Sustainable steelmaking by process integration
Ghanbari Toudeshki, Hamid (2014-11-28)
Åbo Akademi - Åbo Akademi University
28.11.2014
Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty.
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe2014111746340
https://urn.fi/URN:NBN:fi-fe2014111746340
Tiivistelmä
Environmental issues, including global warming, have been serious challenges
realized worldwide, and they have become particularly important for the iron and steel
manufacturers during the last decades. Many sites has been shut down in developed
countries due to environmental regulation and pollution prevention while a large
number of production plants have been established in developing countries which has
changed the economy of this business.
Sustainable development is a concept, which today affects economic growth,
environmental protection, and social progress in setting up the basis for future
ecosystem. A sustainable headway may attempt to preserve natural resources, recycle
and reuse materials, prevent pollution, enhance yield and increase profitability. To
achieve these objectives numerous alternatives should be examined in the sustainable
process design. Conventional engineering work cannot address all of these substitutes
effectively and efficiently to find an optimal route of processing. A systematic
framework is needed as a tool to guide designers to make decisions based on overall
concepts of the system, identifying the key bottlenecks and opportunities, which lead to
an optimal design and operation of the systems.
Since the 1980s, researchers have made big efforts to develop tools for what today is
referred to as Process Integration. Advanced mathematics has been used in simulation
models to evaluate various available alternatives considering physical, economic and
environmental constraints.
Improvements on feed material and operation, competitive energy market,
environmental restrictions and the role of Nordic steelworks as energy supplier
(electricity and district heat) make a great motivation behind integration among
industries toward more sustainable operation, which could increase the overall energy
efficiency and decrease environmental impacts.
In this study, through different steps a model is developed for primary steelmaking,
with the Finnish steel sector as a reference, to evaluate future operation concepts of a
steelmaking site regarding sustainability. The research started by potential study on
increasing energy efficiency and carbon dioxide reduction due to integration of
steelworks with chemical plants for possible utilization of available off-gases in the
system as chemical products. These off-gases from blast furnace, basic oxygen furnace
and coke oven furnace are mainly contained of carbon monoxide, carbon dioxide,
hydrogen, nitrogen and partially methane (in coke oven gas) and have proportionally
low heating value but are currently used as fuel within these industries.
Nonlinear optimization technique is used to assess integration with methanol plant
under novel blast furnace technologies and (partially) substitution of coal with other
reducing agents and fuels such as heavy oil, natural gas and biomass in the system.
Technical aspect of integration and its effect on blast furnace operation regardless of
capital expenditure of new operational units are studied to evaluate feasibility of the
idea behind the research.
Later on the concept of polygeneration system added and a superstructure generated
with alternative routes for off-gases pretreatment and further utilization on a
polygeneration system producing electricity, district heat and methanol.
(Vacuum) pressure swing adsorption, membrane technology and chemical absorption
for gas separation; partial oxidation, carbon dioxide and steam methane reforming for
methane gasification; gas and liquid phase methanol synthesis are the main alternative
process units considered in the superstructure.
Due to high degree of integration in process synthesis, and optimization techniques,
equation oriented modeling is chosen as an alternative and effective strategy to previous
sequential modelling for process analysis to investigate suggested superstructure. A
mixed integer nonlinear programming is developed to study behavior of the integrated
system under different economic and environmental scenarios.
Net present value and specific carbon dioxide emission is taken to compare
economic and environmental aspects of integrated system respectively for different fuel
systems, alternative blast furnace reductants, implementation of new blast furnace
technologies, and carbon dioxide emission penalties. Sensitivity analysis, carbon
distribution and the effect of external seasonal energy demand is investigated with
different optimization techniques.
This tool can provide useful information concerning techno-environmental and
economic aspects for decision-making and estimate optimal operational condition of
current and future primary steelmaking under alternative scenarios. The results of the
work have demonstrated that it is possible in the future to develop steelmaking towards
more sustainable operation.
realized worldwide, and they have become particularly important for the iron and steel
manufacturers during the last decades. Many sites has been shut down in developed
countries due to environmental regulation and pollution prevention while a large
number of production plants have been established in developing countries which has
changed the economy of this business.
Sustainable development is a concept, which today affects economic growth,
environmental protection, and social progress in setting up the basis for future
ecosystem. A sustainable headway may attempt to preserve natural resources, recycle
and reuse materials, prevent pollution, enhance yield and increase profitability. To
achieve these objectives numerous alternatives should be examined in the sustainable
process design. Conventional engineering work cannot address all of these substitutes
effectively and efficiently to find an optimal route of processing. A systematic
framework is needed as a tool to guide designers to make decisions based on overall
concepts of the system, identifying the key bottlenecks and opportunities, which lead to
an optimal design and operation of the systems.
Since the 1980s, researchers have made big efforts to develop tools for what today is
referred to as Process Integration. Advanced mathematics has been used in simulation
models to evaluate various available alternatives considering physical, economic and
environmental constraints.
Improvements on feed material and operation, competitive energy market,
environmental restrictions and the role of Nordic steelworks as energy supplier
(electricity and district heat) make a great motivation behind integration among
industries toward more sustainable operation, which could increase the overall energy
efficiency and decrease environmental impacts.
In this study, through different steps a model is developed for primary steelmaking,
with the Finnish steel sector as a reference, to evaluate future operation concepts of a
steelmaking site regarding sustainability. The research started by potential study on
increasing energy efficiency and carbon dioxide reduction due to integration of
steelworks with chemical plants for possible utilization of available off-gases in the
system as chemical products. These off-gases from blast furnace, basic oxygen furnace
and coke oven furnace are mainly contained of carbon monoxide, carbon dioxide,
hydrogen, nitrogen and partially methane (in coke oven gas) and have proportionally
low heating value but are currently used as fuel within these industries.
Nonlinear optimization technique is used to assess integration with methanol plant
under novel blast furnace technologies and (partially) substitution of coal with other
reducing agents and fuels such as heavy oil, natural gas and biomass in the system.
Technical aspect of integration and its effect on blast furnace operation regardless of
capital expenditure of new operational units are studied to evaluate feasibility of the
idea behind the research.
Later on the concept of polygeneration system added and a superstructure generated
with alternative routes for off-gases pretreatment and further utilization on a
polygeneration system producing electricity, district heat and methanol.
(Vacuum) pressure swing adsorption, membrane technology and chemical absorption
for gas separation; partial oxidation, carbon dioxide and steam methane reforming for
methane gasification; gas and liquid phase methanol synthesis are the main alternative
process units considered in the superstructure.
Due to high degree of integration in process synthesis, and optimization techniques,
equation oriented modeling is chosen as an alternative and effective strategy to previous
sequential modelling for process analysis to investigate suggested superstructure. A
mixed integer nonlinear programming is developed to study behavior of the integrated
system under different economic and environmental scenarios.
Net present value and specific carbon dioxide emission is taken to compare
economic and environmental aspects of integrated system respectively for different fuel
systems, alternative blast furnace reductants, implementation of new blast furnace
technologies, and carbon dioxide emission penalties. Sensitivity analysis, carbon
distribution and the effect of external seasonal energy demand is investigated with
different optimization techniques.
This tool can provide useful information concerning techno-environmental and
economic aspects for decision-making and estimate optimal operational condition of
current and future primary steelmaking under alternative scenarios. The results of the
work have demonstrated that it is possible in the future to develop steelmaking towards
more sustainable operation.