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 limestone, we will reduce the use of scarce resources such as oil, wood, and water that are considered to be at high risk of depletion, and contribute to resource conservation on a global scale.

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. For this reason, LIMEX is attracting attention from regions 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 accelerates new industry around the world.

 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. 

Domestic self-sufficient limestone production and consumption

FY2021 Unit: tons
Source: Limestone Mining Association

Limestone in Japan is mostly used for urban development, as shown in the graph. It can be said that it is an indispensable resource in our lives. The maximum amount of limestone used in LIMEX produced at our own factory is 18,600 tons per year, which is only 0.01% of the amount used in Japan. 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 bleaching pulp.

*1 Limestone Mining Association

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

FY2021 Unit: tons
Source: Limestone Mining Association

Limestone used by LIMEX

The limestone used for LIMEX is not directly mined by TBM, but is brought from suppliers that supply traditional cement and steel production. Procurement sources vary depending on the manufacturing plant and application, but we aim to create local production for local consumption model.

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 maximum amount of limestone used for LIMEX produced at our own factory is 18,600 tons per year, which is 0.01% of the 132,690,000 tons of domestic limestone consumption per year. 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. 

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, which is only about 2.9% of the total shipment of 130 million tons of limestone (*2). Similarly, even if all of the polyethylene and polypropylene (4.5 million tons in 2019)*3, which account for approximately 46% of the total plastic production in Japan, were replaced with LIMEX Pellet, approximately 4.42 million tons of limestone would be required (*4). ), which is about 3.3% of the total shipment of 130 million tons of limestone in Japan.

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

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

These days, there is a need to quantitatively understand the environmental impacts of all products and services throughout their lifecycles and work to reduce them.Petroleum-based plastics are manufactured by drilling crude oil and transporting it to a refinery, fractionating naphtha, and polymerizing the extracted monomers. A lot of energy is consumed and CO 2 is emitted through the heating process. Limestone, on the other hand, requires less energy at the raw material procurement stage than petroleum-based plastics, due to the simple manufacturing and processing process of crushing mined limestone.
Of course, if limestone is also incinerated, it emits CO 2. However, compared to petroleum-based plastics such as polypropylene, it emits approximately 58% less CO2 when burned. Petroleum-based plastics contain a large amount of carbon, which combines with oxygen in the atmosphere during combustion and is released as carbon dioxide (CO 2). Calcium undergoes an endothermic reaction at around 600-800℃ and is decomposed into calcium oxide (CaO) and CO2. The difference in CO2 emissions is due to this difference in chemical structure.


CO2 emissions during combustion

(Source) CO2 emissions during combustion of PP/PE: Japan Plastic Recycling Association,
(Source) Limestone: Calculated from chemical reaction formula assuming 100% calcium carbonate (CaCO 3) (assuming volume of 1 kg of PP)
(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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