New York State Department of Environmental Conservation

Best Available Retrofit Technology Determination

Facility Roseton Generating Station

Location Newburgh, NY
Orange County

Permit ID 3-3346-00075

Source Category Fossil-fuel fired steam electric plant of more than 250 mmBtu/hr heat input

I. Introduction

The above referenced facility contains at least one emission source that falls under the requirements of the federal Best Available Retr ofit Technology (BART) rule under 40 CFR Part 51 and Appendix Y, and the New York State BA RT regulation as codified under 6 NYCRR Part 249. These requirements affect an emission s ource which fulfills the following criteria:

1. Falls within one of 26 sp ecific source categories,

2. Was not in operation prior to August 7, 1962 and was in existence on August 7, 1977, or

underwent reconstruction between August 7, 1962 and August 7, 1977, and

3. Has a potential to emit (collectively, with ot her emission sources at the facility which fulfill items 1 and 2) of 250 tons per year or more of any visibility-impairing pollutant.

In accordance with BART requirements, each BART-eligible facility performed a BART analysis of controls for sulfur dioxide, nitrogen oxides and particul ate matter. This analysis took

into account such factors as the cost of c ontrols, energy and non-air quality environmental impacts of compliance, any existing pollution co ntrol technology in use at the source, the remaining useful life of the source, and the de gree of improvement in visibility which may reasonably be anticipated to result from the use of such technology.

This document summarizes the reasoning be hind the Department’s BART determination, including the level of cont rols and emission limits that constitute BART for this facility’s eligible emission source(s). Each analysis and BART determination was submitted to the Federal Land Managers (FLMs) for their review in accordance with Regional Haze State Implementation Plan (SIP) requirements. Comments received from the FLMs on this determination will be included

with its official submission to the U.S. Environmental Protection Agency (EPA).

The Department has modified this facility’s Title V permit to include the enforceable BART

limits. The modifications were noticed in New York State’s Environmental Notice Bulletin on August 3, 2011. Upon completion of this public notice period, the modified permit was submitted to EPA for review on September 9, 2011. The final modified permit was issued on November 2, 2011. This permit is now being submitted to EPA as a revision to the New York Regional Haze SIP.

1II. BART Analysis Summary

Dynegy submitted a BART analysis for the Ro seton Generating Station dated September 30, 2010. A subsequent version, with revisions to the section d ealing with the BART-eligible Danskammer unit, was submitted on November 2, 2010. The following emission sources had been previously identified as BART-eligible and were therefore included in the analysis:

Boiler No. 1 – Emission Unit U-R0001; Emission Source SR001

• Roseton Unit 1 is a 600 megawatt oil-fire d EGU with a Combustion Engineering tangentially fired steam generating boiler. The unit began commercial operation in December 1974 and was modified in May 1992 to enable the co-firing or exclusive firing of natural gas. The heat input rating is 7,927 mmBtu/hr when burning No. 6 oil and 7,369 mmBtu/hr when burning natural gas. NO

x controls are a combination of fuel oil steam atomization, burners out of service and/or wind-box flue gas recirculation (FGR).

Particulate emissions are controlle d with a mechanical collector.

Boiler No. 2 – Emission Unit U-R0002; Emission Source SR002

• Roseton Unit 2 is a 600 megawatt oil-fire d EGU with a Combustion Engineering tangentially fired steam generating boiler, a nd is essentially identical to Unit 1. One difference is the heat input when burning No. 6 oil, which is 7,691 mmBtu/hr for Unit 2. Similar to Unit 1, NO

x emissions are controlled through a combination of fuel oil steam atomization, burners out of se rvice and/or wind-box FGR, wh ile particulate emissions are

controlled with a mechanical collector.

A summary of the analysis’ findings for each po llutant follows. Note that because of the confidential nature of Dynegy’s BART analysis, so me information (e.g., cost estimates, capacity projections) have been omitted from this summary.

Boiler No. 1

• SO 2

Dynegy reviewed engineering studies to id entify available BART control options for

SO 2 . The table below contains eight options identified; all are noted to be technically feasible. The associated control efficiency for each technology is also presented.

