SPILLS OF LNG ON WATER

Nearly instantaneous spills of large amounts of LNG (250 and 2500 gal) on open ocean several miles from land were conducted by Esso Research & Engineering Co., under contract with the American Petroleum Institute, to measure the parameters required to predict hydrocarbon concentrations downwind from a spill. Distances of 390 and 420 ft to reach the lower flammability limit (LFL = 5% methane) for pool areas of 1650 and 1525 sq ft, respectively, based on direct measurements, agree with a Gaz de France determination of 325 ft for a pool area of 2060 sq ft. Esso data indicate that a spill of 25,000 cu m would result in 3300 ft or 37,000 ft to LFL for gusty or stable weather conditions, respectively, as compared with U.S. Bureau of Mines extrapolations of 25,000 and 150,000 ft, respectively. Experimental equipment and procedures, effects of weather, and details of the calculation methods are discussed.