Suncor Energy is planning a two-year construction project at its Commerce City oil refinery to tear down a 75-year-old flare stack that often sends flames flickering from the top, and reconnect the pipes that funnel excess gases to a newer, more efficient flare on site.
The $16 million project is scheduled to start later this year, pending approval from the Colorado Department of Public Health and Environment.
The work would dismantle the 100-foot-tall flare stack, often called a smoke stack by the general public, built in 1950 as part of what is now called Plant 1. The gases that are burned by that flare will be rerouted to the refinery’s taller gasoline benzene reduction flare, which was built in 2012, said April Maestas, engineering director at the Commerce City refinery.
Suncor filed its construction permit application for the project in October, and it’s under review by the state’s Air Pollution Control Division. Last week, Suncor held two online meetings to explain the project and answer questions from the community — a result of Colorado’s 2021 Environmental Justice Act, which requires more communication between polluters and the communities in which they operate.
The refinery has multiple flares, which are notable, especially at night, when people see flames jumping from the tall pipes. Those flames can be seen from Interstates 70 and 270 and around Commerce City and Denver’s Elyria-Swansea and Globeville neighborhoods.
“Seeing a flame on the flare tip is not bad,” Maestas said during a March 5 public meeting. “It indicates the excess refinery gas is properly controlled and properly combusted through an engineered system.”
The flares burn off excess gas to avoid explosions and are a necessary part of oil refining. The project should improve emissions and safety at the refinery, she said.
“We recover as much excess gas as possible and recycle it back to the refinery to use as fuel gas for furnace operation,” Maestas said.
The gasoline benzene reduction flare is 250 feet tall, which 1.5 times higher than the 75-year-old one that will be taken down. That means pollution including carbon monoxide, nitrogen oxides, sulfur dioxide, volatile organic compounds and particulate matter will be dispersed further from surrounding neighborhoods, she said. That should decrease some impacts from emissions.
Suncor also expects the conversion to reduce the amount of sulfur dioxide and nitrogen oxides because there will be one less flare burning gases and sending byproducts into the air, said Bernd Haneke, the refinery’s environmental and regulatory manager. The taller, newer flare is more efficient.
However, in its construction permit application filed with the Air Pollution Control Division, Suncor said it “is not requesting any new or revised emissions limitations in conjunction with this construction permit application.”
The refinery is a frequent target of criticism because it is one of the largest polluters in the state, and people who live in Commerce City and north Denver suffer from that pollution more than other Colorado residents. They complain of asthma, nosebleeds, cancer and other health problems. They also say the refinery often stinks, making it unpleasant to spend time outside.
Suncor agreed to pay a $10.5 million penalty in February 2024 to settle air permit violations for belching toxic chemicals over a three-year period. In July, the company was notified that it was under investigation by the state and the Environmental Protection Agency for repeated Clean Air Act violations.
A big portion of the work will happen in March 2026, when Suncor is scheduled to shutter Plant 1 for routine maintenance. During that period, the refinery also will refurbish pumps, compressors and electrical systems, and construction workers will use that period to tie gas lines from the old flare into the newer one, Maestas said.
The switch between flares will happen in 2027 if all goes according to the plan, she said.
Suncor has invested “hundreds of millions” in the Commerce City refinery in recent years to improve its equipment and reduce air and water pollution, Maestas said. The company also upgraded its refinery over the past two years to produce reformulated gasoline, which is required in metro Denver and along the northern Front Range during the summer months to reduce ozone pollution.
Suncor operates the only refinery in Colorado, processing about 98,000 barrels of crude oil per day. That oil comes primarily from Canada, but also from the Denver-Julesberg basin.
The refinery employs more than 500 people.
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