Last updated: October 4, 2023

About limestone

Abundant resources around the world

Limestone, which is the raw material of LIMEX, is abundant all over the world, and is a resource that is 100% self-sufficient (*1) even in Japan. By using abundant limestone, we can contribute to resource conservation on a global scale by reducing the use of resources such as oil, wood, and water that are needed to manufacture plastics and paper. increase.

As the world's population continues to grow, the demand for plastics and paper will continue to grow. On the other hand, because of its abundance, limestone has excellent supply stability and is inexpensive as a raw material to replace plastics and paper. For this reason, LIMEX, which is made from limestone, is attracting attention from all over the world, including countries where water resources are scarce and rely on imported paper, and African regions where resource consumption is accelerating due to population growth. It is more than just a new material, it is also a business that distributes new wealth around the world.

The main component of limestone is calcium carbonate. CCU (Carbon Capture and Utilization) technology, which captures, fixes and effectively utilizes CO 2, is currently being developed in countries around the world. As part of this, TBM is working with external partners to fix CO 2 and generate calcium carbonate. In the future, instead of limestone, which is a mineral resource, we aim to use calcium carbonate made from CO2 emitted from factories and power plants as a raw material to further reduce greenhouse gas emissions and realize a carbon negative material. increase.

Domestic production and shipment of self-sufficient limestone

FY2021 Unit: tons
Source: Limestone Mining Association

Limestone in Japan is mostly used for urban development, as shown in the graph. We are familiar with it, and it can be said that it is an indispensable resource in our lives. The amount of limestone used in LIMEX produced at our own factory is only 0.01% of the amount used in Japan. Incidentally, about 600,000 to 900,000 tons of limestone is used annually as a coating agent and filler (preventing see-through) for paper, and as a raw material for pulp bleaching agents.

*1 Limestone Mining Association

The majority of limestone is used for urban development Composition ratio of limestone by application

FY2021 Unit: t
Total: 126.23 million tons (excluding export volume)

Source: Limestone Mining Association

Limestone used by LIMEX

The limestone used for LIMEX is not directly mined by TBM from limestone mines, but procured in the form of calcium carbonate powder from suppliers that supply conventional cement and steel production. Procurement sources vary depending on the manufacturing plant and application. For example, our Shiroishi Plant (Shiroishi City, Miyagi Prefecture) selects limestone from the Tohoku region.

Limestone mining does not have zero impact on the environment and society, but while there are many minerals that require large amounts of energy and substances with a high environmental impact in their extraction and refining processes, limestone does not require such processes. We believe that the environmental impact and social risks that are of concern for other minerals are extremely small.

In addition, TBM strives to understand the environmental and social considerations of each supplier and encourages advanced management. Our suppliers also cooperate with our environmental and social consideration policy, such as having an environmental management system.

How much limestone does LIMEX use?

As mentioned above, the amount of limestone used for LIMEX produced at our own factory is 0.01% of domestic limestone shipments. In addition, limestone is used as a paper coating agent and filler (preventing see-through) at approximately 600,000 to 900,000 tons per year, which is 30 to 50 times the amount of LIMEX, and is also used as a raw material for bleaching pulp. It has been.

As LIMEX becomes more popular in the future, the amount of limestone used is expected to increase. , about 3.79 million tons of limestone is required. It is only about 3.0% of the total shipment of limestone. Similarly, even if all polyethylene and polypropylene (4.5 million tons in 2019)*2, which account for approximately 46% of total plastic production in Japan, were replaced with LIMEX Pellet, approximately 4.42 million tons of limestone would be required (*3). ), which is about 3.5% of the total shipment of limestone in Japan.

*1 Japan Paper Association
*2 The Association for Recycling and Recycling of Plastics "2020 Status of Production, Disposal, Recycling and Processing of Plastic Products"
*3 "Petrochemicals and Synthetic Resins" by the Japan Petrochemical and Mining Association

Currently only 0.01% LIMEX limestone usage

Source: Japan Paper Association, Limestone Industry Association, Plastic Recycling Association "2020 Status of Production, Disposal, Recycling and Treatment of Plastic Products", Petrochemical and Mining Association "Petrochemicals and Synthetic Resins"

Limestone and  CO2 emissions

Nowadays, there is a need to quantitatively understand the environmental impact that all products and services have during their life cycles, and to work to reduce them. Among these, greenhouse gas emissions, especially CO 2 emissions, are attracting the most attention.

petroleum-based plastics are manufactured by drilling crude oil and transporting it to a refinery, then fractionating the naphtha and polymerizing the extracted monomers. Much energy is consumed during the heating process, etc., and CO 2 is emitted. On the other hand, because limestone has a simple manufacturing and processing process of crushing mined limestone, less energy is required at the raw material procurement stage compared to petroleum-based plastics.

Of course, if limestone is incinerated, it also emits CO 2. However, compared to petroleum-based such as polypropylene, CO 2 emissions during combustion are approximately 58% lower due to the difference in molecular structure.

For more information on greenhouse gas (GHG) emissions data such as CO 2 throughout the life cycle (from raw material procurement stage to disposal) of LIMEX, which is made from limestone, please see "Product Introduction."

CO2 emissions during combustion

* Limestone: Calculated from chemical reaction formula assuming 100% calcium carbonate (CaCO3) (assuming volume of 1 kg of PP)
(Source) CO2 emissions during combustion of PP/PE: Japan Plastic Recycling Association,
(Source) LCI database IDEA version 2.3, National Institute of Advanced Industrial Science and Technology, Safety Science Research Institute, Society and LCA Group, Sustainable Management Promotion Organization

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