Sep 2005Power Generation1 Proposed LNG Gas Turbine Interchangeability Study 20 Sep 2005

Sep 2005Power Generation2 Stakeholder Meeting (SoCal Gas) Objectives Evaluate impact of fuel chemistry changes on DLN gas turbine system performance –Mechanical, technical, and physical impacts to the equipment ● Identify environmental impacts related to gas interchangeability ● Fill in key data gaps identified by the NGC+ report ● Use as basis for devising a strategy for the markets

Sep 2005Power Generation3 Stakeholder Meeting (SoCal Gas) Program Details ● Test DLN natural gas fueled turbine to evaluate robustness for changes in fuel quality –Vary fuel quality by controlled blending of higher hydrocarbon gases (ethane, propane, and butane) to simulate qualities of LNG Monitor emissions (NO x, CO, VOC, O 2, CO 2 ), combustor dynamics, heat transfer (by instrumented components) and fuel chemistry by GC. –Vary gas Wobbe Index by blending of gas components and by gas heating Increasing Wobbe with higher hydrocarbons Decreasing Wobbe with nitrogen injection Gas heating to increase or decrease Wobbe Rate-of-change of Wobbe Index

Sep 2005Power Generation4 Stakeholder Meeting (SoCal Gas) Program Details –H2Gen provided gas generator to conduct on-site gas reforming and hydrogen generation Inject hydrogen (or H 2 enriched natural gas), in controlled amounts, to monitor its impact on the combustor dynamics and emissions. ● Monitor equipment response to changes in gas quality ● Make changes to unit (fuel flow splits, heating, etc.) to offset any operability issues created by the fuel quality changes

Sep 2005Power Generation5 Stakeholder Meeting (SoCal Gas) Examples A. Set unit at nominal NO x level (equivalence ratio) Vary gas quality upward by controlled injection of higher hydrocarbons; downward by injection of nitrogen. Hydrogen balancing to determine if gas quality changes can by counterbalanced by add-on device. B.Increase NO x set point (higher equivalence ratio) A.Repeat previous steps C.Repeat for range of equivalence ratios

Sep 2005Power Generation6 Stakeholder Meeting (SoCal Gas) NO x -Thermal NO x Formation At lower combustion temperatures, less NO x is generated. But there is a limit to the minimum temperature. Combustion instabilities (dynamics) become important in lean combustion systems.

Sep 2005Power Generation7 Stakeholder Meeting (SoCal Gas) Combustor Rig Tests Wobbe Index variation, as well as combustor design can affect emissions. Chart shows the response of two different combustor systems to changes in gas composition.

Sep 2005Power Generation8 Stakeholder Meeting (SoCal Gas) Diffusion Combustor Response Calculated for diffusion combustion system. Water Injection for NO x control, and fixed firing temperature. Differences in NO x due to fuel quality changes (Wobbe Index) are indicated..

Sep 2005Power Generation9 Stakeholder Meeting (SoCal Gas) Key Players ● Siemens –Provide mixing/blending skid and technical experience on LNG testing program Conducted test on F-Class peaking unit in 2004 ● Test site (TBD) –Site selection based on availability of unit, combustor design, and end user participation ● Combustion Science and Engineering (CSE) –Overall test auditing, data analysis, and reporting ● H2Gen –Gas generator to evaluate ability of gas chemistry reforming on combustion generated emissions

Sep 2005Power Generation10 Stakeholder Meeting (SoCal Gas) Additional Players ● PG&E –Gas supplier Fuel gases for the program? ● CEC –Financial support

Sep 2005Power Generation11 Stakeholder Meeting (SoCal Gas) Financial ● Siemens –Gas mixing skid and equipment estimated value $800,000 –Technical expertise for the basic turbine design features ● Site: Gas turbine and operating personnel ● CEC: Financial support for –H2Gen, CSE, equipment modifications –Estimate $1,000,000

Sep 2005Power Generation12 Stakeholder Meeting (SoCal Gas) Status ● So far, just proposed ● Participants contacted so far are interested ● Numerous details to be worked out –Timing, availability of site apparatus, staging personnel, equipment modifications, inspections, staff coordination ● Timing? 6 months, at the earliest ● Benefit –Technical evaluation of impact of gas chemistry on the large industrial turbine –Identify strategy for any mitigation measures, if any