Efforts in Resource Recycling

Principle and Outline

Osaka Gas is thoroughly implementing the 3Rs (reduce, reuse, recycle), cutting its resource consumption and waste generation, and endeavoring to reuse and recycle used resources in its efforts to help create a recycling-oriented society. We are recycling resources throughout our business activity value chain by such means as striving for zero emissions at LNG terminals, reusing gas meters, recycling gas pipe materials, reusing excavated soil from gas pipe installation, and recycling used gas equipment.

Consumption of Resources by Daigas Group
(* Partly Includes Consumption by Service Chains)

Toward achieving Environmental Action Targets

The final disposal rate of industrial waste* at LNG terminals in FY2020 was 0.0% (amount generated: 184 tons; amount of final disposal: 0.002 tons). Locations other than LNG terminals achieved the target of FY2020 with a result of 0.4% (amount generated: 2,030 tons; amount of final disposal: 9.0 tons). Regarding the general waste, final disposal rate was 2.6% (amount generated: 432 tons; amount of final disposal: 11.2 tons). All the FY2020 targets were achieved. We continue our effort to achieve the target for FY2021 by effective PDCA of company-wide Environmental Management System (EMS).

  • * Final disposal rate of industrial waste
    Waste disposed of at authorized landfill sites.

Waste Generation and Disposal

Volume of water intake and discharge

Resource Consumption at Affiliates

Resource Recycling Efforts at the Daigas Group

Use of recycled soil at gas pipe construction

The Daigas Group works to reduce the amount of excavated soil and waste asphalt generated as a result of gas pipe installation, which contributes to reduce impact on the ecosystem. Ways to achieve this include the Vermeer method, which requires soil excavation of only two points, and the shallow pipe installation method. In FY2020 these methods allowed us to reduce the amount of excavated soil generated by approx. 459,000 tons compared to what would have been generated using conventional methods. Our soil and asphalt recycling system promotes the reuse of waste asphalt and excavated soil as either recycled asphalt, regenerated roadbed material, or improved soil. These efforts allowed us to reuse 95% of material excavated during gas pipeline construction in FY2020 and send to final disposal approx. 2,000 tons.

■ Final Disposal Amount of Excavated Soil and Recycling Rate
Final Disposal Amount of Excavated Soil and Recycling Rate
  • * Results of a survey on construction byproducts, conducted by the liaison council tasked with dealing with construction byproducts in the Kinki region
■ Reuse of Excavated Soil at Osaka Gas
Reuse of Excavated Soil at Osaka Gas

Replacing pipes without excavation

The method of replacing pipes without excavation is a method of burying polyethylene (PE) pipes in which only each end of the construction stretch is excavated.

Not only does this these methods result in less excavated soil, it they also reduces the impediment of traffic around the construction site.

Vermeer method

The Vermeer method is a method to lay polyethylene (PE) pipes over long distances, with excavating from only both end points of the pipe.

First, jets of muddy water are sprayed from the tip of the drill to make it easy to drill and, while confirming from the ground above the tip of the drill, a steel rod is inserted into the ground. After reaching the correct position, the rod is connected to polyethylene (PE) pipes and then pulled back up, pulling the polyethylene (PE) pipes with it.

■ Vermeer Method - a Non-excavating Method
Vermeer Method - a Non-excavating Method

Non-excavation method: method for laying 90-200 A polyethylene (PE) pipes without excavating.
Horizontal directional drill: A machine that establishes the planned route by piercing through the ground.
Reamer: A tool for expanding the initial hole to a size large enough for gas pipes.

■ Comparison of Conventional Gas Pipe Installation Method with Shallow Pipe Installation Currently in Use
Comparison of Conventional Gas Pipe Installation Method with Shallow Pipe Installation Currently in Use

Shallow pipe installation method, authorized in 1999, allows the laying of shallower pipelines than before.

As a result, excavation widths became narrower and it became possible to greatly reduce the amount of excavated soil generated when laying gas pipes and restored afterward, mitigating environmental impacts.

Recycling of used gas pipes

The polyethylene (PE) pipes waste material generated at work sites is mainly used as covers to protect gas pipes and as post markers to indicate the location of supply pipes. In FY2020, 135 tons of polyethylene (PE) pipe waste was generated and all was reused. Metal pipes, such as steel and cast-iron pipes, are sold to electric furnace manufacturers and recycling companies, who use them as raw materials for products.

