Tokyogasgroup csr report

Contribution to the Environment

Promotion of Environmental Technologies Development

Effective Use of Biomass

Biomass is the generic term for plant and animal-derived organic resources (excluding fossil resources)that can be recycled into energy and material. Examples of biomass are rice straw, forest and fishery products such as livestock excrement, food waste, sewage sludge, and waste wood. Dried-biomass can be combusted directly to obtain heat and electricity from the steam thus generated, and also wet-biomass can be fermented to produce biogas for use as energy by, for example, cogeneration systems. As the CO2 emitted as a result of combusting biomass or biogas is CO2 that had been absorbed from the atmosphere by photosynthesis during organic processes, using energy from biomass in place of energy derived from fossil resources can make a major contribution to reducing total CO2 emissions, which is one of the greenhouse gases driving global warming.

We aim to expand and popularize the use of biomass to help reduce greenhouse gas emissions by promoting not only the technologies for using biogas that we have developed to date (such as mixed combustion of city gas and biogas), but also technologies for generating biogas more economically and efficiently through methane fermentation of biomass such as food waste, together with technologies for upgrading the biogas into higher quality gas.

Pilot methane fermentation plant at a research institute
Pilot methane fermentation plant at a research institute

 

Development of biogas utilization technologies
Tokyo Gas Group possesses technologies for digesting biomass such as food waste and sewage sludge for use as fuel for boilers and power generators, and is currently using biogas generated at customers' sites primarily as fuel for generating electricity by CHP (onsite use). As biogas is a lean fuel consisting of approximately 60% CH4 and 40% CO2, CHP must be specially designed to run on it. We were the first in Japan to begin upgrading biogas, adjusting its calorific value, and odorizing it so that it could be injected to city gas grid. In fiscal 2015 we received 675 thousand m3 of biogas (equivalent to an approximately 1,151-ton reduction in CO2 emissions) derived from food waste into our pipelines.

How Biogas is Fed into Gas Pipelines
How Biogas is Fed into Gas Pipelines

In addition to the above, we have been engaged in joint research with Yokohama City since fiscal 2013 with the goal of broadening the use of biogas generated at the North Yokohama Sludge Recycling Center. For this project, research is being conducted on ways to remove CO2 from digestion biogas using separation membranes to produce concentrated methane, and we are also studying ways of using biogas in high-efficiency CHP such as solid oxide fuel cell (SOFC) systems.
This project to extract methane from sewage gas using separation membranes is one of the longest-running of its kind in Japan. It was awarded the Japan Institute of Energy’s Award for Encouragement  when it was unveiled at the institute’s 25th annual conference in August 2016.
 
Test biogas refiner at the Yokohama City Hokubu Sludge Treatment Plant
Test biogas refiner at the Yokohama City Hokubu Sludge Treatment Plant
DFF Inc., Corporate Social Responsibility Sect, General Administration Dept., Corporate Planning Dept., Resources & Global Business Division, Energy Solution Div, Power Buisiness Dept., Pipeline Network Division, IT Division, Residential Sales Div., Fundamental Technology Dept., Energy Solution Div, Environmental Affairs Dept., Purchasing Dept. , Health Insurance & Employees' Welfare Sect., Personnel Dept., Internal Audit Dept., Audit & Supervisory Board Member's Office, Compliance Dept., Regional Development Div., Finance Dept, TGES, TOKYO GAS COMMUNICATIONS, INC.

Development of the Hydrogen Supply Network

Construction and operation of hydrogen stations
We are building and operating hydrogen stations and contributing to the development of the hydrogen supply infrastructure in order to promote wider use of fuel cell vehicles. Our goal is to reduce carbon emissions and diversify fuels in the transportation sector.
Having previously built and operated two hydrogen stations (one in Senju and another in Haneda) for R&D and demonstration purposes, we began building our first hydrogen stations for ordinary commercial use in fiscal 2013. The first to be completed was the Nerima Hydrogen Station, which became the Kanto region's first commercial hydrogen station when it opened in December 2014. It was followed by the Senju Hydrogen Station, which was repurposed for commercial use in January 2016. One month later, in February 2016, we opened our first hydrogen station in Saitama Prefecture, the Urawa Hydrogen Station.
The Nerima Hydrogen Station uses an "offsite" system for receiving hydrogen produced elsewhere and supplying it to fuel cell vehicles onsite. Our Senju and Urawa stations, on the other hand, are "onsite" stations that supply fuel cell vehicles with hydrogen produced onsite from city gas.
Moving forward, we will pursue more efficient use of hydrogen production systems through the commercial operation of hydrogen stations and seek to strengthen coordination between stations in order to supply hydrogen more reliably.
(There were approximately 1,800 fuel cell vehicles on the road and 88 hydrogen stations in Japan at the end of fiscal 2016.)

 
  • Nerima Hydrogen StationNerima Hydrogen Station
  • Senju Hydrogen StationSenju Hydrogen Station
  • Urawa Hydrogen StationUrawa Hydrogen Station


From city gas to hydrogen supply (an onsite hydrogen station)
Taking advantage of city gas's low CO2 emissions and limited impact on the environment, Tokyo Gas is reforming it to generate hydrogen.
 
An onsite hydrogen station
A device for cooling hydrogen to prevent the temperature in an FCV's fuel tank from rising during refueling.


