CSR Charter ⅡHarmonizing with the Environment and Contributing to Realizing a Sustainable Society
Developing Environmental Technologies
- Principle and Outline
- Efforts to Popularize Independent Dispersed Energy
- TOPICS: Launch of a Demonstration Test Aimed at Reducing CO2 Emissions and Net Energy Consumption to Zero at a Renovated Existing House
- Contributing to a Hydrogen Society
- Utilization of Unused Energy
- Efforts in the Life & Business Solutions Business
- Experimental Residential Complex “NEXT 21”
- “Eco Purge” Vehicle Developed to Lower Gas Pressure in Medium-Pressure Gas Holders
Principle and Outline
Technology forms the foundations for the corporate competitiveness of the Daigas Group, and R&D is therefore considered one of the most important corporate strategies for differentiation. With its environmental friendliness and secured procurement and supply, natural gas is expected to play an important role in creating a low-carbon society. To encourage greater use of natural gas and the utilization of renewable energies, the Daigas Group has been actively engaged in R&D on smart energy networks and household fuel cells as well as R&D and practical application efforts for a variety of new technologies that will lead to greater customer convenience and energy-saving behavior.
Efforts to Popularize Independent Dispersed Energy
Smart Energy House
Osaka Gas is working on the development of the Smart Energy House, which is designed to offer comfortable and environmentally friendly living to people by achieving “smart” management of electricity and heat when they are created, stored and consumed. The Smart Energy House runs on three batteries—a residential fuel cell, a solar power system and a storage battery—and uses IT to achieve the goal.
Osaka Gas and Sekisui House Ltd. conducted a living experiment of the Smart Energy House for three years from February 2011. The results of the experiment break down into three main points, which were released after technological studies were conducted to put them to practical use in the future.
- The experiment conducted under actual living conditions achieved a 103% reduction in CO2 emissions*, an 82% cut in energy consumption and savings of ¥310,000 in utility expenses and fuel costs for the vehicle.
- The experiment confirmed the functionality of our Home Energy Management System (HEMS), which is said to be effective in ensuring both comfort for residents and long-term energy savings.
- The experiment also demonstrated that automatic control systems set up in housing facilities, such as electrically-operated shutters and electric curtains, are effective in increasing convenience and comfort for residents.
Osaka Gas developed “a Smart Energy House Storage System, ” a small-size and lightweight storage system with a storage capacity of 3.2 kWh. The product, capable of charging electricity generated by ENE-FARM type S, a home-use fuel cell developed by Osaka Gas, was developed based on the utility's know-how on enabling optimal control of the three batteries and a storage system developed by KYOCERA Corp. Osaka Gas began selling the new storage system in April 2017.
- * Calculation of CO2 emission reduction
- In addition to CO2 emission reduction to net zero, CO2 emissions are expected to be further decreased by another 3% through the use of the three batteries and by exporting electricity generated by the solar cell back to the grid.
Smart Energy House Conceptual Diagram
Smart Energy Network
A Smart Energy Network is a next-generation energy system that combines a gas cogeneration system, renewable energy, and information and communication technology (ICT), enabling energy interchange as well as integrated control of dispersed sources of power. The SEN provides three new values: 1) promotion of further energy saving and CO2 emission reduction, 2) enhancement of energy security, and 3) acceleration of the introduction of renewable sources of energy. In FY2011 to 2013, Osaka Gas participated jointly with Tokyo Gas Co., Ltd. in the “Dispersed Energy Compound Optimization Demonstration Project” of the Ministry of Economy, Trade and Industry (METI). Osaka Gas successfully completed the demonstration, with cooperation from nine customers. Based on the result of this demonstration, we started verification testing of implementing demand response in June 2012.
We have also developed a smart energy network in the area surrounding the facilities of the Company in Nishi Ward in Osaka City. The network enables the accommodation of electricity among connected facilities in the area, including a shopping mall, a stadium and buildings of the Daigas Group. This network went into operation in July 2013.
Launch of a Demonstration Test Aimed at Reducing CO2 Emissions and Net Energy Consumption to Zero at a Renovated Existing House
Osaka Gas and Sekisui House Ltd. conducted a long-term living experiment in a smart energy house using an existing house. The test, conducted for about two-and-a-half years from December 2016 using the renovated house, is designed to demonstrate that attaining zero CO2 emissions and net zero energy consumption is compatible with leading a healthier and more comfortable life. This marked the first time that a living experiment using a renovated house had been conducted in Japan to demonstrate net zero energy consumption.
