1

MEMORANDUM

Date: August 7 , 2014

Subject: MACT F loor and Beyond

- the

- Floor for Existing Unregulated Emission Sources in the

Amino and Phenolic Resins Production S ource C ategory

From: Nick Parsons, EPA/OAQPS/SPPD/RCG

To: EPA Docket File (EPA

- HQ

- OAR

- 2012

– 0133 )

______________________________________________________________________________

The purpose of this memorandum is to present analyses related to the maximum achievable

control technology ( MACT ) “ floor” and beyond

- the

- floor (BTF) for existing unregulated

emission sources identified in the Amino and Ph e n o lic Resins (APR) Production source

category

. The EPA proposed amendments to the source category on January 9, 2014

, based on

res idual risk and technology reviews.

1.0 Background

1.1 Introduction

On January 20, 2000, the EPA finalized National Emissions Standards for Hazardous Air Pollutants (NESHAP) for the APR source category based on the requirements of section 112(d)

of the Clean Air Act ( CAA ) to control hazardous air pollutants ( HAP ) emissions from existing

sources. C lean A ir A ct section 112(d)(2) calls for the EPA to promulgate national technology

based emission standards for each category or subcategory of sources that is liste d in accordance with 112(c) of the CAA. For “major sources” that emit or have the potential to emit any single hazardous air pollutant at a rate of 10 tons or more per year or any combination of HAP at a rate of 25 tons or more per year, these technology

- b ased standards must reflect the maximum reductions of HAP achievable (after considering cost, energy requirements, and non

- air health and environmental impacts) and are commonly referred to as MACT standards.

Th e MACT “floor” is the minimum control level allowed for MACT standards promulgated

under CAA section 112(d)(3) and may not be based on cost considerations

. The MACT floors for existing sources cannot be less stringent than the average emissions limitation achieved by

the best performing five sources for categories or subcategories with fewer than 30 sources ( APR

has fewer than 30 sources) . In developing MACT s tandards, the EPA must also consider control options that are more stringent than the floor , commonly referred to as beyond

- the

- floor ( BTF )

opt ions. The EPA may establish standards more stringent than the floor based on considerations

of the cost of achieving the emissions reductions, any non

- air quality health and environmental impacts and energy requirements. Where the EPA identif ies emission p oints that were erroneously not previously regulated under a MACT rule, the EPA may identify MACT floor

and BTF control optio ns for existing sources, and set standards for these sources under CAA section 112(d)(2) and (3). T he APR NESHAP, as originally pro mulgated, did not contain MACT standards for certain HAP emissions points

.2

1.2 Proposed Amendments

On January 9, 2014 (79 FR 1676), the EPA proposed amendments to the APR source category following the results of a review required by section 112(d)(6) of the CAA, which directs the EPA to review previously issued NESHAP regulation s and to revise them as necessary (taking

into account developments in practices, processes and control technologies) no less frequently than every 8 years. Section 112(f)(2) of the CA A requires the EPA to assess, within 8 years of promulgation of the original NESHAP for major sources and area sources subject to MACT, the remaining risks due to emissions of HAP from these source categories and determine whether the emissions standards p rovide an ample margin of safety to protect public health. T hese reviews

are collectively referred to as residual risk and technology reviews (RTRs).

At the time of the 2014 proposal, the presence of uncontrolled continuous process vents at two
facilities in the APR source category (Georgia Pacific in Crossett, AR, and Tembec in Toledo, OH) had been identified . Under CAA section 112(d)(2) and (3), the EPA proposed the following

for the MACT floor :

 Reduce organic HAP by 85 percent or more, or

 Limit the concentration of organic HAP to 20 parts per million by volume (ppmv), when using a combustion control device, or

 Limit the concentration of organic HAP to 50 ppmv when using a non

- combustion

control device.

