AIR QUALITY PERMITTING CRITERIA INCLUDING BEST AVAILABLE TECHNOLOGY CRITERIA FOR HEATSET WEB OFFSET LITHOGRAPHIC PRESSES

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1 7.8 Heatset Web Offset PERMIT Lithographic Presses AIR QUALITY PERMITTING CRITERIA INCLUDING BEST AVAILABLE TECHNOLOGY CRITERIA FOR HEATSET WEB OFFSET LITHOGRAPHIC PRESSES BACKGROUND The air pollutants from the web offset presses typically include ink oils from the inks and volatile organic compounds (VOC) from the fountain solutions. Due to low vapor pressures the ink-oils are classified not as VOCs but as organic particulate matter. Up to 80% of the ink-oils are removed in the dryer to produce an acceptable finished product. Upon release to the atmosphere, the ink-oils condense into an aerosol. Uncontrolled heatset web offset presses have in the past caused visible emissions in violation of 25 Pa Code Recent substitutes for isopropyl alcohol result in a fountain solution containing less than 7% VOC. VOCs are precursors for ozone formation. Appropriate air pollution control devices are readily available and widely employed in the web offset printing industry. APPLICABILITY This document specifies certain plan approval requirements and contains criteria which serve as guidelines to satisfy the Best Available Technology (BAT) requirement as established by 25 Pa Code (a)(5) for heatset web offset lithographic presses: (1) with more than two printing units; and (2) with two or less printing units and having potential ink-oil emissions exceeding 5 pounds per hour. Permitting requirements for other heatset web-offset presses will be established via case-by-case determinations. For screening purposes, the procedures set forth in Appendix A are suggested to estimate ink-oil emissions from the dryers. Actual emissions will be verified by source sampling methods. Department may waive testing requirements if proper controls are in place. These criteria/or guidances will be periodically revised as control technology improves /February 23, 1996/Page 73

2 7.8 Heatset Web Offset PERMIT DEFINITION Heatset web offset lithographic press - A printing press which: (a) utilizes a heated dryer to evaporate ink-oil from the printing film; (b) transfers ink and fountain solution from the plate cylinder to the substrate via a blanket cylinder; and, (c) prints on a continuous roll fed substrate. A. General Requirements 1. The emissions from the dryers shall be controlled by a control system with an efficiency of at least 90% at maximum organic material loading. The resulting emission rate to the atmosphere is not to be exceeded when the emission controls are operated under less than maximum loading. The control system may be, but is not limited to, any of the following: a catalytic incinerator, a thermal incinerator, a condenser/filter, or a cooler/electrostatic precipitator. 2. The fountain or wetting solutions used in the press shall not contain more than 7% VOC. Exemption from this requirement may be granted if a satisfactory explanation for requiring higher VOC in the fountain solution is given and total VOC emissions are less than 10 tons per year. When VOC emissions equal or exceed 10 tons per year, the dryers shall be controlled by an incinerator or a similar control system with a VOC control efficiency of at least 90%. A detailed plan describing how the applicant will minimize the use of clean-up solvents must be submitted to and approved by the Department before the issuance of a plan approval. B. Visible Emission Limitation Visible air contaminants shall not be emitted in such a manner that the opacity of the emissions is equal to or greater than 20% for a period or periods aggregating more than 3 minutes in any one hour or equal to or greater than 30% at any time / February 23, 1996 / Page 74

3 7.8 Heatset Web Offset PERMIT C. Source Testing Source tests, if required, are to be conducted in accordance with the organic testing method referenced in the Source Testing Manual's Special Testing Section. An alternate testing method may be employed if the method is approved by the Department prior to the testing. Approved by: (orig. signed) James M. Salvaggio, Chief Division of Abatement & Compliance Bureau of Air Quality July 28, / February 23, 1996 / Page 75

4 7.8 Heatset Web Offset A-1 PERMIT METHOD 1: APPENDIX A EMISSION CALCULATIONS U = S x 60 x 12 x A x N x W x F x P C E = U x O x Where: S = Web speed (FPM) I = No. of impressions per hour C = Web cut off length (in.) { = S x 12 x 60 } I A = Printable area (sq.in./impression) N = No. of websides W = No. of webs used at a time with the corresponding ink coverage P = Total ink coverage (%)* U = Ink consumption (lbs/hr) E = Ink oil emissions (lbs/hr) F = Emission factor: 0.72 for coated paper; or, 1.05 for uncoated paper * Maximum possible ink coverage per printing unit is 100 %, e.g., total ink coverage for a 4-unit press is 400 %. In the absence of impression area information (A) the ink consumption (U) can be calculated using the web width (D) as follows: U = S x 60 x 12 x D x N x W x F x P Where: D = Web width (in.) / February 23, 1996 / Page 76

5 7.8 Heatset Web Offset A-2 PERMIT METHOD 2: EMISSION CALCULATIONS - Continued Ink usage rate (U) in pounds per hour is estimated using the following: U = S X 60 X 12 X D X P 10 6 Where S = Web speed (fpm) D = Web width (in.) P = Ink coverage - 4 units process colors only w/perfecting web lbs 10 6 in. 2 * 1.0 lbs. = light, e.g. mostly text, some pictorial (single color and/or isolated light multicolor line images) 2.0 lbs. = medium, e.g. mostly text and pictorial (single and two color at low frequency) 3.0 lbs. = heavy, e.g. minor text, mostly art and pictorial (process color at medium to high frequency) 4.0 lbs. = maximum, e.g. negligible text, all art and pictorial (process color with high frequency dominated by shadow areas and/or press varnished) * For single, two, or three unit press, coverage is to be estimated using lower ink coverage under lbs. single unit 0.5 lbs. two units 0.7 lbs. three units Where: U = Ink consumption (lbs/hr) E = Ink oil emissions (lbs/hr) Ink-oil Emission rate: E = U x O x (1-R) 100 Where: E = Ink oil emissions (lbs/hr) U = Ink consumption (lbs/hr) R = Ink-oil Retention Factor (0.2 to 0.8) / February 23, 1996 / Page 77