere are likely to be greatly reduced, and carbon wastes including CO₂ and coal waste streams will serve as feedstocks for carbon-based chemicals and materials, as well as for carbon storage in long-lived products. The report considers how chemicals and materials manufacturing could be adapted to take advantage of carbon wastes, particularly CO₂ and coal wastes, using low-carbon energy, and identifies circumstances in which CO₂ and coal wastes are advantaged feedstocks over biomass and other carbon wastes such as plastics. Specifically, it analyzes market opportunities, infrastructure requirements, and research, development, and demonstration (RD&D) needs for converting CO₂ into useful products, providing an update to the research agenda laid out in the 2019 National Academies’ report Gaseous Carbon Waste Streams Utilization: Status and Research Needs (NASEM 2019). It also addresses the feasibility of deriving carbon materials and critical minerals from coal waste streams.

1.2 WHAT IS CO₂ UTILIZATION, AND HOW CAN IT CONTRIBUTE TO A NET-ZERO EMISSIONS FUTURE?

This study defines CO₂ utilization as the chemical transformation of CO₂ into a marketable product, which could include organic carbon-based fuels, chemicals, and materials (including polymers), inorganic carbonates, or elemental carbon materials. CO₂ conversion can occur via chemical, biological, or mineralization routes, with each having different requirements for energy, additional feedstocks, and infrastructure. CO₂ utilization processes

___________________

² In some limited applications, it may be technically or economically difficult to replace fossil carbon feedstocks with sustainable carbon feedstocks or to develop alternative non-carbon-based solutions in the near to medium term. As a result, during the transition, for some small-volume products, net zero may still be achieved by continued manufacture from fossil feedstocks accompanied by durable offsetting capture of CO₂ and geologic sequestration, or removals of CO₂ from the atmosphere. In the long term, these solutions are not viable because the production cost of oil and associated carbon costs will be prohibitively high.

span technology readiness levels, including a few large-scale, fully commercial activities (e.g., production of urea, salicylic acid, and organic carbonates); some pilot, demonstration, or limited-scale commercial facilities (e.g., production of methanol, carbon monoxide, and mineralized CO₂ products); and much research at the laboratory scale across all production routes and product classes. Priority products for CO₂ utilization are detailed in Chapter 2, and Chapters 5–8 cover RD&D needs for the various CO₂ utilization routes.

CO₂ utilization has two primary roles in a net-zero future: enabling circularity of carbon flows and carbon storage (Figure 1-1). Atmospheric, aquatic, or biogenic CO₂ is a feedstock for enabling a circular economy or net-zero-emissions approach to making carbon-based products,³ alongside approaches that use biomass and other waste carbon feedstocks. CO₂ has several advantages and disadvantages relative to other sustainable carbon feedstocks for circularity of chemicals and materials. As a ubiquitous waste product of chemical combustion and decay, CO₂ is widely available. After gas stream purification, it is a uniform, nontoxic substance that can be cleanly inserted into chemical industry processes, as compared to mixed feedstocks of biomass and recycled waste products. CO₂ has lower land and, in many cases, water requirements than biomass cultivation, and it is easier to transport, although the most efficient transport is in pipelines, which can be challenging to plan and site. The primary disadvantage of CO₂ is its low energy, which makes chemical transformations very energy intensive; however, this is a necessary feature of a feedstock for circular carbon fuels. CO₂’s single-carbon, oxidized chemical structure requires restructuring the chemical industry around processes that use more energy and hydrogen, and can build carbon-carbon bonds. (See Section 2.2.1 on factors that impact the ease of making products from CO₂.)

