Bio-CCS: Feasibility comparison and economic potential of large scale carbon-negative solutions

The urgency to stabilize the global temperature rise at 2°C as highlighted in the IPCC Fifth Assessment Report calls for solutions that can remove CO2 from the atmosphere. Achieving negative CO2 emissions by removing CO2 from the atmosphere is possible by applying carbon capture in biomass-fired processes (Bio-CCS). Biomass has the capability of withdrawing and storing atmospheric CO2. As a result, CO2 released during biomass combustion can be captured and stored permanently underground, thus depriving the atmosphere of CO2. The objective of this paper is to assess the most rational deployment opportunities of Bio-CCS from climate and 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. 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 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 the potential technologies for Bio-CCS and the feasibility of the solutions are compared both from a sustainability and cost point of view. There are four major biomass conversion routes where Bio-CCS is applicable; biochemical conversion (fermentation and hydrolysis), thermo-chemical conversion (e.g. gasification), power production (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. The main Bio-CCS technologies assessed in this study are Fischer-Tropsch diesel production, bio-SNG production, lignocellulosic ethanol production, torrefaction and biomass based power production such as co-firing biomass in a coal-based condensing power plant and biomass-based CHP (combined heat and power) production. The most applicable industry sector for introduction of Bio-CCS is obviously pulp and paper industry but some potential exists also in cement industry, iron and steel industry and oil and gas refineries. As the potential of Bio-CCS is very much bound to the availability and usage of biomass raw materials, the sustainability of the raw materials is of essence. The current biomass flows and potentials set the initial limits for the wider deployment of Bio-CCS. Efficient utilization of constrained resources is an essential question, when the target is to optimize the impact on the system level, from the society point of view. The ultimate objective is to give suggestions weather deployment really gives desired impact to the CO2 concentrations in the atmosphere. As biomass can be used in many ways, the primary purpose of utilisation and products containing biogenic carbon also add up to this. When biomass is utilised for products other than energy, the impact to environment and economy differs. The opportunities with these solutions, realistic potential and the main threats related to Bio-CCS are discussed in the light of sustainability and economic potential.