SO 2 Control Option Control Efficiency

Wet Limestone Forced Oxidation FGD 98%

No. 6 Oil Combustion ‐ 1% Sulfur 23%

No. 6 Oil Combustion ‐ 0.7% Sulfur 46%

No. 6 Oil Combustion ‐ 0.5% Sulfur 62%

No. 6 Oil Combustion ‐ 0.3% Sulfur 77%

Gas Co

‐ Firing (35%) 35%

Gas Co

‐ Firing (60%) 60%

Gas Firing (100%) 99.96%

2The cost-effectiveness for each option is pres ented for the base case and for operations under the projected capacity factor; these figur es are contained in Table 2-11 of Dynegy’s report. Dynegy factored in the projected capac ity factor for this unit when estimating the costs of controls, as a baseline made on the a ssumption of “potential to emit” (PTE) is not indicative of future operations. Only th e Wet Limestone Forced Oxidation FGD has direct energy impacts and additional fuel re quirements. The modeled visibility impacts indicate excessive cost-per-deciview values for all options modeled. Although gas cofiring was analyzed in this study and appears to be feasible due to negative annualized costs, it was ultimately ruled out due to high price volatility and the potential reliability concerns on the state’s electric system due to limited supply, part icularly during the

winter.

Dynegy submits that a reduction in its permitted fuel sulfur content be considered BART

for SO 2 for Roseton Unit 1. Dynegy proposes a reduction from the current 1.3 percent annual weighted average fuel sulfur limit in N o. 6 oil, to a 1.0 percen t fuel sulfur limit. This 23 percent reduction will result in a reduction in allowable SO 2 emissions of 10,734

tons per year.

• NO

x

Dynegy identified a number of poten tial BART control options for NO

x . The table below presents the list of options. Controls which were deemed technically infeasible (as explained in the analysis) have been crossed out.

NO

x Control Option Control Efficiency (%)

Separated Overfire Air (SOFA) 15

Fuel Lean Gas Reburning (FLGR) 25

SOFA + FLGR 32

Selective Catalytic Reduction (SCR) 85

Selective Non

‐ Catalytic Reduction (SNCR) N/A

Amine Enhanced FLGR N/A

SOFA + Amine Enhanced FLGR N/A

Fuel Specification Change 15

Gas Reburn 35

Hybrid SCR/SNCR N/A

SOFA + SCR 92

SOFA + SNCR N/A

SOFA + Hybrid SCR/SNCR N/A

Wind

‐ box Optimization; NOx emission limit

lowered from 0.25 to 0.20 lb/mmBtu 20

The latter NO

x control option (wind-box optimization) comes at no additional cost. Dynegy concluded that all other controls ar e economically infeasible when taking into

3account the unit’s projected capacity factor; thes e costs are contained in Table 2-4 of their analysis. Dynegy additionally demonstrated through visibility mode ling that excessive cost-per-deciview values would accompany these control options (Table 2-7).

Dynegy’s recommended method of BART compliance for NO

x is the reduction of the current permitted NO

x limit from 0.25 lb/mmBtu to 0.20 lb/mmBtu (based on a 24-hour average during the ozone season and a 30- day average during the non-ozone season) through wind-box optimization. This 20 percen t reduction will result in a decrease in

allowable NO

x emission of 1,736 tons per year.

• PM

The potential PM control technologies id entified by Dynegy for Roseton Unit 1 are identified in the table below, along with their associated c ontrol efficiencies:

PM Control Option Control
Efficiency (%)

Electrostatic Precipitator (ESP) 90

Gas Co

‐ Firing (35%) 32

Gas Co

‐ Firing (60%) 56

Gas Firing (100%) 92

As mentioned above, the issues with gas firing or co-firing are the vol atility of natural gas prices and reliability concerns due to the re strictions on wintertime use of natural gas in New York State. The ESP option was ruled ou t due to the high control cost when taking into account the projected capacity factor of Unit 1.