CO₂ utilization can enable the storage of CO₂-derived carbon in solid form in durable products, sequestering it from the atmosphere for climate-relevant timescales. In this role, CO₂ utilization is advantageous over alternatives like land- and ocean-based carbon dioxide removal and carbon capture and storage because it creates products with market value. However, the likely scale of CO₂-derived durable products is a few-gigatonnes annual global demand (Chapter 2 and NASEM 2023) compared to the projected tens of gigatonnes annual global removal required in the future (Pett-Ridge et al. 2023). Thus, geologic storage of CO₂ is preferred over durable CO₂-derived products for

___________________

³ Zero-carbon energy carriers such as hydrogen and electricity are preferred over carbon-based fuels where feasible, owing to the energy efficiency of electricity use in motors and hydrogen use in fuel cells over combustion of fuels, the lower land and water requirements for electricity and hydrogen relative to biomass-based systems, and the avoided conversion energy and resource requirements for formation of carbon-based products.

meeting the full needs for carbon removal. CO₂ utilization is not likely to be a dominant source of carbon removal, nor of emissions mitigation for achieving net zero relative to other options for reducing emissions; however, it likely will contribute to product circularity and durable storage, where it has advantages. The extent of emissions reductions from CO₂ utilization could be impacted by factors such as societal acceptance of geologic carbon storage, ability to make long-lived products, and availability of renewable energy and hydrogen resources.

The use of CO₂ as a feedstock does not inherently reduce emissions relative to the use of fossil carbon feedstocks. To determine net-zero or net-negative product status, all emissions from the full product life cycle need to be considered, including upstream and downstream emissions associated with process, feedstock origin, energy use, product fate, co-product fate, and associated waste (see Chapter 3). For CO₂ utilization, it is particularly important to consider and match CO₂ source feedstocks and product sinks that can provide net-zero or net-negative emissions pathways. Specifically, long-lived products (lifetime >100 years⁴), such as concrete and aggregates, durably store carbon and can be produced sustainably with fossil or nonfossil CO₂. On the other hand, short-lived products (lifetime < 100 years), such as fuels, chemicals, and many plastics, store CO₂ from the atmosphere only temporarily and must be produced using atmospheric, aquatic, or biogenic sources of CO₂ to participate in a circular carbon economy.

Transitioning from today’s heavily fossil fuel–dependent economy to a future economy with sustainable carbon feedstocks and net-zero or net-negative GHG emissions requires careful consideration of policies and technologies that promote emissions mitigation while ensuring that other societal needs and objectives are met. Current uses of fossil feedstocks do not include an internalized cost for the waste GHG products they emit, and as such, materials produced from fossil feedstocks are less expensive than they would be if their eventual fossil emissions to the atmosphere were priced. A future net-zero economy will require a new policy landscape to encourage net-zero or net-negative emissions technologies, and limit net-positive emissions technologies. Constraints on the use of fossil carbon will be stringent and may include preventing or pricing the incorporation of fossil-derived CO₂ into products that reemit CO₂ on a short timeframe (e.g., chemicals or fuels). These policies will also include economy-wide caps on emissions of fossil CO₂ and/or other GHGs or a price on carbon that is sufficiently high to greatly reduce fossil emissions. Emissions constraints would build on policies already being implemented to support technology development for a net-zero transition, such as tax credits for renewable energy production and sequestration or utilization of CO₂. While such forward-looking analysis is valuable to define and plan for an end goal, it overlooks complexities that will arise during the transition period as society decreases fossil fuel use. For example, in the near term when fossil emissions are being wound down, cost-effective emissions reductions may be achieved using fossil CO₂ as a feedstock for chemicals and fuels, even though this approach will not provide the net-zero emissions required in the long term. Collaborative transition planning by governments and the private sector will be needed to optimize investments and minimize stranded assets. This planning is particularly relevant for CO₂ utilization, where siting decisions have to consider fundamental shifts in product needs as well as matching CO₂ source with product lifetime. CO₂ utilization infrastructure planning is discussed further in Chapter 10, and more detail on policy options for CO₂ utilization can be found in Chapter 4.

