The non-fluorinated chemicals sector includes facilities that manufacture adipic acid, ammonia, hydrogen, nitric acid, petrochemicals, phosphoric acid, silicon carbide, titanium dioxide, and other chemicals (i.e., facilities with various NAICS codes related to chemical production). Reported emissions from the non-fluorinated chemicals sector have increased from 163.1 million metric tons (MMT) CO₂e to 177.0 MMT CO₂e (8.5 percent) from 2011 to 2019. After a slight decrease (3 percent) from 2011 to 2012, emissions steadily increased by 1 to 5 percent per year through 2018, before decreasing by 6.2 MMT CO₂e (3 percent) for 2019. While petrochemical production, hydrogen production, and ammonia manufacturing are the three largest contributors to emissions from the non-fluorinated chemicals sector, the 2018 to 2019 emissions decrease was due primarily to adipic acid production. Emissions from the other subsectors were either relatively steady or declined, but the magnitude of these emissions is small relative to the larger subsectors.

Adipic Acid Production. Reported emissions from the adipic acid production subsector have varied greatly between 2011 and 2019, with the highest emissions in 2011 and 2018 (11.9 MMT CO₂e). Between 2018 and 2019, the emissions from adipic acid production decreased by 41.8 percent (5.0 MMT CO₂e). This change is due to one facility that employs a nitrous oxide abatement device but varies the percent of time that the device is in service. The higher the percentage of time that the abatement device is in service, the lower the nitrous oxide emissions. This facility has acknowledged the variation in emissions is due to the nitrous oxide abatement device and has verified that the emissions are correct.

Ammonia Manufacturing. While somewhat variable from year to year, reported emissions from ammonia manufacturing increased by 41.3 percent (10.3 MMT CO₂e) from 2011 to 2018. This is mostly due to an increase in the number of ammonia manufacturing facilities, from 22 in 2011 to 29 in 2019. New ammonia manufacturing facilities were opened in 2013, 2016, and 2017 (one in 2013, four in 2016, and two in 2017). For 2018 and 2019, the number of facilities did not change from 2017. There was a slight decrease in emissions of 1.7% (0.62 MMT CO₂e) from 2018 to 2019 with minimal impact to the overall emissions from the non-fluorinated chemicals sector.

Hydrogen Production. Reported emissions from the hydrogen production subsector increased by 17.6 percent (6.6 MMT CO₂e) from 2011 to 2019. The overall increase in emissions is at least partly driven by increased demand for hydrogen by petroleum refineries due to an expansion of the scope of engines required to use low sulfur and ultra-low sulfur diesel fuel. Lowering the sulfur content of diesel fuel is achieved by increasing hydro-treating capacity of fluid catalytic crackers and requires additional inputs of hydrogen at refineries. Emissions from hydrogen production decreased by 2.8 percent (1.3 MMT CO₂e) from 2018 to 2019, mainly due to yearly fluctuations in hydrogen demand.

Petrochemical Production. Reported emissions from the petrochemical production subsector increased by 10.3 percent (5.4 MMT CO₂e) from 2011 to 2019. The majority of the emissions increase over the time series (3.5 MMT CO₂e) occurred from 2017 to 2018 as a result of new process units at 2 petrochemical production facilities.