adeq draft operating air permit · pdf fileadeq draft operating air permit pursuant to the...

Click here to load reader

Post on 18-Apr-2018




2 download

Embed Size (px)



    AIR PERMITPursuant to the Regulations of the Arkansas Operating Air Permit Program, Regulation #26:

    Permit #: 1533-AOP-R3


    Temple-Inland Forest Products CorporationRoute 4, 100 Temple Drive

    Hope, AR 71801Hempstead County

    CSN: 29-0120


    March 9, 1998 and March 8, 2003



    Keith A. Michaels Date Modified

  • 2


    PERMITTEE: Temple-Inland Forest ProductsCorporation

    CSN: 29-0120PERMIT NUMBER: 1533-AOP-R3

    FACILITY ADDRESS: Route 4, 100 Temple DriveHope, AR 71801

    COUNTY: Hempstead

    CONTACT POSITION: Mr. John CummingsTELEPHONE NUMBER: (870) 722-400

    REVIEWING ENGINEER: Shawn Hutchings

    UTM North-South (Y): 3733.0UTM East-West (Y): 441.4Zone 15

  • Temple-Inland Forest Products CorporationPermit #: 1533-AOP-R3CSN #: 29-0120



    Summary of Permit Activity

    Temple-Inland Forest Products Corporation (TIFPC) (CSN:29-0120) owns and operates aparticleboard manufacturing facility on Route 4, 100 Temple Drive near Hope (HempsteadCounty) Arkansas. This modification allows for TIFPC to divert approximately 20% of theexhaust from the hot oil heater to the pre-dryer (SN-16). The exhaust is to be diverted when thepre-dryer is idle to prevent condensation buildup which causes corrosion. This modification alsoallows TIFPC to use an additive in their resin water mix known as Additive A. This additiveallows for greater penetration and absorption of the resin into the wood particles during theblending operation. Neither of these modifications will affect the facilitys permitted emissionrates.

    Process Description

    Temple Inland Forest Products Companys (TIFPC's) particleboard plant in Hope, Arkansas, wasdesigned to utilize wood residue from other wood processing plants in the southwest Arkansasarea. The plant will utilize a maximum 347,600 oven-dried tons (ODT, 0% moisture content) ofwood residue annually for a 7 days/week operation with a maximum annual production rate of220,000 thousand square feet (MSF) of board per year on a 3/4 inch basis. The maximum hourlyshort term level of production for the press is 32,000 square feet (SF) of board on a 3/4 inch basisand 51.3 ODT for the primary dryers.

    Raw Material Processing

    All raw materials are delivered to the plant by truck then off-loaded and stored in an enclosedstorage building. TIFPC utilizes a hydraulic truck dumper with a receiving screw conveyordischarge hopper for the unloading process. All mechanical conveying is performed in anenclosed system which minimizes fugitive emissions. The truck is backed into the unloaderfacility where it is lifted and tilted backward. The raw material falls into an unloading bin that ishooded and enclosed as much as possible. This style of truck dumper reduces these fugitiveemissions. The raw materials are metered directly to the Raw Material Storage (RMS) buildingutilizing a totally enclosed conveyor. The wood residuals are stored in piles in the enclosed rawmaterial storage building. This stored material is reclaimed as needed, then conveyed to theprocess storage metering bins.

    Two types of residue are used as raw material, green ($18% Oven Dried (OD) moisturecontent) material and dry (

  • Temple-Inland Forest Products CorporationPermit #: 1533-AOP-R3CSN #: 29-0120


    primarily sawdust generated from sawmills cutting untreated lumber, whereas the "dry" materialis primarily shavings and sawdust produced when planing or cutting kiln dried lumber.

    Acceptable material from the RMS building is fed to one of three storage silos; dried material,green material and dried green material which are equipped with bin vent filters (SN-27, 28 & 29respectively). Once the material is in the silos, it is conveyed to the reciprocating shaker screens,which classifies the material. Overs from the screens are conveyed to a hammermill whichrecycles material back to the screens. Dust generated at the hammermill is controlled by a smallbaghouse (SN-35). Reject material from the forming line and hogged trim material from thefinished boards are collected in a separate silo and re-enters the system to optimize materialusage.

