What requirements must I meet for process vents, storage tanks, or equipment that are in ethylene oxide service?

§ 63.2493 What requirements must I meet for process vents, storage tanks, or equipment that are in ethylene oxide service?

This section applies beginning no later than the compliance dates specified in § 63.2445(i). In order to demonstrate compliance with the emission limits and work practice standards specified in Tables 1, 2, and 4 to this subpart for process vents and storage tanks in ethylene oxide service, you must meet the requirements specified in paragraphs (a) through (c) of this section. In order to demonstrate compliance with the requirements specified in Table 6 to this subpart for equipment in ethylene oxide service, you must meet the requirements specified in paragraphs (d) and (e) of this section.

(a) Initial compliance. For initial compliance, you must comply with paragraphs (a)(1) through (4) of this section, as applicable.

(1) If you choose to reduce emissions of ethylene oxide by venting emissions through a closed-vent system to a flare as specified in Table 1, 2, or 4 to this subpart, then you must comply with § 63.2450(e)(4) and (6) and the requirements in § 63.983, and you must conduct the initial visible emissions demonstration required by § 63.670(h) of subpart CC as specified in § 63.2450(e)(5).

(2) If you choose to reduce emissions of ethylene oxide by venting emissions through a closed-vent system to a non-flare control device that reduces ethylene oxide by greater than or equal to 99.9 percent by weight as specified in Table 1, 2, or 4 to this subpart, then you must comply with § 63.2450(e)(4) and (6) and the requirements in § 63.983, and you must comply with paragraphs (a)(2)(i) through (viii) of this section.

(i) Conduct an initial performance test of the control device that is used to comply with the percent reduction requirement at the inlet and outlet of the control device. For purposes of compliance with this paragraph (a)(2), you may not use a design evaluation.

(ii) Conduct the performance test according to the procedures in §§ 63.997 and 63.2450(g). Use Method 18 of 40 CFR part 60, appendix A–6, or Method 320 of appendix A to this part to determine the ethylene oxide concentration. Use Method 1 or 1A of 40 CFR part 60, appendix A–1, to select the sampling sites at each sampling location. Determine the gas volumetric flowrate using Method 2, 2A, 2C, or 2D of 40 CFR part 60, appendix A–2. Use Method 4 of 40 CFR part 60, appendix A–3, to convert the volumetric flowrate to a dry basis.

(iii) Calculate the mass emission rate of ethylene oxide entering the control device and exiting the control device using Equations 1 and 2 to this paragraph (a)(2)(iii).

EEtO,inlet = K CEtO,inlet MEtO Qinlet (Eq. 1) EEtO,outlet = K CEtO,outlet MEtO Qoutlet (Eq. 2)

Where:

EEtO,inlet, EEtO,outlet = Mass rate of ethylene oxide at the inlet and outlet of the control device, respectively, kilogram per hour. CEtO,inlet, CEtO,outlet = Concentration of ethylene oxide in the gas stream at the inlet and outlet of the control device, respectively, dry basis, parts per million by volume. MEtO = Molecular weight of ethylene oxide, 44.05 grams per gram-mole. Qinlet, Qoutlet = Flow rate of the gas stream at the inlet and outlet of the control device, respectively, dry standard cubic meter per minute. K = Constant, 2.494 × 10−6 (parts per million)−1 (gram-mole per standard cubic meter) (kilogram per gram) (minutes per hour), where standard temperature (gram-mole per standard cubic meter) is 20 °C.

(iv) Calculate the percent reduction from the control device using Equation 3 to this paragraph (a)(2)(iv). You have demonstrated initial compliance if the overall reduction of ethylene oxide is greater than or equal to 99.9 percent by weight.

Percent reduction = (EEtO,inlet−EEtO,outlet)/EEtO,inlet * 100 (Eq. 3)

Where:

EEtO,inlet, EEtO,outlet = Mass rate of ethylene oxide at the inlet and outlet of the control device, respectively, kilogram per hour, calculated using Equations 1 and 2 to paragraph (a)(2)(iii) of this section.

(v) If a new control device is installed, then conduct a performance test of the new device following the procedures in paragraphs (a)(2)(i) through (iv) of this section.

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