Potential market niches for biomass energy with CO2 capture and storage—Opportunities for energy supply with negative CO2 emissions
Introduction
The third and latest assessment report of the Intergovernmental Panel on Climate Change (IPCC) states that most of the observed global warming over the last 50 years is likely to have been due to the increase in greenhouse gas (GHG) concentrations in the atmosphere. The IPCC further concludes that the stabilisation of the atmospheric CO2 concentration requires CO2 emissions to eventually drop well below current levels [1]. In analysing measures for reducing CO2 emissions, the IPCC concludes [2] that none of the following measures alone would be sufficient to stabilise atmospheric CO2 concentrations: demand reductions and/or efficiency improvements; substitution among fossil fuels; switching to renewables or nuclear energy; CO2 capture and storage; or afforestation. Thus, in identifying strategies for mitigation of climate change, combinations of multiple technologies in all sectors must be considered.
CO2 capture and storage technologies that could minimise CO2 emissions from fossil fuel combustion have been discussed extensively. These technologies contribute significantly to global CO2 emission reductions in several IPCC GHG emission mitigation scenarios [2]. However, the technologies must be further investigated regarding their reliability and safety of long-term storage, and the IPCC credits that these technologies could provide major contributions to CO2 abatement by 2020 [2]. Nevertheless, it is important to note that fossil-based energy systems with CO2 capture and storage will always give rise to positive net CO2 emissions [2]. It is not technically and economically feasible to capture all of the CO2 from a gas stream. Biomass energy with CO2 capture and storage (BECS), on the other hand, can yield negative CO2 emissions because the CO2 put into storage comes from biomass and the biomass absorbs CO2 as it grows (Fig. 1). BECS is a new concept that has received little analysis in technical literature and policy discussions (including the IPCC).
Increased interest in terrestrial carbon sink management has intensified the discussion about trade-offs between sequestering carbon in standing biomass to offset a share of fossil fuel emissions, and the increased use of biomass for fuels e.g., [3], [4], [5]. The advantage of incorporating CO2 capture and storage into bioenergy systems is that it allows for a sustained removal of carbon from the atmosphere while simultaneously fulfilling energy needs [6]. In light of the dual role of biomass as both a fossil-fuel substitute and a carbon sink, it becomes clear that extending the discussion concerning CO2 balances of biomass energy systems to include CO2 capture and storage is worthwhile. Assuming that safe solutions for long-term CO2 storage are found, BECS gives added leverage to the GHG-reduction potential of the world's biomass resources. Moreover, Obersteiner et al. [7] argued that technologies enabling rapid removal of GHGs from the atmosphere are instrumental as a climate risk management tool. This is important should unforeseen catastrophic climate-related damages start to significantly decrease human welfare. Drastically increased bioenergy use combined with CO2 capture and storage could potentially lead to a net decrease of atmospheric CO2 levels while sustaining a significant part of global energy and raw material demand.
In this paper, CO2 balances of selected BECS options are presented and compared to fossil-based systems with CO2 capture and storage. Furthermore, preliminary results of an economic assessment of CO2 capture and storage in bioenergy systems is presented. The CO2 reduction potentials of the selected BECS technologies are discussed in a regional and global context.
Section snippets
Technologies and potential market niches for biomass energy with CO2 capture
Assuming that CO2 capture and storage from mobile or small stationary sources is probably not viable for technical and economic reasons we concentrate our attention on industrial-size biomass-energy conversion facilities trying to show their suitability for CO2 capture and storage. Today, a substantial share of large-scale biomass-energy conversion occurs for heat production or combined heat and power production (CHP) mainly in the forest products sector and sugar cane processing industries. In
Specific CO2 emissions and CO2 reduction potential
The following BECS technologies were selected for in-depth examination:
- •
CO2 capture by chemical absorption from the flue gases of the black liquor recovery and bark boilers in a Kraft pulp mill (post-combustion CO2 capture).
- •
CO2 capture by physical absorption from the fuel gas in a black liquor integrated gasification combined cycle (BLGCC) in a Kraft pulp mill (pre-combustion CO2 capture).
- •
Capture of CO2 from fermentation and biomass residue combustion in sugar cane-based ethanol production.
The
Regional and global aspects on CO2 reduction potentials of the studied BECS technologies
Based on the current black liquor processing of the Swedish pulp and paper sector of 131 PJ yr−1 (LHV) [20], our results indicate that approximately could be avoided if all Swedish Kraft pulp mills were equipped with modern recovery boilers with post-combustion CO2 capture. of the reduction is due to CO2 capture, and is due to a net increase in electricity production.3
Discussion
This paper has shown that it is possible to achieve negative CO2 emissions with BECS. However, this can only be achieved provided that the reliability and safety of long-term CO2 storage technologies is secured. This study estimates that the accumulated C reduction potential this century for BECS in sugar mills and Kraft pulp mills amounts to 17 Gtonnes C and 6 Gtonnes C, respectively. The IPCC [3] estimates that the amount of C emissions that must be avoided during this century ranges from 300
Conclusions
We have discussed the potential for negative CO2 emissions through implementation of biomass energy with CO2 capture and storage (BECS). In principal, the same technologies for CO2 capture that can be applied to coal are suitable for biomass. In addition, CO2 can be recovered from the process of fermenting sucrose to produce ethanol. Providing that safe solutions for long-term CO2 storage are found, BECS can give leverage to the carbon-reduction potential of the world's biomass resources. The
Acknowledgements
The work has been carried out under the auspices of The Energy Systems Programme, which is financed by the Swedish Foundation for Strategic Research, the Swedish Energy Agency and Swedish industry. Financial support from the Kempe foundation is also gratefully acknowledged.
References (29)
- et al.
Towards a standard methodology for greenhouse gas balances of bioenergy systems in comparison with fossil energy systems
Biomass Bioenergy
(1997) Cost effectiveness of measures for the reduction of net accumulation of carbon dioxide in the atmosphere
Biomass Bioenergy
(1998)- et al.
The alcohol program
Energy Policy
(1999) - et al.
Comparison of CO2 removal systems for fossil-fuelled power plant processes
Energy Conversion and Management
(1997) - Intergovernmental Panel on Climate Change (IPCC). Climate change 2001: the scientific basis. Cambridge: Cambridge...
- Intergovernmental Panel on Climate Change (IPCC). Climate change 2001: mitigation. Cambridge: Cambridge University...
- Intergovernmental Panel on Climate Change (IPCC). Land use, land-use change, and forestry. IPCC Special Report....
- et al.
Economic evaluation of biomass-based energy systems with CO2 capture and sequestration in Kraft pulp mills—the influence of the price of CO2 emission quota
World Resources Reviews
(2001) - et al.
Managing climate risk
Science
(2001) - et al.
A Future for Biomass
Mechanical Engineering
(1997)
Final report on the development of a hydrogen-fueled combustion turbine cycle for power generation
Journal of Engineering for Gas Turbines Power
Biomass for energy: supply prospects
The Brazilian fuel–alcohol program
Cited by (198)
Solar-driven biomass chemical looping gasification using Fe<inf>3</inf>O<inf>4</inf> for syngas and high-purity hydrogen production
2024, Chemical Engineering JournalBECCS as climate mitigation option in a Brazilian low carbon energy system: Estimating potential and effect of gigatonne scale CO<inf>2</inf> storage
2023, International Journal of Greenhouse Gas ControlCarbon sequestration via shellfish farming: A potential negative emissions technology
2023, Renewable and Sustainable Energy ReviewsReflecting on the environmental impact of the captured carbon feedstock
2023, Science of the Total Environment