Dynegy recommends that current operations be considered as BART for PM on Roseton Unit 1 due to the high costs of an ESP unit a nd the aforementioned issu es associated with natural gas firing. Dynegy notes the secondary condensable PM emission reductions that will result from its proposed NO

x and SO 2 BART measures.

Boiler No. 2

• SO 2

Because of the physical and operational si milarities between Units 1 and 2, the SO 2 control options analyzed for Unit 2 are the sa me as those listed for Unit 1 in the table

above. The control efficiencies are also assu med to be the same as previously noted. Cost-effectiveness under the PTE and projecte d operating rate are pr esented in Table 3- 11, and costs associated with visibili ty improvement are in Table 3-14.

As with Unit 1, Dynegy proposes to limit the sulfur level of No. 6 fuel oil from the existing 1.3 percent weight to 1.0 percent. Th is reduction will resu lt in a decrease in annual allowable emissions of 10,734 tons

4• NO

x

The NO

x control options analyzed for Unit 2 were again the same as those analyzed for Unit 1; see the list in the above section. The costs of controls under the PTE and projected operating rate are presented in Table 3-4; visibi lity costs are contained in Table

3-7.

After analyzing the control costs, additional fuel and energy requirements, and the costs associated with visibility improvement, Dynegy again selected windbox optimization and recommends a reduction of the current permitted NO

x limit from 0.25 lb/mmBtu to 0.20 lb/mmBtu (based on a 24-hour average dur ing the ozone season and a 30-day average during the non-ozone season) fo r compliance with BART for NO

x . This reduction will

result in a decrease of allowable NO

x emissions of 1,736 tons annually.

• PM

Dynegy again concludes that cu rrent operations should be cons idered as BART for PM. Dynegy sites the high cost asso ciated with an ESP, and th e reliability concerns of switching to gas (part- or fu ll-time) to reduce emissions. The secondary condensable PM reductions that will result from the proposed NO

x and SO 2 BART measures were cited as also reducing overall PM emissions.

III. BART Determination

The Department finds that the following sha ll constitute BART for the Roseton Generating

Station emission sources:

Boilers No. 1 and No. 2

• SO 2

The Department accepts Dynegy’s BART propos al of lowering its permitted No. 6 fuel sulfur limit from 1.5 percent to 1.0 percent by weight. Control options were deemed economically infeasible on a cost -per-ton basis under recent/projected capacity factors, as well as on a cost-per-deciview basis, and gas firing was ru led out due to reliability concerns. This limit is in line with the guida nce provided by EPA for sulfur in fuel of 1.0 percent or less by weight (A ppendix Y, Section IV.E.4, “SO 2 limits for Utility Boilers”).

EPA also notes in the BART rule that “the most appropriate contro l option for oil-fired EGUs, regardless of capacity, is to set limits on the sulfur content of the fuel oil burned in the unit” (70 FR 39133).

It should be noted that the Department is pursuing a regulatory re vision to 6 NYCRR Part 225-1 to lower the acceptable fuel sulfur limit to 0.5 percent statewide (not including the New York City and lower Hudson Valley ar eas, which are already subject to more stringent limits). This revision is tentatively scheduled to be effective for 2014. The Department has made owners aware of this upcoming requirement and indicated it may

56 supersede BART limits such as the 1.0 percent limit recommended by Dynegy for Roseton Units 1 and 2. Dynegy has committed to meeting any revisions to the Department’s fuel sulfur requirements for No. 6 oil.

• NO

x

The Department accepts Dynegy’s pr oposal to lower its permitted NO

x limit from 0.25 lb/mmBtu to 0.20 lb/mmBtu through wind-box op timization. Other control options were demonstrated to be economically infeasible . Compliance will be measured on a 24-hour average during the ozone season and 30-da y average during the non-ozone season.

• PM

The Department accepts that current operations are BART for PM. Other options were

ruled out due to economic or technical infeasibility. These units will retain their 0.1 lb/mmBtu particulate emission limits.