Participants in the experiment will be asked to list the indoor conditions and Internet of Things (IoT) systems they see as important in enabling residents to lead a comfortable and convenient life in a smart energy house. The experiment will study how to realize zero CO2 emissions and net zero energy consumption while taking into account such comments from people who are participating in the test. Osaka Gas expects the ongoing test to lead to the creation of a feasible smart house in which people can live healthier and more comfortable lives.
Contributing to a Hydrogen Society
Development of hydrogen generators and the establishment of hydrogen filling stations
Osaka Gas has developed a compact on-site hydrogen generator, “HYSERVE-300” , which makes hydrogen from natural gas with an output capacity of 300 m³ N/h. The move has been in response to increasing demand in recent years for hydrogen-generating devices for use at filling stations, amid the anticipated spread of fuel cell automobiles, considered to be the ultimate clean car.
We have also developed an LPG model, “HYSERVE-300P”, which went on sale in January 2015. The launch of this product enhanced our lineup of the on-site hydrogen generator which can meet various customer needs.
In step with the development of hydrogen-generating devices, Osaka Gas has been conducting empirical research on hydrogen filling stations for their diffusion since FY2002. In April 2015, the company opened Kita-Osaka Hydrogen Station, which is equipped with its “HYSERVE-300” hydrogen generator, in Ibaraki City, Osaka Prefecture. In March 2016, it also opened Kamitoba Hydrogen Station, a movable filling station in Kyoto City. At each filling station, hydrogen generated from city gas is provided to fuel cell vehicles.
Osaka Gas will continue to support the creation of a low-carbon society through the establishment of hydrogen-supplying infrastructure facilities, and the development and sales of hydrogen generators.
Utilization of Unused Energy
Promoting commercialization of CMM enriching technology
At underground coal mines, coal mine methane (CMM) retained in the coal layer is extracted outside to ensure the safety of workers. Of the extracted CMM, 30% or lower concentration CMM is disposed of in the atmosphere since it is of limited use.
Methane has approximately 21 times greater greenhouse effect than CO2. However, when used as a fuel, methane emits less CO2 than other fossil fuels.
The Daigas Group has successfully developed a method of enriching CMM for use as town gas using our proprietary methane adsorption technology. Since this technology also contributes to the reduction of greenhouse gas, we will introduce the technology to coal mines in China and other Asian countries.
Development of a high-efficiency methane fermentation system to help resolve waste and resource depletion issues
Osaka Gas is developing a high-efficiency methane fermentation system employing biotechnology to help resolve waste reduction and fossil resource depletion issues. This system uses technology (solubilization) that dissolves raw garbage and other organic waste (biomass) at high temperature (80℃), thereby increasing the methane gas generated by 20% over biomass dissolution by conventional fermentation processes. This technology also makes stable methane fermentation possible by solubilizing high-oil organic waste for which methane fermentation is difficult.
In 2009, we participated in the Kyoto Biocycle Project, a project for developing technology to combat global warming organized by the Ministry of the Environment and supervised by local governments and universities, which verified the effectiveness of ultra-high-temperature solubilization technology using school lunch garbage and other waste. These results will be utilized in future to study the practical application of methane fermentation processing to domestic food waste, an approach being considered by local governments.
Verification test for a small-scale biogasification system
Osaka Gas has been working with Daiki Axis Co., Ltd., to jointly develop small-scale biogas devices that biogasify small volumes of food waste economically.
The use of conventional biogasification systems has been deemed impractical in terms of installation space and cost in small-scale food product factories, apartment complexes and other facilities generating small volumes of food waste (less than one ton per day). Small-scale biogasification devices integrate the receiving tank, the solid/liquid separator tank, the biogasification tank, and the wastewater processing tank all into one tank, and substantially reduce pumps and other machinery/devices. This makes the equipment more compact and reduces installation costs.
Demonstration testing began in November 2014 using test equipment able to process about 400 kg per day, and it was confirmed that more than 100 m³ of biogas could be reliably produced for each ton of food waste generated by restaurants.
Details of Biogasification System
Commercialization of energy-creating wastewater treatment process
Wastewater containing aromatics, which comes from facilities such as semiconductor and chemical plants, has been difficult to process under conventional methods. Combustion treatment is used, but this generates significant CO2 emissions and results in high costs.
