Replacing Coal used in Steelmaking with Biocarbon from Forest Industry Side Streams

Research output: Book/ReportReportProfessional

Abstract

Steelmaking is a highly carbon-intensive process due to its extensive use of coal as both an energy source and a reductant. The CO2 release of Finnish steel production plants exceeds 5 million tonnes/a, accounting for nearly 10% of Finland's CO2 impact. Approximately 80% of these emissions originate from the blast furnace ironmaking process, the production of which currently exceeds 2 million tonnes/a of raw steel. Blast furnaces will remain the major steel production route in Finland for the foreseeable future.
In the last 10–15 years a remarkable research and development effort has been focused within the steel industry on improving the performance and energy efficiency of the blast furnace. While significant advances have been made, possibilities to gain further decreases in fuel or reductant consumption are limited due to the high level of maturity and efficiency of the current furnace technology. Thus, new technologies are needed to further reduce greenhouse gas (GHG) emissions associated with steel production. For this, the substitution of fossil carbon with biocarbon has been proposed. The first option is to use biocarbon as a component of the pulverized coal injection (PCI), which takes place through tuyeres in the lower part of the blast furnace.
In this research, two kinds of side streams from the forest industry were tested and evaluated as raw materials for PCI biocarbon. Softwood bark from biorefineries (e.g. in the form of black pellets from steam explosion) or residual hydrolysis lignin from sawdust-based bioethanol production were used. Both raw materials were treated with slow pyrolysis and the physical, chemical and rheological properties of the biochar thus produced were compared with those of typical injection coal. Both materials appear to be viable PCI substitutes.
Various scenarios for integrating pyrolysis to either the forest industry or steel industry site were examined and techno-economic analysis of the use of biocarbon as a substitute for fossil PCI coal was carried out for each case. It is inferred that there will be sufficient sources of both bark from biorefineries and hydrolysis lignin in Finland in the near future to replace substantial fractions of PCI coal. Use of biochar will decrease GHG emissions; however, the extent is dependent on the operational environment and the power source used to compensate the respective biomassbased electricity and district heat production. The economy of biochar usage as a PCI substitute is becoming more viable with rising CO2 emission costs.
Original languageEnglish
PublisherVTT Technical Research Centre of Finland
Number of pages141
ISBN (Electronic)978-951-38-8684-4
DOIs
Publication statusPublished - 2019
MoE publication typeD4 Published development or research report or study

Publication series

NameVTT Technology
PublisherVTT
No.351
ISSN (Print)2242-1211
ISSN (Electronic)2242-122X

Fingerprint

Steelmaking
Coal
Industry
Blast furnaces
Steel
Iron and steel industry
Lignin
Gas emissions
Greenhouse gases
Hydrolysis
Raw materials
Pyrolysis
Sawdust
Bioethanol
Carbon
Softwoods
Economic analysis
Explosions
Energy efficiency
Furnaces

Keywords

  • co2
  • PCI Coal
  • blast furnace
  • substitute of fossil carbon
  • biocarbon
  • reductant

Cite this

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title = "Replacing Coal used in Steelmaking with Biocarbon from Forest Industry Side Streams",
abstract = "Steelmaking is a highly carbon-intensive process due to its extensive use of coal as both an energy source and a reductant. The CO2 release of Finnish steel production plants exceeds 5 million tonnes/a, accounting for nearly 10{\%} of Finland's CO2 impact. Approximately 80{\%} of these emissions originate from the blast furnace ironmaking process, the production of which currently exceeds 2 million tonnes/a of raw steel. Blast furnaces will remain the major steel production route in Finland for the foreseeable future. In the last 10–15 years a remarkable research and development effort has been focused within the steel industry on improving the performance and energy efficiency of the blast furnace. While significant advances have been made, possibilities to gain further decreases in fuel or reductant consumption are limited due to the high level of maturity and efficiency of the current furnace technology. Thus, new technologies are needed to further reduce greenhouse gas (GHG) emissions associated with steel production. For this, the substitution of fossil carbon with biocarbon has been proposed. The first option is to use biocarbon as a component of the pulverized coal injection (PCI), which takes place through tuyeres in the lower part of the blast furnace.In this research, two kinds of side streams from the forest industry were tested and evaluated as raw materials for PCI biocarbon. Softwood bark from biorefineries (e.g. in the form of black pellets from steam explosion) or residual hydrolysis lignin from sawdust-based bioethanol production were used. Both raw materials were treated with slow pyrolysis and the physical, chemical and rheological properties of the biochar thus produced were compared with those of typical injection coal. Both materials appear to be viable PCI substitutes. Various scenarios for integrating pyrolysis to either the forest industry or steel industry site were examined and techno-economic analysis of the use of biocarbon as a substitute for fossil PCI coal was carried out for each case. It is inferred that there will be sufficient sources of both bark from biorefineries and hydrolysis lignin in Finland in the near future to replace substantial fractions of PCI coal. Use of biochar will decrease GHG emissions; however, the extent is dependent on the operational environment and the power source used to compensate the respective biomassbased electricity and district heat production. The economy of biochar usage as a PCI substitute is becoming more viable with rising CO2 emission costs.",
keywords = "co2, PCI Coal, blast furnace, substitute of fossil carbon, biocarbon, reductant",
author = "Juha Hakala and Petteri Kangas and Karri Penttil{\"a} and Matias Alarotu and Martin Bj{\"o}rnstr{\"o}m and Pertti Koukkari",
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language = "English",
series = "VTT Technology",
publisher = "VTT Technical Research Centre of Finland",
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Replacing Coal used in Steelmaking with Biocarbon from Forest Industry Side Streams. / Hakala, Juha; Kangas, Petteri; Penttilä, Karri; Alarotu, Matias; Björnström, Martin; Koukkari, Pertti.

