Energy Recovery from
Industrial Waste Streams
Toxics Use Reduction Institute Continuing Education Conference
November 20, 2014
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
With fuel prices increasing and environmental pressure to reduce emissions, it makes sense to consider recovering exhausted energy from plant processes and waste streams that would otherwise be vented or incinerated.
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
Recovered energy from waste heat can be used for preheating process air and liquid streams for HVAC applications and to generate electricity.
Utilizing waste heat not only reduces fuel consumption, but helps to improve efficiency and reduce green house gas emissions.
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
•For every 1 million BTU of natural gas burned there is approximately 118 pounds of CO2* Generated. •Over an 8700 hour operating year, that is 1,026,600 Lbs (or 513 tons) of CO2 emissions. A 1 million BTU/Hr recovery rate can eliminate this pollution exhaust.
•Recovering one million BTU/Hr will release about 1000 lbs fewer Nitrogen Oxides into the atmosphere each year.
•Particulate matter and VOC emissions are also reduced by recovering waste heat to reduce total fuel burned.
*Source: Union Gas Ltd.
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
Fuel CH4
Air @ 70oF
O2, N2, Ar
Flue Gas @ 350 oF CO2 H2O N2 Ar
Heat
Energy From the Fuel 1. Process – 77%
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
Fuel CH4
Air @ 70oF
O2, N2, Ar
Flue Gas @ 350 oF CO2 H2O N2 Ar
Heat
Energy From the Fuel 1. Process – 77% 2. Vaporize H2O – 15%
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
Fuel CH4
Air @ 70oF
O2, N2, Ar
Flue Gas @ 350 oF CO2 H2O N2 Ar
Heat
Energy From the Fuel 1. Process – 77% 2. Vaporize H2O – 15% 3. Heat the Air – 6%
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
Fuel CH4
Air @ 70oF
O2, N2, Ar
Flue Gas @ 350 oF CO2 H2O N2 Ar
Heat
Energy From the Fuel 1. Process – 77% 2. Vaporize H2O – 15% 3. Heat the Air – 6% 4. Losses – 2%
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
How Much Energy Is Lost in Exhaust Gases?
Assume 80 Degree Ambient Temp.
Boiler Size – 500 HP (16MMBTU/HR)
Gas Outlet Temperature = 350 oF
13,760 #/Hr Exhaust at 350 oF Application: Firetube Boiler
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
How Much Energy Is Lost in Exhaust Gases?
Assume 80 Degree Ambient Temp.
Boiler Size – 500 HP (16MMBTU/HR)
Gas Outlet Temperature = 350 oF
13,760 #/Hr Exhaust at 350 oF
1,000,000 BTU/Hr lost to atmosphere!
Application: Firetube Boiler
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
Application: Dryer
How Much Energy Is Lost in Exhaust Gases?
Assume 90 Degree Ambient Temp.
Process Exhaust Flow = 26,000 CFM
Gas Outlet Temperature = 196 oF 94,500 #/Hr Exhaust at 196 oF
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
Application: Dryer
How Much Energy Is Lost in Exhaust Gases?
2,400,000 BTU/Hr lost to atmosphere!
Assume 90 Degree Ambient Temp.
Process Exhaust Flow = 26,000 CFM
Gas Outlet Temperature = 196 oF 94,500 #/Hr Exhaust at 196 oF
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
Application: Thermal Fluid Heater
How Much Energy Is Lost in Exhaust Gases?
Assume 80 Degree Ambient Temp.
Unit heat input = 7.5MMBTU/Hr
Gas Outlet Temperature = 500 oF
6,450 #/Hr Exhaust at 500 oF
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
Application: Thermal Fluid Heater
How Much Energy Is Lost in Exhaust Gases?
Assume 80 Degree Ambient Temp.
Unit heat input = 7.5MMBTU/Hr
Gas Outlet Temperature = 500 oF
6,450 #/Hr Exhaust at 500 oF
704,000 BTU/Hr lost to atmosphere!
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
Application: Engine
How Much Energy Is Lost in Exhaust Gases?
Assume 80 Degree Ambient Temp.
Exhaust gas flow = 775 CFM Gas Outlet Temperature = 755 oF
Cooling water flow = 60 GPM Cooling water outlet temperature = 183 oF
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
Application: Engine
How Much Energy Is Lost in Exhaust Gases?
Assume 80 Degree Ambient Temp.
Exhaust gas flow = 775 CFM Gas Outlet Temperature = 755 oF
806,000 BTU/Hr lost to atmosphere!
Cooling water flow = 60 GPM Cooling water outlet temperature = 183 oF
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
Not all exhausted energy is practical to recover Recovery equipment becomes very large and costly when trying to drop exhaust temperatures down close to ambient temperatures. Exhaust gases must maintain enough heat to allow for buoyancy with a positive flow and plume through the stack effect. T1 (stack temperature) > T2 (ambient temperature)
T1
T2
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
What to look for in your plant Heat Sources •Boilers •Thermal Fluid Heaters •Gas Turbines •Ovens •Dryers •Engines •Incinerators •Fume Hoods
Heat Sinks •Building Make Up Air •Make Up Water •Process Water/Fluids •Clean Up Water (CIP) •Domestic Hot Water •Swimming Pool •Combustion Air Preheat •HVAC Heating •HVAC Cooling •Electricity Generation
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
• Heat sources from natural gas combustion are most effective for energy recovery.