Osaka Gas has developed a process for the rapid breakdown of organic substances in wastewater by passing high-temperature, high-pressure wastewater through a catalyst specially processed using nickel. In this treatment process, a flammable gas is generated and effectively used to power the boilers and other equipment on-site. Compared to combustion treatment, this method reduces CO2 emissions approximately 110%* and results in wastewater treatment costs that are approximately 40% lower.*
The system won the Environmental Minister's Award for Global Warming Prevention Activities in FY2015.
- * Calculation of CO2 emissions and wastewater treatment cost
- Processing 200 m³ per day
Energy-creating Wastewater Treatment Process
Technology to convert thermal energy into light with a wavelength suitable for power generation by a solar cell
Osaka Gas and Kyoto University joined hands and succeeded for the first time in developing technology to convert thermal energy into light with a wavelength whereby a solar cell can generate electricity most efficiently. The development is expected to improve power generation efficiency using thermal energy sources.
In their joint studies, Osaka Gas and Kyoto University used silicon, a chemical element mainly used to develop semiconductors, to form a photonic nanostructure. They used this structure to develop a thermal radiation light source that exclusively emits light with a wavelength whereby a solar cell can generate electricity efficiently when the temperature is high. A power generation efficiency of 40% or higher is expected with this technology—much higher than the figure of around 20% recorded with an ordinary solar cell. Thermal sources are not limited to solar power with this technology. Equally efficient power generation can be expected using other thermal sources such as combustion heat.
Conceptual Image of Conversion of Thermal Energy into Light Through a Thermal Radiation Light Source
Efforts in the Life & Business Solutions Business
Development and sale of the “Spot Silencer” a noise canceling device
Osaka Gas developed the “Spot Silencer” , a noise control device designed to reduce the level of noise using a sound with different phase. Sasakura Engineering Co., Ltd. began selling the product.
The device is designed to offset low-frequency sound, which is a kind of sound difficult to absorb or insulate, with the sound of the opposite waveform. Installed adjacent to the source of noise, the “Spot Silencer” can prevent the noise from spreading spatially. The device is small in size, yet incorporates all of the necessary functions in a uniform manner which eliminates redesigning responding to the place where it is installed. A high degree of quietness can be achieved if it is used for a gas cogeneration system. Its use in commercial facilities and factories, both notorious for noise arising from compressors and transformers, is expected to grow.
Technology to mitigate air pollution
Osaka Gas developed the NNC Panel (NOx & Noise Cut Panel), the first of its kind in the world designed to reduce NOx, an air pollutant, and street noise at the same time. The panel, made of carbon materials, has already been installed on soundproof walls erected alongside a section of Route 23 in Nagoya City, marking its first practical use.
In recent years, health concerns from inhaling PM2.5 (fine particles with a diameter of 2.5 micrometers or less) has grown worldwide. NOx is considered one of the main sources of PM2.5 and effective ways of reducing the chemical compound are being explored. The NNC Panel uses activated carbon fiber (ACF), which is said to be capable of removing more than 70% of the NOx in the atmosphere and is also durable. ACF used in the panel also functions to reduce noise. ACF is a fine textile with a miniscule diameter of 15 micrometers, a characteristic that enables the fiber to absorb sound. The ability of ACF used in the panel to absorb sound is equal to conventional sound-absorbing materials such as fiberglass.
The ACF is shaped like pleats because that shape can increase the fiber's contact with the atmosphere. In addition, the structure of the sound-absorbing panel used in the NNC Panel has been upgraded to enable the effective intake of air. As a result, the noise reduction level reached 33.3 dB, far topping the benchmark 25 dB set by NEXCO, while significant air purification was achieved. (A test to measure the sound transmission loss showed that noise was cut by 33.3 dB for sound sources with a center frequency of 400 Hz.)
Osaka Gas will continue to step up marketing of the NNC Panel through its subsidiary Osaka Gas Engineering Co., Ltd., targeting places where atmospheric purification and noise reduction are necessary, such as soundproofing walls on expressways and trunk roads.
Simulation technology developed by Osaka Gas
Development of highly efficient, compact industrial burner required few prototypes
Osaka Gas applies simulation technology in the development of industrial burners in order to enable customers to achieve higher levels of energy efficiency at their own sites. Among the various types of industrial burner, it used to take a lot of time and effort to determine the optimal operating conditions for large industrial burners and to design such burners. By performing simulations, however, it is possible to predict combustion properties under various conditions and with various shapes, enabling the optimal solution to be identified in a short space of time.
