Super Boiler the New Industrial Steam Generation System > Rick Knight Gas Technology Institute Atmos Energy/ESC Gas Utilization Seminar for Key Customers Grapevine, Texas Sept 12, 2007
Presentation ti Summary GTI overview Super Boiler technology Contact information
WHO WE ARE Gas Technology Institute > Leading U.S. research, development, and training organization serving the natural gas industry and energy markets An independent, 501c (3) not-for-profit Serving the Energy Industry Since 1941 > Over 1,000 patents, p > Nearly 500 products commercialized
GTI: Facilities & Staff > Main Facility: 18-Acre Campus Near Chicago Over 200,000 ft 2 of laboratory space 28 specialized laboratories and facilities > More than 220 employees 70% are scientists and engineers Offices & Labs Flex-Fuel Test Facility Energy & Environmental Technology Center
GTI: Major R&D Units Expanding energy supply Reducing energy delivery costs Increasing energy efficiency Developing clean energy solutions Exploration & Production Technology Kent Perry Managing Director > Unconventional gas resources > LNG > Methane hydrates > CO 2 sequestration Distribution & Pipeline Technology Edward Johnston Managing Director > O&M cost control > Reliability, safety, & security > Automation > Environmental services & research > Hydrate flow issues Gasification & Gas Processing Vann Bush Managing Director > Gasification & hot gas cleanup > Process engineering > Thermal waste stabilization > Gas processing & conditioning End Use Solutions William Liss Managing Director > Combustion & efficiency for res/comm/industrial markets > Distributed power, combined heat & power > Catalytic synthesis > Hydrogen, fuel cells, and alternative vehicle fuels
GTI: End Use Solutions Labs Industrial Labs Residential/Commercial Labs Distributed Generation Labs Fuel Cell and Hydrogen Labs Over 65 engineers, scientists, t and technicians i Specialized Testing System Modeling Emissions measurement High-speed data acquisition
GTI: Industrial Labs > Leading national facility for large- scale combustion and industrial process equipment development Six research furnaces (<5 MMBtu/h) Two boiler simulators (<12 MMBtu/h) 20 MMBtu/h watertube package boiler Submerged melter test facility Sensors laboratory Full emissions measurement Infrared heater testing platform Burner and radiant tube evaluation
Super Boiler Background > U.S. industrial and commercial steam boilers Consume over 6 quads of natural gas per year Wide range of steam uses from process steam to space heating > Installed base of steam boilers Largely over 30 years old Average efficiency 76% Typical NOx emissions 85 ppmv Significant potential for improved technology
Project Origin & Goals > Super Boiler program Started by DOE and gas industry in 2000 GTI team selected to carry out project > Goals: Maximum efficiency NOx and CO less than 5 ppmv Reduced footprint and weight Cost-effectiveness
Project Moves Forward > Define program Industrial Advisory Group Cleaver-Brooks as manufacturing partner > First-generation Super Boiler Platform Combustion Heat transfer Heat recovery Controls
PLATFORM Boilers are constructed in a variety of configurations including firetube, watertube, natural circulation, once-through, and hybrid varieties Selected boiler platform dictates methods available to meet the technical objectives
Platform: boiler construction > Watertube vs. Firetube Cleaver-Brooks perspective Package boiler market growth Technical flexibility Equipment cost Firetube platform selected WATERTUBE FIRETUBE
COMBUSTION Natural gas combustion produces heat for steam generation, but also unwanted emissions (NOx, CO, VOC, PM) Combustion at low excess air improves energy efficiency Minimizing NOx while achieving complete fuel burnout at low excess air is a challenge
Combustion: parallel approaches > Single-stage g Commercially available NatCom burner Internal staging and FGR > Two-stage Extension of FIR burner technology Staged premixed combustion with interstage t heat removal No FGR required Requires special boiler design
