air quality

Monitoring emissions is a big priority for Chevron and, since 1991, the refinery has cut emissions in half using various emission control technologies to reduce pollutants. Our Health, Environment & Safety group focuses on ensuring that all the work we do is performed in a safe and environmentally responsible manner. Air compliance personnel “sniff” different components in the refinery to ensure they are operating within air quality standards.

The current blend of reformulated gasoline and low sulfur diesel manufactured at the refinery is known a CaRFG 3 (California Reformulated Gasoline) or CARB 3 (California Air Resources Board). CaRFG 3, a requirement of the California Air Resources Board, reduces hydrocarbon emissions. Seeing the importance of this new requirement, the refinery completed the CaRFG 3 conversion ahead of schedule by nearly a year.

The refinery has its own cogeneration facility (Cogen) on site in order to increase energy efficiency. In addition, this state-of-the-art facility has helped to reduce air emissions significantly since it came on line in the 1980s. Our Cogen can generate up to 175 megawatts of electricity per day, which is enough for a typical city of 320,000 people. In the event we produce more power than we need, we can export electricity to the local power grid for use in the surrounding communities. 

We use steam as a clean source of power in turbines to drive pumps, compressors and other equipment. This white, billowy steam, which is often mistaken as “smoke,” is merely water vapors and is completely harmless. Occasionally during the early morning hours the steam appears to be dark gray due to atmospheric conditions and light refraction.  The chart below shows how steam reacts in different weather.

A flare is a safety device used to eliminate excess pressure buildup in the refinery. Whenever pressure in the plant begins to rise, the material is safely diverted to a relief system where it is burned in smokeless flares. These flares turn hydrocarbon vapors into harmless water vapor and carbon dioxide. Flares are designed for this process, so there is no need to be alarmed when you see them doing their job.

Occasionally, you may see smoke coming from the flares. This may happen during an unplanned shutdown when steam cannot be added to the system quickly enough to eliminate smoking. Fortunately, these events are infrequent and are usually of short duration.