Worst-case PTE Summary for Boilers

Worst-case PTE Summary for Boilers

(2) – Natural gas fired emissions, unless noted otherwise

Establishing the actual-to-potential increase in emissions for PSD analysis is difficult with respect to the boilers. Since the drying operations have several options available, heat for drying may come from the hood burners, from hot water, or from steam. As will be seen at a later point in this memorandum, the full actual-to-potential emission increase is assumed to occur for the hood burners. While it is certainly possible that steam could just as easily be used, the increases in burner capacity due to this project are more than adequate to cover the planned production increases. The applicant has proposed that increases in actual-to-potential for steam from the boilers be based on the comparison between maximum actual production as the facility is currently configured and the maximum production that the applicant hopes to achieve after the current project is completed. The current maximum daily production achieved is 1,224 ADT and the design capacity is 1,476 ADT. Facility records for actual production and actual steam use during the two-year period 2002-2003 show an average steam use equivalent to 7 MMBTU/ADT. Thus, the increase to 1,476 ADT would require

(1,476 – 1,224) ADT  7 MMBTU/ADT  365 days/year = 643,860 MMBTU/year.

All boilers were reviewed to determine the conservatively highest emissions that could be realized by combusting the BTUs required. The first table following shows the emission factors used in this analysis. Factors for SO₂, NO_X, and PM₁₀ are maximum allowables from Subpart D and/or Subchapters 19, 31, and 33. All others are footnoted. The second table shows additional project emissions from each boiler, citing the highest emissions from each. Note that gas for boilers 2 and 3 is used only for ignition or flame stabilization and cannot be delivered to these boilers in sufficient amount to allow for operation solely on gas.

2. Uncontrolled Post-NSPS Large Wall-Fired Units emission factor from Table 1.4-1 of AP-42 (7/98), assuming 1,000 BTU/CF.

3. Total Non Methane OC emission factor for Dry Bottom Units from Table 1.1-19 of AP-42 (9/98), using 17.68 MMBTU/ton as in note 1.

4. Emission factor from Table 1.4-2 (7/98), assuming 1,000 BTU/CF.

5. The highest average value from three runs for each boiler during stack testing in May 2003.

6. The highest average value, including soot-blowing times, from three runs for each boiler during stack testing on January 7 and 8, 2003.

The following table lists average annual fuel consumption for the burners in each paper machine hood for 2002 and 2003, as well as the potential fuel consumption after the project, assuming 8,760 hours per year of operation.

Emission calculations for the existing tunnel dryer at the polyethylene printer and for the three new dryers are based on factors from Tables 1.4-1 and 2 of AP-42 (7/98), as shown in the following table. The new tunnel dryers may be rated as high as 3.2 MMBTUH. If desired, hourly emission rates can be found by dividing the annual emissions by 8,760 hours.

The catalytic oxidizer was evaluated in the Memorandum for the Part 70 permit using emission factors from Tables 1.4-1 and 2 of AP-42 (7/98) for a rating of 2 MMBTUH. The new regenerative thermal oxidizer has not been selected, but the largest unit currently being evaluated is rated at 10.4 MMBTUH. The same factors are used in evaluating the new unit, except for NO_X. The manufacturer has supplied NO_X emission factors based on PTE, expected emission rate with no VOC present, and expected rate with VOC present. The highest of these is equivalent to the emission factor used for the smaller unit. The existing catalytic unit has been tested at 98.6% destruction efficiency, while the new RTO is estimated to be more than 95% efficient, although 95% will be used as a conservative number for this discussion. Only annual totals are listed in the following table, while hourly rates may be calculated by dividing each number by 8,760 hours per year.

VOC emissions from polyethylene printing depend on capture and destruction efficiency. The existing single printer has capture efficiency of only 70%, which is a datum agreed upon by the facility and DEQ in discussions surrounding the Part 70 permit. As stated above, testing indicates 98.6% destruction efficiency. Average 2002-2003 uncontrolled VOC from the printer was 197.5 TPY. Fugitive emissions were 30% of this number, or 59.3 TPY. The 70% portion captured was reduced by 98.6%, leaving stack emissions of 1.9 TPY. Plans for the new printers include constructing an enclosure around all four units, leading to 100% capture. Assuming conservatively low destruction efficiency of 95% and using potential printer VOC emissions of 971 TPY leads to zero fugitive emissions and 48.6 TPY of stack emissions. The following table summarizes these calculations.

The following table summarizes all groups discussed for EUG 2, and shows their total increase in emissions.

Steam use may increase as a result of this project, and a method of calculating actual-to-potential emissions is needed. The increase will be discussed more fully later in this memorandum. Emission estimates have been calculated for this EUG, but the only limits placed in the pending Part 70 permit concern opacity. An analysis of the factors used, their origin, and some of the discussion with the applicant concerning these estimates may be found in the memorandum associated with the pending Part 70 permit. The following table summarizes the conclusions of that discussion, but is not used for setting a limit here, nor is it offered as support for PSD considerations. Coal throughput for 2003 was 519,362 tons. Using 8,300 BTU/lb as a lower value for sub-bituminous coal and assuming the continuous operation of Boilers 2, 3, and 4 at rated capacity implies maximum coal throughput of 820,200 tons. The table indicates that the actual-to-potential increase in PM emissions is 49.0 TPY.