Development of hydrogen technologies
Tokyo Gas is pursuing R&D on hydrogen stations for supplying hydrogen fuel to fuel cell vehicles as a participant in the FY2013-17 research and development project on hydrogen utilization technology run by the New Energy and Industrial Technology Development Organization (NEDO). Through this program, we are investigating methods of controlling the quality of hydrogen fuel dispensed to fuel cell vehicles, assessing measurement accuracy when refueling, and studying ways of refueling fuel cell vehicles other than passenger cars (i.e., buses and motorcycles). We are also developing industry guidelines on these methods and are working to have them incorporated into international standards. We are further exploring efficient ways to run commercial hydrogen stations and to reduce maintenance costs.

Refueling a Toyota MIRAI FCV
Refueling a Toyota MIRAI FCV
 
DFF Inc., Corporate Social Responsibility Sect, General Administration Dept., Corporate Planning Dept., Resources & Global Business Division, Energy Solution Div, Power Buisiness Dept., Pipeline Network Division, IT Division, Residential Sales Div., Fundamental Technology Dept., Energy Solution Div, Environmental Affairs Dept., Purchasing Dept. , Health Insurance & Employees' Welfare Sect., Personnel Dept., Internal Audit Dept., Audit & Supervisory Board Member's Office, Compliance Dept., Regional Development Div., Finance Dept, TGES, TOKYO GAS COMMUNICATIONS, INC.

Innovations in gas cogeneration technology

Improvement of generating efficiency and total efficiency
Gas cogeneration systems (CGSs) are the object of growing customer interest because of the contribution that they can make to environmental performance, energy conservation, and BCP, and improvements to their economic competitiveness and energy security are expected to drive their wider adoption. In the future, gas cogeneration is likely to be made even more efficient by the use of high-temperature solid oxide fuel cells (SOFCs).
As of the end of March 2017, pilot-scale testing was being conducted in association with manufacturers on SOFCs (ranging in capacity from several to hundreds of kilowatts) at Tokyo Gas Senju Techno Station. We are also assessing durability and the reductions in energy consumption and CO2 emissions achieved in use by installing SOFCs at various types of business facilities, and manufacturers aim to bring commercial models to market during fiscal 2017.
 

Commencement of 5 kW-class commercial fuel cell demonstration trial at a public facility in Arakawa
 

In March 2016, we installed a 5 kW-class commercial fuel cell at the Arakawa Sogo Sports Center in Arakawa, Tokyo, and a demonstration trial is now underway. The approximately one-year trial will run until the end of March 2017 and is being conducted under an agreement on real-world testing of 5 kW-class commercial fuel cells signed between Arakawa and Tokyo Gas at the end of 2015. It is the first trial of its kind to be conducted at a public facility in Japan.

Electricity generated by a commercial SOFC will power first-floor lighting at the center, while waste heat will be used to produce some of the hot water for locker room showers. During the trial, a monitor will be displayed showing the amount of electricity generated by the SOFC, and visitors will be able to experience the hot water produced for themselves. The project will be used to raise awareness of fuel cells and the contribution that they can make to creating a low carbon society.

 

Presentation on the 5 kW-class commercial fuel cell demonstration trial
Presentation on the 5 kW-class commercial fuel cell demonstration trial
  
Breaking the 80% power generation efficiency barrier: Successful development of a theoretical 
design for an innovative concept to dramatically improve solid oxide fuel cell efficiency

 

In a joint study, Kyushu University's Next-Generation Fuel Cell Research Center (NEXT-FC) and Tokyo Gas have succeeded in designing an innovative concept to dramatically improve the electrical efficiency over 80% LHV (lower heating value) of SOFCs and proving its mechanism in a world first. This result was published in July 2015 in Scientific Reports, Nature's sister online publication.

Super-efficient energy conversion from fossil fuel to electricity is expected to make a major contribution to reducing CO2 emissions and provide the core energy technology for creating a highly environmentally friendly smart energy society. In addition, super-efficient power generation systems are potentially far more adaptable to market needs because they produce so little waste heat during the power generation process that they can eliminate the need to make use of waste heat.

Schematic of Innovative Concept for Further Improving the Electrical Efficiency


Schematic of Innovative Concept for Further Improving the Electrical Efficiency

DFF Inc., Corporate Social Responsibility Sect, General Administration Dept., Corporate Planning Dept., Resources & Global Business Division, Energy Solution Div, Power Buisiness Dept., Pipeline Network Division, IT Division, Residential Sales Div., Fundamental Technology Dept., Energy Solution Div, Environmental Affairs Dept., Purchasing Dept. , Health Insurance & Employees' Welfare Sect., Personnel Dept., Internal Audit Dept., Audit & Supervisory Board Member's Office, Compliance Dept., Regional Development Div., Finance Dept, TGES, TOKYO GAS COMMUNICATIONS, INC.

DFF Inc., Corporate Social Responsibility Sect, General Administration Dept., Corporate Planning Dept., Resources & Global Business Division, Energy Solution Div, Power Buisiness Dept., Pipeline Network Division, IT Division, Residential Sales Div., Fundamental Technology Dept., Energy Solution Div, Environmental Affairs Dept., Purchasing Dept. , Health Insurance & Employees' Welfare Sect., Personnel Dept., Internal Audit Dept., Audit & Supervisory Board Member's Office, Compliance Dept., Regional Development Div., Finance Dept, TGES, TOKYO GAS COMMUNICATIONS, INC.