Oklahoma Department of Environmental Quality s14

PERMIT MEMORANDUM 2007-152-TVR 27

OKLAHOMA DEPARTMENT OF ENVIRONMENTAL QUALITY

AIR QUALITY DIVISION

MEMORANDUM August 30, 2007

TO: Phillip Fielder, P.E., Permits and Engineering Group Manager,

Air Quality Division

THROUGH: Matt Paque, Supervising Attorney, Air Quality Division

THROUGH: Kendal Stegmann, Senior Environmental Manager, Compliance

and Enforcement

THROUGH: Grover Campbell, P.E., Existing Source Permits Section

THROUGH: Phil Martin, P.E., New Source Permits Section

THROUGH: Peer Review

FROM: David Schutz, P.E., New Source Permits Section

SUBJECT: Evaluation of Permit Application No. 2007-152-TVR

Armstrong World Industries

Vinyl Flooring Production Facility

4115 N. Perkins Road

Stillwater, Payne County, Oklahoma

Latitude 36.164oN, Longitude 97.047oW

SECTION I. INTRODUCTION

Armstrong World Industries has applied for a renewed Title V operating permit for their facility (SIC 3996). The facility is currently operating under Permit No. 97-297-TV (M-3) issued June 1, 2005, and Permit No. 97-297-C (M-6) issued October 3, 2005. The current Title V permit will expire on January 29, 2008. The application for permit renewal was received on a timely basis on July 27, 2007.

This permit will make several changes to Permit No. 97-297-TV (M-3), most of which incorporate requirements of several construction permits issued between the latest operating permit and this operating permit renewal. The names of contents of several tanks will be changed from specific products to generic specifications.

SECTION II. PROCESS DESCRIPTION

There is a single significant operating scenario. The four primary systems (lines) for the production of sheet flooring are the Calendar Process, Gel Line, the Rotogravure Printing Press Line, and the Coating & Fusion Line. The plant also includes various auxiliary units for receiving, storing, and blending inks and plastic coatings and their carrier solvents. Process heat is supplied by two boilers (10.4 MMBTUH and 14.65 MMBTUH) and by several heaters (one 19.2 MMBTUH heater, one 5 MMBTUH heater, four 4 MMBTUH heaters and eighty-three 0.3 MMBTUH space heaters). All heaters are fired with commercial-grade natural gas.

Vinyl flooring is manufactured by printing a pattern on a felt (paper) web and coating that web with vinyl. A maximum production rate of 105 million square yards of flooring per year is anticipated.

Felt is first coated with a PVC / limestone blend, which is then dried. Coated felt proceeds to the “Gel Line” which places a vinyl coating on the felt in preparation for printing of the decorative pattern. The gel coating is also dried. Rolls of coated felt are then transferred to the Printing Operation, where the patterns are printed. Inks are dried in preparation of placing the final coating layers, the wear surfaces. All products receive an outer layer of vinyl at the Coating & Fusion Line.

Gel Line

The plastisol system can provide batch plastisol coating formulations to both the Gel Line and to the Coating and Fusion Line. The system consists of equipment for liquid and dry materials unloading, storage, conveying and weighing, batching, vacuum mixing and intermediate storage. (Note: the term "plastisol" is used interchangeably with the gel coating applied to the base felt prior to printing and with the final coating applied as a protective layer.)

Volatile organic compounds from the Gel Line are vented to the “Large REECO” (LR). A capture efficiency of 95% is anticipated.

Printing

The rotogravure press line consists of eight color printing press stations capable of a line speed of 242 ft/min. The line prints prepared substrates processed by the gel line. Each print station has a dryer positioned above each cylinder, a dryer which is supplied with steam regulated to dry the applied coating and maintain the web temperature at any press speed. Exhausts from these dryers are ducted to a regenerative thermal oxidizer (RTO) designated “large REECO (LR).”

Ink components consist primarily of ink pigments, extenders, and solvents. No heavy metals are used in the pigments. A confidential file summarizes materials utilized and includes MSDSs for the raw materials. All ink used by the press is mixed to order on-site using pigment concentrate, extender, and solvent blend in the "Red Label Area" of the plant.