1.3 WHAT IS COAL WASTE UTILIZATION AND HOW CAN IT CONTRIBUTE TO NATIONAL NEEDS?

In addition to CO₂ utilization, this report examines the feasibility of and opportunities for utilizing coal waste streams to produce carbon-based products and extract critical minerals and materials. Various waste streams arise from mining, processing, and using coal, including coal combustion residuals (fly ash, bottom ash, boiler slag, and flue gas desulfurization products), impoundment waste (coarse and fine refuse), and acid mine drainage. Coal combustion residuals are already used today as filler and raw materials in concrete, wallboard, asphalt, and other structural applications, as well as for soil modification (ACAA 2023; EPA 2023). Given the abundance, low cost, and high carbon density of coal waste streams, research efforts are targeting additional potential utilization opportunities in a wide spectrum of carbon-based products, from high-volume building materials and polymers to high-value graphite and carbon fiber (Stoffa 2023). Fly ash, wastes from coal mining and processing, and acid

___________________

⁴ This committee’s first report (NASEM 2023) chose a product lifetime of 100 years, in line with the United Nations Framework Convention on Climate Change, to differentiate between short- and long-lived products.

mine drainage are also potential sources of critical minerals and rare earth elements, and pilot-scale efforts are under way to develop separation and extraction processes (Kolker 2023). Using coal waste streams could enable environmental remediation, expand domestic supply chains for critical minerals and materials, and produce carbon-based products with improved performance and/or economics (Stoffa 2023). However, because these wastes contain nearly every element in the periodic table, separations can be challenging and pose safety and toxicity concerns (Kolker 2023; Stoffa 2023). Chapter 9 addresses opportunities and challenges with utilizing coal wastes.

1.4 CURRENT POLICY ENVIRONMENT FOR CO₂ UTILIZATION

Most uses of CO₂ within the scope of this study currently rely on subsidies or other incentives to be competitive with incumbent products, owing to various transient and persistent factors, including the unpriced costs of fossil hydrocarbon pollution from incumbent products, the small production scale of most CO₂ utilization products, the still-developing CO₂ utilization technologies, and the fundamental challenges of CO₂ conversion into organic products. A primary policy driver in the United States is the 45Q tax credit (IRA § 13104), which provides up to $60/tCO₂ for utilization (or up to $130/tCO₂ if paired with direct air capture [DAC]) (IRA 2022). The 45V tax credit for clean hydrogen production (IRA § 13204) could also benefit CO₂ utilization projects that require hydrogen as a feedstock, although the same facility cannot claim both the 45Q and 45V credits (IRA 2022). Additionally, the Carbon Dioxide Transportation Infrastructure Finance and Innovation (CIFIA) program, administered through the Department of Energy’s (DOE’s) Loan Programs Office with $2.1 billion in appropriations between 2022 and 2026, finances common carrier transportation infrastructure to move CO₂ from the point of capture to the point of use or storage (DOE-LPO n.d.). The Utilization Procurement Grants (UPGrants) program, run by DOE’s Office of Fossil Energy and Carbon Management and the National Energy Technology Laboratory, will facilitate procurement and use of CO₂-derived products by state and local governments and public utilities (NETL n.d.). Beyond government-funded initiatives, the voluntary carbon market and willingness of companies to pay a “green premium” for more sustainable products also support current CO₂ utilization efforts.

This study focuses on needs for a net-zero future, in which there will be significant constraints on the emission of fossil-derived CO₂ to the atmosphere, such as an explicit price on CO₂ or a limit on emissions. The committee considers opportunities and enabling environments for CO₂ utilization within this context, where there will be increased incentives for producing short-lived products in a circular carbon system, as well as for long-duration carbon storage, including in products (see Chapter 4). Applying constraints on CO₂ emissions to CO₂ utilization products or processes will require accounting for life cycle emissions of a CO₂ utilization process and the resulting product for compliance purposes. Products originally derived from a fossil feedstock could have end-of-life emissions associated with their use or degradation, and these emissions will need to be considered and managed. Emissions associated with enabling inputs such as electricity and hydrogen, transportation of CO₂ and CO₂-derived products, and any upstream or downstream processing may also impact the feasibility of certain CO₂ utilization pathways when total system emissions are constrained. Chapter 3 discusses life cycle assessment considerations for CO₂ utilization.

