§98.513 Calculating GHG emissions.

(a) You must determine annual N ₂ O process emissions from each caprolactam, glyoxal, and glyoxylic acid process line using the appropriate default N ₂ O generation factor(s) from table 1 to this subpart, the site-specific N ₂ O destruction factor(s) for each N ₂ O abatement device, and site-specific production data according to paragraphs (b) through (e) of this section.

(b) You must determine the total annual amount of product i (caprolactam, glyoxal, or glyoxylic acid) produced on each process line t (metric tons product), according to §98.514(b).

(c) If process line t exhausts to any N ₂ O abatement technology j , you must determine the destruction efficiency for each N ₂ O abatement technology according to paragraph (c)(1) or (2) of this section.

(1) Use the control device manufacturer's specified destruction efficiency.

(2) Estimate the destruction efficiency through process knowledge. Examples of information that could constitute process knowledge include calculations based on material balances, process stoichiometry, or previous test results provided the results are still relevant to the current vent stream conditions. You must document how process knowledge (if applicable) was used to determine the destruction efficiency.

(d) If process line t exhausts to any N ₂ O abatement technology j , you must determine the abatement utilization factor for each N ₂ O abatement technology according to paragraph (d)(1) or (2) of this section.

(1) If the abatement technology j has no downtime during the year, use 1.

(2) If the abatement technology j was not operational while product i was being produced on process line t , calculate the abatement utilization factor according to equation 1 to this paragraph (d)(2).

Equation 1 to paragraph (d)(2)

Where:

AF _j = Monthly abatement utilization factor of N ₂ O abatement technology j from process unit t (fraction of time that abatement technology is operating).

T _i,j = Total number of hours during month that product i (caprolactam, glyoxal, or glyoxylic acid), was produced from process unit t during which N ₂ O abatement technology j was operational (hours).

T _i = Total number of hours during month that product i (caprolactam, glyoxal, or glyoxylic acid), was produced from process unit t (hours).

(e) You must calculate N ₂ O emissions for each product i from each process line t and each N ₂ O control technology j according to equation 2 to this paragraph (e).

Equation 2 to paragraph (e)

Where:

E _N2Ot = Monthly process emissions of N ₂ O, metric tons from process line t .

EF _i = N ₂ O generation factor for product i (caprolactam, glyoxal, or glyoxylic acid), kg N ₂ O/metric ton of product produced, as shown in table 1 to this subpart.

P _i = Monthly production of product i , (caprolactam, glyoxal, or glyoxylic acid), metric tons.

DE _j = Destruction efficiency of N ₂ O abatement technology type j , fraction (decimal fraction of N ₂ O removed from vent stream).

AF _j = Monthly abatement utilization factor for N ₂ O abatement technology type j , fraction, calculated using equation 1 to paragraph (d)(2) of this section.

0.001 = Conversion factor from kg to metric tons.

(f) You must determine the annual emissions combined from each process line at your facility using equation 3 to this paragraph (f):

Equation 3 to paragraph (f)

Where:

N ₂ O = Annual process N ₂ O emissions from each process line for product i (caprolactam, glyoxal, or glyoxylic acid) (metric tons).

E _N2Ot = Monthly process emissions of N ₂ O from each process line for product i (caprolactam, glyoxal, or glyoxylic acid) (metric tons).

[89 FR 31948, Apr. 25, 2024]