SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix B: Emissions Reducti on Analysis September 20, 2007

Final Staff Report with Appendices for Revised Proposed Amendments to Rule 4703 

# APPENDIX B

Emissions Reduction Analysis for Revised Proposed Amendments to Rule 4703 (Sta tionary Gas Turbines)

September 20, 2007SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix B: Emissions Reducti on Analysis September 20, 2007

Final Staff Report with Appendices for Revised Proposed Amendments to Rule 4703 B-2 NOx EMISSIONS REDUCTION ANALYSIS

Rule 4703 (Stationary Gas Turbines)

I. SUMMARY

District staff has estimated the NOx emissions reduction fr om stationary gas turbines that would comply with the pr oposed Tier 3 NOx emis sion limits of Rule 4703. About 74 turbines (71 are less than te n (10) MW and 3 are 25 MW ) would be subject to the proposed NOx limits. Some of the turbines are already in complianc e with the proposed NOx limits and some are exempt from the NOx limits. Appr oximately 65 turbines would need to be retrofit, replaced or reduce their opera ting hours to comply with the proposed NOx limits. This appendix identifies the esti mated NOx emissions re duction and outlines the methodology used to calc ulate the NOx emissions re duction for the proposed

amendments to Ru le 4703.

The 2007 Ozone Plan indicated that for St ationary Gas Turbines (S-COM-5) the 2012

baseline NOx emissions are about 5.1 tons per day and t hat a reduction of about 0.68 tons of NOx per day is anticipated upon final implementation. The analysis indicates

that the NOx emissions reduction from tu rbines due to the proposed amendments is approximately 786 tons per y ear (2.2 tons/day), whic h represents about 43 percent

reduction.

II. BACKGROUND

The latest amendments to the NOx emission limits of Rule 4703 we re in April 2002. For gas fueled units rated no more than 10 MW, the amendm ents of April 2002 specified NOx emissions limits of 25 ppmvd to 50 ppmvd, at 15% O 2 . The amendments of April 2002 specif ied NOx emissions limits of 3 ppmvd to 25 ppmvd, at

15% O 2 , for gas fueled units rate d greater than 10 MW.

This analysis estimates the NOx emissions reduction from gas fueled stationary gas turbines that would comply with the proposed NOx emission limits in Section 5.1.3 of Rule 4703. The proposed NOx limits are listed in the following table.SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix B: Emissions Reducti on Analysis September 20, 2007

Final Staff Report with Appendices for Revised Proposed Amendments to Rule 4703 B-3 Table 1 Proposed NOx Compliance Limits

NOx Compliance Limit, ppmvd at 15% O 2 Turbine Classification Rating

Gas Fuel Liquid Fuel

a) Less than 3 MW. 9 25

b) 3 MW to 10 MW pipeline gas turbine. 8 during steady

state and12 during nonsteady state 25

c) 3 MW to 10 MW and per mit condition for less than 877 hrs/yr operation. 9 25

d) 3 MW to 10 MW and per mit condition for 877 hrs/yr operation or greater. 5 25

e) Greater than 10 MW, Simple cycle, and permit

condition for no greater than 200 hr s/yr operation, except as provided in Section 5.1.3.3. 25 42

f) Greater than 10 MW, Simple cycle, and permit condition for greater than 200 hrs/yr ope ration but no greater than 877 hrs/yr operation. 5 25

District staff feels that t he proposed Tier 3 NOx limits c an be met through the use of SCR technology, combustion design technology or replacement units and that the cost of such technologies is reasonable. The proposed limits for the units no greater than 10 MW are not as stringen t as the limits for larger units as th e smaller units are usually not as efficient as the larger units.

III. TURBINES AFFECTED BY PROPOSED NOX LIMITS

In order to determine the NO x emissions reduction from the proposed amendments of this project, District staff identified the number of units that would be affected and pertinent operating characteristi cs of such units. The District’s Permits database was used to identify the units currently under permit. Based on the information in the database, District staff identified 74 turbines that could be subject to the proposed Tier

3 NOx emission limits. Of the 74 turbines identified, two of the turbines are either exempt or dormant. Of the 72 active gas turbines that could be affected by the proposed Tier 3 NOx emission limits, seven (7) turbines are already in compliance with the proposed Tier 3 NOx emission limits, therefore, 65 turbines would need to take action to comply with the proposed emission limits.SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix B: Emissions Reducti on Analysis September 20, 2007

Final Staff Report with Appendices for Revised Proposed Amendments to Rule 4703 B-4 IV. EMISSIONS REDUCTION ANALYSIS

The expected NOx emissions reduction depends on the number of units in operation, the size of the units in operation, t he annual operating hours of the units, the operating load of the units, and t he level of emission control of the units. The permit database was also used to gather other in formation for the units such as unit manufacturer and model, heat input rating, NOx emission limit, control system and annual operating hours. The NOx emissions reduction analysis was performed as

follows:

A. Emissions Reduction Methodology

The estimated current annual NOx emissions and the estima ted potential annual NOx

emissions were calculated us ing the following equation:

NOx = LF x MMBtu/hr x HR x EF / 2,000 lb/ton

Where:

NOx = Current annual NOx emissions or Potential annual NOx emissions in tons/year

LF = turbine load factor MMBtu/HR = heat input rating

HR = annual hours of operation

EF = NOx emission fact or in pounds per MMBtu

Where:

EF = NOx emission fact or in ppmv x 0.00366 ppmv = NOx emissions in parts per million corrected to 15% oxygen 0.00366 = Conversion factor used: 0.00366 lb/MMBtu per ppmv NOx

The estimated annual NOx em issions reduction was calculated using the following equation:

NOx Emissions Reduction = Current annual NO x emissions - Potential annual NOx

emissions.

B. Sample Calculation

Current NOx = LF x MMBtu/hr x HR x EF / 2,000 lb/ton

= 0.75 x 40.9 x 7884 x (35 x 0.00366) / 2000

= 0.0424 tons/day

Potential NOx = LF x MMBtu/hr x HR x EF / 2,000 lb/ton

= 0.75 x 40.9 x 7884 x (9 x 0.00366) / 2000

= 0.0109 tons/daySAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix B: Emissions Reducti on Analysis September 20, 2007

Final Staff Report with Appendices for Revised Proposed Amendments to Rule 4703 B-5 Emissions Reduction = 365 x (Current NOx em issions - Potential NOx emissions) = 365 x (0.0424 tons/day - 0.0109 tons/day)

= 11.51 tons/year

C. Assumptions for NOx Emissions Reduction Analysis

The assumptions used in the NOx emissi ons reduction analysis are listed below. Unless otherwise noted, the listed assumptions apply to all turbines considered in the analysis.

1. It was assumed that units would comply with the proposed limits and not be replaced with a different power source.

2. It was assumed that units are operated at 75% of rated power.

3. It was assumed, except fo r units referred to in Item 4 below, that turbines with an annual hours limit on their permit were avai lable for the full amount of those hours and that other turbines were operated 90% of the year due to maintenance, etc.

4. It was assumed that ther e would not be any emissions reduction from the three units greater than 10 MW, Simple cycle, and permit condition for no greater than 877 hrs/yr operation as they would comply with the proposed amendments by modifying their permits to specify “no greater than 200 hrs/yr operation”.SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT

Appendix B: Emissions Reducti on Analysis September 20, 2007

Final Staff Report with Appendices for Revised Proposed Amendments to Rule 4703 B-6 This page left intentionally blank.