Whatever the application, a significant portion of the energy used in thermal process systems winds up as waste energy due to inefficiencies inherent in fossil-fuel combustion, as well as faulty or poorly maintained equipment or process controls. This waste energy not only results in higher operating costs for owners, but in NOx and GHG emissions and other forms of environmental pollution.
Prodded by increasingly stringent federal and state emissions regulations, oil refiners, petrochemical and industrial plant owners and operators are scrambling to come up with cost-effective solutions, including development of new thermal process and emissions control technologies. Seattle's ClearSign Combustion Corp. believes it has one.
Combustion Rules
Two-thirds of global energy production is used in the combustion of hydrocarbon fuels in burners, furnaces, boilers, and other types of thermal process equipment, ClearSign CEO Rick Rutkowski said.
The innovation in combustion and emissions-control technology came about after the company was approached and asked to find a solution to a problem that has long bothered oil refiners and petrochemical plant owners and operators – how to design more efficient, better-behaved burners by better controlling the shape and stability of flames, Rutkowski said.
If the new technology matches or exceeds its past performance in smaller scale tests, “for the first time it will be possible to align environmental goals with goals of process excellence, reduced maintenance and greater capacity,” Rutkowski said.
Oil, Gas and NOx Emissions in the San Joaquin Valley
The San Joaquin Valley has been a center of oil and gas exploration development and production in California for over a century. The San Joaquin Valley Air Pollution Control District (SJVAPCD) also has some of the most stringent limits on NOx emissions in the nation for the boilers, steam generators and process heaters used in EOR and oil refineries, said SJVAPD Chief Communications Office Jaime Holt.
The latest in a series of more stringent ambient air quality standards stretching back 22 years, SJVAPCD instituted a limit on NOx emissions from these sources as low as 7 ppmv (parts per million by volume) at 3 percent O2 in 2008. Over the last 21 years, SJVAPCD's latest NOx emissions standard for these sources represents a 77 percent decrease, Holt highlighted.
Overall NOx emissions from stationary sources in the San Joaquin Valley have come down over 90 percent and those from EOR, oil refineries and petrochemical plants over 90 percent since 1990, “resulting in significant improvements to air quality in the Valley,” Holt said.
“NOx is the key driving pollutant for ozone in the summer and [particulates] in the winter, so NOx will continue to be the focus of the District's [air pollution reduction] efforts. Meeting these new standards will require extensive additional emissions reductions and transformative change, particularly with respect to the over 80 percent of remaining NOx emissions in the Valley now attributed to mobile sources,” Holt said. “In that effort, we will continue work collaboratively with Valley stakeholders to seek out additional opportunities to further reduce emissions.”
Enhanced Oil Recovery in the San Joaquin Valley
Presently, ClearSign is gearing up for the first commercial-scale test of its Duplex Tile combustion technology at an EOR operation in Bakersfield, Calif. “It's a very challenging environment. Surrounded by mountains on three sides, emissions “have a tendency to just sit there, and an awful lot of oil and gas is produced there,” Rutkowski explained.
In August, the company signed a contract to integrate it with once-through steam generators used to extract petroleum from tar-like heavy crude at a facility in Bakersfield owned and operated by Aera Energy.
A joint venture between ExxonMobil and Shell, Aera Energy employs once-through steam generators to pump steam underground to reduce the viscosity of heavy oil and facilitate extraction. “Even single-digit improvements are a big deal when you're using that much energy and operating a razor-thin profit margins,” Rutkowski said.
NOx-ious Emissions
Air quality in the California's South Coast Basin has improved significantly since the 1970s, when the Los Angeles Basin became the poster child for summertime smog – a noxious combination of ground-level ozone and volatile organic compounds known as VOCs.
Those improvements have come about as a result of determined and persistent efforts on the part of federal, state and local agencies working with industry and the public to reduce NOx and VOC emissions, as well as sulfur dioxides (SO2) and greenhouse gases, from stationary and mobile sources. A lot of work still needs to be done, however.
Reducing ground-level ozone down to the levels required has been the most difficult Clean Air Act (CAA) quality standard to achieve for both the South Coast and San Joaquin Valley Air Quality Management Districts (AQMD), South Coast AQMD Executive Director Barry Wallerstein explained.
As per CAA standards, a ground-level ozone target of 80 parts per billion (ppb) must be met by 2023. Ozone concentration needs to fall further, to 75 ppb, by 2032. That means reducing NOx emissions further, roughly another two-thirds by 2023 and three-quarters by 2032.
“The bottom line is that no rock can be left unturned when it comes to reducing NOx emissions,” Wallerstein said. “We need to make use of all existing technologies, apply them in new ways, and we're going to need substantial technology advancements.”
NOx Cap-and-Trade
Given the need to achieve substantial reductions over and above those already attained, SCAQMD is re-evaluating current RECLAIM standards for NOx emissions, Wallerstein said. That includes NOx emissions from stationary sources, such as EOR operations and oil refineries. By early 2Q 2015, “we will bring to our board a proposal to further tighten allowed NOx emissions from these sources.”
RECLAIM is a NOx cap-and-trade program under which annual caps on emissions have been set. Those facilities whose emissions come in under the cap can sell NOx emissions credits to those whose emissions come in above. Overall, allowed NOx emissions under RECLAIM decline annually.
“For those whose NOx emissions are above four tons per year, we're going to tighten up on them,” Wallerstein said. “The question is how we do the 'shave' – across the board for all facilities, or just for some – but the bottom line is that NOx emissions will significantly decrease.”
The Bottom Line
ClearSign is keen to prove its new combustion and emissions control technology in the field. “The demand scenario has aligned beautifully,” Rutkowski said. “We're now ready to aggressively enter the marketplace at a time when there's a great deal of need.”
Commenting on the need for new combustion and emissions control technology, SCAQMD's Wallerstein said: “Any company that develops a new NOx control technology – one that's technologically feasible, cost-effective and has been demonstrated in practice – has a significant potential market in California.”
In the meantime, Wallerstein and his staff continue to work closely with RECLAIM program participants as they finalize a proposal for instituting new NOx emissions limits. “We have a very open process of rules development and we get down in workshops and individual company meetings to discuss potential changes to requirements,” he said. “Ultimately, we propose what we think is the best solution for all involved – mindful that the bottom line is the protection of public health.”
This story was originally published by FutureStructure.