2 .0 MACT Flo or

2

. 1 C ontinuous P

roce ss V ents

– Spray Dryers

Determination of the MACT floor

Following the January 2014 proposal, the EPA received information that there are additional existing facilities with uncontrolled process vents in the APR source category

. According to industry, t here are currently f our facilities that operate continuous process vents in the APR

sourc e category

, and these facilities are shown in Table 1.

Table 1. Existing APR Facilities with Continuous Process Vents

– Spray Dryers

Facility Location Control Device Georgia Pacific Crossett, Arkansas No HAP Control Georgia Pacific Conway, North Carolina No HAP Control Georgia Pacific Taylorsville, Mississippi No HAP Control

Tembec Toledo, Ohio No HAP Control

These four facilities have spray dryers (Tembec has three process vents with three separate spray dryers at its facility and each Georgia Pacific facility has one spray dryer process vent ), which is3

a continuous process used by industry to dry different types of resins that are in liquid form into

a po wder form. Currently, these existing continuous process vents do not have emissions control requirements and represent a potentially significant source of HAP emissions

.

As stated above , t he MACT “floor” is the minimum control level allowed for MACT standards promulgated under CAA section 112(d)(3) and may not be based on cost considerations. Also, the emission standard cannot be less stringent than, but can be more stringent than, th e average emission limitation achieved by the best performing 5 sour ces (for which the Administrator has

or could reasonably obtain emissions information) in the category or subcategory for categories

or subcategories with fewer than 30 sources

. Since there are six unregulated continuous spray dryer process vents in the AP R source category (i.e., less than 30) , the MACT floor for exi s ting

sources is the 3 rd best source (or median) of the top five so urces

.

In order to calculate the existing MACT floor, the EPA looked at HAP emissions data and production information provided by the two companies (Georgia Pacific and Tembec) . In order to account for variability associated with the manufacturing process, including fluctuations in the amount of product produced and different types of product produced (i.e., various resin types), as well as to consider possible future process modifications to alter other production variables , it was determined appropriate to establish a production

- based MACT floor . Emissions are highly dependen t on these factors and a production

- based limit takes th ese factors into account

. The

estimated uncontrolled production

- based emission rates from spray dryer process vents are presented in Table 2

.

Table 2. Existing Uncontrolled Continuous Spray Dryer Process Vent HAP Emission Rates (lb of HAP /ton of resin produced )

Process Vent HAP Emission Rate (lb of HAP

/ton of resin produced ) Rank

(Lowest to Highest Emitter)

Spray Dryer A 0.1 1 Spray Dryer B 0.2 2 Spray Dryer C 0.7 3 Spray Dryer D 8.7 4 Spray Dryer E 10.4 5 Spray Dryer F * 13.4 6

MACT Floor Analysis

Median 0.7 lb/ton Average 4.0 lb/ton

Standard Deviation 5.1 lb/ton

% Standard Deviation 127% *Spray Dryer F was not included in the MACT floor analysis since it is ranked 6 th

.

In order to determine the level of the MACT floor, the emission rates of the top five best performing spray dryers (A

- E ) were ranked and the median emission rate was chosen as the4

MACT floor

. Process vent C represents the median performer with a HAP emissi on rate of 0.7 lb

of HAP/ton of resin produced and is therefore the MACT floor level

.

T he EPA looked at how the HAP emission rates from the top five process vents in Table 2

varied

, and as the table illustrates, there is a notable difference between the five process vent

emission rates

. As shown in Table 2, the percent standard deviation based on the average lb of

HAP/ton of resin produced of the top 5 process vents is 127 percent. In order to incorporate variability into the final standard, the EPA appli ed a variability factor to the MACT floor level. It was determined appropriate to apply a variability factor of two standard deviations to accommodate for differences between facility emission rates and to allow facilities that are at or

close to the MACT floor level some flexibility to remain in compliance as they currently operate. As a result, to incorporate emissions rate variability, the final MACT floor is 1.9 lb of HAP/ton

of resin produced

. This method of incorporating variability into the final sta ndard is similar to the approach followed for the NESHAP for Group I Polymers and Resins, which was finalized in April 2011 (77 FR 22566). Spray Dryers A

