In 2012 the chemicals sector ranked in second place in terms of emission intensiveness, following the iron and steel sector, with total annual emissions amounting to 18.4 million tonnes of CO2. The sector’s carbon footprint is derived from the combustion of fossil fuels, indirect emissions from electricity consumption, and process emissions (i.e. inherent to the processes of chemical reactions).
Over the past decades we have observed significant progress to reduce energy consumption per unit of product in the sector; however, a clear message emerging from interviews with industry stakeholders has been that decarbonisation is often a lower priority than the need to ensure compliance with existing regulations.
What role for CCS in chemicals sector decarbonisation?
The study finds that the maximum decarbonisation (or Max Tech as illustrated in the graph below) potential of the chemicals sector is a reduction of emissions by 88% in 2050 compared to 2012. This magnitude of reduction necessitates the deployment of CCS on both process and combustion emissions; along with a range of other options including decarbonisation of the electricity grid; decarbonisation of heat by supplying heat using low-carbon biomass; decarbonisation of methane, and further improvements in energy efficiency among others.
The graph above illustrates the different emissions pathways relative to 2012 through to 2050 based on different deployment of various decarbonisation options in the chemicals sector. The basic assumptions used for the different decarbonisation pathways are as follows:
- The reference pathway is where no decarbonisation options are deployed; it shows only the combined effect of production growth and grid decarbonisation over time;
- The Business-As-Usual (BAU) pathway shows a continuation of existing trends in energy efficiency and decarbonisation; this scenario provides a 20-40% reduction pathway;
- The 40-60% pathway assumes some increased drivers for decarbonisation (e.g. policy incentives or increased demand for customers for low-carbon products), resulting in more or faster deployment of some decarbonisation options;
- The Max Tech pathway assumes that all potentially technically feasible options are deployed when they become available without cost being a limitation, but while also being reasonably foreseeable with further technical deployment;
- The Max Tech (no biomass) pathway is similar to Max Tech but assumes that low-carbon biomass is not available. As a result, some other technologies are deployed more extensively. This pathway also provides a 60-80% reduction pathway.
12.9 million tonnes of CO2 would be reduced under the Max Tech (no biomass) pathway.
The graph below illustrates a breakdown of the 2050 total emission reductions for the Max Tech (no biomass) pathway (excluding grid decarbonisation). In this scenario, we can clearly see the important role envisaged for CCS, as 49.4% of emissions reduced would stem from CCS applied to process emissions and 13.1% from CCS applied on CO2 generated by combustion processes.
The report notes that achieving a maximum decarbonisation pathway would require a mix of options delivered both from within and outside the sector. This is because some of these decarbonisation options are outside of the direct control of the chemicals sector itself (e.g. electricity grid decarbonisation), while others will depend in part on the progress achieved outside the sector (e.g. supply of low-carbon biomass and development of CCS networks).
Need for the establishment of shared transport and storage network: a pre-requisite for CCS deployment in the chemicals sector.
According to survey findings, no individual plant in the chemicals sector produces sufficient emissions to justify its own CO2 transport and storage network. In addition to the capital investment required, the production of low-carbon chemicals will have increased operating costs compared to polluting chemical plants. In order for CCS to be deployed, it is therefore important that shared transport and storage networks are established. Once in place, these networks would enable individual plants to ‘plug in’ when their own capture processes were implemented. This clearly shows the inter-related nature of decarbonisation pathways across the various industrial sectors.