The third factory study tour in this semester was held at Tokyo Gas Co., Ltd. at the Sodegaura LNG Terminal on Tuesday, December 8th 2009. Sodegaura LNG Terminal is located at 1-1 Nakasode, Sodegaura City, Chiba.
Tokyo Gas has several production terminals such as Sodegaura Terminal, Ohgishima Terminal, Negishi Terminal, etc. Sodegaura Terminal is the largest terminal of all. This Sodegaura Terminal is one of the world largest LNG receiving terminals. It receives LNG from Brunei, Malaysia, Australia, Indonesia, Alaska, and Qatar. Every year this terminal imports about 68.14 MMton gas from those countries above. This terminal has a production capacity of 26.31 million cubic meters of city gas per day.
LNG is the acronym for liquefied natural gas. Natural gas is liquefied when it is cooled to -162°C. At this temperature, we should not touch the LNG with bare hands because it can freeze every living things to death as shown by one of the staff of Tokyo Gas. The flowers put into the LNG became hard and frozen and died. A rubber ball put into the LNG hardened and it broke into pieces when it was dropped to the floor. In its liquefied state, the volume of LNG is 1/600th of its volume in gas form, therefore mass transportation by carrier becomes possible.
LNG is an environmentally friendly energy source. It has the least amount of emissions during combustion compared to petroleum and coal. It has energy efficiency about 70-80%, larger than other combusted energy sources such as petroleum and coal.
Sodegaura terminal has two piers and three berths to receive LNG imported from supplier countries. There are also several ships owned by Tokyo Gas to carry the LNG bought by Tokyo Gas from suppliers. The ships usually arrive at the Sodegaura terminal, get their LNG removed to the storage tanks, and then set out the next morning to be refilled with LNG from suppliers again.
Sodegaura terminal has many tanks to store the LNG imported. The tanks are differentiated according to the source of the LNG. Tanks for LNG from Indonesia are marked by a picture of orangutan, tanks for Australia are marked by a picture of koala. The LNG stored in the terminal is then heated by means of seawater to return it to gaseous state. It is then piped to customers after caloric value adjustment and odorization. Formerly, the gas is odorless but odor is added before it is distributed to customers as a safety precaution. The customers will be more aware if the gas pipes leak and can easily detect the source of the gas leak by smelling the gas odor.
The city gas produced in the Sodegaura terminal is delivered to customers via gas pipelines and is also supplied to three power plants of Tokyo Electric Power Co., Inc. as fuel of electric power generation. Tokyo Gas also ships and sells LNG by using tank trucks and domestic LNG tankers to districts where local city gas providers and pipeline networks are not available and to industrial customers.