Negative Emissions in the Industrial Sector

Preventing the worst impacts from the ongoing climate crises requires rapid and dramatic reduction of anthropogenic emissions of greenhouse gases to “net zero”. However, it is highly likely that we will also need to remove greenhouse gases from the atmosphere to compensate for residual and/or historic emissions. In particular, the industrial sector is expected to be a source of residual emissions of carbon dioxide due to production technologies that are difficult to electricity, or that produce carbon dioxide as part of a non-energy chemical conversion process, or that produce products that result in carbon dioxide emissions during use or end-of-life.

This dissertation explores under what conditions could the integration of so called “negative emission technologies”, such as bioenergy with carbon capture and storage (bioCCS), allow for industries to achieve or exceed carbon neutrality within the system of production, rather than needing compensation elsewhere in society. To do so, this dissertation first defines the criteria necessary for negative emissions technologies to result in the net reduction in atmospheric greenhouse gases, then provides an overview of existing research of bioCCS-in-industry and identifies the main trends in why bioCCS may be useful in specific sectors, and then investigates specific configurations of negative emission technologies in industry, including bioCCS in the steel, cement, and chemical sectors, as well as the potential of natural and accelerated mineralization in concrete production. The primary methodological focus thesis is the comparative modeling of possible technological configurations with life cycle accounting of carbon dioxide and other greenhouse gas emissions, and also includes the review and synthesis of existing literature, as well as a technoeconomic case study.

Negative emission technologies such as bioCCS may be particularly useful in decarbonizing sectors where a substantial amount of carbon dioxide is unavoidably produced during industrial production, such as via the calcination of limestone in cement or the fermentation of ethanol; where the process is already biogenic, such as for paper and bioethanol; where it can be retrofitted into existing infrastructure that cannot be quickly replaced, such as for steel and cement; or where the product itself emits carbon dioxide in a difficult-to-capture way, such as in ethanol or urea production. However, using bioCCS to allow for “carbon neutral” or “carbon negative” production is non-trivial, as it requires ensuring that the greenhouse gas emissions in the supply chains of biomass production and logistics; industrial feedstocks, production and use; and carbon capture, transport, and permanent storage do not exceed the amount of carbon dioxide that is removed from the atmosphere and permanently stored, all of which can be obscured by overly narrow system boundary choices. Other issues of industrial negative emission technologies discussed in this thesis include asynchrony of carbon emissions and removals; the role of non-CO₂ greenhouse gases; the carbon and resource intensity of the technologies; and mismatches in the system boundaries used for life cycle assessment and cost assessment of industrial negative emission technologies.