Combustion: single-stage version > 80 HP lab boiler Conventional single firetube furnace with NatCom burner Cleaver-Brooks integral front head design 15-20% FGR for NOx control <9 ppmv NOx at 4-5% O 2
Combustion: single-stage field demo > 300 HP field demonstration Set up NatCom burner for added pressure drop of heat recovery NOx confirmed below 9 ppmv Installed at Specification Rubber Products (Alabaster, AL) Started operation July 2006 Over 6300 hours logged
Combustion: single-stage controls > Operator interface via Hawk ICS touchscreen PLC control panel > PLC control Fuel/air ratio control via jackshaft with VFD trim FGR damper control from jackshaft O 2 ti trim managed dby in-situ it O 2 sensor Separate combustion setups for heat recovery and bypass modes
Combustion: two-stage version * FUEL PRIMARY AIR SECONDARY AIR FUEL-AIR MIXER FUEL-AIR MIXER > 80 HP lab boiler Staged burner with internal recirculation Interstage cooling pass No FGR required <5 ppmv NOx at 1-2% O 2 * U.S. Patent No. 6,289,851 (Sept 2001)
Combustion: two-stage field demo > 300 HP field demonstration Scaled up with integral head design Pre-tested t and set up for heat recovery and bypass modes at CB Thomasville plant Sited at Clement Pappas & Co. (Ontario CA) Installation and UL approval process under way Startup Oct-Nov 2007
Combustion: two-stage controls > Operator interface via Hawk ICS touchscreen PLC control panel > PLC control Critical first stage fuel/air ratio control via fuel delta-p and windbox air delta-p Control implemented via parallel positioning (PP) controllers with VFD trim O 2 trim integrated t into air split management Separate setups for heat recovery and bypass modes
HEAT TRANSFER Heat transfer from fireside to waterside determines boiler size Heat transfer rate also determines efficiency up to boiler exhaust outlet Increased convective pass heat transfer will p reduce boiler size and make downstream heat recovery easier
Heat Transfer: convective pass > Enhanced firetube heat transfer Firetubes with extruded aluminum inserts Heat transfer 18X higher than rifled tubes 2-pass boiler can deliver 4-pass performance in smaller size RIFLED TUBES CLEAVER-BROOKS TUBE INSERTS
Heat Transfer: impact on boiler size % relative to base case Design case #1 #2 #3 Footprint 61 75 70 Cross-section 71 56 50 Volume 51 56 49 Weight 51 59 51 > Conventional boiler base case: 10-MMBtu/h (250 hp) 3-pass firetube boiler w/450 F flue gas 88" shell ID, 127-ft 2 footprint, 728-ft 3 volume, 11.2-ton dry weight > Compare versions with enhanced firetubes > Equivalent capacity and heat removal
Heat Transfer: field demonstrations > 300 HP field demonstration Both AL and CA demos use finned firetube inserts in two- pass design Flue gas cooled to 35 F above steam temperaturet California Super Boiler: 38% lighter & 31% smaller footprint than conventional 300 HP boiler Standard CB 300HP boiler 123 sq ft 300HP Super Boiler 85 sq ft
HEAT RECOVERY Natural gas combustion produces about 18% water from oxidation of H in fuel Water vapor up the stack accounts for 10% of fuel energy input, or 65% of stack loss Key to higher energy efficiency is to recover y g gy y both sensible and latent heat
Heat Recovery: general approach > Flue gas heat recovery Remove sensible heat with two economizers Fuel in Remove latent heat with Transport Membrane Condenser (TMC) Flue gas exits at low temperature but not at saturation Steam Out Boiler Ambient air BFW HPE Deaerator/ Make-Up Tank LPE TMC Make-up water Flue gas out
Heat Recovery: TMC concept * > Transport Membrane Condenser (TMC) Nanoporous ceramic membrane tubes Water vapor permeation via capillary condensation Partial vacuum required on shell side Counterflow configuration Warm water out to deaerator Cool feed water in Warm humid flue gas in Cool dry flue gas out * U.S. Patent No. 6,517,607
Heat Recovery: TMC hardware > Downflow Version 1.0 Cylindrical shell design Media & Process tube bundles (17 x 4 diam), 99 tubes ea Water on shell side with bottom inlet for natural counterflow Flue gas cooled from ~160 F to ~130 F Shell-side vacuum 3 psid Flue gas pressure drop <4 inwc TMC (3 MMBtu/h) TMC (11 MMBtu/h)
