Pathway to achieve negative CO2 emissions:combining biomass with CCS

The urgency to stabilize the global temperature rise at 1.5°C as highlighted in Paris COP21 and the IPCC Fifth Assessment Report calls for solutions that can remove CO2 from the atmosphere. The ability of carbon negative processes to offset historic emissions and emissions across different sectors is also highlighted in recent scenarios by IEA and WEC. Achieving negative CO2 emissions by removing CO2 from the atmosphere is possible by applying carbon capture in processes utilizing biomass (bio-CCS). Biomass has the capability of withdrawing and storing atmospheric CO2. As a result, CO2 released during biomass thermo-chemical conversion can be captured and stored permanently underground, thus depriving the atmosphere of CO2. The objective of this paper is to assess different deployment opportunities of bio-CCS from GHG emissions and plant economy point of view; to evaluate what is the best way to use constrained biomass resources by assessing the effects that raw materials types, different processes and end products have on carbon stocks and on the overall GHG mitigation from the global point of view. It also describes an implementation pathway incorporating bio-CCU processes as an intermediate step towards low carbon societies in 2050. Bio-CCU applications, incorporating power-to-gas (P2G) and RES boosted hybrid processes as intermediate steps for fully carbon neutral energy supply are seen as a critical bridging technology in business wise deployment pathway. These technologies also have an essential role in bringing new aspects to the sustainability and greenhouse gas impact discussions as biomass, despite being a globally evenly distributed and renewable raw material, is in the end also a constrained resource that should be utilised in the most reasoned applications taking into account all aspects of sustainability. There are three major biomass conversion routes where bio-CCS is applicable; biochemical conversion (fermentation and hydrolysis), thermo-chemical conversion (e.g. gasification and combustion) and industrial processes. In addition to ethanol fermentation the thermo-chemical biomass conversion processes are considered the first-phase targets for applying capture of CO2, both from a logistic and cost point of view. A concrete example on how more thorough deployment of bio-CCS could penetrate in near-term markets is given as a Finnish bio-CCS roadmap with scenarios highlighting the major bottlenecks and constrains. The roadmap assessment is based on power plant, industrial plant and emission database calculations with future projections on existing installations. In this paper a deployment pathway to a low carbon society is described and discussed. The potential technologies for bio-CCS and bio-CCU are introduced with the feasibility of the solutions compared both from the sustainability and cost point of view