1.5 BRIEF REVIEW OF FIRST REPORT’S CONCLUSIONS

The committee’s first report (NASEM 2023) examined the state of CO₂ capture, utilization, transportation, and storage infrastructure and analyzed opportunities for investment in CO₂ utilization infrastructure to serve a net-zero future. It found that most of the existing infrastructure, which was developed for enhanced oil recovery, does not align with opportunities for sustainable (i.e., net-zero) CO₂ utilization. Thus, to evaluate future infrastructure opportunities, the committee first considered factors that would influence the extent of CO₂ utilization in a net-zero economy. It found that the volume of CO₂ utilized will be driven by the market value of carbon-based products and competitiveness of CO₂ as a feedstock, as well as demand for services provided by carbon-based products; their relative cost compared to fossil-based products and other alternatives; availability of required inputs like clean hydrogen and clean electricity; and policy incentives and regulatory frameworks (Finding 3.10, NASEM 2023). As discussed above, another important consideration is the potential climate impact of the CO₂-derived product based on the CO₂ source, product lifetime, and any emissions associated with production, transportation, and use.

Considering these factors, the committee identified two priority near-term opportunities for CO₂ utilization infrastructure investment: (1) combining high-purity, low-cost CO₂ off-gas from bioethanol plants with clean hydrogen to make sustainable chemicals or fuels for heavy-duty transportation (e.g., shipping and aviation) and (2) mineralization using fossil or nonfossil CO₂ sources to generate mineral carbonates for construction materials, including concrete (Finding 6.1, NASEM 2023). It recommended strategies for infrastructure planning, such as co-locating CO₂ utilization with clean electricity, clean hydrogen, and other carbon management infrastructure; building in flexibility to connect CO₂ transport infrastructure to future utilization opportunities; and developing industrial clusters to manage large volumes of CO₂ without extensive pipeline networks and maintain jobs in regions with a large industrial presence (Recommendations 4.5, 6.2, 6.3, and 6.4, NASEM 2023). The committee also emphasized the importance of community engagement and equitable infrastructure development, recommending that regulatory agencies account for distributional impacts of CO₂ utilization projects, engage impacted communities early and throughout the project, and allow for alterations to project design and implementation (Recommendation 5.6, NASEM 2023). This report expands upon the findings and recommendations from the first report.

1.6 REPORT TASKING, SCOPE, AND KEY CONCEPTS

A congressional mandate in the Energy Act of 2020 required DOE to enter into an agreement with the National Academies of Sciences, Engineering, and Medicine to perform a study “to assess any barriers and opportunities relating to commercializing carbon, coal-derived carbon, and carbon dioxide in the United States” (U.S. Congress 2020, § 969A). DOE commissioned that this study be undertaken in two parts. In a first report, the committee would describe the current state of infrastructure for CO₂ transportation, use, and storage in the United States and identify priority opportunities for developing infrastructure to enable future CO₂ utilization processes and markets in a safe, cost-effective, and environmentally benign manner. The committee released this first report in December 2022 (NASEM 2023). A second, more comprehensive report (the present report) would provide additional detail on potential markets for products derived from CO₂; the economic, environmental, and climate impacts of CO₂ utilization infrastructure; RD&D needs to enable commercialization of CO₂ utilization technologies and processes; and opportunities for and feasibility of coal waste–derived carbon products and critical minerals. The full statement of task for the study is provided in the next section, followed by a description of the study scope and definitions of relevant concepts used in the report (Box 1-1).

