Assessment of a Gas Quality Survey for Interchangeability David Rue, William Liss Gas Technology Institute Algonquin Gas Pipeline Northeast Stakeholders Group June 15, 2006

Regional Natural Gas Composition Variations Exist Average Natural Gas Composition -- Twenty Six US Cities Source: Gas Technology Institute

Natural Gas and LNG Adjust gases are typical U.S. natural gases at city gates (GRI, 1992)

LNG Adjustment Methods In-tank BlendingMix low and high-Btu LNG. Requires inventory of low-Btu LNG Pipeline Blending Best when large volumes of low-Btu gas are available (Gulf Coast) Air InjectionUp to 3.8% air. Capital cost and oxygen content concerns Nitrogen injection Up to 2% nitrogen. Capital cost. Used by Distrigas and Cove Point. NGL strippingCapital cost. Need market for liquids StreamingCargo ‘streamed’ through terminal to less-sensitive user (e.g. power)

Approaches to Interchangeability Prediction – Focus on Appliances Single index (Wobbe, modified Wobbe, etc.) –Incapable of describing all possible situations Multiple indices (AGA, Weaver, etc.) –Specific to burner type –Do not account for all fuel gases or emissions –Most common U.S. approach Diagrams –Do not account for all fuel gases or emissions –Attempt to combine Wobbe index with composition parameters –Many variations and not universally accepted –Often used in Europe

Wobbe Number Generally accepted as the best SINGLE index to determine interchangeability For natural gas – alkanes – heat input through an orifice (Btu/h) at constant pressure is –proportional to heating value and –inversely proportional to the square root of specific gravity Wobbe Number does not fully address interchangeability because changes in flame characteristics are not addressed W = HHV / (sp. gr.) 0.5

Interchangeability is Defined As - The ability to substitute one gaseous fuel for another in a combustion application without materially changing operational safety or performance and without materially increasing air pollutant emissions Source – NGC+ Working Group on Interchangeability White Paper presented to FERC, Feb. 2005

Possible Combustion Problems With High BTU Gas Reported ProblemFrom Flame liftingExcess air BackfiringOw excess air or low velocity High COIncomplete combustion High NO x Higher flame temperature Yellow tipping Flame lengthening from incomplete combustion SootingUnburned hydrocarbon buildup

Interchangeability For Appliances The American Experience AGA and USBM indices set limits for appliance fuel interchangeability ANSI codes are not specific for interchangeability Interchangeability studies have been made by GTI, IGT, A.D. Little, SoCalGas, and others –No appliance failed AGA Index or ANSI limits with LNGs –CO is most sensitive measure of performance –Some appliances have high CO with ‘hot’ LNGs Indices developed for older appliances do not always predict behavior of new, high-efficiency appliances AGAYellow tipping Flashback Lifting USBMYellow tipping Air Supply Flashback Heat release Lifting Incomplete combustion

Effects of Fuel Changes: Appliances and Industrial Burners Different appliance burners show changes in performance No burner exhibited a failure case of flame lifting, excessive yellow tipping, or high CO emissions Important performance characteristics are different for industrial burners than for residential appliances Industrial burners are monitored more closely but operated at more demanding conditions Source: Gas Technology Institute

Effects of Fuel Changes: Appliances and Industrial Burners Industrial burners can be categorized –Some burner types, like appliances, are relatively unaffected by changing fuel Burners sensitive to changing fuel include: –Burners for which flame temperature changes strongly impact the process –Burners in high temperature processes or where emissions are tightly regulated –Burners operating close to stability limits Only sensitive burner types need to be evaluated for gas interchangeability

Industrial Burners – Interchangeability Concerns Unlike appliances, industrial burners are complex, highly engineered, and operate under precisely controlled conditions Changing fuel can affect industrial burners –Performance Flame length, temperature, flame shape, mixing patterns, etc. –Safety Stability, operating range, air/fuel ratio, etc. –Meeting regulations Emissions of NO x, CO, etc. Wobbe is still best index of interchangeability

