Shanghai’s Yangshan Deep-Water Port plans to use cold energy
released during vaporization of liquefied natural gas for power
generation and other industrial uses.
The project is expected to save the city about 750 million
kilowatts per hour, with a minimum value of 75 million yuan (US$9.9
million), after its first phase is completed in 2009, port managers
told the city's top advisory body members yesterday.
"It's a terrific project, not only because it's energy saving
but most importantly, it complies with the global strategy of CO2
emission reduction and environmental protection," said Ren
Xianzheng, senior port engineer.
LNG, which is minus 162 degree Celsius under normal air
pressure, sends out large amounts of cold energy when it is
vaporized.
Average cold energy released by each ton of LNG reaches 830
kilojoules, equaling to about 240 kilowatts per hour, according to
Gu Anzhong, low-temperature studies professor at Jiao Tong
University.
However, common vaporization practice nowadays is to heat the
liquid gas via heat exchange with ocean water. But that simply
discharges the cold energy into oceans without being used.
Earlier this year, members of the Shanghai Committee of the
Chinese People's Political Consultative Conference put forward a
proposal calling on the city government to make use of possible LNG
energy.
Shanghai, which has signed an agreement with Malaysia for LNG
imports, is building a liquefied gas receiving station with an
annual capacity of six million tons at the eastern part of the
Yangshan Deep-Water Port.
Once the LNG cold energy project works, low-temperature cold
energy can be used for power generation without any fuel
needed.
It can be used in other industrial applications such as
separating air into nitrogen and oxygen, desalinating seawater and
making dry ice.
(Shanghai Daily September 6, 2007)
