Abstract
The iron and steel industry is one of the largest
emitters of industrial CO2, accounting for around 6% of
global anthropogenic CO2 emissions each year. In Europe,
the recently proposed stricter emission reduction targets
for 2030 are likely to increase the price for CO2
emission allowances. Various different GHG emission
mitigation alternatives have been considered to enable
decarbonisation of the iron and steel industry, such as
energy efficiency, biogenic reducing agents, hydrogen and
CCS. However, not all of these can be deployed for the
most important production route - the blast furnace and
basic oxygen furnace route (BF + BOF) - and all the
solutions have advantages and disadvantages. CCS is
currently the only mitigation option available for
significantly reducing emissions from this
energy-intensive industry. A full chain assessment of
carbon capture and storage (CCS) applications for the
iron and steel industry was performed in order to screen
technology options and build a development pathway to low
carbon steelmaking for future carbonconstrained world. A
techno-economic assessment of application of CCS with
various technologies in the iron and steel industry was
carried out to create a knowledge base for a Nordic steel
producer. The assessment was conducted for two different
CO2 capture alternatives, namely post-combustion carbon
capture and oxygen blast furnaces (OBF) with flue gas
circulation. Processes were assessed by technical
modelling based on the Aspen Plus process simulator and
the economic evaluation toolkit CC-SkynetTM using two
indicators: the break-even price of CO2 emission
allowances for CCS and the impact of CCS on steel
production costs. With the whole chain approach,
including CO2 capture, processing, transport and storage,
the results show a significant reduction potential at an
integrated steel mill for all carbon capture technologies
assessed. The application of an OBF would require a
larger modification of the processes of the existing
steel mill than that required by the application of
post-combustion capture. The staged construction and
implementation of CCS in order to minimise the financial
investment risk was considered and several pathways for
implementation were analysed. Only transportation of CO2
by ship was considered due to the coast-line location of
the installation far from other emission sources,
pipeline infrastructures and storage sites. Results show
the cost structure and feasibility of the studied
technologies. Cost break-even points for CCS at an
integrated steel mill, for the plant owner and costs for
globally avoided emissions are calculated. The direct
site emissions were reduced by 0.28-2.93 Mt CO2/a. The
cases resulting in significant reductions represent
48-73% of direct site emissions. The net GHG impact of
emission reductions are between 45-62% of the site
emission reductions. The cost of emission reductions are
estimated from the site owner perspective, with the costs
in majority of the cases being between 40-70/t CO2.
Oxygen blast furnace with top gas recirculation was
estimated to be slightly cheaper than post-combustion
capture of CO2. As presented in the results of this
study, BePs (break-even prices) are very sensitive to
several factors which are uncertain regarding the time
frame of large investments. The results also showed that
the costs for CCS are heavily dependent not only on the
characteristics of the facility and the operational
environment, but also on the chosen system boundaries and
assumptions.
Original language | English |
---|---|
Qualification | Doctor Degree |
Awarding Institution |
|
Supervisors/Advisors |
|
Award date | 27 Nov 2015 |
Place of Publication | Espoo |
Publisher | |
Print ISBNs | 978-951-38-8357-7 |
Electronic ISBNs | 978-951-38-8358-4 |
Publication status | Published - 2015 |
MoE publication type | G5 Doctoral dissertation (article) |
Keywords
- iron and steel industry
- techno-economic evaluation
- CCS
- feasibility
- post-combustion capture
- oxygen blast furnace
- Aspen Plus modelling
- Skynet tool