Before town gas is delivered● Supply system before town gas is deliveredCurrently, most of the natural gas consumed in Japan is LNG (Liqueed Natural Gas) imported LNG produced overseas is imported in special tankers and received at a LNG terminal. It then factories, buildings, households, etc. via a piping network from high to low pressure.In some areas where there are no connecting pipes or LNG receiving terminals, lorries vaporization, caloric adjustment and odorization before delivery.Changes from a liquid to a gas.LPG is added to natural gas to adjust the caloric value to the prescribed value.Even in the event of a gas leak, an odor is given off to make it easier to detect.Approx. 80 million tons are imported annually!Japan imported 80.55 million tons of LNG in 2018.Although the volume has been declining since reaching a peak of 89.07 million tons(FY2014), a high level of imports exceeding 80 million tons has continued since fiscal year 2011 when it surged due to the shutdown of nuclear power plants following the Great Eastern Japan Earthquake.In 2018, there were 18 importing countries, the largest of which was Australia at 29.44 million tonnes, accounting for 36% of all imports.Before town gas is madeLNG (Liqueed Natural Gas) that has been liqueed and transported is stored in an LNG tank, then vaporized and adjusted for caloric value, before a specic odor is added to turn it into town gas.LNG tankerMined natural gas is converted into natural gas at -162 °C and then transported mainly to Japan from the country of origin over 7 to 30 days (2 to 3 days from Sakhalin).LNG vaporizerThe liquid is vaporized by spraying seawater onto pipes in which LNG ows at a temperature of -162 °C.Tanker truckIn areas where pipes have not been installed, natural gas is supplied in LNG tanker trucks.LNG tankThe world's largest 230,000 kl tank holds an amount that is equivalent to the annual volume used by about 330,000 households.The size is big enough to accommodate the castle tower of Osaka Castle including the foundation.As LNG is stored as a liquid at -162 °C, a special alloy that can withstand ultra low temperatures is used inside the tank.Governor station(High to medium pressure)A governor is a device to regulate the pressure. A high pressure governor is installed in the governor station to lower the pressure to medium pressure.High pressure pipeVaporizationOdorCalorie adjustmentTown GasTransportStockpile/vaporizationJapan’s LNG importsTriviaProduction process of town gasPointTown Gas Supply System(Source: Gas Energy Newspaper July 15, 2019 issue)35Town Gas Supply System
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