Influence of Emission Estimates on BACT for Iron

Influence of Emission Estimates on BACT for Iron Foundry Core Making Steven Klafka, PE, DEE Wingra Engineering, S. C. A&WMA Conference 2002 Wingra Engineering, S. C. 1

Iron Foundry Case Study n n n Existing iron foundry in Indiana. Addition of two coldbox core making machines with combined capacity of 6 tons per hour. Project required Prevention of Significant Deterioration (PSD) air quality permit. Permit requirements included determination of Best Available Control Technology (BACT). PSD applicability based on plant-wide VOC emissions increase from “debottlenecking”. Wingra Engineering, S. C. 2

Core Making Process n n n Cores form internal space in castings. Molten iron poured into molds flows around core to form internal voids. Cores - mixture of sand & organic resin. Resin type is phenolic-urethane. Catalyst used to activate resin. Wingra Engineering, S. C. 3

Core Making Process Cont’d n Mixing n n Core Forming n n Organic binder mixed with silica sand. Sand/resin mixture blown into the mold box. Catalyst injected to cure resin. Catalyst purged from core machine. Storage n Core removed for finishing, storage, delivery. Wingra Engineering, S. C. 4

Core Making Flow Diagram PM, VOC Baghouse Scrubber Mixing Core Machines Wingra Engineering, S. C. VOC Core Storage 5

VOC Emissions from Catalyst n n VOC generated by catalyst and resin Catalyst Emissions n Triethyl Amine or TEA n Typical usage: 2 -7 lbs/ton of core n Proposed usage: 3 lbs/ton of core n Assume 100% of catalyst emitted from core machines. Wingra Engineering, S. C. 6

VOC Emissions from Resin n Resin Emissions n Evaporation of VOC constituents from mixing, core machine & storage n Function of resin usage & VOC content n Little attention to resin losses in prior BACT analyses or permits. n Loss Range = 0. 1 - 1. 0 lbs/ton of core Wingra Engineering, S. C. 7

Resin VOC Emission Methods n n American Foundryman’s Society (AFS) “Form R” booklet. Ohio Cast Metals Association (OCMA) study in 1998. Resin manufacturers evaporation tests Core making stack tests Wingra Engineering, S. C. 8

AFS Form R Booklet n n Produced by AFS and the Casting Industry Suppliers Association. Assist foundries with Form R TRI. Provides estimates for reportable chemicals in core and mold binder. Estimates fraction of resin remaining in core and fraction released. Wingra Engineering, S. C. 9

Resin Loss Using AFS Form R Total Resin Loss = 0. 215% Wingra Engineering, S. C. 10

1998 OCMA Study n n Laboratory resin evaporation tests. Measured weight loss during mixing, forming, and storage. No catalyst used during test. Based on 1% resin in core sand. Wingra Engineering, S. C. 11

Resin Loss using OCMA Study Total Resin Loss = 3. 26% Wingra Engineering, S. C. 12

Resin Manufacturer Tests n n n Based on OCMA methodology. Various resins evaluated to compare evaporative losses. Resin alternatives suitable for Indiana project. Wingra Engineering, S. C. 13

Resin Loss from Manufacturers Total Resin Loss = 1. 2 to 3. 0% Wingra Engineering, S. C. 14

Core Making Stack Tests Conducted on existing operations n Tests for mixing and core machine n Testing of core storage area not practical due to open area. n Total VOC measured by Method 25 n TEA measured by Method 25 A n Wingra Engineering, S. C. 15

Resin Loss using Stack Tests n Mixing n n n Method 25 A: 0. 54 lbs VOC/hr, 0. 40% of resin Method 25: 0. 61 lbs VOC/hr, 0. 45% of resin Core Machine n n n Method 25 A: 14. 0 lbs VOC/hr Method 25: 16. 5 lbs VOC/hr Method 25: 17. 6 lbs TEA/hr, 3. 4 lbs VOC/ton TEA emissions > Total VOC Resin loss measurements not possible. Wingra Engineering, S. C. 16

Resin Loss Comparison Method AFS OCMA Mfg B Test Resin Loss (%) 0. 215 3. 26 3. 0 1. 2 0. 45 VOC @1% (lbs/ton) 0. 043 0. 65 0. 60 0. 24 0. 09 VOC @1. 5% (lbs/ton) 0. 06 0. 98 0. 90 0. 36 0. 14 Wingra Engineering, S. C. 17

Final Mixing Loss Estimate n Mixing Loss n n Test used Resin A; project to use Resin B Combined stack test and mfg lab tests Resin B Loss = 0. 45% Resin A Loss x (1. 2/3. 0) = 0. 18% Resin B Loss = 0. 14 lbs/ton Resin A Loss x (1. 2/3. 0) = 0. 05 lbs/ton Wingra Engineering, S. C. 18

Core Machine Loss Estimate n Core Machine Loss n n Combined stack test and mfg lab tests Mfg Total Resin B Loss – Mixing Loss 0. 36 – 0. 05= 0. 31 lbs/ton Storage Loss n Losses included with core machine. Wingra Engineering, S. C. 19

BACT Control Options n Mixing n n n Regenerative Thermal Oxidizer Carbon Adsorption Core Machine n n n Packed Bed Scrubber Regenerative Thermal Oxidizer Carbon Adsorption Wingra Engineering, S. C. 20

Mixing BACT Analysis Wingra Engineering, S. C. 21

BACT for Mixing n n n High cost effectiveness due to relatively low VOC emissions. IDEM feasibility “threshold” of $8, 000 per ton of VOC removed. No add-on controls required. Wingra Engineering, S. C. 22

Core Machine BACT Analysis Wingra Engineering, S. C. 23

BACT for Core Machine n n n RTO and carbon adsorption exceed IDEM threshold for economic infeasibility. RTO exceeds cost effectiveness used for prior Wheland BACT of $4, 928/ton. Packed bed scrubber considered BACT. Wingra Engineering, S. C. 24

RTO Cost Effectiveness Versus Resin Loss BB AA Wingra Engineering, S. C. 25

Effect of VOC Loss on RTO Cost n n n Cost effectiveness varies with catalyst usage and resin losses. Typically values can result in RTO as BACT. If case study foundry had used Resin A -n n n Core machine resin loss increases from 0. 36 to 0. 90 lbs/ton. Cost effectiveness decreases to $7, 676/ton. RTO becomes economically feasible and BACT. Wingra Engineering, S. C. 26

Conclusions n n n Use of RTO on core making operations will receive serious consideration for future BACT evaluations. Cost effectiveness and feasibility of control options are dependent on catalyst usage and resin losses. Resin losses, though small, effect the outcome of the BACT analysis. Wingra Engineering, S. C. 27