    Milling and DryingThe two screen systems produce two separate process stream flows; both core and face. Bothscreen systems deliver material via a covered conveying system to the Milling and Drying(M&D) area. The finer portion of the wood fiber is used in the surface layers of the board("face"), while the coarser material is used in the middle board layers ("core").

    Face and core materials are processed through hammermills and refiners, respectively. Refiningis accomplished as the material is plug-fed by screw conveyors into the center of each of the fourrefiners and is sheared by the attrition plates. The gap spacing is determined by the type offurnish being produced. The face material leaves the screens and is sent to one of sixhammermills. The hammermills pulverize the material into smaller particle sizes which can thenbe accepted by the process. The refining process controls the geometry of the finished particleand influences both the density and weight of the board. Centrifugal force causes the material toexit the refiners. The refined material is then air conveyed through large cyclones to meteringbins that feed one of three rotary drum dryers. Exhaust from these cyclones is conveyed to four(4) large, designated baghouses (SN-03, 04, 05 & 06) for particulate control.

    The green material is initially sent to a MEC Model 1360-T Predryer (SN-16) which reduces themoisture content of the material to

  • Temple-Inland Forest Products CorporationPermit #: 1533-AOP-R3CSN #: 29-0120


    one of the three primary dryers. All three dryers are MEC Model 1248-T traditional triple passdryers.

    The three rotary dryers are directly heated through a common plenum by exhaust heat generatedfrom the combustion of sander dust and/or natural gas. The flame temperatures of these burnersare usually in the 1700 0F to 2000 0F range. However, this exhaust gas is diluted and cooledimmediately upon exiting the combustion chamber with diluent air. This exhaust gas is combinedwith the exhaust from the hot oil heater system (recirculating oil system for supplying heat to thepress) which also utilizes sander dust for fuel. The rotary dryer furnace or blending box alsobrings in additional diluent air to further lower the air temperature at the entrance of the rotarydryers.

    Dryer inlet air averages from 200 0F to 300 0F, and the raw material moisture content is 15-18%on average. The dryer exhaust air ranges in temperatures from 1500F to 2300F. The determiningfactor for the exhaust gas temperature is the inlet air temperature and the moisture contained inthe wood particles. The average moisture content of the wood particles after drying is 3 to 5%.The exhaust gases from each primary dryer enters a dedicated multicyclone separator.

    Drying and Former Preparation

    The multicyclones are designed to remove wood particles from the exhaust gas of the dryers at arelatively high efficiency. The exhaust gas from each dryer multicyclone is sent to a commonstack (SN-15). The dried material exits the bottom of the multicyclones, and is conveyed into thedry storage bins, one bin for each type of furnish, face and core. Each bin has a bin filter (SN-32and SN-33 respectively).

    Material from the dry storage bins is conveyed to the blending area where a urea-formaldehyde(UF) resin (used as a thermosetting binder) is applied in a rotary mixing device. A small amountof wax emulsion is also applied at this point as a moisture inhibitor during the pressing operation.Some excess formaldehyde, which is required as part of the thermosetting chemical reaction,could potentially be released from the resin in the hot pressing operation, but is controlled withan RTO (SN-17A). Usually, a formaldehyde scavenger is used to reduce free formaldehyde. TheUF resin is stored in two storage tanks along with urea and wax storage tanks inside the building.The emissions from all these tanks are vented inside the process building and are consideredinsignificant.

    Blending of the resin laden furnish is accomplished in water cooled blenders. The blenders arecooled to prevent pre-curing as the material is discharged to mechanical conveyors which carry itover to the forming line.

  • Temple-Inland Forest Products CorporationPermit #: 1533-AOP-R3CSN #: 29-0120


    Former and Press System

    The Hope facility has a moving flexible screen forming line. This forming process is an airclassification process in which bottom face material is first placed on the moving flexible screensby a combination of gravity and induced air to form the bottom quarter of the mat. As the screenenters the former, the face furnish is blown countercurrent onto the screen. This ensures that thefinest, lightest material will blow onto the flexible screen first for a smoother finished boardsurface. As the screen reaches the end of the bottom face chamber, the larger particles fall ontothe mat to form the intermediate levels. The core chambers use gravitational discharge to spreadthe core material through the middle half of the mat. The thickness consistency is controlled byvarying the speed of the belt feeding the chamber. Finally, the top face is put on the mat in thesame manner as the bot