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JP-2026075961-A - Pellet storage method and pellet storage equipment

JP2026075961AJP 2026075961 AJP2026075961 AJP 2026075961AJP-2026075961-A

Abstract

[Problem] To provide a method for storing biomass-derived pellets that can suppress spontaneous combustion when the pellets are stored. [Solution] A method for storing pellets, comprising: a deposit formation step of stacking biomass-derived pellets to form a pellet deposit; and a suppression means placement step of placing a water vapor movement suppression means on at least a portion of the deposit being stacked during the deposit formation step; wherein, after the suppression means placement step, pellets are further stacked on the placed water vapor movement suppression means to form the pellet deposit, and the water vapor movement suppression means is a means for suppressing the movement of water vapor from the inner side to the surface side of the pellet deposit. [Selection Diagram] Figure 5

Inventors

  • 細谷 郁雄

Assignees

  • 出光興産株式会社

Dates

Publication Date
20260511
Application Date
20241023

Claims (14)

  1. A method for storing pellets, A sediment formation process involves stacking biomass-derived pellets to form a pellet deposit, The process includes a step of arranging a means to suppress water vapor movement, in which a means to suppress water vapor movement is placed in at least a portion of the sediment being piled up during the sediment formation process. After the step of arranging the suppression means, pellets are further piled on top of the arranged water vapor transfer suppression means to form the pellet deposit. The water vapor movement suppression means is a means for suppressing the movement of water vapor from the inner side to the surface side of the pellet deposit. How to store pellets.
  2. The aforementioned pellet piles are at least one of the following: pellet piles piled up on the ground, pellet piles piled up in silos and warehouses, and pellet piles piled up in containers. The method for storing pellets according to claim 1.
  3. The step of arranging the suppression means is the step of arranging the water vapor transfer suppression means so as to cover at least a portion of the deposits that are being piled up. A method for storing pellets according to claim 1 or claim 2.
  4. The step of arranging the suppression means is performed two or more times during the stacking of the pellets. A method for storing pellets according to any one of claims 1 to 3.
  5. The step of arranging the suppression means is the step of arranging the water vapor transfer suppression means so as to follow the contour of the sediment being piled up. A method for storing pellets according to claim 3 or claim 4.
  6. After the aforementioned sediment formation process is carried out, the pellet sediment has a pellet-dry region mainly composed of pellets with a moisture content of less than 6% by mass, and a pellet-wet region mainly composed of pellets with a moisture content of 6% by mass or more. The pellet drying region is a region that occurs on the surface side of the pellet deposit when the moisture content of the pellets present in the surface layer of the pellet deposit becomes lower than the moisture content of the pellets immediately after the formation of the pellet deposit. The aforementioned pellet-wet region is a region that occurs on the inner side of the pellet deposit, The water vapor transfer suppression means is arranged to cover at least a portion of the area that may become a pellet wet area. A method for storing pellets according to any one of claims 1 to 5.
  7. The region that may become a pellet-wet region is 30% to 90% by volume of the total volume of the pellet deposit. The method for storing pellets according to claim 6.
  8. The water vapor transfer suppression means is positioned between the region that may become a pellet wet region and the region that may become a pellet dry region. A method for storing pellets according to claim 6 or claim 7.
  9. The water vapor transfer suppression means is arranged horizontally with respect to the bottom surface of the pellet deposit. A method for storing pellets according to any one of claims 1 to 7.
  10. The water vapor transfer suppression means is arranged at intervals of 0.5 m to 5.0 m from the top to the bottom of the pellet deposit. The method for storing pellets according to claim 9.
  11. The water vapor transfer suppression means is at least one selected from the group consisting of sheet members and plate members. A method for storing pellets according to any one of claims 1 to 10.
  12. The aforementioned pellet is at least one selected from the group consisting of woody biomass pellets, herbaceous biomass pellets, crop residue biomass pellets, and palm oil biomass pellets. A method for storing pellets according to any one of claims 1 to 11.
  13. The aforementioned pellets are wood-based biomass pellets. A method for storing pellets according to any one of claims 1 to 12.
  14. A pellet storage facility, A means of stacking biomass-derived pellets in a storage area to form a pellet deposit, The storage area includes means for arranging a water vapor movement suppression means in at least a portion of the storage area to suppress the movement of water vapor from the inner side to the surface side of the pellet deposit, The aforementioned storage location is at least one of the following: the ground, a silo, a warehouse, and a container. The water vapor transfer suppression means is at least one selected from the group consisting of sheet members and plate members. Pellet storage facility.

