PanCanadian originally pursued thermosyphon technology to lower operating costs. However, it is now apparent that a more significant benefit is reduction of greenhouse gas (GHG) emissions. Other benefits include loss management, increased safety, improved operability and maintenance cost reduction.
A prototype Thermflo™ thermosyphon process heater was developed by Hudson Products Corporation (HPC) as a joint effort with PanCanadian Petroleum Ltd. The unit was installed in a 320 m3 atmospheric heavy oil tank in northeastern Alberta in November '97. Performance testing was carried out over the next several months and evaluated using API Standards & Recommended Practices.
The testing was carried out in two phases. In phase one, we compared the performance of the thermosyphon to a naturally drafted venturi style nozzle burner in a firetube located in an adjacent tank. Both units were fired using sales utility gas. Increased combustion efficiency and improved heat transfer reduced fuel gas consumption by 33% and cut GHG emissions by 40%. In phase two of the testing, the prototype successfully burned solution gas normally vented to atmosphere. This translates to an annual operating cost saving of about $40,000 and GHG emission reduction of about 10,000 tonnes per year.