Advanced Wastewater Treatment Technology Mechanical Vapor Recompression and Membrane Polishing Presented to 10 th Annual Chemical Management Services Workshop San Francisco, California John Burke Director of Engineering Services Houghton International Page 1
Introduction What is this new wastewater treatment technology? How does it fit within an existing manufacturing facility? How does each step work, and work together? Cost Comparison Advantages to Chemical Managers Summary Page 2
Basic Issue With Wastewater Treatment Manufacturing Facility Wastewater Aluminum Processing Facility Wastewater Treatment Waste Water Treatment System One waste stream becomes two waste streams Two Waste By-products Waste- Water Both are Regulated Used Oil Sludge Cost To Discharge Cost To Haul Page 3
Advanced Waste Treatment Makes Sense Manufacturing Facility Wastewater Fluid Recycling System Two commodity Byproducts Water For Re-use A WWT Only one is Regulated One waste stream becomes two commodities. Used Oil For Sale Page 4
Design Objective Treat any oil-like liquid, both water dilutable and not, such as from aluminum metalworking fluids, detergents and similar process fluids Separate the water phase for re-use Separate the oil-like phase for sale. Oil-like materials can be from mineral, vegetable and animal origin. Why? Economic benefits One less regulatory issue to worry about. Improves environmental image, both internally and externally Page 5
Increasing Solubility What are Some of the Contaminants in Aluminum Metalworking Wastewaters? Hydrocarbon Products (Floatable, Suspended / emulsifiable, and Settleable Organics) Petroleum Oils, Vegetable Oils, Animals Oils, Waxes, Fatty Acid Soaps (Ca, Fe, Al), Chlorinated Esters and Paraffins Floatable, Suspended, and Settleable Solids Graphite, Vibratory Debur, Floor Dirt Metals Iron, Aluminum, Copper, Lead, Chrome, Zinc, Nickel, Manganese, Molybdenum Non-metals Arsenic, Selenium Dissolved Solids Salts (Sodium and Potassium Salts) Dissolved Organics Amines, Amides, Esters, Glycols, Surfactants, Detergents, Fatty Acids, Fatty Alcohols, Antimicrobials, Phosphate Esters Page 6
Common Treatment Approaches Chemical treatment Salt Splitting Polymer with / without salt splitting Membrane Separation Ultrafiltration Microfiltration Combined Technologies Chemical / Biological Membrane / Biological Membrane / Biological / Membrane Membrane / Membrane ( UF/RO or UF/NF) Page 7
Issues With Common Treatment Approaches Chemical Inflexible on various wastes Requires skilled Operator Creates salts within the process Membrane (single) Membrane sensitive to fouling Salts and metals pass through membrane Biological Not every chemical is readily biodegradable Industry is moving toward bio-stable chemistries Combined Technologies Issues are generally compounded, not reduced High Reject rates Page 8
Product Rate to Reject Rate Manufacturing Facility Wastewater Wastewater Treatment Two Waste By-products Aluminum Processing Facility Waste Water Treatment System Product 98% Reject 2% Waste- Water Used Oil Sludge Page 9
So What is Mechanical Vapor Recompression? 1. Distillation, Followed by 2. Mechanical Compression of the Distillate 3. Recovery of the Heat into the Boiling Zone 4. Condensing of the Vapor HEAT Compressor Mechanical Vapor Recompression Heat Exchanger HEAT Output (Warm Condensate) HEAT Page 10
Conventional Distillation /Condensation Model Vapor Input Boiling Vessel Heat Exchanger Heat Removed Cold Water IN Warm Water Out Heat Added Heat Removed Output (Warm Condensate) Page 11
Conventional Mechanical Vapor Compression Distillation Model Vapor Vapor Compressor More Heat Added Input Boiling Vessel Heat Recovered Heat Exchanger Heat Added Heat Removed Output (Warm Water Condensate) Page 12
Current Technology Basic Thermal Evaporation Purpose: Concentrate waste by evaporating water using thermal energy Page 13
Basic Thermal Evaporation Two forms of energy required to boil water: a. Raise water to boiling ( 212 Degrees F ) Sensible heat ( 1 BTU required to raise one pound of water one degree F) b. Turn water into steam at 212 degrees F ) Latent Heat (960 BTUs required to turn one pound of water at 212 degrees F into steam vapor at 212 degrees F) Page 14
Basic Thermal Evaporator Model 960 BTUs/ to turn one pound of water into vapor ALL LATENT HEAT LOST HEAT 50% Overall Process Efficiency = 50% VAPOR Vapor Zone Wastewater LOST HEAT 50% Wastewater - in HEAT 100% Concentrated Wastewater - out Page 15
Basic Mechanical Vapor Compression Evaporator Model HEAT Vapor Zone VAPOR Wastewater Wastewater in HEAT Page 16
Basic Mechanical Vapor Compression Evaporator Model HEAT Vapor Zone VAPOR Wastewater Wastewater in HEAT Page 17
