TECHNO-ECONOMIC ASSESSMENT OF GEOLOGICAL CO_2 SEQUESTRATION IN ONTARIO

摘要

The Kyoto protocol sets target for Canada to reduce GHG emission by 6% of the 1990 level by 2008-2012. Several options are being considered to achieve this target and it appears that CO_2 sequestration is the suitable one if fossil fuel power plants, in particular coal-based plants are to remain in operation. In the case of Ontario, the preferred option for CO_2 sequestration is to inject CO_2 into a saline aquifer covered with a cap rock located at least 800m beneath the earth's surface where CO_2 can be stored under supercritical condition. The injection pressure and temperature should be [1] above the critical temperature and pressure of CO_2 [31.1℃ and 73.8 bar].rnTwo different major reservoirs with approximate storage capacities of 289 million and 442 million tonnes of CO_2 were identified in Southwestern Ontario for CO_2 sequestration; one located in the southern part of Lake Huron and the other located inside Lake Erie. This paper also evaluates the capital and operating cost for CO_2 sequestration in Southwestern Ontario from a single 500 MW coal-fired power plant. It is found that a significant amount of capital investment is necessary to transfer CO_2 from the 500 MW fossil fuel power plant to the injection location and to store it underground. Major components of the cost include: cost of pipeline, cost of drilling injection wells and installing platforms since the more plausible injection area is under the Lake Erie. The estimated cost of sequestration of 14000 tonnes/day of CO_2 (assumed emission from a 500MW power plant) at approximately 110 bar in Southwestern Ontario is between 7.5-14 US$/tonne of CO_2 stored.