Towards a Framework for Discussing and Assessing CO2 Utilisation in a Climate Context

Ultra-Cheap Renewable Energy as an Enabling Technology for Deep Industrial Decarbonization via Capture and Utilization of Process CO2 Emissions

Rapidly declining costs of renewable energy technologies have made solar and wind the cheapest sources of energy in many parts of the world. This has been seen primarily as enabling the rapid decarbonization of the electricity sector, but low-cost, low-carbon energy can have a great secondary impact by reducing the costs of energy-intensive decarbonization efforts in other areas. In this study, we consider, by way of an exemplary carbon capture and utilization cycle based on mature technologies, the energy requirements of the “industrial carbon cycle”, an emerging paradigm in which industrial CO2 emissions are captured and reprocessed into chemicals and fuels, and we assess the impact of declining renewable energy costs on overall economics of these processes. In our exemplary process, CO2 is captured from a cement production facility via an amine scrubbing process and combined with hydrogen produced by a solar-powered polymer electrolyte membrane, using electrolysis to produce methanol. We show that solar heat and electricity generation costs currently realized in the Middle East lead to a large reduction in the cost of this process relative to baseline assumptions found in published literature, and extrapolation of current energy price trends into the near future would bring costs down to the level of current fossil-fuel-based processes.

Photoelectrochemical reduction of CO2 to formate over a hybrid system of CuInS2 photocathode and formate dehydrogenase under visible-light irradiation

A hybrid system with a CdS-modified CuInS₂ photocathode and biocatalytic FDH was prepared for photoelectrochemical reduction of CO₂ to formate.

The technological and economic prospects for CO2 utilization and removal

The capture and use of carbon dioxide to create valuable products might lower the net costs of reducing emissions or removing carbon dioxide from the atmosphere. Here we review ten pathways for the utilization of carbon dioxide. Pathways that involve chemicals, fuels and microalgae might reduce emissions of carbon dioxide but have limited potential for its removal, whereas pathways that involve construction materials can both utilize and remove carbon dioxide. Land-based pathways can increase agricultural output and remove carbon dioxide. Our assessment suggests that each pathway could scale to over 0.5 gigatonnes of carbon dioxide utilization annually. However, barriers to implementation remain substantial and resource constraints prevent the simultaneous deployment of all pathways.

The Link between Economic Complexity and Carbon Emissions in the European Union Countries: A Model Based on the Environmental Kuznets Curve (EKC) Approach

The aim of the paper is to apply the Environmental Kuznets Curve (EKC) model in order to explore the link between economic complexity index (ECI) and carbon emissions, in 25 selected European Union (EU) countries from 1995–2017. The study examines a cointegrating polynomial regression (CPR) for a panel data framework as well as for simple time series of individual countries. In the model is also included the variable ‘energy intensity’ as main determinant of carbon emissions. Depending on economic complexity, the CO2 emissions pattern was found to exhibit an inverted U-shaped curve: in the initial phase, pollution increases when countries augment the complexity of the products they export using and after a turning point the rise of economic complexity suppress the pollutant emissions. The panel cointegration test indicates a long-run relationship between economic complexity, energy intensity and carbon emissions. It was also found that a rise of 10% of energy intensity would lead to a 3.9% increase in CO2 emissions. The quadratic model incorporating ECI is validated for the whole panel as well as for six countries (Belgium, France, Italy, Finland, Sweden and the United Kingdom). The graphical representation of the EKC in these countries is discussed. Policy implications are also included.