Heat Recovery: expanded system * > Applications with high condensate return Limited make-up Steam Out water in many systems reduces Fuel in Boiler TMC capacity Cool water by recycling it through humidifying air heater (HAH) Air humidification also suppresses NOx Preheated humidified air Ambient air BFW Condensate return HPE HAH Deaerator/ Make-Up Tank LPE TMC Make-up water Flue gas out *U.S. Patent No. 7,066,396
Heat Recovery: HAH concept > Humidifying Air Heater (HAH) Cools TMC outlet water for recycle Heat exchanger coils transfer heat Nanoporous tubes transfer additional heat through evaporation Air is heated and humidified, water is cooled and sent back to TMC Ambient air in Cool water out Hot water from TMC Warm humid air out
Heat Recovery: HAH hardware HAH 3 (MMBtu/h) > Compact design Inlet & outlet water distribution panels Media & Process tube bundles (34 x 3 diam), 36 tubes ea Separate PVC air duct for each bundle Copper coil heat exchanger surrounds each bundle Air-side pressure drop 1.5 inwc HAH (11 MMBtu/h)
Heat Recovery: y Alabama field demo
Heat Recovery: Alabama field demo > TMC design & operation 304SS shell with aluminum tube sheets 94 membrane bundles Venturi vacuum pump driven by compressed air Low-NPSH water outlet pumps > TMC control Water level Vacuum Startup and shutdown
Heat Recovery: Alabama field demo > HAH design & operation 30 tube bundles Separate PVC air duct for each bundle Mounted on boiler air inlet Fiber air filter > HAH control Water flow Water pressure Startup and shutdown
Heat Recovery: y Alabama field demo
Heat Recovery: controls S FV 150 P 160 TO STACK HAH controlled by water temp and exit air humidity COMPRESSED AIR Water level in TMC chamber is critical - maintained by level controller FV 160 S VENT LPE P 130 VSD 130 LIC-130 TAH 110 TIC 110 VSD 110 P 110 I DAMPER FV 170 S VENT AIR OUT RME 110A RMC 110A HPE MAKE-UP WATER MUT level maintained via control valve LT 140 LIC 140 LALL 140 LALL 140 I I FROM LIC-140 TMC TO STACK LCV 140 FILTER DRAIN FV 140 TE 110A LCV FROM LIC-130 130B LCV 180 LCV 110 CRT HAH AIR IN FV 110 DRAIN PLANT CONDENSATE LT 180 Boiler Condensate transfer pump p regulates condensate flow to MUT NATURAL GAS Float valve set to open in case of HRS failure LT 130 LIC 130 FLOAT MUT P 150 P 180 VSD 180 FROM BOILER LEVEL CONTROL LIC 180 TMC - TRANSPORT MEMBRANE CONDENSER HAH - HUMIDIFYING AIR HEATER HPE - HIGH-PRESSURE ECONOMIZER LPE - LOW-PRESSURE ECONOMIZER MUT - MAKE-UP TANK CRT - CONDENSATE RECEIVER TANK
Heat Recovery: California field demo > Clement Pappas & Co. in Ontario CA Heat recovery system (HRS) similar to Alabama site Minor improvements to vacuum control, pump location, etc. HRS mounted entirely above boiler
Heat Recovery: improved TMC design > Upflow Version 2.0 Modular design under development 25-HP low-cost tube bundle modules optimized for maximum membrane surface utilization Water inside tubes with staged downward flow Flue gas directed upward for above-boiler e mounting Easier to construct, assemble, install, and service More compact Less ductwork
Heat Recovery: Utah field demo > Third Dimension Inc. in West Jordan UT TMC Version 2.0 retrofit to standard 200 HP CB boiler No condensate return/ no HAH Low-cost compact LPE panel integrated with TMC Economizer and TMC mounted directly above boiler Integrated boiler/hr controls Startup planned for Nov 2007 TMC LPE HPE
What s Next > Commercialization TMC heat recovery will be the first commercial product Licensing i under negotiation > Continuing activities Multi-fuel capability for two-stage boiler Watertube Super Boiler Additional field demonstrations at different sizes Optimization for cost-effectiveness and ease of operation
Acknowledgment > Thanks to DOE ITP, GRI, Southern California Gas, GTI-SMP, UTD NFP, California Energy Commission, California Air Resources Board, South Coast Air Quality Management District, and Cleaver-Brooks for the financial support of this project
CONTACT Gas Technology Institute: Rick Knight Technology Development Manager (847) 768-0584 rick.knight@gastechnology.org Cleaver Cleaver-Brooks: Dan Willems Vice President R&D (414) 438-5460 dwillems@cleaver-brooks.com