VTT Technical Research Centre of Finland, 2019. 141 p. (VTT Technology; No. 351).

Research output: Book/ReportReportProfessional

TY - BOOK

T1 - Replacing Coal used in Steelmaking with Biocarbon from Forest Industry Side Streams

AU - Hakala, Juha

AU - Kangas, Petteri

AU - Penttilä, Karri

AU - Alarotu, Matias

AU - Björnström, Martin

AU - Koukkari, Pertti

PY - 2019

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N2 - Steelmaking is a highly carbon-intensive process due to its extensive use of coal as both an energy source and a reductant. The CO2 release of Finnish steel production plants exceeds 5 million tonnes/a, accounting for nearly 10% of Finland's CO2 impact. Approximately 80% of these emissions originate from the blast furnace ironmaking process, the production of which currently exceeds 2 million tonnes/a of raw steel. Blast furnaces will remain the major steel production route in Finland for the foreseeable future. In the last 10–15 years a remarkable research and development effort has been focused within the steel industry on improving the performance and energy efficiency of the blast furnace. While significant advances have been made, possibilities to gain further decreases in fuel or reductant consumption are limited due to the high level of maturity and efficiency of the current furnace technology. Thus, new technologies are needed to further reduce greenhouse gas (GHG) emissions associated with steel production. For this, the substitution of fossil carbon with biocarbon has been proposed. The first option is to use biocarbon as a component of the pulverized coal injection (PCI), which takes place through tuyeres in the lower part of the blast furnace.In this research, two kinds of side streams from the forest industry were tested and evaluated as raw materials for PCI biocarbon. Softwood bark from biorefineries (e.g. in the form of black pellets from steam explosion) or residual hydrolysis lignin from sawdust-based bioethanol production were used. Both raw materials were treated with slow pyrolysis and the physical, chemical and rheological properties of the biochar thus produced were compared with those of typical injection coal. Both materials appear to be viable PCI substitutes. Various scenarios for integrating pyrolysis to either the forest industry or steel industry site were examined and techno-economic analysis of the use of biocarbon as a substitute for fossil PCI coal was carried out for each case. It is inferred that there will be sufficient sources of both bark from biorefineries and hydrolysis lignin in Finland in the near future to replace substantial fractions of PCI coal. Use of biochar will decrease GHG emissions; however, the extent is dependent on the operational environment and the power source used to compensate the respective biomassbased electricity and district heat production. The economy of biochar usage as a PCI substitute is becoming more viable with rising CO2 emission costs.

AB - Steelmaking is a highly carbon-intensive process due to its extensive use of coal as both an energy source and a reductant. The CO2 release of Finnish steel production plants exceeds 5 million tonnes/a, accounting for nearly 10% of Finland's CO2 impact. Approximately 80% of these emissions originate from the blast furnace ironmaking process, the production of which currently exceeds 2 million tonnes/a of raw steel. Blast furnaces will remain the major steel production route in Finland for the foreseeable future. In the last 10–15 years a remarkable research and development effort has been focused within the steel industry on improving the performance and energy efficiency of the blast furnace. While significant advances have been made, possibilities to gain further decreases in fuel or reductant consumption are limited due to the high level of maturity and efficiency of the current furnace technology. Thus, new technologies are needed to further reduce greenhouse gas (GHG) emissions associated with steel production. For this, the substitution of fossil carbon with biocarbon has been proposed. The first option is to use biocarbon as a component of the pulverized coal injection (PCI), which takes place through tuyeres in the lower part of the blast furnace.In this research, two kinds of side streams from the forest industry were tested and evaluated as raw materials for PCI biocarbon. Softwood bark from biorefineries (e.g. in the form of black pellets from steam explosion) or residual hydrolysis lignin from sawdust-based bioethanol production were used. Both raw materials were treated with slow pyrolysis and the physical, chemical and rheological properties of the biochar thus produced were compared with those of typical injection coal. Both materials appear to be viable PCI substitutes. Various scenarios for integrating pyrolysis to either the forest industry or steel industry site were examined and techno-economic analysis of the use of biocarbon as a substitute for fossil PCI coal was carried out for each case. It is inferred that there will be sufficient sources of both bark from biorefineries and hydrolysis lignin in Finland in the near future to replace substantial fractions of PCI coal. Use of biochar will decrease GHG emissions; however, the extent is dependent on the operational environment and the power source used to compensate the respective biomassbased electricity and district heat production. The economy of biochar usage as a PCI substitute is becoming more viable with rising CO2 emission costs.

KW - co2

KW - PCI Coal

KW - blast furnace

KW - substitute of fossil carbon

KW - biocarbon

KW - reductant

U2 - 10.32040/2242-122X.2019.T351

DO - 10.32040/2242-122X.2019.T351

M3 - Report

T3 - VTT Technology

BT - Replacing Coal used in Steelmaking with Biocarbon from Forest Industry Side Streams

PB - VTT Technical Research Centre of Finland

ER -