Use of predicated power generation at wind farms for the assessment of project feasibility
To assess the viability of wind power, you must be able to predict how much power will be generated with a high degree of accuracy and certainty. And since many wind farms in Japan are in mountainous areas, you must be able to predict how the wind will react to the terrain. Osaka Gas has experience in simulations involving predicting how exhaust gas is dispersed from cogeneration systems around buildings and in urban areas. We applied this expertise to predicting the generating amount of a wind farm, a big help in our development of highly efficient, natural energy system.
Amount of Electricity Predicted through Simulations and Actual Amount of Electricity
Use of a weather simulation model to forecast energy demand and support operations of renewable energy systems
The consumption of energy like electricity and gas, and the amount of electricity generated through natural energy sources, such as solar power and wind power, are greatly influenced by weather conditions, prompting Osaka Gas to step up developing and making use of weather simulation technologies.
Osaka Gas operates Weather Research Forecasting (WRF), a weather simulation model developed by a U.S. research laboratory, while combining it with the Japan Meteorological Agency's Grid Point Value (GPV) data. The Company limits the use of the WRF to western Japan regions and forecasts their weather and solar radiation quantity every 30 minutes within an area of 2 km² , up to about 80 hours ahead. By operating the WRF in such a manner, Osaka Gas can obtain more accurate and detailed weather data than expected under normal weather forecasts. This weather simulation model has wider applications, such as in forecasting energy demand and supporting operations of systems to use natural energy sources in a more efficient manner. The simulation model is expected to be instrumental in saving energy and reducing CO2 emissions in society.
Development of biodegradable plastic film composed mainly of plant-derived polylactide plastic
Osaka Gas has developed biodegradable plastic film by improving polylactide (PLA) to render it soft and extensible.
PLA is a biodegradable plant-derived plastic, which is traditionally difficult to form (by inflation molding) into a film bag because of its hardness and brittleness. Using the long-cultivated plastic reforming technology, Osaka Gas has successfully developed an improved PLA plastic that can be formed into a soft and strong film without losing its biodegradability.
Because of the biodegradable characteristics, the developed PLA plastic has various other applications, including bags for throwing garbage into compost bins, and agricultural multi-purpose film that needs not be removed from farming land or incinerated. The PLS plastic film is expected to contribute to resource recovery from waste, CO2 emission reduction, and energy conservation.
Development of a 3HB biogas process for organic materials that employs bioprocesses
In a joint project with the National Institute of Advanced Industrial Science and Technology, Osaka Gas has employed a bioprocess (fermentation) to develop a method of producing (R)-3-hydroxybutyric acid (3HB).
3HB is a distinctive bioprocess compound that is difficult to obtain from chemosynthesis processes.
3HB, which is synthesized within the human body, has various bioactive functions, so it is hoped that it will eventually be possible to use it for new biological functions. And due to its chemical structure, 3HB is also expected to have potential as a material capable of reducing the environmental impact of medicines, food products, and biodegradable plastics by being used as a new raw material for biodegradable polymers or as a polymer additive.
The bioprocess we developed employs a unique type of Halomonadaceae bacteria identified by the National Institute of Advanced Industrial Science and Technology. Aerobic fermentation is used to cause biopolyester (PHB) to accumulate in the cells, after which a switch is made to anaerobic fermentation (culturing the microorganism in the absence of oxygen). This causes the PHB accumulated in the cells to hydrolyze and be released from the bacteria as 3HB.
By separating, concentrating, and purifying the 3HB released from the cells using conventional methods, we succeeded in producing 3HB with a purity of 95% or more at low cost.
Although there have been many reports of bioprocesses being used to accumulate 3HB, it is the first time in the world that 3HB has been efficiently generated and isolated.
Development of fluorene cellulose with potential for use as a heat-resistant plastic filler material
Osaka Gas has developed fluorene cellulose obtained by causing a chemical reaction between a fluorene derivative and the surface of cellulose fibers.
Cellulose is the most abundant biomass material on the planet, and is the main component of wood and paper. Fiber comprised of cellulose (cellulose fiber) one-fifth the weight of steel yet is five times stronger. In addition, because its linear thermal expansion coefficient* is 1/50 that of glass, it is expected to be usable as a plastic filler material (fiber for strengthening plastic). It would be an alternative to fillers such as glass fiber, and offer superior heat resistance.
However, because cellulose fiber is extremely hydrophilic (have a strong affinity with water), it is difficult to combine it with plastic, which is hydrophobic (has a weak affinity with water), which has made it hard to use it as a plastic filler.
