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 177.7 MMT CO₂e (9.0 percent) from 2011 to 2020. After a slight decrease (2.7 percent) from 2011 to 2012, emissions steadily increased by 1 to 5 percent per year through 2018, before decreasing by 6.3 MMT CO₂e (3.4 percent) for 2019, and then increasing by 0.9 MMT CO₂e (0.5 percent) for 2020. Adipic acid production, ammonia production, hydrogen production, and petrochemical production were the four largest contributors to emissions changes from the non-fluorinated chemicals sector between 2019 and 2020, as detailed below. The large increase in emissions from adipic acid (2.9 MMT CO₂e) was balanced out by the large decrease in emissions from hydrogen production (2.9 MMT CO₂e). The increase in emissions from ammonia production (1.4 MMT CO₂e) was balanced out by the overall combined decrease in emissions from nitric acid, silicon carbide, titanium dioxide, and other chemicals (1.4 MMT CO₂e). Therefore, the bulk of the 2019 to 2020 emissions increase was due to a slight increase in emissions from petrochemical production of 0.8 MMT CO₂e.

 Adipic Acid Production. Reported emissions from the adipic acid production subsector have varied greatly between 2011 and 2020, with the highest emissions in 2011 and 2018 (11.9 MMT CO₂e and 12.1 MMT CO₂e, respectively). Between 2019 and 2020, the emissions from adipic acid production increased by 42.5 percent (2.9 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. The nitrous oxide abatement device was in service for less time in 2020 than in 2019, resulting in an increase in emissions between the two years. 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 Production. While somewhat variable from year to year, reported emissions from ammonia production increased by 46.8 percent (11.6 MMT CO₂e) from 2011 to 2020. This is mostly due to an increase in the number of ammonia production facilities, from 22 in 2011 to 29 in 2020. New ammonia production facilities were opened in 2013, 2016, and 2017 (one in 2013, four in 2016, and two in 2017). The number of facilities has not changed since 2017 but there was an increase in emissions of 3.9% (1.4 MMT CO₂e) from 2019 to 2020, due to an increase in market demand for ammonia between 2019 and 2020.

 Hydrogen Production. Reported emissions from the hydrogen production subsector increased by 9.9 percent (3.7 MMT CO₂e) from 2011 to 2020. 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 6.5 percent (2.9 MMT CO₂e) from 2019 to 2020. One facility with 2019 emissions of 1.0 MMT CO₂e stopped reporting hydrogen production in 2020 due to a merger with a neighboring petrochemical production facility. The remaining emissions reduction is likely due to a drop in hydrogen demand during the COVID-19 pandemic, as hydrogen is used in oil refining, steel production and chemicals production.

Petrochemical Production. Reported emissions from the petrochemical production subsector increased by 11.5 percent (6.0 MMT CO₂e) from 2011 to 2020. Most of the emissions increase occurred from 2017 to 2018 (3.3 MMT CO₂e) as a result of new process units at 2 petrochemical production facilities. Emissions from 2019 to 2020 increased slightly by 1.4 percent (0.8 MMT CO₂e), which is primarily due to a significant increase in flaring at one facility, startup of two new process units in 2020, increased production in 2020 of one process unit that started up in 2019, and the merged hydrogen production and petrochemical facility reporting the integrated process emissions under the petrochemical subsector.