MELBOURNE�Suncor Energy Management, operator of the Stuart oil shale pilot plant near Gladstone in Queensland, has completed a successful 6-day test run of the unit, which uses the Taciuk process (OGJ, Oct. 4, 1999, p. 46). The company, a unit of Suncor Ltd., Calgary, says the run was designed to test the effect of an initial series of planned operational and facility improvements to mitigate odor, sulfur dioxide, and shale particulate emissions noted at the plant on earlier commissioning runs.
Shale input rates were maintained at the planned 160 tonnes/hr�64% of the plant�s capacity�for 100 hr. The Taciuk retort and oil recovery equipment performed reliably, said Suncor, and air emissions were substantially reduced. Raw naphtha and medium shale oil were produced at a combined rate of around 2,500 b/d.
Suncor said several changes were implemented for the test run, and these contributed to reduced emissions. They included addition of lime and limestone to the retort to dry-scrub sulfur dioxide emissions, improvements to seals in the preheat section of the retort to reduce hydrocarbons in the flue gas, an increase in the operating temperature of the burner in the main flue gas stack to improve dispersion of emissions, and an increase in the height of the high-pressure flare to 65 m from 17 m (the flare incinerates excess gases and improves air dispersion).
Data from the test will be incorporated into other planned facility changes that will reduce air emissions further. These changes are now in the engineering and procurement stage and will be implemented in the next few months.
There is now 7,500 bbl of raw naphtha and shale oil in storage on site. This is sufficient to complete commissioning of the naphtha hydrotreater, which Suncor will scheduled in the next few weeks.
Suncor's partners in the project are Central Pacific Minerals NL and Southern Pacific Petroleum NL, both of Australia. The plant processes shale from the Stuart deposit on Queensland's Coral Sea coast.
