7 Del. Admin. Code § app I § 1124-A-I-4.0
Current through Register Vol. 28, No. 3, September 1, 2024
Section 1124-A-I-4.0 - ProcedureFollow the procedure below and complete the worksheets using configuration and operating data specific to the process unit or units and VOC emission control system for which the rolling balance period determination is being made.
4.1 Solvent Properties. The purpose of this step is to determine representative values for the molecular weight and liquid density of the solvent or solvents used in the process. 4.1.1 Single Component Solvent. If a single component solvent (not a mixture) is used exclusively for the process unit or units served by the emission control system, then record the chemical name of the solvent, its molecular weight, and liquid density in lines 1a, 2, and 3, respectively, of Worksheet A of this appendix and proceed to 4.2 of this appendix.4.1.2 Multiple Solvent or Solvent Mixtures. If multiple solvents or solvent mixtures are used, complete Worksheet A of this appendix. List the chemical names of the individual organic compounds, including the major components of the solvent mixtures, in block 1 of Worksheet A of this appendix. The organic constituents listed should account for at least 90% of the total solvent. Use equation (I-1) of this appendix to calculate the weighted average molecular weight, ML, and liquid density, dL, of the solvents used in the process unit or units. Record these values on lines 2 and 3, respectively, of Worksheet A of this appendix. Click here to view Image
where
Y = Weighted average molecular weight (ML) or liquid density (dL).
Yi = Molecular weight (Mi) or liquid density (di) for VOC i.
Xi = Fraction of total solvent for VOC i.
n = Number of VOC species in the solvent or solvents.
WORKSHEET A SOLVENT DESCRIPTION | | | | |
Solvent Composition | Annual Usage (gal/yr) | (100.xi) Percent of Total Solvents Listed | (M i) Molecular Weight (lb/lb mole) | (di) Liquid Density (lb/gal) | | | | |
1a | | | | | | | | |
1b | | | | | | | | |
1c | | | | | | | | |
1d | | | | | | | | |
1e | | | | | | | | |
1f | | | | | | | | |
1g | | | | | | | | |
1h | | | | | | | | |
Total | | | | | | | | |
2. Solvent Molecular Weight (weighted average), (Mi) | | | lb/lb mole | | |
3. Solvent Liquid Density (weighted average), (di) | | | lb/lb mole | | |
4.2 Emission Source and Control System Description. In this step, the site-specific system design and operation information needed to determine the appropriate rolling balance period is developed and compiled in Worksheet B of this appendix. Complete Worksheet B of this appendix by providing the indicated information specific to the emission source process unit or units and emission control system for which this rolling balance period determination is being made. Unless otherwise specified, the information requested refers to the aggregate of all the process units of the emission source linked to and served by the emission control system containing the carbon solvent recovery control device. 4.2.1 Number of Process Units. Record the total number of process units (e.g., dip tanks, spray booths) connected to the capture system and manifolded to the solvent recovery control system on line 1 of Worksheet B of this appendix.4.2.2 Solvent Usage. The maximum daily solvent usage reported on line 2 of Worksheet B of this appendix is the maximum total solvent throughput of the process unit or units that would be used in a day under peak production. The average daily solvent usage requested in line 3 of Worksheet B of this appendix is the annual total solvent throughput of the process unit or units divided by the number of days in the year the process unit or units was in operation.4.2.3 Unmeasured Process Holding Capacity for Solvent. Estimate (+10 gallons) the unmeasured solvent holding capacity of each process unit served by the capture and solvent recovery systems in this analysis. Compute the aggregate total unmeasured volume of these process units, and then compare this total to 10% of the value listed in Worksheet B, line 3 (0.1xQ'SP), of this appendix for the average daily solvent usage. Enter on line 4 the smaller of the values of the estimated aggregate total unmeasured process holding capacity and 10% of the average daily solvent usage reported on line 3 of Worksheet B of this appendix.4.2.4 Capture System Air Flow Rate. Report on line 5 of Worksheet B of this appendix the total volumetric air flow rate (adjusted to the standard conditions of 70°F and 1.0 atm) output from the capture system to the solvent recovery system. WORKSHEET B EMISSION SOURCE AND CONTROL SYSTEM DESCRIPTION | |
Emission Source - Process Units | |
1. Number of Process Units | | |
2. Maximum Daily Solvent Usage, QSP | gal/day | |
3. Average Daily Solvent Usage, Q'SP | gal/day | |
4. Unmeasured Solvent Holding Capacity In Process, VP | gala | |
Emission Control System - Capture Unit | |
5. Average Air Flow Rate, GCU | scfmb | |
6. Maximum VOC Concentration In Outlet Air, CO | ppmv | |
Emission Control System - Solvent Recovery Control Unit | |
7. Number of Carbon Beds | | |
8. Total Carbon in Solvent Recovery Unit, WC | lb | |
9. Maximum Solvent Loading On Carbon, VA | gal | |
10. Unmeasured Capacity In Support Equipment, VS | gal | |
11. Total Unmeasured Capacity, VR = VA + VS | gal | |
a Maximum value limited to 10% of the value in line 3, (Q'SP).
