Global economic and population growth is bringing about increased energy production and consumption. In its latest forecast, CEDIGAZ, an international not for profit association dedicated to natural gas information, predicts that global natural gas demand will grow by 1.8% a year from 2013 to 2035 with the largest portion of this growth coming from Asia-Oceania and the Middle East. Natural gas share in world primary energy supply is projected to increase from 21.3% to 23.6% over the same period. As the demand and supply of natural gas increases, the volume of transportation of natural gas will also expand.
Whilst LNG has been employed mostly in large scale gas fields due to the substantial investment required in liquefaction and storage plants, growing demand for natural gas is generating increased expectation for small to medium scale gas field development and the study of different modes of natural gas transportation at sea. One of these methods is via CNG carriers in which natural gas is stored compressed in the cargo tanks onboard for transportation. The investment for the entire project can be reduced since no liquefaction, storage, or regasification plant is needed making CNG suitable for short distance transportation.
Currently, the International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code) outlines safety requirements for LNG carriers. However, there are no applicable international rules for CNG carriers that take into account the hazards associated with the handling and transport of CNG. Utilizing its wealth of technical expertise and extensive experience in gas carrier R&D and ship classification, ClassNK has developed its Guidelines for Compressed Natural Gas Carriers which provide safety requirements for the design and construction of CNG carriers. The guidelines consist of safety requirements applicable to CNG carriers based on the IGC Code as well as additional requirements taking specific hazards arising from the handling of CNG into consideration. Source: Class NK