CLIC Innovation Ltd coordinates research within the Carbon Capture and Storage Pro-ject (CCSP) that supports the development of carbon capture and storage (CCS) tech-nologies [1]. This thesis contributes to the project by evaluating the carbon capture op-tions for Kraft pulp mills and assessing the related bio-CCS potential as well as the ef-fect of political instruments on the economic feasibility of the studied technologies.
Climate change drives governments around the world to reduce greenhouse gas (GHG) emissions. The Finnish government aims to reduce the total GHG emissions from Fin-land by 80-95 % from the 1990 level by 2050, as stated in the government report Ener-gy and Climate Roadmap 2050 [2, p. 9]. According to the report, reaching this goal de-pends largely on the successful commercialization of carbon capture and storage (CCS) technologies. Much research on the subject has already been conducted [3-7], but most of the existing research has been focusing on applications for energy production, espe-cially coal-fired power plants, steel industry, oil refining and cement industry because of their large carbon dioxide (CO2) emissions and energy consumption. Some of the cap-ture methods developed for other industry sectors could also be implemented in the pulp and paper industry.
In most cases it is currently not economically feasible to capture carbon and therefore market supporting mechanisms are needed. Utilizing the captured CO2 would be opti-mal, but the associated capture potential is currently small compared to the emissions.
Even in the USA, the industrial need for CO2 was only 2 % of the emissions and en-hanced oil recovery (EOR) accounted for 80 % of that in 2002 [7, p. 42]. An example of a market supporting mechanism for CCS is the European Union Emission trading sys-tem (EU ETS) [8]. EU ETS regulates the maximal amount of fossil CO2 and other GHG that may be emitted by large energy intensive industries and aviation. To support CCS in pulp mills, the current EU ETS should be modified to include also biogenic emis-sions. The support from EU ETS should also be more reliable, as the emission allow-ance price has fluctuated from 30 €/t(CO2) to zero [8, p. 4; 9, p. 17] and between 6 and 8 €/t(CO2) in 2015 [10]. With the CO2 reduction goals as strict as Finland has, other political measures may be needed. The effects of the EU ETS and other political in-struments are discussed in more detail in Chapter 2.3.
In the Nordic countries the role pulp and paper industry is very significant. As the Finn-ish public statistics reveal, pulp and paper industry accounted for 50.6 % of the energy consumption [11] and around 30 % of the fossil CO2 emissions [12, p. 291] of the Finn-ish manufacturing industry in 2012. Even if the fossil CO2 emissions of the pulp and
paper industry are less than a third of the total manufacturing industry emissions in Fin-land, the biogenic CO2 emissions that originates from wood holds a much greater cap-ture potential, since the pulp and paper industry in Finland uses as much as 82 % wood-based fuels [13, p. 11].
When CO2 is released to the atmosphere, it acts the same way regardless of its origin.
However, biogenic CO2 originates from the carbon of living organisms, which in turn have absorbed the carbon from the atmosphere through photosynthesis. By extracting biogenic carbon from the normal growth cycle a possibility to remove CO2 from the atmosphere arises. This effect is also referred to as negative emissions and the concept as bio-CCS [14, p. 22] or biomass energy with carbon capture and storage (BECCS) [15, p. 4]. According to Kemper the term BECCS relates to power production whereas bio-CCS is considered to represent a wider context [16]. Thus the term bio-CCS is used in this work on pulp and paper industry.
Bio-CCS is usually associated with the risks of indirect change in land use (ILUC).
ILUC means that when biofuel raw ingredients are grown on land suitable for food pro-duction and the need for the food persists, the cropland for the food is obtained else-where such as from forests and grass lands [17]. However, the forest and grass lands store greater amounts of carbon than the biofuel crop. When additional biomass needs to be grown for bio-CCS purposes, the concerns about ILUC may be relevant. This is however not the case when implementing bio-CCS in pulp mills, as the aim is to store the biogenic CO2 that is currently being emitted to the atmosphere.
By producing wood-based products, the forest industry temporarily stores significant amounts of carbon [18, p. 555; 20]. Effective use of raw material is also essential for minimal impact on the climate. This is achievable as the same companies that own pulp mills also often have saw mills and thus timber waste is efficiently used for pulping [19].
In Figure 1, an overview of the biogenic carbon cycle of a wood-based product is pre-sented.
Figure 1. An overview of the biogenic carbon cycle regarding wood-based prod-ucts. Wood product average life times [20, p. 2]: biofuels and newspapers < 1
year, furniture 10-30 years and wooden buildings 75 years.
The pulp and paper industry alters the natural carbon cycle of the forest. The natural cycle consists of growing trees storing CO2 and dying trees releasing CO2 until a satura-tion of stored carbon is reached [18, p. 547]. Producing wood based products adds an-other temporary storage to the cycle, but some of the CO2 is emitted at the mill. Recy-cling products lengthens the carbon storage time. Eventually the carbon is released to the atmosphere, when the product decays or is burnt in a waste treatment plant. Last, CCS implemented in a pulp mill captures biogenic carbon and stores it permanently underground, thus removing CO2 from the atmosphere and creating negative emissions.
It is a valid question, which of these storages should be preferred, or all of them. The focus of this thesis is highlighted in the drawing with a white hatched box: is the CO2 capture from pulp mills feasible.
In this thesis it is shown by which means CO2 can most feasibly be captured from the Finnish pulp mills. To examine the different aspects of technical and economic feasibil-ity, the following research questions were chosen:
Which carbon capture technologies are implementable in pulp mills in the near future?
How much CO2 could potentially be captured with each technology?
What is the break-even price (BeP) for the emission allowance if biogenic emis-sions were included?
The break-even price is the price that covers the costs of applying a carbon capture technology, but in this thesis the transportation and storage costs are excluded. To an-swer the research questions, an extensive literature review on carbon capture technolo-gies was conducted. Three novel carbon capture technolotechnolo-gies were modelled and one calculated based on mass and energy balances and then compared with a reference Kraft pulp mill scaled to the production capacity of 1200 ADt/d to assess the costs of each technology. Finally, the previous results and the technologies studied within this thesis were compared under same assumptions regarding the commodity costs, investment parameters and applicable policies. The readiness of each technology was evaluated based on previous research in pulp and paper industry as well as in other industry sec-tors. The capture potential of each carbon capture option was investigated by examining two of the most significant factors: first, in how many and how large mills could the technology be implemented and second, how much carbon could be captured.
The context for the analyses was the current and expected pulp and paper industry in Finland by 2030. When comparing the technologies, the system boundaries were set to contain only the carbon capture process and the immediately affected units. The trans-portation and storage costs were only briefly reviewed based on previous research [5, 21].
In this study it has been shown how much the carbon capture should be supported in order to be economically feasible. Technologies including new by-products or other revenue streams may be profitable even without support, but the associated carbon cap-ture potential seems limited. Some of these technologies are still in early stages of de-velopment and more pilot and demonstration plants are needed. Such practical studies could be facilitated by cooperation between researchers and the industry.