Description

This invention relates to a method for storing pellets and a pellet storage facility. In recent years, biomass fuels have been considered as a way to reduce CO2 emissions, which are considered a cause of global warming. Burning biomass releases CO2 , but since plants absorb CO2 as they grow, the use of biomass fuels produced from wood and other materials does not change the amount of CO2 in the atmosphere overall (carbon neutral). Using this biomass fuel as fuel for power plants is expected to significantly reduce CO2 emissions compared to power plants that conventionally use fossil fuels such as coal. While other renewable energy sources such as solar and wind power are also being promoted, biomass fuels, compared to those that depend on natural conditions (sunlight and weather, etc.), can be stored in silos, allowing for flexible power generation to match electricity demand (supply and demand adjustment function). Therefore, it is a superior renewable energy source in that it can be operated in the same way as conventional thermal power plants that use fossil fuels. On the other hand, because biomass has a tendency to generate heat spontaneously, technologies to improve the safety of biomass are being considered. For example, Patent Document 1 discloses a biomass containment device. This biomass containment device comprises a containment container for containing either herbaceous biomass or woody biomass, or both, and means for preventing the formation of a reducing environment that suppresses the growth of microorganisms in the containment container. The means for preventing the formation of a reducing environment is described as a means for blowing gas (e.g., oxidizing gas and inert gas, etc.) above the growth limit temperature of microorganisms attached to the biomass from vertically below the upper surface of the biomass contained in the containment container. Furthermore, Non-Patent Document 1 describes the results of an investigation into the spontaneous combustion mechanism when wood pellets are stored, as well as a method for evaluating their spontaneous combustion properties. Non-Patent Document 2 describes a method for evaluating the spontaneous heating properties when coal is stored. Japanese Patent Publication No. 2014-118187 "Investigation on the Spontaneous Combustion Potential of Wood Pellet Storage," Masayoshi Kimoto, Masami Tozawa, Research Report: M08022, Central Research Report of Electric Power Industry, May 2009."Study on Evaluation Methods for Spontaneous Heat Generation in Coal Storage Management," Masaharu Matsumoto, 55th Japan Coal Science Conference (Kitakyushu City), October 29, 2018. A diagram illustrating the mechanism by which pellets piled up in a pellet deposit spontaneously combust.Schematic diagram of a spontaneous heating test apparatus.A graph showing the results of the spontaneous heating test for samples 1 and 2.Graphs showing the results of spontaneous heating tests in Test Examples 1-4.This figure illustrates a first example of a storage method according to this embodiment.This figure illustrates a second example of the storage method according to this embodiment. In this specification, a numerical range represented by "~" means a range that includes the number written before "~" as the lower limit and the number written after "~" as the upper limit. In this specification, mass percentage concentration (unit: mass%) and weight percentage concentration (unit: weight%) are the same value. [First Embodiment] [Storage method for pellets] The pellet storage method according to this embodiment (hereinafter also referred to as "the storage method according to this embodiment") comprises a deposit formation step of stacking biomass-derived pellets to form a pellet deposit, and a suppression means placement step of placing a water vapor transfer suppression means in at least a portion of the deposit being stacked during the deposit formation step. After the step of arranging the suppression means, pellets are further piled on top of the arranged water vapor movement suppression means to form the pellet deposit. The water vapor movement suppression means is a means for suppressing the movement of water vapor from the inner side to the surface side of the pellet deposit. According to the storage method of this embodiment, a water vapor movement suppression means is placed in at least a portion of the pile during stacking. This suppresses the movement of water vapor from the deeper part of the pellet pile to the surface. As described later, the movement of water vapor from the deeper part of the pellet pile to the surface is considered a factor that causes spontaneous combustion of pellets. Therefore, according to the storage method of this embodiment, spontaneous combustion can be suppressed when pellets are stored. The water vapor transfer suppression means is preferably at least one selected from the group consisting of sheet members and plate members, and more preferably a