AP-42 Emission Factor Changes for Refinery Processes (including all industrial flares)

On April 20, 2015 the U.S. EPA issued new and revised emission factors for refinery processes (including all industrial flares). In addition U.S. EPA determined that no revisions were necessary for tank and wastewater treatment system emission factors. [80 FR 26925] The changes were the result of a consent decree with Air Alliance Houston, Community In-Power and Development Association Inc., Louisiana Bucket Brigade and Texas Environmental Justice Advocacy Services. 

The emission factor changes are available on the AP-42 Emission Factor website http://www.epa.gov/ttn/chief/ap42/index.html. The changes were published in Section 5.1 – Petroleum Refining http://www.epa.gov/ttn/chief/ap42/ch05/final/c05s01_2015.pdf, Section 8.13 – Inorganic Chemical Industry Sulfur Recovery http://www.epa.gov/ttn/chief/ap42/ch08/final/c08s13_2015.pdf, and Section 13.5 – Industrial Flares – http://www.epa.gov/ttn/chief/ap42/ch13/final/C13S05_4-20-15.pdf

In addition, U.S. EPA updated the Emissions Estimation Protocol for Petroleum Refineries http://www.epa.gov/ttn/chief/efpac/protocol/Protocol%20Report%202015.pdf

In Section 5.1 – Petroleum Refining, new emission factors were added for total hydrocarbons (THC) for catalytic reforming units, nitrogen oxides (NOx) for hydrogen plants, and hydrogen cyanide (HCN) for fluid catalytic cracking units.

In Section 8.13 – Sulfur Recovery, new emission factors were added for NOx, CO and THC.

In Section 13.5 – Industrial Flares, an emission factor for volatile organic compounds (VOC) was added and the emission factor for carbon monoxide (CO) was lowered from 0.37 lb/MM Btu to 0.31 lb/MM Btu. In the draft Section 13.5, it was proposed to change the nitrogen oxides (NOx) emission factor from 0.068 to 2.9 lb/MM Btu.   The public comments from industry and trade associations pointed out errors in the NOx emission factor development and the NOx emission factor was not changed.

This article was excerpted from publically available information, and was authored by Joyce Gentry.

Joyce McCune Gentry, P.E., MS, has more than twenty years of experience in the environmental arena. Joyce is a Registered Professional Engineer in West Virginia. She works with industrial and commercial clients, providing technical consulting services, including water and air permitting, pollution prevention planning, the development and implementation of waste management programs, as well as advice on client-specific environmental issues. In addition to providing support for industrial and commercial clients, she has provided litigation support, such as environmental data analysis and data management.
» See more articles by Joyce A. Gentry
» Read the full biography of Joyce A. Gentry at Steptoe & Johnson