• Dryer exhaust with entrained moisture are also good heat sources.
• Must be careful of exhaust streams with sulfur or other corrosive constituents at reduced temperatures. Special materials and/or coatings are required.
• Particulate in the gas stream may limit the type and efficiency of the recovery equipment.
• Must keep in mind the pressure requirements of the system.
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
Sensible and Latent Heat
Air to Air Heat Exchangers, Energy Wheels & Standard Economizers utilize Sensible Heat Recovery (heat available through temperature change only)
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
Sensible and Latent Heat
Condensing Economizers are designed to take advantage of latent heat recovery by condensing the water out of flue gases.
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
Fuel CH4
Air @ 70oF
O2, N2, Ar
Flue Gas @ 350 oF CO2 H2O N2 Ar
Heat
Energy From the Fuel 1. Process – 77% 2. Vaporize H2O – 15%
Condensing Heat Recovery Systems – The Energy Bonus!
Condensing Heat Recovery Systems
A condensing economizer improves heat recovery by recovering energy well below the dew point of the flue gas.
Standard heat recovery systems can reduce boiler stack temperatures to about 250 F, and are designed to avoid condensation of the flue gas.
The Goal: Recover the maximum amount of usable heat possible from your exhaust gas – you paid for it, you might as well use it!
HOW CONDENSING HEAT RECOVERY WORKS:
• Incoming cold fluid enters the Condensing exchanger
• Some of the tube and fin temperatures are below gas dew point and cause the vapors to condense out.
• The flue gas and heated liquid are not in contact (indirect contact heat exchange) with each other and the water remains pure.
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
Because each installation is custom engineered, the required materials of construction are established based on the site specific requirements.
Standard material of construction is 304L stainless steel. Specialized metallurgy such as titanium, Incoloy or Hastelloy are used.
WATER RECOVERY FROM EXHAUST GAS
Condensed water recovery rates vary from 4 – 60 Gallons Per Minute, depending on the application. Water is reusable in many applications such as boiler make up water or process water.
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
An Example of Year Round Energy Recovery for HVAC
Yearly Average Energy Recovered = 600,000 BTU/Hr Offsets gas fired space heating in the winter and electric costs for air conditioning in the summer. Reduced stack temperatures from 500F to 130F
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
An Example of Year Round Energy Recovery for Domestic Hot Water
Gas fired engines used to drive chillers for the ice rink generate hot gas and hot engine cooling fluid. The waste heat from the engine is used to heat domestic hot water for the adjacent High School. Three engines provide 500,000 BTU/Hr of waste heat each, that is transferred to the domestic water.
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
CASE HISTORY Heinz Inc – Stockton, CA
Cylindrical In-Stack Condensing Economizer Installed on a 350 HP boiler.
Recovers 1,264,000 Btu/hr. Yearly savings $105,900.00 Annual CO2 Emissions
reduction: 732 Tons/year Annual Water Recovery:
544,530 Gallons per year
Cylindrical In Stack Condensing Economizer - Capable of outlet water temperature
control
- Includes partial or full bypass capability
- Mounted as a section of the existing stack
CASE HISTORY Coca – Cola Company – College Park, Atlanta
ConDex System Recovers heat from 2 – 125 HP and 2 – 150 HP boilers. System heats boiler make up water from 60 °F up to 175 °F System recovers and re-uses 1,240,000 Btu/hr. Annual savings estimated at $100,000 per year. Annual CO2 emissions reduction is estimated at 545 Tons!
Standard Condensing Economizer • Can take hot gas from
multiple generators
• Does not interfere with existing exhaust flow
• Includes ID Fan, stack and controls.
INDIANA STATE UNIVERSITY
System recovers 4,760,000 Btu/hr.
Yearly savings $490,000.00
ConDex System heats condensate return water to 175 deg F.
Flue gases from multiple boilers.
Case Study Graphic Packaging – Santa Clara, CA
ConDex System Recovers waste heat from gas turbine / HRSG exhaust.
Heats 1,300 GPM of process water to 180 deg F
Recovers 25,000,000 Btu/hr at average load.
At peak load, ConDex System recovers up to 28 GPM of water from the exhaust gas!
Simmons Foods – Sulfur Fume Thermal Oxidizer Heat Recovery
Condensing Economizer installed on Thermal Oxidizer exhaust. System uses recovered energy to heat water that would otherwise be heated with virgin fuel. 6,632,190 gallons per year of water recovered from flue gas 6,465 ton CO2 emission reduction! 8% plant efficiency improvement.