1.6.1 Statement of Task

The National Academies of Sciences, Engineering, and Medicine will convene an ad hoc committee to assess infrastructure and research and development needs for carbon utilization, focused on a future where carbon wastes are fundamental participants in a circular carbon economy. In particular, the study will focus on regional and national market opportunities, infrastructure needs, and the research and development needs for technologies that can transform carbon dioxide and coal waste streams into products that will contribute to a future with zero net carbon emissions to the atmosphere. The committee will analyze challenges in expanding infrastructure, mitigating environmental impacts, accessing capital, overcoming technical hurdles, and addressing geographic, community, and equity issues for carbon utilization.

The committee will provide a first report that:

1. assesses the state of infrastructure for carbon dioxide transportation, use, and storage as of the date of the study, including pipelines, freight transportation, electric transmission, and commercial manufacturing facilities.
2. identifies priority opportunities for development, improvement, and expansion of infrastructure to enable future carbon utilization opportunities and market penetration. Such priority opportunities will consider how needs for carbon utilization infrastructure will interact with and capitalize on infrastructure developed for carbon capture and sequestration.

The committee will develop a second report that will evaluate the following:

1. Markets
   1. Identify potential markets, industries, or sectors that may benefit from greater access to commercial carbon dioxide to develop products that may contribute to a net-zero carbon future; identify the markets that are addressable with existing utilization technology and that still require research, development and demonstration;
   2. Determine the feasibility of, and opportunities for, the commercialization of coal waste–derived carbon products in commercial, industrial, defense, and agricultural settings; for medical, construction and energy applications; and for the production of critical minerals;
   3. Identify appropriate federal agencies with capabilities to support small business entities; and determine what assistance those federal agencies could provide to small business entities to further the development and commercial deployment of carbon dioxide–based products;
2. Infrastructure
   1. Building off the study’s first report, assess infrastructure updates needed to enable safe and reliable carbon dioxide transportation, use, and storage for carbon utilization purposes. Assessment of infrastructure will consider how carbon utilization fits into larger carbon capture and sequestration infrastructure needs and opportunities;
   2. Describe the economic, climate, and environmental impacts of any well-integrated national carbon dioxide pipeline system as applied for carbon utilization purposes, including suggestions for policies that could: (i) improve the economic impact of the system; and (ii) mitigate climate and environmental impacts of the system;
3. Research, Development, and Demonstration
   1. Identify and assess the progress of emerging technologies and approaches for carbon utilization that may play an important role in a circular carbon economy, as relevant to markets determined in section 1a;
   2. Assess research efforts under way to address barriers to commercialization of carbon utilization technology, including basic, applied, engineering, and computational research efforts; and identify gaps in the research efforts;
   3. Update the 2019 National Academies’ comprehensive research agenda on needs and opportunities for carbon utilization technology RD&D, focusing on needs and opportunities important to commercializing products that may contribute to a net-zero carbon future.

The first and second reports will provide guidance to infrastructure funders, planners, and developers and to research sponsors, as well as research communities in academia and industry, regarding key challenges needed to advance the infrastructure, market, science, and engineering required to enable carbon utilization relevant for a circular carbon economy.

1.6.2 Scope of Report

The committee determined the limits of its scope based on the congressional mandate for the study and the study’s statement of task. The committee’s definitions of relevant concepts and explanation of the study scope are outlined below.

1. How is carbon utilization defined for the purposes of this report? What classes of carbon utilization are not in scope?
   1. Carbon utilization is defined for the purposes of this report as the chemical transformation of concentrated CO₂ collected from the atmosphere, a body of water, or a waste gas stream into a carbon-containing product with market value.

