Though unattractive, the century-old refineries to the north of Salt Lake are more than pulling their weight regarding air quality improvements and emissions reductions.
When it comes to placing the blame on bad air quality, it’s easy to point the finger at the five refineries in the Salt Lake Valley. They are very visual: stacks with billowing plumes of grey matter and flares.
First, to clarify: It’s not smoke. It’s water vapor. Mixed with the vapor are, among other things, SO2 (sulfur dioxide) and NOx (nitrogen oxides), sources of irritation to eyes, nose, throat and lungs and contributors to acid rain. Gas-powered vehicles emit the same, every time we drive them.
In the meantime, three Salt Lake Valley refineries, Chevron, Andeavor and Silver Eagle, are committed to being a part of the solution when it comes to cleaning up Utah’s air.
In recent interviews with the people who run this industry locally, I found a common theme: They all live and work here and, just like the rest of us, want to have the best air quality possible. So, as long as we require the transportation fuels they produce, refinery spokespeople say they are committed to reducing their impacts on the airshed as best they can.
The sources of air pollution
On an average winter day along the Wasatch Front, here’s how air pollution sources rank, according to the emissions inventory from the Utah Division of Air Quality (DAQ):
48%: mobile sources (vehicle emissions)
39%: area sources (homes, buildings, small businesses)
13%: point sources (all industry, including the refineries, which contribute 3%)
The same amount of pollution enters our air shed every day. A “red” day is different only because the weather, such as an inversion, traps it in the valley and as each day goes on, the pollution accumulates.
There are a lot of misconceptions about the refineries. The biggest misconception is that the refineries are major polluters in our state. In fact, only 3% of emissions come from Utah’s five refineries combined.
Andeavor, formerly Tesoro, is Salt Lake’s largest refinery, processing crude oil from Utah, Colorado, Wyoming and Canada and manufacturing gasoline, diesel, and jet fuel (supplied to Salt Lake City International Airport), heavy oils and liquefied petroleum gas. Andeavor’s Salt Lake refinery supplies a network of Tesoro, Shell, and ExxonMobil stations mostly in Utah, Idaho and Nevada. Andeavor has invested over $300 million in emissions reductions projects.
Sulfur dioxide (SO2), a gas that comes naturally from the refining process, reacts with other chemicals and leads to the formation of both wintertime PM 2.5 pollution and summertime ozone pollution. Sulfur recovery units (SRU) on Andeavor stacks remove sulfur from the fuel they refine. The recovered sulfur is sold to companies who use it for various products including fertilizer. Their tail gas treating project, completed in 2015, takes sulfur recovery one step further by converting the sulfur compounds left over from the SRU and recycling them back for additional processing. The result has been a huge reduction in SO2 emissions.
The refineries have limits as to how much pollution they can emit annually. This is laid out in the air quality permits issued, and it is regulated under the Federal Clean Air Act. All of these refineries implement the emissions reductions projects and equipment to comply with those limits, but at least Chevron, Silver Eagle and Andeavor pollute much less than they are allowed under their permits. They exceed the standards placed on them. Industry, like the refineries, are the most regulated sources of air pollution, and this is really important. Remember that with these regulations in place, all five refineries combined emit only 3% of the total air pollution captured in our valley.
Tier 3 fuel
In 2014, before any state incentives to do so, Andeavor committed to produce Tier 3 gasoline in Utah. With their permit to produce the lower sulfur fuel recently approved, the company expects to have the project underway this spring. Tier 3 is the newest fuel standard under federal regulation that drops the sulfur content in fuel from the current Tier 2 standard of 30ppm to 10ppm. (See CATALYST, November 2017:”More Cars, Less Pollution.”) Less sulfur means the fuel burns cleaner. This product also allows a vehicle’s emissions controls to work more efficiently as sulfur builds up over time on the catalyst.
Chevron has also committed to producing Tier 3 gasoline for sale in Utah and Silver Eagle Refinery has set a goal to become a “net-zero emitter” in Davis County. If Silver Eagle can sell 2,000 barrels per day of their own Tier 3 gasoline in Davis County, the estimated overall reductions in tailpipe emissions would be roughly equivalent to the total emissions from their Woods Cross facility, in total tons.
