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 here. The changes were published in Section 5.1 – Petroleum Refining here, Section 8.13 – Inorganic Chemical Industry Sulfur Recovery here, and Section 13.5 – Industrial Flares – here.

In addition, U.S. EPA updated the Emissions Estimation Protocol for Petroleum Refineries here.

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.