Environment/EnergyHigh-pressure Containers

Make the fuel tanks of natural gas vehicles lighter to improve the stability of these vehicles. Carbon fiber composite materials help ensure safety in life.

Many trucks and buses carrying a natural gas (CNG) tank are already on the road, and self-contained breathing apparatuses (SCBA) used by fire-fighters and in medical applications widely adopt lightweight, carbon fiber tanks, as well. These tanks weigh around one-third of conventional iron tanks. Particularly with buses, a CNG tank is carried on top of the vehicle body to keep the floor low, but since an iron tank is not only heavy but it also has a high center of gravity, a CFRP tank is needed to ensure safety by preventing the bus from rolling over. These high-pressure gas containers are normally manufactured by the filament winding method and are constituted by an aluminum or plastic liner with carbon fiber wrapped around it. Burst pressure, which is a key performance of any high-pressure container, is dominantly controlled by the tensile strength of carbon fiber, which means that high-pressure containers offer an application field where the high specific strength of carbon fiber can be utilized most effectively. For fuel cell vehicles currently under development to be able to drive 500 km with one charge of hydrogen gas just like gasoline vehicles can with one refueling of gasoline, a high-pressure hydrogen of 70 MPa (CHG) tank is required, and carbon fiber is the only material that allows for manufacturing of such high-pressure tank which is also light enough to be installed in an automobile. Clearly, CNG, SCBA and CHG tanks and carbon fiber pressure containers represent a key application field which already accounts for a high percentage of general industrial applications and which is expected to grow further.