1. 2. In scope:
      1. Chemical, microbial, and mineralization transformations of CO₂.
   3. Out of scope:
      1. Processes like enhanced oil recovery, fire suppression, and beverage carbonation that leave CO₂ untransformed.
      2. CO₂ transformed into products via the growth of terrestrial plants and crops.
2. What sources of carbon dioxide are considered in this report?
   1. CO₂ captured and concentrated from the atmosphere through direct air capture.
   2. CO₂ captured from point sources before emission to the atmosphere, such as from power plants or industrial facilities.
   3. CO₂ dissolved from the atmosphere in natural or other bodies of water, where the dissolved CO₂ in those waters is used as feedstock for carbon utilization processes.
3. What pathways to activate carbon dioxide are discussed in this report?
   1. Chemical pathways to inorganic (mineral) products
   2. Chemical pathways to organic products
      1. Thermochemical
      2. Electrochemical
      3. Photochemical
      4. Plasmachemical
      5. Hybrid pathways
   3. Biological pathways to organic products
      1. Photosynthetic
         1. Algae
         2. Cyanobacteria
      2. Nonphotosynthetic
         1. Chemolithotrophs
         2. Bio-electrochemical processes
4. To what extent is coal waste discussed in this report?
   1. Utilization of coal waste streams, which was not discussed in the study’s first report, is discussed herein.
   2. Coal waste includes coal combustion residuals (fly ash, bottom ash, boiler slag, and flue gas desulfurization products) and impoundment waste (coarse and fine refuse). Acid mine drainage also is considered as a potential source of critical minerals.
   3. Utilization of raw coal to produce mineral- or carbon-based products and selective mining of rare earth element-enriched portions of coal beds are out of scope for the study.
5. What product classes are discussed in this report?
   1. Inorganic carbonates
   2. Elemental carbon materials
   3. Fuels and commodity chemicals
   4. Polymer precursors and polymers
   5. Critical minerals and rare earth elements (only from coal waste)
6. What assessments of carbon utilization products and processes does this report examine?
   1. Life cycle assessments
   2. Techno-economic assessments
   3. Societal/equity assessments

7. What CO₂ utilization infrastructure is considered in this report?
   1. CO₂ utilization infrastructure systems, including capture, purification, transportation, utilization, and geologic storage.
   2. A U.S. regional- or national-scale pipeline system for carbon management, as applied to utilization.
   3. Enabling infrastructure for CO₂ utilization, including for
      1. Hydrogen
      2. Electricity
      3. Water
      4. Energy storage
      5. Land use
      6. Product transportation

1.7 OVERVIEW OF REPORT CHAPTERS AND CONTENT

This introductory chapter provides context and motivation for the study, describes the connection between this report and the committee’s first report, and explains the study tasking and scope. Chapter 2 identifies market opportunities and requirements for carbon utilization in a net-zero future, considering the projected demand for carbon-based products and cases where CO₂ or coal waste is an advantageous feedstock. This is followed in Chapter 3 by a discussion of life cycle, techno-economic, and societal/equity assessments of CO₂ utilization processes, technologies, and systems. Chapter 4 assesses policy and regulatory frameworks needed to support sustainable CO₂ utilization; opportunities for small businesses to compete for CO₂ as a commodity; and environmental justice considerations when selecting, siting, and developing CO₂ utilization projects. Together, Chapters 2–4 lay the groundwork for understanding how and where CO₂ utilization could contribute to a net-zero future.

The next four chapters focus on RD&D needs for CO₂ utilization technologies and processes to generate inorganic carbonates (Chapter 5); elemental carbon materials (Chapter 6); and chemicals, fuels, and polymers via chemical routes (Chapter 7) or biological routes (Chapter 8). Chapter 9 examines the feasibility of and opportunities for deriving carbon-based materials and critical minerals from coal wastes. Chapter 10 discusses infrastructure needed to support CO₂ utilization, building on the first report’s analysis with more detail on integrated infrastructure planning and the economic, environmental, health and safety, and environmental justice impacts of CO₂ utilization infrastructure development. Chapter 11 discusses the crosscutting research needs of CO₂ capture and purification and presents a research agenda for CO₂ and coal waste utilization, based on the committee’s analyses in Chapters 5–9.

1.8 REFERENCES