Utilizing Innovative Waste Heat Recovery Technology for the First Time in Alberta
Funded through Round 2: Industrial Energy Efficiency in 2011, the Whitecourt Recovered Energy Project (WREP) involved the installation of a waste heat recovery generation system at the Alliance Windfall Compressor station. The project was completed in 2014 and was the first installation of the ORegen™ System for waste heat recovery.
The ORegen™ System captures waste heat from gas turbine exhaust to produce 13.8 megawatts of power through the organic Rankine cycle (ORC). The traditional Rankine cycle uses water for steam generation and is widely used by power plants such as coal-fired power plants or nuclear reactors, whereas ORC uses organic fluids like refrigerants and hydrocarbons. The ORegen™ System captures waste heat from the exhaust of a gas turbine at the Alliance Windfall Compressor Station, converting organic fluids into steam, which then expands through a turbine, producing electricity. The organic fluid has a low boiling point, allowing it to vaporize at relatively low temperatures compared to water in a traditional steam cycle. The 13.8 megawatts of power produced results in a significant reduction in greenhouse gas emissions, with an estimated offset of around 70,000 tonnes of emissions annually.
Overcoming Challenges to Improve Future Projects
Because this was the first installation of the ORegen™ System for waste heat recovery, there were several start-up and operational issues, which were resolved throughout and after the project. No previous prototyping was conducted, and there were no previous projects to assist with the engineering. These factors led to construction difficulties, vessel quality issues, mechanical reliability of the turbo expander, modifications to the control system and numerous smaller commissioning issues, ultimately delaying the project. The initial design experienced leaking of the hydrocarbons and required disassembling the affected components, inspecting them for damage and replacing them to prevent further leaks. Additionally, impurities within the hydrocarbons led to damage in the pump seals. To resolve this, the project team installed more robust and suitable seals designed to handle the specific characteristics of cyclopentane. Ensuring the application of these lessons learned during this project will assist in a successful field execution, commissioning and start-up for future projects.
What’s next?
As of 2024, the project is still active, with NRGreen continuing to utilize the waste heat recovery system. As of 2023, NRGreen operates five waste heat recovery facilities along the Alliance Pipeline. The lessons learned from this project were applied to improve these additional installations, ensuring more efficient and effective waste heat recovery systems.