Our global society releases massive amounts of waste
gases as by-products of its
energy, industrial, and agricultural processes.
Compliance with environmental regulations is costly. Non compliance
results in fines, more costly.
The Problem:
Food Processing Plant Coal Mine
Dairy or Poultry Farm WasteWater Treatment Plant
Ethanol Plant
Oil & Gas
Landfill
Coating & Printing
Sources of Low BTU waste gases
Existing solutions destroy gases and do not use them productively
Direct-Fired Open Flare
Regenerative
Thermal Oxidation Scrubbers Venting
Packed Bed
Ventilation Air
Methane
Acids Gas
Why do Industries not use their waste gases?
…because combustion limits us!
For over 250 years, our industries have
used and improved combustion-based
processes to convert fuels into energy.
We have more power with more fuel
efficiency, BUT combustion does not
work on the poor quality gases
produced as by-products from
industries.
Gradual Oxidizion generates clean power from these waste gases…
• Preventing and reducing emissions
• Generating electricity and heat to be used in an industrial process
The Solution:
Oxidation: A Natural Process Oxidation occurs when a substance comes into contact with oxygen molecules—almost everything, over time, reacts with oxygen… However oxidation can be a very slow process.
Ener-Core’s accelerates the
oxidation of methane to 2-3 seconds!
Methane (in atmosphere) 10-20 years
Sterling Silver
2 weeks
Banana 5-7 days
Ener-Core 2-3
seconds!
Gradual Oxidation is different than Combustion
Operating Temperature
Range Reaction Time Pollution
Open Flame 2700°F+ Very Short
(milliseconds) Worst
Lean Combustion 2400°F+ Very Short
(milliseconds) Medium
Flameless Combustion
2200°F+ Very Short
(milliseconds) Low
Gradual Oxidation Below 2200°F
Long (seconds)
Near Zero
Combustion is burning of high quality fuels, a flame with intense heat and associated pollution Oxidation is different:
• A lower temperature, slower process than combustion • Distributed reaction at very low fuel concentrations • Long reaction time allows releasing all heat and chemical energy from fuel • No flame; no pollutants
A Unique Technology for Power Generation
Power Cycle
Turbine
Inlet Air
Generator
Direct InjectConfiguration
Fuel Input
Power to Grid
Recuperator
Compressor Turbine
Exhaust
Heat Recovery
Aspirated Configuration
Fuel Input
Gradual Oxidizer
Ener-Core’s Gradual Oxidizer
Major Components of the Solution
Bespoke Interface
Source of Low-
Quality or Off-Spec
Gas
Conventional Gas Turbine (modified
for external combustion)
AC Generator
Turbine Package
Major Components of Ener-Core Powerstation
Oxidizer
Oxidizer Piping
Main Pipe Support
Exhaust Stack
Gas Turbine
Generator Braking Resistor
Fuel Control System
Mounting Skid
Ener-Core Provides Two Powerstations
KG2-3GO
• Paired with a Dresser-Rand KG2-3G turbine
• Electrical output 1,850 kW • Fuel operating range 0.93 - 97
MJ/m3 (25-2,600 BTU/scf) • Emissions <1 ppm NOx
FP250
• Paired with a Flex Energy MT250 turbine
• Electrical output 250 kW • Fuel operating range 0.55 -
97 MJ/m3 (15-2,600 BTU/scf) • Emissions <1 ppm NOx
Recuperated and Simple Cycle The simple cycle option does not have a recuperator and is therefore less efficient (i.e. consumes more fuel). This system is preferred in situations where useable heat output is preferred
Air Inlet
KG2-3G Gas
Turbine
Exhaust Silencer
Recuperator
Gradual Oxidizer
Simple Cycle KG2-3GO (w/o Recuperator)
KG2-3GO with Recuperator
Oxidizer Filter
FP250 Technical Specifications
Attero Landfill – Schennin, Netherlands • Closed landfill with below 30% methane; past problems with reciprocating engines running inconsistently • First Commercially sold unit • 250kW system was successfully installed and is currently operating • Has accrued over 1000 hours since commissioning in 2014
FP250 at Schennin Landfill
Capital Cost for 2 MW Powerstation: - $5.2 Million Annual Electricity Savings: + $1.1 Million Annual Gas Savings: + $750K Avoided Cost of Emissions Destruction Equipment: + $500K Payback without equipment financing: 3-4 years Economics with equipment financing: cash-flow positive in 1st year
Waste Gas
Industrial Operation
Electrical Consumption
Fuel Required
Ener-Core Powerstation
Heat
Electricity
Typical Project Economics
P.O. Box 583 Hampton, NH 03843 Phone: (603) 929-0769 Fax: (603) 929-0727 E-Mail: [email protected]
Many Benefits of Waste Heat Recovery
•Fuel Savings = Increased profits
•Efficiency gain
•Reduced greenhouse gas Emissions
•Recovery of substantial amounts of water from flue gas (condensing)
•Reduced thermal emissions
•Increased plant capacity
•Positive plant image
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