This area consists of the ink pigment and extender bulk storage, day solvent tank and day ink pigment module storage, solvent distillation room, and the make-ready room (parts washing, cleaning rag storage, drum washing, and ink formulation). A drum and container washing machine and station are provided in the make-ready room for ink concentrate containers, mixed ink drums, etc. The machine utilizes solvent from the day tank and still. A fume evacuation hood at the washing area collects and conveys VOC emissions to the 85,000 ACFM thermal oxidizer designated “LR” (“Large Reeco”). Similarly, VOC emissions from a drum washing and two pump-washing stations are collected and conveyed to the “LR” thermal oxidizer.

The Red Label area consists of several sections: make-ready, ink storage, "still" (distillation), ink pigment pumps, and press. Air collection pipes (“floor sweeps”) in the red label area collect and vent VOC emissions to the atmosphere. A steam-heated solvent reclaimer is capable of storing 250 gallons of dirty solvent from the washing operations and distilling the solvent at the rate of 50 gallons per hour. A total of 1,200,000 pounds of ink solvents are anticipated per year in this process.

Coating & Fusion Line

The Coating & Fusion line is a continuous process line which applies and cures plastisol wear coatings at a maximum rate of 150 ft/min. A coater continuously applies plastisol wear coating to the web prior to the curing operation. A curing oven, consisting of twelve 10-feet long gas-fired modules, is utilized to cure the plastisol coating. The modules can operate up to 475oF. The Finish Coater is normally exhausted to a 20,000 SCFM capacity thermal oxidizer (designated “Small REECO,” or “SR”), while the Clear Coater is vented to Calendar Process RTO, designated “CP.” From the curing oven, material passes through a cooling section (driven cooling drums). A collection hood is provided along the entire length of the cooling section and is ventilated at about 10,000 ACFM to collect plastisol aerosols emitted from the product during cool-down. The exhausted air is discharged through an ESP (“Smog Hog”) for particulate matter removal.

Calendar Process

In the Calendar Process, PVC resin is applied to felt, then sealed by heat and pressure. The Calendar Process includes two silos, one for receiving limestone and one for receiving PVC resin. PM emissions from each silo are controlled by baghouses with emissions guarantees of 0.04 gr/DSCF. Materials from these silos are transferred to a blender unit served by a 20,000 SCFM baghouse with an emission guarantee of 0.04 gr/DSCF. The limestone/PVC mixture is then blended with organic solvent carrier and is used to place an initial coating on the felt. The volatile organic compounds are then dried off the coated felt. Off-gases from this process are treated first by a baghouse with a PM emissions guarantee of 0.04 gr/DSCF, then by an RTO. Since the PVC forms an impermeable layer, only a fraction of solvents used are emitted; the balance is trapped in the product. Emissions from this unit have been determined by stack testing.

Back Coating / Finish Coating

Additional operations have been installed which can place “back coating” or “finish coating,” additional layers on top and/or on bottom of vinyl on the present vinyl coating. The raw material preparation operations and the coating placement and curing operations are identical to other vinyl coating operations.

Other Operations

The facility includes numerous silos for receiving and storing PVC and limestone as well as numerous small tanks for storing solvents.

Scrap handling is conducted by conveying chopped edge-trim to an open-top dumpster using a blower and duct system. A six-foot diameter cyclone with a mesh screen over the outlet is provided to minimize loss of scrap. Because of the large size of the scrap, minimal emissions of particulate matter are expected from the scrap-handling operation. Cutting is done by a rotating knife, not by any sawing. The facility was authorized under Permit No. 97-297-TV (M-3) to install a “scrap granulator” which separates felt from PVC, allowing recycling of the PVC.

Production operations are anticipated at 24 hours per day, seven days per week, 52 weeks per year, 8,760 hours per year. Maximum production of flooring is 105 million square yards per year. The maximum anticipated throughput of the new processes is 70 million square yards per year.

SECTION III. EQUIPMENT

EUG 1A: Gel and Printing Lines; Coating & Fusion Line Curing Section

EUG 1B: Calendar Process

EUG 1C: Calendar Process Raw Material Receiving and Blending

EUG 2: Coating & Fusion Lines

EUG 3A: Large Fuel-Burning Equipment

EUG 3B: Boiler Subject to NSPS Subpart Dc

EUG 3C: Small Fuel-Burning Equipment

EUG 4A: Small Storage Tanks

(1)  Synpron 1363 and 1396 are proprietary blends.