What Needs to be Learned? ApplicationConcernStatusNeed AppliancesMillions of unregulated units Studies made, results must be compared Testing of old, maladjusted, and new units Commercial/ Industrial Burners Widest range of use, efficiency, emissions Not yet addressed Extensive testing Engines and Boilers Knock, efficiency, emissions, stable combustion Mobile engines studied, others not yet addressed Review mobile engine data and testing Turbines/ Microturbines Efficiency, emissions, turbine life New FL study planned with full- scale turbines Collect turbine maker data and testing Non-combustion Uses Added process cost, plant modification Not yet addressed Market analysis and data collection

Work Scope Receipt of – –Survey of northeast industrial gas customers by SIC (or NAICS) code, engines, turbines –Current natural gas and expected LNG ranges Identification of industrial burners used by specific industrial customers – largest combustion uses Itemizing of engines and turbines by manufacturer, model, type, and quantity Ranking of burners, engines, and turbines into categories – considering gas composition ranges Explanations provided of interchangeability reasons for placement of combustion systems into categories

Ranking Criteria Burners and processes not expected to have any operational, performance, or emissions concerns over the full range of specified fuel gas compositions Burners and processes that may have some concerns over the specified fuel gas range and may eventually need to be looked at more closely. These include –those considered to be of some concern, but likely will handle the charges in gas composition with no difficulties –those for which insufficient information is available and may need to be studied before making a judgment Burners and processes with operations, performance, or emissions concerns over at least part of the range of gas compositions. Further study would be advised for these systems before introducing a new fuel gas such as LNG.

Deliverable – Final Report Summary overview of industrial burners, engines, and turbines identified in survey –Number and type listed where possible –Burner types summarized by SIC codes Analysis of burners, engines, and turbines –General comments on impacts of proposed gas ranges on listed combustion systems –Ranked in three classes based on changing gas Little or no impact expected Some impact expected or too little information available to decide about impacts Impacts expected and more detailed study of combustion systems recommended

Cost and Schedule Cost –Project cost - $69,000 –Includes initial and final trips to meet with sponsors Schedule –Work planned from June 15, 2006 through August 15, 2006 –GTI will start work immediately with partial survey results –Work completion is dependent on completed Northeast Stakeholders Group surveys –Work can be slowed if all survey results are not available

Classification of Industrial Burners

1.Mixing Type 2.Fuel Type 3.Oxidizer Type 4.Draft Type 5.Heating Type 6.Burner Geometry Classification Criteria

GTI Proprietary & Confidential 1.Mixing Type 2.Fuel Type 3.Oxidizer Type 4.Draft Type 5.Heating Type 6.Burner Geometry Classification Criteria Diffusion Mixed –Non-Staged –Air Staged –Fuel Staged Partial Pre-mixed –Non-Staged –Air Staged Pre-Mixed –Non-Staged

1.Mixing Type 2.Fuel Type 3.Oxidizer Type 4.Draft Type 5.Heating Type 6.Burner Geometry Gas Liquid Solid Dual Classification Criteria

1.Mixing Type 2.Fuel Type 3.Oxidizer Type 4.Draft Type 5.Heating Type 6.Burner Geometry Classification Criteria Air Oxygen Oxygen Enriched Air Preheated Air

1.Mixing Type 2.Fuel Type 3.Oxidizer Type 4.Draft Type 5.Heating Type 6.Burner Geometry Classification Criteria Forced Draft Natural Draft Inspirated Aspirated

1.Mixing Type 2.Fuel Type 3.Oxidizer Type 4.Draft Type 5.Heating Type 6.Burner Geometry Classification Criteria Direct Indirect

1.Mixing Type 2.Fuel Type 3.Oxidizer Type 4.Draft Type 5.Heating Type 6.Burner Geometry Classification Criteria Round Nozzle Rectangular Nozzle Swirl

Burner Types 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy-Fuel Burners 8.Flare Burners

Burner Types 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy-Fuel Burners 8.Flare Burners Radiant Wall Thermal Radiation Radiant Tube