Because the five refineries in the Salt Lake Valley are considered small refineries, they do not necessarily have to produce fuel that meets the new Tier 3 standard. HollyFrontier and Big West are the two refineries that have not made such a commitment.
The benefit of having Tier 3 gas for sale in Utah will be significant. When Tier 3 is combined with the newest, cleanest Tier 3 vehicle, vehicles will run 80% cleaner.
Silver Eagle is already producing Tier 3 fuel, just not at its Utah plants. A few years back,the company shut down their old and inefficient equipment locally and moved gasoline production to their Evanston, Wyoming facility where they began producing Tier 3 gasoline in 2012. Seventy-five percent of the Tier 3 gas they produce makes its way back to Utah for sale at local gas stations (look for it at Costco, Smith’s and smaller unbranded gas stations throughout Salt Lake, Davis and Utah counties).
New technologies pull more pollutants from the stacks
The newest and best equipment to hit Utah’s refineries is Andeavor’s wet gas scrubber. A water mist spray captures sulfur and dust particles that would otherwise be emitted into the atmosphere, sequestering them inside the refinery’s system for further treatment, resulting in a 94% reduction in the refinery’s emissions. The scrubber will reduce SO2 emissions from 550 tons per year (tpy) to under 40 tpy. Nitrogen oxide will be reduced 60%, down to less than 100 tpy. Direct particulate matter will be virtually eliminated.
In a big effort to reduce their VOC (volatile organic compounds) emissions, a source of both wintertime PM 2.5 pollution and summertime ozone, Silver Eagle installed floating roofs in all of their crude tanks. VOCs are a major source of emissions coming from refineries. The tanks are sort of dome shaped, so liquid naturally remains level with a “bubble” on top where gases form and escape. The floating roofs act as a seal, cutting off VOCs that would normally offgas.
At the Chevron refinery, inefficient equipment is slowly being retired and replaced. For example, the old burners, which resulted in big NOx emissions, are being replaced with Ultra Low NOx models. This technology reduces the NOx emissions by nearly 75%. Chevron also employs some of the best leak detection strategies available to mitigate fugitive emissions that would otherwise enter the air.
Addressing perhaps the most visual part of a refinery, the big flare stack, Andeavor and Chevron have installed new Flare Gas Recovery systems that make it necessary to burn flares only in emergency situations. Flaring is an essential safety mechanism and a part of the refining process. A simple way of thinking about it is when a buildup of gas vapor needs to escape for safety reasons, it is sent to the flare stack and is burned because it can’t be released into the atmosphere in its raw state. With some new technology in place, these two companies are now able to, in non-emergency situations, collect and repurpose excess gas that would normally be sent to the flare stack.
Out in the community
Though Silver Eagle is owned by a Canadian company, they are working on becoming good neighbors to the Woods Cross community in which they work. In fact, Silver Eagle, Chevron and Andeavor are all highly invested in the local community not just through new pollution controls. Concerned with air quality challenges, Silver Eagle has voluntarily invested in efforts to reduce their emissions footprint by over 57%. And they have begun providing new air quality monitors for local schools.
Andeavor, meanwhile, has partnered with Salt Lake County to expand the Vehicle Repair and Replacement Program (VRAP), which repairs emissions equipment on vehicles that fail emissions testing. The VRAP program is a huge air quality benefit as it provides assistance that actually helps fix the problem. Andeavor also partnered with Chevron and Utah Clean Air Partnership (UCAIR) for the wood stove exchange program in 2017. Chevron invests more than $1.3 million in the state of Utah annually.
All of these emissions reductions projects undertaken by the refineries are a step towards cleaner air in Utah. We can breathe easier knowing that these companies are taking meaningful steps to be a part of the solution. We hope that the other two refineries in the valley, HollyFrontier and Big West, will follow their lead.
Their efforts to produce cleaner fuel will also help reduce mobile source pollution—which comes from all of us who drive vehicles with combustion engines and purchase goods delivered to Utah by truck.
Ashley Miller, J.D., is the program and policy director for Breathe Utah. She is a member of the state’s new Air Quality Policy Advisory Board and is also the Salt Lake County Health Department Environmental Quality Advisory Commission.