Recycling of used gas appliances

Electronic issuance of a manifest certifying waste disposal via the Daigas Group's e-cycle system

The Daigas Group has developed a unique “e-cycle” system to expedite waste disposal through the issuance of a manifest certifying each disposal process. Under the system, gas appliance sales agents, waste shipping firms, and disposal companies are connected to each other via the Internet. After the gas equipment collected by the sales agents is handled appropriately by the shipping firms and the disposal companies, a manifest certifying each process of disposal is issued. The general public can expeditiously confirm the disposal through the manifest.

The manifest is electronically issued, as the Daigas Group's e-cycle system is connected to the Japan Industrial Waste Information Center (JWNET) through the EDI.*

  • * EDI
    EDI stands for electronic data interchange. Electronic data are exchanged between the JWNET and Osaka Gas's e-cycle system.

Compliance with the Home Appliance Recycling Law

The Daigas Group appropriately disposes of gas air conditioners for household use and clothes dryers, covered by the Home Appliance Recycling Law, in line with the law.

In FY2021, about 147 tons of gas air conditioners for household use were collected, and 90% of them were recycled, higher than the minimum mandatory recycling rate of 80%. The amount of clothes dryers collected during the same year came to about 21 tons, 89% of which was recycled, far above the mandatory recycling rate of 82%.

■ Air Conditioners
  FY2017 FY2018 FY2019 FY2020 FY2021
Number of units recycled (units) 3,870 4,205 4,728 4,348 3,656
Gross weight recovered (t) 159 t 173 t 195t 177t 147 t
Weight recycled (t) 144 t 156 t 178t 161t 134 t
Recycling rate 90% 90% 91% 91% 90%
■ Clothes Dryers
  FY2017 FY2018 FY2019 FY2020 FY2021
Number of units recycled (units) 321 347 591 476 523
Gross weight recovered (t) 13 t 14 t 24t 19t 21 t
Weight recovered (t) 11 t 12 t 21t 17t 19 t
Recycling rate 87% 87% 88% 88% 89%

Reusing of gas meters

  • To measure the amount of gas used by customers, Osaka Gas has installed approximately 7.4 million gas meters. Under the Japanese Measurement Law, these devices must be replaced every 10 years.*1

    After 10 years in use, gas meters are repaired (taken apart, inspected, and fixed) to make them perform as well as new ones. They are then installed at customer sites. In the past, this type of repair was conducted a third time to give the gas meters a total lifespan of 40 years. After conducting evaluations including durability tests*2 jointly with the gas meter manufacturers, we came to a decision that these gas meters can be used another 20 years if twice of additional repairs are conducted.

    As a component material, around 2 kg*3 of aluminum is used in each gas meter body. Reusing gas meter reduce 80%*4 of CO2 emissions, that includes CO2 emission that would have been emitted in the process of casting a new gas meter body, giving a cumulative total reduction of 85,000 tons over the next 20 years, compared with producing new meters.
  • Gas meter which is taken apart after 10 years in use

    Gas meter which is taken apart after 10 years in use

    Gas meters which are reused

    Gas meters which are reused

  • *1 Replacement of meters
    Some exceptions apply. (Meters from #25 or higher need to be replaced every seven years)
  • *2 Durability test
    Cyclic tests, accelerated temperature tests, etc.
  • *3 Calculation of aluminum use
    A body of gas meter contains approximately 2 kg (average of from #2.5 to #6) of aluminum.
  • *4 Calculation of CO2 emissions
    Calculated with new meters also using regenerated aluminum.

Recycling of used alarm devices and styrene foam used for packaging

More than half of used alarms and machine-wrapping styrene foam had been incinerated or put into landfill in the past. However, we have been recycling all of them since FY2013 by converting them into so-called RPF, or refuse paper & plastic fuel.

And since November 2014, Osaka Gas has been reclaiming rare metals contained in the substrates of alarm devices and recycling plastics used in the devices.

  • Used alarm devices

    Used alarm devices

  • Used styrene foam from wrapping Machines

    Used styrene foam from wrapping Machines

  • RPF (Refuse Paper & Plastic Fuel)

    RPF (Refuse Paper & Plastic Fuel)

Efforts to actively use returnable packages

In accordance with our “Green Purchasing Policy” (formulated in 2000 and revised in 2020), Osaka Gas has been cooperating with business partners in “Green Purchasing&rduqo; that prioritizes the procurement of eco-friendly products and installation contracts. Osaka Gas is reducing the amount of material used for gas appliances packaging. For “Eco-Jozu” high-efficiency water heaters, we introduced returnable packaging that can be reused about 10 times and expanded its use in FY2013. In FY2020, the number of units shipped with returnable packaging (2,741 units) was about 4% of all “Eco-Jozu” shipments.

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