- C will be able to meet t he existing MACT floor without any additional controls. Spray Dryers D

- F will need to have HAP control s installed in

order to meet the MACT floor emissions rate limit

. Carbon adsorber s are highly effective at reducing HAP emissions

, and i t is expected that this technology will be used to reduce HAP

emissions from uncontrolled spray dryer process vents in order to meet the MACT floor

emissions rate limit

. Based on uncontrolled levels, HAP emissions reductions of 78, 82, and 86

percent will be needed for Spray Dryers D

- F , respectively, to meet the standard.

2

. 2 C ontinuous P

roce ss V ent s

– U rea
- F ormaldehyde Concentrate (UFC) Production

Following the January 2014 proposal, the EPA was made aware of a different type of continuous process vent (a non

- dryer type) located at Georgia Pacific’s Crossett facility. Georgia Pacific indicated that it has a continuous process vent that is significan tly different than the six spray dryer process vent s listed in Table 2 that would also be subject to the APR NESHAP. At the

Crossett facility, there is a formaldehyde/urea formaldehyde concentrate (UFC) process that

opera tes continuously to manufacture thi s product

. This type of production (UFC manufacture) is present onl y at the Crossett, AR facility. The formaldehyde/UFC manufacturing production c an switch from formaldehyde production to UFC production with few adjustments and minor process modifications. While this unit can produce either formaldehyde or UFC resins, the primary product of the unit was previously f ormaldehyde resins

, and the unit was subject to the hazardous organic NESHAP (HON). However, the primary product has since switched to UFC

resin s, which are regulated by the APR NESHAP and not the HON. The Crossett facility has a

separate unit dedicated to formaldehyde production, and for approximately 6 years, the formaldehyde/UFC unit has been producing 100 percent UFC, although it is permitted to produce both UFC and formaldehyde. Due to the previous requirement to control the formaldehyde/UFC processes according to the HON regulation, the facility routed emissions from the proce ss to a regenerative thermal oxidizer (RTO) to achieve the required emissions

reduction. However, while the primary product has switched, and the facility is no longer required to comply with the HON but is required to comply with the APR NESHAP for this u nit, which does not have a HAP emissions reduction requirement, the facility has continued to

control the emissions from this unit with the RTO. According to Georgia Pacific, the UFC5

process operates continuously, with occasional breaks for maintenance. Th e process is permitted to run 8,760 hours per year, and generally comes close to that.

I nformation provided by Georgia Pacific indicates that, in addition to the formaldehyde/UFC production unit, several other process vents are simultaneously controlled b y the same RTO. Thus, Georgia Pacific is unable to provide reliable RTO inlet and outlet exhaust stream data for just the formaldehyde/UFC production line. Although Georgia Pacific has made a good faith effort to provide engineering estimates of what the e mission rate for the formaldehyde/UFC production line may be, the EPA does not believe these estimates are reliable a nd accurate enough to be used in a MACT floor analysis

.

While the EPA considered including this process vent in the MACT floor analysis fo r continuous process vents associated with spray dryers described above

, it was decided to not include the UFC process at the C rossett facility in the continuous process vents MACT floor analysis based primarily on the lack of reliable emissions data . The fact that the UFC process is a significantly different process

, which exhausts to an RTO due to prior regulation by another NESHAP , also played a part in this decision

.

The EPA notes that the emission estimates and production data provided by Georgia Pacific for the UFC process line results in an emission rate of approximately 0.5 lb HAP/ton of resin produced

. If the UFC process line emission rate would have been included in the continuous

process vent MACT floor analysis, the resu lting MACT floor would have been 0.5 lb HAP/ton

of resin produced rather than 0.7 lb HAP/ton of resin produced . Given the uncertainty believed to

be inherent in the Georgia Pacific emission estimate, the EPA believe s that the UFC process is operating at es sentially the MACT floor level of control, and excluding this process line from the MACT floor analysis did not significantly affect the final result. Further, given the close proximity of the Georgia Pacific emission estimate to the MACT floor, subcategor ization of the UFC process does not appear warranted.

