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EP-4737537-A1 - METHOD FOR PRODUCING COKE

EP4737537A1EP 4737537 A1EP4737537 A1EP 4737537A1EP-4737537-A1

Abstract

Provided is a new index for biomass-derived raw material that can replace a portion of coal used in the production of coke for blast furnaces, and a means for producing high-strength coke even when biomass-derived raw material is blended with coal. Carbonized biomass having a shrinkage rate of 4.0 % or more and 10.0 % or less at 600 °C to 1000 °C is blended with a coal blend to produce coke.

Inventors

  • KAWAI, YUYA
  • TAKASHIMA, TAKANORI

Assignees

  • JFE Steel Corporation

Dates

Publication Date
20260506
Application Date
20240425

Claims (4)

  1. A method of producing coke, the method comprising: dry-distilling a mixture obtained by blending a defined proportion of carbonized biomass with a coal blend for coke production, wherein a proportion of the carbonized biomass having a particle size of 3.0 mm or less is 70 mass% or more and 100 mass% or less, and the carbonized biomass has a shrinkage rate of 4.0 % or more and 10.0 % or less at 600 °C to 1000 °C.
  2. A method of producing coke, the method comprising: dry-distilling a mixture obtained by blending a defined proportion of carbonized biomass with a coal blend for coke production, wherein a proportion of the carbonized biomass having a particle size of 1.0 mm or less is 70 mass% or more and 100 mass% or less, and the carbonized biomass has a shrinkage rate of 2.0 % or more and 10.0 % or less at 600 °C to 1000 °C.
  3. The method of producing coke according to claim 1 or 2, wherein the defined proportion of the carbonized biomass in the mixture is 1.0 mass% or more and 10.0 mass% or less.
  4. The method of producing coke according to any one of claims 1 to 3, wherein a proportion of the coal blend for coke production having a particle size of 3.0 mm or less is 70 mass% or more and 100 mass% or less.

Description

TECHNICAL FIELD The present disclosure relates to a method of producing coke using biomass as a portion of raw material. BACKGROUND Coke is a mainly carbon agglomerate product obtained by dry-distilling coal. Blast furnace coke used in a blast furnace functions as a heat source and a reducing agent, and also as a support material that secures gas permeability and liquid permeability inside the blast furnace. Therefore, in order to secure stable operation of the blast furnace, the agglomerate coke is required to have sufficient mechanical strength. In the production of blast furnace coke, a coal blend in which multiple types of coal are blended in a defined proportion is used. The coal blend is dry-distilled at a temperature of 1000 °C or higher either as is or after being molded, to obtain agglomerated coke in which coal particles are bonded together. By using a type of coal called caking coal, which has a property of easily softening and melting, as a portion of the coal blend, it is possible to obtain coke that has high strength. Two types of measured values of coal have conventionally been used as indices for managing coke strength. One is an average maximum reflectance of vitrinite (hereinafter referred to as "Ro") as specified in Japanese Industrial Standard M 8816:1992 "Solid mineral fuels - Methods of microscopical measurement for the macerals and reflectance". The higher the Ro value of coal, the higher the degree of carbonization and the stronger the coke matrix tends to be. The other is maximum fluidity according to a Gieseler plastometer (hereinafter referred to as "MF"), as specified in Japanese Industrial Standard M 8801:2004 "Coal-testing methods". The higher the MF value of coal, the more the coal tends to soften, melt, and flow when heated. In recent years, societal efforts to mitigate the impact of global warming by decreasing carbon dioxide emissions into the atmosphere, one of the greenhouse gases, have been accelerating. For this reason, studies are underway to replace a portion of the coal used to make coke with carbon-neutral raw material such as biomass. For example, in Patent Literature (PTL) 1, a method of producing highly reactive blast furnace coke is described, in which biomass is heated to 1000 °C or higher to pyrolyze the biomass, and the resulting solid biomass char having a diameter of 1 mm or less is added to a coal blend. CITATION LIST Patent Literature PTL 1: JP 2014-077086 A SUMMARY (Technical Problem) When attempting to replace a portion of the coal used to make coke with a biomass-derived raw material, even a small substitution ratio can significantly decrease the strength of the resulting coke. Conventionally, Ro and MF, which are effective indices for managing the strength of coke, are both indices for measurement of coal. Therefore, when attempting to measure Ro and MF for a sample consisting only of biomass-derived raw material, the properties of coal and biomass are significantly different, and therefore it is either impossible to carry out the measurements, or even if the measurements could be carried out, the measured values could not be used as indices for managing the strength of such coke. Therefore, a new index for managing the strength of coke is required. In view of the problems described above, it would be helpful to provide a new index for biomass-derived raw material that can replace a portion of the coal used in producing coke for blast furnaces, and to provide a means of producing high-strength coke even when biomass-derived raw material is blended with coal. (Solution to Problem) The primary features of the present disclosure are as follows. [1] A method of producing coke, the method comprising: dry-distilling a mixture obtained by blending a defined proportion of carbonized biomass with a coal blend for coke production, wherein a proportion of the carbonized biomass having a particle size of 3.0 mm or less is 70 mass% or more and 100 mass% or less, andthe carbonized biomass has a shrinkage rate of 4.0 % or more and 10.0 % or less at 600 °C to 1000 °C.[2] A method of producing coke, the method comprising: dry-distilling a mixture obtained by blending a defined proportion of carbonized biomass with a coal blend for coke production, wherein a proportion of the carbonized biomass having a particle size of 1.0 mm or less is 70 mass% or more and 100 mass% or less, andthe carbonized biomass has a shrinkage rate of 2.0 % or more and 10.0 % or less at 600 °C to 1000 °C.[3] The method of producing coke according to [1] or [2], above, wherein the defined proportion of the carbonized biomass in the mixture is 1.0 mass% or more and 10.0 mass% or less.[4] The method of producing coke according to any one of [1] to [3], above, wherein a proportion of the coal blend for coke production having a particle size of 3.0 mm or less is 70 mass% or more and 100 mass% or less. (Advantageous Effect) According to the present disclosure, a property of biomass-derived raw materi