Basic Mechanical Vapor Compression Evaporator Model HEAT Blower or Fan (Compressor) More heat added VAPOR Vapor Zone Wastewater Wastewater in HEAT Page 18
Basic Mechanical Vapor Compression Evaporator Model Vapor Zone Wastewater HEAT VAPOR Reclaimed Heat (Latent) Blower or Fan (Compressor) More heat added Heat Exchanger #1 Condensed Vapor (hot) Wastewater in HEAT Page 19
Basic Mechanical Vapor Compression Evaporator Model HEAT VAPOR Blower or Fan (Compressor) More heat added Heat Exchanger #1 Vapor Zone Wastewater Reclaimed Heat (Latent) Condensed Vapor (hot) Heat Exchanger #2 Wastewater - in Reclaimed Heat (Sensible) HEAT Condensed Vapor out (warm) to Ultrafilter Page 20
Basic Mechanical Vapor Compression Evaporator Model HEAT VAPOR Blower or Fan (Compressor) More heat added Heat Exchanger #1 Vapor Zone Wastewater Reclaimed Heat (Latent) Condensed Vapor (hot) Heat Exchanger #2 Wastewater - in Reclaimed Heat (Sensible) HEAT Condensed Vapor out (warm) to Ultrafilter Page 21 Concentrated waste Oil / water - out
Output (Hot Vapor) VAPOR HEAT HEAT Compressor Conventional Evaporation Mechanical Vapor Recompression Heat Exchanger HEAT HEAT Output (Warm Condensate) 960 BTUs/ to turn one pound of water into vapor 1 BTUs to raise one pound of water one degree Fahrenheit Page 22
Cost Comparison Conventional Evaporation VS. Mechanical Vapor Recompression Energy Required to Treat 1,000 Gallons of Oily Wastewater Conventional Evaporation @ 50 % Efficiency Mechanical Vapor Recompression As Measured 15,936,000 BTUs 920,833 BTUs (16.2 X less energy) Page 23
Page 24 Lab Test Evaporation / Condensation Unit
Page 25 20 Gallon Per Minute Unit
Page 26 Influent Feed Pump
Page 27 Primary Heat Exchanger
Page 28 Secondary Heat Exchanger
Page 29 Recirculating Pump
Progressive View of Sample Concentration Less than 1% oil 80% oil Page 30
Starting Sample Concentrate from MVR 99.7 % Volume Reduction Salable Oil Page 31
Treatment Process Steps 1. Storage and flow equalization 2. Emulsified oil, most soluble organics, metals, and fine solids separation (Mechanical Vapor Recompression Distillation System) 3. Trace insoluble organic separation ( Ultrafilter System) Page 32
Overall Flow Schematic Water Return water to Manufacturing Processes Virgin Lubes, Chemicals, Etc. Evaporative Losses Manufacturing Processes Rolling oils, washers, etc. Industrial Wastewater From Plant Primary Wastewater Storage Day Tank Mechanical Vapor Recompression System MVR Oil Reject Day Tank Ultrafilter U F Day Tank Dilute Oil Reject Tank Tank Decant water Used oil - out Page 33
Basic Ultrafilter Model - Flow Schematic Treated Effluent Permeate Wastewater (influent From MVR 10 PSI For Re-use Concentrate Membrane Surface Day Tank Clean Tank 120 o F Ultrafilter 45 PSI Feed Pump Pump To Oil Reject Tank Page 34
Page 35 Ultrafilter 50 Gallons Per Minute
Starting Sample Condensed Distillate From MVR Polished Sample After Ultrafilter Page 36
Design Objective Must Meet the The Basic Requirement 1. Does it fit with the Personality of the Organization? All Mechanical System No Chemicals (Defoamer, UF Detergent) Industry Common Components Blowers Pumps Heat Exchangers Automatic Valves Steam Traps Easily Automated Easy to Trouble Shoot Energy Efficient Page 37
System Performance Influent Effluent BOD5 5,000 10,000 200-400 COD 20,000 35,000 400-650 Oil and Grease 500 _ 5,000 < 10 TPH 250 3,500 < 5 TKN 200 400 < 20 TDS 5,000 10,000 < 20 TSS 3,000 6,000 < 0.1 Fe 300 < 0.01 Zn 15 < 0.01 Cu 5 < 0.01 Pb 2 < 0.01 Ni 1 < 0.01 ph 8.0 8.8 7.0 7.5 Page 38
System Performance Operating Cost Comparison Cost ( $ USD) / 1000 US Gallons Method Chemicals Electricity Total Chemical Methods NOR $ 4.00 $ 1.00 $ 5.00 WOR $ 5.00 $ 2.00 $ 7.00 WOR+ ATR $ 5.05 $ 5.50 $ 10.55 Product / Reject Ratio 65 / 35 Membrane Methods NOR $ 0.50 $ 2.50 $ 3.00 WOR $ 1.50 $ 3.50 $ 5.00 WOR+ ATR $ 1.55 $ 7.00 $ 8.55 Product / Reject Ratio 70 / 30 MVR/ UF WOR + ATR $ 0.00 $ 4.00 $ 4.00 Product / Reject Ratio 99 / 1 Page 39 NOR = No oil recovery WOR= With Oil recovery ATR = Ability To Recycle Water phase back into the process Energy cost assumed at $ 0.05 / kilowatt-hour
Benefits to Chemical Managers Allows the use of more complex metalworking fluids and detergents. Can be applied where water is scarce Can be applied where discharge to local sewer is restricted Can be added on to existing treatment (only MVR required?) Turns oil into a commodity (adds value). Easily Automated. Page 40
Advantage Summary One waste stream becomes two commodities. Water For Re-use A WWT One waste stream becomes two commodities. Used Oil For Sale Page 41
Thank You Contact Information John Burke Houghton International 27181 Euclid Ave. Cleveland, Ohio 44094 USA Office Phone 216-289-3991 Cell Phone 216-235-1995 Fax Phone 216-235-3991 Email jburke@houghtonintl.com Page 42