LNG and world energy needs. Part 1: Gas liquefaction and world resources

Abstract

The development of international trans-shipment of LNG will be reviewed, comparing the present achievement with the world potential. The scope for further development will be discussed together with the problems that delay it. Base-load liquefaction plants have already achieved a high level of efficiency and reliability, and the possibility of major improvement has become small. Present technical interest centres on the practicability of offshore liquefaction, including the problems of liquefaction on a floating barge, floating storage and flexible pipeline systems for LNG transfers. Land-based LNG storage systems have developed greatly, especially in Japan, where important strides have also been made in utilising the ‘cold’ available from re-evaporation. Whilst significant developments have been made with both above-ground and in-ground storage the present preferences appear to lie with a compromise solution involving an insulated tank partially submerged in the ground, the excavated earth being mounded around the tank up to the level of the tank top. There are now fleets of ocean-going tankers for LNG, and a few are laid-up awaiting charter. The largest has a capacity in excess of 130 000 m 3. Several different insulation systems are employed, the criteria being cost, evaporation losses and safety. Much attention is being devoted to the elimination of hazards which could arise with shipping accidents. Other uses of LNG are relevant to energy conservation on a smaller scale. These include peak-shaving plants, the enrichment of lean natural gas, satellite stations and diurnal storage.