Nagoya, April 3, 2003 - Toyoda Gosei Co., Ltd., today announced the successful development of a revolutionary all-composite compressed natural gas (CNG) tank for natural gas vehicles (NGVs). The new CNG tank is made considerably lighter in weight through the use of a newly developed plastic liner and a carbon fiber reinforced plastic (FRP) tank. This tank passed the High Pressure Gas Safety Institute of Japan's test of standards for commercial product design on February 14 of this year.
The market for NGVs has been steadily expanding in Japan and overseas in recent years. Approximately 15,000 NGVs are in use in Japan, particularly in urban areas, as cargo-carrying pick-up trucks, local buses, trucks, and commercial vehicles, while nearly 2 million NGVs are in use throughout the world, including in Italy and in North and South America. The majority of these NGVs are equipped with metal CNG tanks. NGVs have been promoted as an option for environmentally friendlier automobiles in Japan and have been designated as one of the types of vehicles to be promoted as part of the Low-Pollution Vehicle Development and Promotion Action Plan of Japan's Ministry of Economy, Trade and Industry, Ministry of Land, Infrastructure and Transport, and Ministry of the Environment.
Against this background, the new all-composite CNG tank is the most recent response of Toyoda Gosei in meeting the growing need for lightweight CNG tanks for NGVs, which will further require better fuel efficiency, higher levels of performance, and larger load-carrying capacities. Toyoda Gosei took on the challenge of developing Japan's first all-composite alternative to the conventional metal CNG tank in order to reduce the weight of the NGV substantially. Compared to an average metal CNG tank, the new plastic tank is 60% lighter. Its liner is made of Toyoda Gosei's recently developed rubber alloyed polyphenylenesulphide (PPS),*1 which has non-conductive properties and excels as a gas barrier. PPS is highly connectable as well, which allows the liner to be easily welded together. It also has expandable and flexible characteristics and resists temperature changes.
The new all-composite tank does not compromise on gas barrier properties, which are ensured by the adoption of a new self-sealing cylinder sleeve structure*2 that has been designed to avoid high concentrations of gas pressure at the connecting point with the plastic liner. Compatible with the gas leak containment level of conventional metal tanks, the all-composite tank achieves a gas permeable level that is a mere one tenth of the standard of 0.25 cc/L·h set by the High Pressure Gas Safety Institute of Japan.
Toyoda Gosei plans to start the sample shipment of the new all-composite CNG tanks during the fiscal year ending March 31, 2004 (fiscal 2004) and to begin mass production of the product in fiscal 2005. The company aims to achieve annual sales of 3 billion yen by fiscal 2011. Expanding on the technology of CNG tanks, Toyoda Gosei is also working on the development of all-composite high-pressure hydrogen tanks for fuel cell vehicles.
Specifications of the all-composite CNG tank
Length: 815 mm
Tank body circumference: 317.5 mm
Capacity: 46 L
Weight: 20.1 kg
Tank pressure: 20 MPa