3.0 Beyond

- the Floor

For those facilities that have to control their APR process vents to meet the MACT floor level of control, installation of a carbon adsorber is believed to be the most logical choice. A scrubber is also a viable option, although facilities without existing wastewater treatment capabilities would incur significant additional expense to dispose of the resulting wastewater from the scrubber. The

BTF control option identified for spray dryers in the APR source category that may achieve a higher level of control than a carbon adsorber or scrubber is a n RTO

. This BTF option would require a significant capital investment as well as substantial annual operation and maintenance

costs.

Spray Dryers A

- C are located at one facility, and it is assumed that one RTO would be used to control all three dryers. T he capital cost associated with an RTO for Spray Dryers A

- C is

estimated to be $2.2 million with an annual cost of $773 ,000 per year

. T he cost per ton of HAP

removed is approximately $40 ,000 for these spray dryers. The capital cost for Spray Dryers D

- F

is more than $2 million per facility with annual costs between $700,000 and $800,000 per year per facility

. T he cost per ton of HAP remove d varies from $11,000 to $30 ,000 per ton of HAP6

removed for Spray Dryers D

- F

. The costs and cost effectiveness of an RTO are shown in Table

3. More information on how the costs and cost effectiveness were calculated are available in the

memorandum entitled “National Impacts Associated with the Final NESHAP for Existing Amino

and Phenolic Resins Continuous Process Vents,” available from the rulemaking docket (EPA

HQ

- OAR

- 2012

- 0133).

Table 3 . Cost Effectiveness of BTF O ption for APR Spray Dryers 1

Process Vent Baseline

Emissions (tpy) Emissions

Reductions (tpy) Capital

Cost Annual

Cost Cost

Effectiveness ($/ton HAP) Spray Dryers A

- C 19.8 19.4 $2.2 million $773,000/yr $40,000 Spray Dryer D 63.9 62.7 $2.2 million $784,000/yr $12,500 Spray Dryer E 24.3 23.8 $2.1 million $723,000/yr $30,000 Spray Dryer F 76 74.5 $2.3 million $822,000/yr $11,000

Total 184.0 180.5 $8.8 million $3.1 million/yr $17 ,000

1 Some discrepancies are due to rounding.

The incremental cost effectiveness associated with requiring an RTO instead of a carbon adsorber on the spray dryers is presented in Table 4. As the table shows, the incremental cost effectiveness of requiring an RTO instead of a carbon adsorber on Spray D ryers A

- C is 800,000/ton HAP. For Spray Dryers D

- F the incremental cost effectiveness associated with using an RTO instead of a carbon adsorber ranges from approximately $40,000 to $115,000.

Table 4

. Incremental Cost Effectiveness of BTF Option for APR Sp ray Dryers 1

Process Vent Emissions

Reductions (tpy) Annual

Cost Incremental

Cost

Effectiveness ($/ton HAP) 2 Carbon

Adsorber RTO Carbon

Adsorber RTO

Spray Dryers A

- C 18.8 19.4 $294,000/yr $773,000/yr $800,000
Spray Dryer D 49.9 62.7 $286,000/yr $784,000/yr $39,000 Spray Dryer E 19.9 23.8 $282,000/yr $723,000/yr $114,000 Spray Dryer F 65.4 74.5 $294,000/yr $822,000/yr $58,000

Total 15 4.0 180.5 $1.2 million/yr $3.1 million/yr $74,000

1 Some discrepancies are due to rounding.

2 For Spray Dryers A

- C the incremental cost effectiveness is the $/ton of HAP reduced associated with increasing the control efficiency from 95 to 98%. For Spray Dryers D

- F it is the difference

between 78/82/86% to 98%.