Burner Types 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy-Fuel Burners 8.Flare Burners Radiant Wall –Natural Draft –Forced Draft Pre-mixed Non-Premixed Thermal Radiation Radiant Tube

Burner Types 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy-Fuel Burners 8.Flare Burners Radiant Wall Thermal Radiation –Porous Ceramic –Ported Ceramic –Fiber Metal –Flame Impingement –Catalytic –Perforated Ceramic –Porous Refractory –Wire Mesh Radiant Tube

Burner Types 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy-Fuel Burners 8.Flare Burners Radiant Wall Thermal Radiation Radiant Tube –Non-Circulating –Recirculating –Forced Draft –Inspirating

Burner Types 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy-Fuel Burners 8.Flare Burners Pre-mixed Diffusion Mixed Partially Pre-mixed Air Staged

Burner Types 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy- Fuel Burners 8.Flare Burners One Box Two Box Rotary / Heat Wheel Radiant Tube

Burner Types 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy- Fuel Burners 8.Flare Burners Round Flame Wall Fired Flat Flame Radiant Wall Flat Flame

Burner Types 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy-Fuel Burners 8.Flare Burners Low NOx Ultra Low NOx Conventional

Burner Types 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy- Fuel Burners 8.Flare Burners Low NOx –External Flue Gas Recirculation (EFGR) –Air Staged –Fuel Staged –Fuel Induced Recirculation Ultra Low NOx Conventional

Burner Types 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy-Fuel Burners 8.Flare Burners Low NOx Ultra Low NOx –Pre-mixed –Partially Premixed –Rapid Mix –Internal Flue Gas Recirculation Conventional

Burner Types 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy-Fuel Burners 8.Flare Burners Low NOx Ultra Low NOx Conventional –Swirl –Register

Burner Types 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy-Fuel Burners 8.Flare Burners Duct –Linear Grid –Grid Make-up Air

Burner Types 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy- Fuel Burners 8.Flare Burners Air-Oxy Fuel –Concentric Pipe –Multiple Nozzle –Flat Flame –Staged Oxy-Fuel –Polishing –Forehearth

Burner Types 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy- Fuel Burners 8.Flare Burners Single Point –Non Assisted –Simple Steam Assisted –Advanced Steam Assisted –Low Pressure Air Assisted Multi-point Enclosed

Burner Types 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy- Fuel Burners 8.Flare Burners Single Point Multi-point –Non Assisted –Simple Steam Assisted –Advanced Steam Assisted –Low Pressure Air Assisted Enclosed

Burner Types 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy- Fuel Burners 8.Flare Burners Single Point Multi-point Enclosed –Non Assisted –Simple Steam Assisted –Advanced Steam Assisted –Low Pressure Air Assisted

Burner Applications 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy-Fuel Burners 8.Flare Burners Thermal Radiation –Drying –Plastic thermoforming –Paint curing Radiant Tube –Indirect heating Radiant Wall –Process Industry

Burner Applications 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy- Fuel Burners 8.Flare Burners Metals Industry Ceramic/Glass Industry

Burner Applications 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy- Fuel Burners 8.Flare Burners Zinc Distillation Metals Industry Glass Industry

Burner Applications 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy- Fuel Burners 8.Flare Burners Chemical and Hydrocarbon Process Industries

Burner Applications 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy- Fuel Burners 8.Flare Burners Steam Generation Water Heating Space Heating

Burner Applications 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy-Fuel Burners 8.Flare Burners Space Heating Turbine Exhaust Uniform Spread Heating

Burner Applications 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy- Fuel Burners 8.Flare Burners Metal Heating Metal Melting Glass Melting Mineral Calcining

Burner Applications 1.Radiant Burners 2.High Velocity Burners 3.Regenerative Burners 4.Natural Draft Burners 5.Boiler Burners 6.Linear Grid / In-Duct Burners 7.Oxygen Enhanced / Oxy- Fuel Burners 8.Flare Burners Petrochemical Industries