INNOVATION July-August 2014

methane migrates to the refrigerant gases and the methane cools to the point at which it turns to a liquid. “The refrigerant gases are exactly the same as the gases you have in your refrigerator, but on an industrial scale,” says Brigden. “The production of LNG is not a compression process. It’s a heat exchange process. We’re just cooling down the methane.” The liquefied natural gas is then transferred to storage tanks aboard a floating offloading vessel where it remains at atmospheric pressure. Although these tanks are heavily insulated, a certain amount of heat from the atmosphere manages to migrate through the insulation which causes the surface of the liquid gas to return to a gaseous state. That gas is returned to the liquefaction facility and goes through the process again. The LNG will be loaded onto ocean-going vessels that are 244 m long by 44 m wide and will dock adjacent to the floating storage unit. Under the current plans, one such vessel will leave Woodfibre’s Squamish terminal every 10 days to help meet the growing worldwide demand for natural gas. Global LNG trade grew three-fold from 10 bcf per day in 1997 to 32 bcf per day in the 15 years between 1997 and 2012, and that growth is expected to continue. Current estimates sug- gest that world consumption of natural gas will grow from 310 bcf per day in 2010 to 507 bcf by 2040. Much of the growth will occur in Asian countries. Japan currently accounts for just over one-third of world LNG consumption and South Korea is also a major consumer. China and India are expected to increase their LNG imports to meet the demands of their growing economies and to reduce their emis- sions of carbon dioxide and other greenhouse gases. Natural gas is regarded as a sensible alternative. It is low in CO 2 content, produces no ash, contains no sulphur dioxide and only minimal amounts of nitrogen oxide, another pollutant. BC is ideally positioned to tap these burgeoning markets for natural gas. Based on current estimates, the province’s reserves will last 150 years. And BC has a geographical advantage: LNG shipped from coastal terminals can reach Asian markets up to two days faster than product shipped from further south in the continental US. Small wonder, then, that Asia has become the new frontier for Canada’s natural gas producers. v

site, including the control centre, administration building, warehouse, canteen, first-aid centre and heli-pad. Since the property is located in a seismic zone, one of his first tasks was to conduct a geotechnical survey of the entire site. That involved drilling, collecting and analyzing core samples to ensure that the underlying bedrock is solid and could sustain the build- ings erected on the surface. As well, two creeks run through the site. Bridges must be erected and buildings positioned around them and flood control infrastructure must be designed and built to provide protection should the level of the sea rise. As Project Director, Brigden has worked on such projects in Europe, the Middle East and the Far East. The natural gas liquefac- tion and storage units for the Woodfibre LNG facility will be inte- grated into a floating barge and verification of the design will be carried out by one of the internationally recognized classification societies (e.g., Lloyd’s Register, Det Norske Veritas) that are famil- iar with such complex and specialized facilities. The international classification society will verify the design against international standards. This will provide a comprehensive approach to the design registration and ensures highly specialized experts review the design for this type of facility. Once designed, the liquefaction and storage units will likely be constructed and pre-commissioned in a purpose built shipyard in the Far East. They will then be towed to the site near Squamish for final hook-up and commissioning. The liquefaction of natural gas and the transportation by marine vessels is a well-established industry that has been around since the mid-1960s. Indeed, FortisBC owns a small natural gas liquefaction plant in Delta, which serves as a so-called peaking facility that is typi- cally required in winter when demand spikes. The utility buys gas in the summer, when consumption as well as prices are usually lower, liquefies it and stores it until it is required during the winter. Such a facility allows the utility to save money and ensure a reliable supply. Natural gas must be cooled to minus 162 degrees Celsius before it turns to liquid and there are two stages in the process. The feed gas used in liquefaction is exactly the same commodity that residential consumers burn to heat their homes. It contains a number of substances such as water, carbon dioxide and hydro- carbons like propane, butane and benzene. These substances will freeze at temperatures higher than minus

162 and therefore must be removed through a pre-treatment process. What remains, Brigden explains, is pure methane, which is then fed into the liquefaction equipment and the second stage in the process begins. First, refrig- erant gases such as butane, isobutane and pentanes are fed through a valve that compresses and liquefies them. When they are released from the valve, the pres- sure immediately dissipates, they expand and in so doing they become extremely cold. They are then pumped into a heat exchanger, commonly called a cold box, and they travel through it in one direc- tion while warm methane passes through in the opposite direction. The heat in the

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