b Standard conditions: 70°F and 1.0 atm.
4.2.5 Maximum VOC Concentration in Capture System Outlet. Use equation (I-2) of this appendix to estimate the maximum concentration of VOC in the outlet air stream of the capture unit (inlet (2)(3) air stream to the carbon adsorber beds of the solvent recovery control unit). If actual VOC concentrations (measured on the same capture unit under the current operating conditions within the past two years using an EPA approved test method) are available and their average exceeds the concentration calculated in equation (I-2) of this appendix, then record the average of the measured concentrations on line 6 of Worksheet B of this appendix; otherwise record the concentration from equation (I-2) of this appendix on line 6 of Worksheet B of this appendix. Click here to view Image
(I-2)
where
CO = Concentration of VOC in outlet air of capture unit, ppmv.
QSP = Maximum daily solvent throughput to the process units, gal/day (Worksheet B, line 2, of this appendix).
dL = Solvent liquid density, lb/gal (Worksheet A, line 3, of this appendix).
ML = Solvent molecular weight, lb/lbmole (Worksheet A, line 2, of this appendix).
GCU = Capture unit outlet air flow rate, scfm (Worksheet B, line 5, of this appendix).
4.2.6 Quantity of Carbon in Solvent Recovery System. Report the number of carbon adsorber beds (both online and offline for regeneration) in the solvent recovery system on line 7 of Worksheet B of this appendix. Determine the total mass of carbon in the solvent recovery system by summing the masses in each of the carbon adsorber beds, and enter the total on line 8 of Worksheet B of this appendix.4.2.7 Maximum Solvent Loading on the Carbon. To estimate the maximum solvent loading (i.e., solvent holding capacity) for the total carbon in the solvent recovery control unit, use equations (I-3) and (I-4) of this appendix. Record the value calculated for VA in equation (I-4) on line 9 of Worksheet B of this appendix. Click here to view Image
(I-3)
where,
Click here to view Image
X = ln(CO)
b0 = -3.047598
b1 = 0.275410
b2 = -0.003271
b3 = -0.000486
CO = Maximum VOC concentration in capture unit outlet air, ppmv (Worksheet B, line 6, of this appendix).
WA = Amount of VOC adsorbed on the carbon, lb VOC/lb carbon.
Click here to view Image
(I-4)
where
VA = Maximum solvent loading on the carbon in the solvent recovery unit, gal.
WA = Amount of VOC adsorbed on the carbon (equation (I-3) of this appendix).
WC = Total quantity of carbon in the solvent recovery unit, lb carbon (Worksheet B, line 3, of this appendix).
dL = Solvent liquid density, lb/gal (Worksheet A, line 3, of this appendix).
4.2.8 Unmeasured Solvent Capacity in Support Equipment. In addition to the solvent adsorbed on the carbon, the solvent recovery system may contain time-varying quantities of solvent in its support equipment such as condensate tanks, decanters, and surge/collection tanks, which are not measured as part of the daily material balance. Estimate that portion of the volume in the support equipment over which the unmeasured quantity of solvent it contains may vary between material balances. Do not include the capacity where the solvent inventory remains essentially constant over time. Compare this estimated value of the unmeasured solvent holding capacity in the support equipment with the value corresponding to 10% of the average daily solvent usage (Worksheet B, line 3, of this appendix), and record the smaller of these two values as VS on line 10 of Worksheet B of this appendix.4.2.9 Unmeasured Solvent Capacity for Solvent Recovery System. The unmeasured solvent holding capacity of the solvent recovery system is the sum of the maximum solvent loading on the carbon and the unmeasured holding capacity of the support equipment. On Worksheet B of this appendix, sum the values on lines 9 and 10 and record this sum on line 11.7 Del. Admin. Code § app I § 1124-A-I-4.0