Negative emissions technologies and carbon capture and storage to achieve the Paris Agreement commitments

How will the global atmosphere and climate be protected? Achieving net-zero CO₂ emissions will require carbon capture and storage (CCS) to reduce current GHG emission rates, and negative emissions technology (NET) to recapture previously emitted greenhouse gases. Delivering NET requires radical cost and regulatory innovation to impact on climate mitigation. Present NET exemplars are few, are at small-scale and not deployable within a decade, with the exception of rock weathering, or direct injection of CO₂ into selected ocean water masses. To keep warming less than 2°C, bioenergy with CCS (BECCS) has been modelled but does not yet exist at industrial scale. CCS already exists in many forms and at low cost. However, CCS has no political drivers to enforce its deployment. We make a new analysis of all global CCS projects and model the build rate out to 2050, deducing this is 100 times too slow. Our projection to 2050 captures just 700 Mt CO₂ yr^-1, not the minimum 6000 Mt CO₂ yr^-1 required to meet the 2°C target. Hence new policies are needed to incentivize commercial CCS. A first urgent action for all countries is to commercially assess their CO₂ storage. A second simple action is to assign a Certificate of CO₂ Storage onto producers of fossil carbon, mandating a progressively increasing proportion of CO₂ to be stored. No CCS means no 2°C.This article is part of the theme issue 'The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels'.

Negative emissions technologies and carbon capture and storage to achieve the Paris Agreement commitments

How will the global atmosphere and climate be protected? Achieving net-zero CO₂ emissions will require carbon capture and storage (CCS) to reduce current GHG emission rates, and negative emissions technology (NET) to recapture previously emitted greenhouse gases. Delivering NET requires radical cost and regulatory innovation to impact on climate mitigation. Present NET exemplars are few, are at small-scale and not deployable within a decade, with the exception of rock weathering, or direct injection of CO₂ into selected ocean water masses. To keep warming less than 2°C, bioenergy with CCS (BECCS) has been modelled but does not yet exist at industrial scale. CCS already exists in many forms and at low cost. However, CCS has no political drivers to enforce its deployment. We make a new analysis of all global CCS projects and model the build rate out to 2050, deducing this is 100 times too slow. Our projection to 2050 captures just 700 Mt CO₂ yr^-1, not the minimum 6000 Mt CO₂ yr^-1 required to meet the 2°C target. Hence new policies are needed to incentivize commercial CCS. A first urgent action for all countries is to commercially assess their CO₂ storage. A second simple action is to assign a Certificate of CO₂ Storage onto producers of fossil carbon, mandating a progressively increasing proportion of CO₂ to be stored. No CCS means no 2°C.This article is part of the theme issue 'The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels'.

Catalytic dehydrogenation of propane by carbon dioxide: a medium-temperature thermochemical process for carbon dioxide utilisation

The dehydrogenation of C₃H₈ in the presence of CO₂ is an attractive catalytic route for C₃H₆ production. In studying the various possibilities to utilise CO₂ to convert hydrocarbons using the sustainable energy source of solar thermal energy, thermodynamic calculations were carried out for the dehydrogenation of C₃H₈ using CO₂for the process operating in the temperature range of 300–500 °C. Importantly, the results highlight the enhanced potential of C₃H₈ as compared to its lighter and heavier homologues (C₂H₆ and C₄H₁₀, respectively). To be utilised in this CO₂ utilisation reaction the Gibbs free energy (Δ_rGθm) of each reaction in the modelled, complete reacting system of the dehydrogenation of C₃H₈ in the presence of CO₂ also indicate that further cracking of C₃H₆ will affect the ultimate yield and selectivity of the final products. In a parallel experimental study, catalytic tests of the dehydrogenation of C₃H₈ in the presence of CO₂ over 5 wt%-Cr₂O₃/ZrO₂ catalysts operating at 500 °C, atmospheric pressure, and for various C₃H₈ partial pressures and various overall GHSV (Gas Hourly Space Velocity) values. The results showed that an increase in the C₃H₈ partial pressure produced an inhibition of C₃H₈ conversion but, importantly, a promising enhancement of C₃H₆ selectivity. This phenomenon can be attributed to competitive adsorption on the catalyst between the generated C₃H₆ and inactivated C₃H₈, which inhibits any further cracking effect on C₃H₆ to produce by-products. As a comparison, the increase of the overall GHSV can also decrease the C₃H₈ conversion to a similar extent, but the further cracking of C₃H₆ cannot be limited.