Natural gas vehicles and demand for carbon fiber fuel tanks

Malcolm Rosenow, an industry consultant, says use of carbon fiber in Type III and Type IV pressure vessels for compressed natural gas vehicles could be substantial over the next 10 years.

Malcolm Rosenow, an industry consultant based in Aiken, S.C., discussed potential demand for carbon fiber to support growth of the natural gas vehicle market by 2020. Rosenow reported that there are currently 11 million to 12.5 million natural gas vehicles (NGVs)on the road today, worldwide. By 2020, he said, this number could increase to 53 million to 82 million vehicles. In regions like North America and Europe, natural gas is stored in Type III and Type IV composite overwrapped pressure vessles (COPVs); in other regions of the world (~93 percent) vessels are fabricated from Type I (fiberglass) and Type II (heavy steel) pressre vessels.

Composites are appealing for storage vessels for many reasons: ligh weight, durability, and storage density. The weight and cost of CNG pressure vessels, said Rosenow, are important factors to consider when specifying the number and types of tanks to be put in a vehicle.

The top five NGV using countries — Pakistan, Argentina, Brazil, Iran, and India — account for 72.5 percent of the worlds's total NGVs. The top 10 represent 88.6 percent, with six from the Asia-Pacific region. Much growth is expected in China, where the government has mandated conversion of commercial vehicles in certain cities to CNG.

Rosenow said to expect 65 million NGVs by 2020, with demand for 166,500,000 pressure vessels. The question outstanding, he said, is what type of pressure vessel will prevail. The fastest growing CNG vehicle markets use Type I and Type II vessels, however, with favorable supply and pricing, demand could increase for use of Type III and IV (carbon fiber) vessels.

This demand will depend on market forces, said Rosenow — specifically, if and how much will North American and European governments mandate some sort of conversion to CNG vehicles. Under his "business as usual" scenario, Rosenow expects carbon fiber demand for Type III and IV vessels to range from 5,100 to 10,200 metric tonnes/year. Under his low-end "policy-governed" scenario, Rosenow expects carbon fiber demand to range from 34,500 to 69,000 metric tonnes/year.