Clean Air

Air Emissions Performance

We continue to work on reducing air emissions from our operations. In addition to tracking our greenhouse gas emissions (see page 27), we track emissions of sulfur oxides (SO_x), nitrogen oxides (NO_x), particulate matter (PM) and volatile organic compounds (VOCs). SO_x, NO_x and PM originate from the combustion of hydrocarbons in our operations. SO_x and NO_x can contribute to the formation of acid rain. VOCs are hydrocarbons associated with natural gas and crude oil and represent lost product when released. They can serve as a precursor to smog, which in high concentrations can pose health risks.

For SO_x, NO_x and PM, we have seen a return from our investment in control technologies with reduced emissions. For VOC, we have made strides in reducing emissions from marine transport through new technology – however, our total emissions have grown along with our increased operations.

Overall, the company’s SO_x emissions in 2006 (figs. 1 & 2) were about 59,600 metric tons, a decrease of 17 percent from 2005. The main source of our SO_x emissions is the refining and marketing business sector. Emissions were reduced in this business sector through installation of controls, asset dispositions and marine transport reductions, partly offset by an increase from our acquisition of the Wilhelmshaven refinery. In the exploration and production and midstream sector, SO_x emissions increased due to the acquisition of the Burlington Resources assets.

NO_x emissions in 2006 (figs. 3 & 4) were about 119,000 metric tons, an increase of 31 percent from 2005. The exploration and production and midstream sector contributed approximately two-thirds of our NO_x emissions. Increased drilling activity and the addition of the Burlington Resources assets accounted for an increase in NO_x emissions. In the refining and marketing business sector, NO_x emissions decreased due to installation of controls, marine transport reductions, asset dispositions and a refinery turnaround, partly offset by an increase from the addition of the Wilhelmshaven refinery.

ConocoPhillips’ PM emissions in 2006 (figs. 5 & 6) were about 6,700 metric tons, a decrease of 14 percent from 2005. The refining and marketing business sector contributed the majority of the company’s PM emissions and decreased their emissions primarily through asset dispositions, as well as improved plant performance, installation of wet gas scrubbers at several facilities and improved measurement through stack testing. Emissions from the exploration and production and midstream sector increased due to the addition of the Burlington Resources properties.

ConocoPhillips’ VOC emissions in 2006 (figs. 7 & 8) were approximately 193,000 metric tons, an increase of 24 percent from 2005. Over two-thirds of the company’s VOC emissions were from exploration and production and midstream sector, which increased mainly due to the addition of the Burlington Resources assets, partly offset by a reduction in Indonesia offshore operations. The marine operations decreased VOC emissions due to marine transport reductions.

Refining Emissions Reductions

We are working diligently to meet and exceed the requirements of an agreement signed with the U.S. Environmental Protection Agency (EPA) in January 2005 to reduce air emissions at nine of our 12 U.S. refineries. Our other three U.S. refineries were included in a similar settlement reached in 2001.

The 2005 agreement requires us to invest more than $525 million in control technologies to reduce emissions from these refineries. However, our clean air initiatives will go beyond EPA requirements, and by 2011 we expect to have invested more than $1 billion in projects to reduce air emissions.

Between 2002 and 2012, we expect to achieve reductions in SO_x emissions from our U.S. refineries of 80 percent, or more than 33,600 metric tons per year; in NO_x emissions by 40 percent, or more than 9,100 metric tons per year. We also expect a similar percentage reduction in PM emissions, or more than 1,800 metric tons per year.

Marine Emissions Reductions

Our Polar Tankers fleet employs a program called E-Speed that enables our vessels to slow down and arrive in port on a just-in-time basis when safe and practical to do so, reducing fuel consumption and emissions. By reducing engine power by 50 percent, a tanker’s speed can drop just 20 percent, leading to fuel savings of 30 percent and a corresponding reduction in air emissions. The E-Speed program also saves approximately $25,000 per trip. Since the program began in April 2006, we have cut emissions of SO_x, NO_x and PM from six tankers in the fleet by 25 percent per year and total fuel costs by $2 million per year. The program is being extended to other tanker operations when production, pipeline throughput, inventories and delivery schedules allow.

To reduce SO_x and PM emissions from our Polar vessels, especially in coastal areas, we are fitting slide valves, a type of fuel injector, to their engines. This effort particularly will benefit Prince William Sound on Alaska’s south coast, where local atmospheric conditions tend to trap low-level smoke. Our tankers already complied with the International Convention for the Prevention of Pollution from Ships (MARPOL) Annex VI criteria for NO_x emissions, but the valves will enable the vessels to surpass those standards, as well as improving fuel consumption. In addition, we are fitting new engine lubrication systems to the Polar vessels to reduce lubricating oil consumption, which can be another cause of SO_x and PM emissions.

VOC Emissions Reductions

The Randgrid master on the bridge, overlooking the white VOC recovery unit.

A significant source of VOC emissions is the loading and offloading of crude oil tankers. To reduce these emissions, we are constructing a VOC recovery plant at our Teesside oil terminal in the United Kingdom. Each year some 25 million metric tons of crude oil are exported through the terminal, which in 2006 accounted for approximately 9 percent of exploration and production’s total VOC emissions. Due for completion in 2007, the plant is expected to reduce annual VOC emissions more than 85 percent. It captures the light VOC gases that would otherwise be emitted from tanker vents during loading and returns the VOCs back to the crude oil cargo.

In 2005, our Randgrid oil tanker, which serves the Heidrun field in the Norwegian North Sea, also was fitted with a system to recover light VOC gases that would otherwise be emitted during loading and transportation. Crude oil loading from offshore buoys accounts for about 40 percent of Norway’s VOC emissions. The Randgrid’s system captures VOCs during the loading operation at the buoy and from pressure vents on the storage tanks during shipment. The gas is filtered and cooled to a liquid, then returned to the cargo. The plant recovers some 100 metric tons of liquid per shipment, providing economic, as well as environmental, benefits. The Randgrid’s engines also burn low-sulfur fuel oil, reducing sulfur dioxide emissions more than 200 metric tons per year compared to using regular fuel oil.

Go back to top

---

Go back to top