However, by causing a reaction between our own fluorene derivative and the cellulose fiber surface, we have succeeded in developing a fluorene cellulose that is hydrophobic. This fluorene cellulose is easily mixed with plastics such as polylactic acid, and as plastic filler derived from biomass, it offers potential for use as an eco-friendly structural material for home appliances and automobiles.
- * Linear thermal expansion coefficient
- This coefficient shows the ratio of the increased length when temperature is raised by 1 degree Celsius compared to the original length.
Development of an environment-friendly material geopolymer concrete
Osaka Gas is working on the development of geopolymer concrete, which has drawn public interest as a new environment-friendly material.
Geopolymer concrete, made from fly ash, an industrial byproduct, is known as next-generation concrete. It has stronger acid and heat resistance than conventional concrete materials. Geopolymer concrete is said to be suitable for use in facilities where strong acids are generated, such as sewage plants, and where temperatures are high, such as steel mills. Since it does not use cement, the concrete emits about 80% less CO2 in its manufacturing process. In view of this environmental friendliness, the industry hopes that geopolymer will become significantly disseminated.
Geopolymer concrete starts hardening faster than other concrete materials, while solidification at high temperatures is necessary for its strength to reach the required level. In light of these characteristics, the concrete has mainly been produced at factories for secondary use at construction sites. However, Osaka Gas has established a method to produce the concrete for on-site use at construction and engineering sites. This achievement, the first in Japan, was made in collaboration with Nishimatsu Construction Co., Ltd. and Obayashi Corp.
Experimental Residential Complex “NEXT 21”
Osaka Gas launched a new five-year habitation experiment (the fourth phase of the experiment) in June 2013 at its experimental residential complex “NEXT 21” * (Tennoji-ku, Osaka City; 18 housing units with a total floor area of 4,577 m², six stories above the ground and one story underground), and in FY2016, it presented an interim report on its findings for the two-year first half of the period.
Environmentally friendly enriched lifestyles are the aim of the urban multiple-unit housing under the phase-four experiment, lasting until around 2020. The experiment is directed at how to concretize proposed ideal lifestyles creating links between people, rebuilding the relationship between human beings and nature and achieving an energy-saving and smart way of living.
In examining housing and lifestyles, we confirmed that setting up an intermediate domain between the private spaces of residences and the public spaces of common areas can create links between people and enhance comfort. In testing energy systems by utilizing “ENE-FARM type S” to transfer electric power and heat between houses and making maximum use of SOFC presupposing a reverse power output flow, we achieved a 31% reduction in energy consumption and a 51% reduction in CO2 generation.
Going forward, we will ascertain future social issues and needs and develop comprehensive lifestyle proposals from the perspectives of housing and energy.
- * Experimental residential complex “NEXT 21”
- The “NEXT 21” was constructed in October 1993 by Osaka Gas to propose an ideal neo-futuristic urban multiple-unit housing under the concept of “Achieving both comfortable and convenient life and energy-saving / environmental preservation.” The demonstration experiments were conducted in four phases over the past 20 years, with Osaka Gas's employees and their families residing in the housing. Each phase was designed to meet the theme suited to the times. Through the demonstration experiments, many proposals and presentations have been made concerning the energy-saving and CO2-emission-reduction solutions for the entire building, the greenery restoration and environmental symbiosis in the urban area, and ideal forms of residence capable of responding to diverse lifestyles, as well as the development of products for commercialization.
“Eco Purge” Vehicle Developed to Lower Gas Pressure in Medium-Pressure Gas Holders
Osaka Gas introduced its first “Eco Purge” vehicle in 2004. The vehicle is designed to return town gas remaining in medium-pressure gas holders or medium-pressure pipes through a medium-pressure pipe network when the gas pressure is reduced from medium pressure to low pressure, by sucking out the gas and compressing it using a gas engine-driven compressor. The fourth model, developed and introduced in 2013, incorporates improved noise reduction. In 2016, we developed and introduced a small noise-reduction vehicle that can be used even on narrow roadways.
Before the “Eco Purge” was developed, gas pressure was reduced by burning the remaining gas in a gas holder or pipe using a burner. The environmentally friendly “Eco Purge” was developed to reduce the load on the environment. At present, four “Eco Purge” vehicles are in use, contributing to an annual cut of about 300,000 m³ in unnecessary gas consumption and an annual reduction of about 5,000 tons of CO2 emissions.
Principle of Decompression