Texas Administrative Code › Title 30 - ENVIRONMENTAL QUALITY › Part 1 - TEXAS COMMISSION ON ENVIRONMENTAL QUALITY › Chapter 115 - CONTROL OF AIR POLLUTION FROM VOLATILE ORGANIC › Subchapter B - GENERAL VOLATILE ORGANIC COMPOUND SOURCES › Division 6 - BATCH PROCESSES › Section 115.160 - Batch Process Definitions

Current through Reg. 49, No. 28; July 12, 2024
The following words and terms, when used in this division
						(relating to Batch Processes), shall have the following meanings, unless the
						context clearly indicates otherwise. Additional definitions for terms used in
						this division are found in §§
											3.2,
						101.1, and
						115.10 of
						this title (relating to Definitions).
(1) Aggregated--The summation of all process
					 vents containing volatile organic compounds (VOC) within a process.
(2) Annual mass emissions total--The sum of
					 all VOC emissions (pounds per year), evaluated before control but after the
					 last recovery device, from a process vent. Annual mass emissions shall be
					 calculated from an individual process vent or groups of process vents by using
					 emission estimation equations contained in Chapter 3 of EPA's Control of
					 Volatile Organic Compound Emissions from Batch Processes-Alternative Control
					 Techniques Information Document (EPA-453/R-94-020, February 1994) and then
					 multiplying by the historical duration and frequency of the emission or groups
					 of emissions over the course of a year. For process vents that are included in
					 a new source review air permit, standard permit, or permit by rule registered
					 by Form PI-8, the annual mass emissions total shall be based on the maximum
					 allowable emission rate (MAER) levels in the permit or Form PI-8 (adjusted to
					 represent the level before control, but after the last recovery device),
					 whether they correspond to the maximum design production potential or to the
					 actual annual production estimate.
(3) Average flow rate--The flow rate in
					 standard cubic feet per minute (scfm) averaged over the amount of time that
					 VOCs are emitted during an emission event. For the evaluation of average flow
					 rate from an aggregate of sources, the average flow rate is the weighted
					 average of the average flow rates of the emission events and their annual
					 venting time, or:
Attached
						Graphic
(4)
					 Batch--A noncontinuous process involving the bulk movement of material through
					 sequential manufacturing steps. Mass, temperature, concentration, and other
					 properties of a system vary with time. Batch processes are not characterized by
					 steady-state conditions. Reactants are not added and products are not removed
					 simultaneously.
(5) Batch cycle--A
					 manufacturing event of an intermediate or product from start to finish in a
					 batch process.
(6) Batch process
					 (for the purpose of determining reasonably available control technology (RACT)
					 applicability)--The batch equipment assembled and connected by pipes, or
					 otherwise operated in a sequence of steps, to manufacture a product in a batch
					 fashion.
(7) Batch process
					 train--An equipment train that is used to produce a product or intermediates in
					 batch fashion. A typical equipment train consists of equipment used for the
					 synthesis, mixing, and purification of a material.
(8) Emissions before control--The emissions
					 total before the application of a control device but after the last recovery
					 device, or the emissions total if no control device is used. The emissions
					 total may not be reduced to account for discharge of VOC into wastewater if the
					 wastewater is further handled or processed with the potential for VOC emissions
					 to the atmosphere.
(9) Primary
					 fuel--The fuel that provides the principal heat input to a device. To be
					 considered a primary fuel, the fuel must be able to sustain operation without
					 the addition of other fuels.
(10)
					 Process vent--A vent gas stream that is discharged from a batch process.
					 Process vents include gas streams that are discharged directly to the
					 atmosphere or are discharged to the atmosphere after diversion through a
					 recovery device. Process vents exclude relief valve discharges, leaks from
					 equipment, vents from storage tanks, vents from transfer/loading operations,
					 and vents from wastewater. Process gaseous streams that are used as primary
					 fuels are also excluded. The lines that transfer such fuels to a plant fuel gas
					 system are not considered to be vents.
(11) RACT--Reasonably available control
					 technology.
(12) Recovery
					 device--An individual unit of equipment capable of and used for recovering
					 chemicals for use, reuse, or sale. Recovery devices include, but are not
					 limited to, absorbers, carbon adsorbers, and condensers.
(13) Unit operations--Those discrete
					 processing steps that occur within distinct equipment that are used to prepare
					 reactants, facilitate reactions, separate and purify products, and recycle
					 materials.
(14) Volatility--As
					 follows.
(A) Low volatility VOCs are those
					 which have a vapor pressure less than or equal to 75 millimeters of mercury (mm
					 Hg) at 20 degrees Celsius.
(B)
					 Moderate volatility VOCs are those which have a vapor pressure greater than 75
					 and less than or equal to 150 mm Hg at 20 degrees Celsius.
(C) High volatility VOCs are those which have
					 a vapor pressure greater than 150 mm Hg at 20 degrees Celsius.
(D) To evaluate VOC volatility for single
					 unit operations that service numerous VOCs or for processes handling multiple
					 VOCs, the weighted average volatility can be calculated from the total amount
					 of each VOC emitted in a year and the individual component vapor pressure, as
					 follows.
Attached
						Graphic