Recycling of Cleaning Fluids to Meet Green Cleaning Process Targets By Steve Stach Austin American Technology
Setting recycling targets? Paying for recycling? What can be recycled? Review of the 4 basic types of fluid recycling
Absorption Distillation Filtration Replenishment
Estimating the cost and saving Estimating system life Cost Model review
Government Regulations Few direct mandates Significant cost/liability regarding waste;
i.e. generation, storage, transportation, disposal
Corporate Directives Avoid liability by not generating
Cut manufacturing expenses Marketing “Green Manufacturing” sells product
Water Saving – up to 99% reduction Chemical Savings – 50-99% reduction Energy Saving – 10-50% reduction Waste Disposal – 50-90% reduction
Water
Just about everything!
Tap, DI
Water Mixtures, Neutral pH Buffered aqueous mixtures
Water Mixtures, Alkaline
Emulsions, Homogenous mixtures
Organic, nonflammable Halogenated solvents
Organic, combustible Glycols, oils, esters
Organic, Flammable Alcohols, light hydrocarbons
1. It depends on the Solvent 2. It depends on what is happening in the solvent?
Alkaline/Saponifier Water/Emulsion Organic Solvent
Reacting w/Soils Accumulating Soils Evaporation
Identify & Understand Your Recycling Method Recycling System Choices Recycle Method
Used with
Waste stream
Waste disposal handler
System Complexity level
Safety concern
Chemical addition
Reactive Aqueous Mixtures (saponifiers)
Soil loaded tank dump
Company
Technician
Medium
Ion Exchange
Rinse water Alcohols Glycols Esters
Depleted DI resins
Third party
Operator
Low
Carbon Adsorption
Rinse water
Carbon media with organics
Third party
Operator
Low
Zeolite Absorption
NPB CFC’s HCFC’s
Zeolite with adsorbed contaminate
Third party
Operator
Low
Chelation
Water with heavy metals
Chelation media with heavy metals
Third party
Operator
Low
Distillation
NPB CFC’s HCFC’s
Non volatile residues
Company
Technician
High
Filtration
All fluids
Filters with contaminate
Company
Technician
Medium
Reverse Osmosis
Rinse water
Reject fluid stream
Company
Technician
Medium
Cleaning/Rinsing Agent
Adsorption
Distillation
Filtration
Replenish Ingredient
Water Only
Recommend for high purity
Rarely Used
Recommended for General use
Not Used
Water + additive, Neutral pH
Not Used
Not Used
Recommended for General use
Recommend
Water Alkaline
Not Used
Not Used
Recommended for General use
Recommend
Organic Non-flammable
Used
Recommend
Recommended for General use
Not Used
Organic Combustible
Recommend
Used
Recommended for General use
Not Used
Organic Flammable
Recommend
Used
Recommended for General use
Not Used
H2O IPA
NPB
Key Ingredient Replacement Common in aqueous mixture to replace drag out
or reactive losses ▪ Saponifing agents ▪ Degreasing stabilizers
Filtration Use of filters to remove soils
Distillation Removes contaminates with higher boiling points
Absorption Use of Carbon, DI resins, Zeolites and other Media to Adsorb contaminates
One of the oldest recycling methods Configuration Cartridge, Bag, Plate, Cake
Filter Size 1to10 micron typical
Design Type Mono or Multi-Filament Absolute vs Standard
Recommended uses Used in most closed or open loop cleaning systems
Boiling fluid is vaporized and condensed
High boiling soils are left behind for disposal
Recommended for nonflammable, single solvents or azeotropic solvent blends
Not usually recommended for water or flammable solvents
Ionic soils are captured by ion exchange resins
Cations (Na+, K+,NH3+) are removed by cationic exchange resins
Anions (OA-, Br-,CO3-) are removed by anionic exchange resins
Mixed Beds remove both Anions and Cations
Recommended for purifying water and most organic solvents
Not recommended for solutions containing amines
RO is most commonly used for feed water generation to closed loop cleaners RO typical removed ~90% of dissolved solids from tap water
Molecular sized microscopic pores block large molecules and allow smaller molecules to pass
Absorptive medias capture metal ions Cations (Pb+2, Ag+2,Cu+2) are captured by cationic exchange resins GAC can do the same Use new GAC and DI media or find regenerator with metal cheatlation system
A molecular sieve traps molecular soils in microscopic pores. Naturally occurring materials are referred to as zeolites Man made materials are called molecular sieve. Molecular sieve comes in different pore sizes ranging from 3 to 12 angstrom Commonly used as a desiccant Available in round or extruded pellets
Useful in removing water, flux residues, and most ions from organic cleaning solvents
35X
700X
4,500X
Molecular Sieve filters to remove contamination from Degreasing Solvents Organic solvents
Organic soils are captured by Granular Activated Carbon (GAC)
Works on basis that “Like attracts Like”
Capacity depends on the molecule
Often used in conjunction with DI closed loop systems Carbon Exhaustion Foams Rinse
GAC is made by anaerobic heating organic material to drive off all volatiles Most GAC is acid washed to remove acid soluble impurities Coconut shell and anthracite coal are two type that product low powdering GAC can be partially regenerated by steam stripping – not recommended
Compound
Mole Weight
Water Solubility %
Adsorption g soil/ g GAC
Adsorption % reduction
2-ethyl butanol
102.2
0.43
.170
85.5%
Mono-ethanol amine
61.1
∞
.015
7.2%
Di-ethanol amine
105.1
95.4
.057
27.5%
Nitro-benzene
123.1
0.19
.196
95.6%
Butyric acid
88.1
∞
.119
59.5%
Ethylene glycol mono butyl ether
118.2
∞
0.112
55.9%
Test solution1g/liter
Mass Balance analysis looks at all materials entering and leaving the cleaning process. Shows where you are loosing or gaining fluids/ingredients
Fluid Feed, Make-up
Parts
Mist-Evaporative And Drag-Out Losses
w/soils
Fluid Tank
Recycling System
Waste
Cleaning System
Cleaning Fluid With Soils Sewer or Disposal
Vent
Dry FilterMΏ GAC Mixed Carbon
Turbine
Rinse 1g/m
1g/m
Wash
The impact of the recycling location
The impact of the recycling location
Chem pump MΏ GAC Filter Mixed Turbine Carbon ~25gallons 1g/m 1g/m
In Situ (in the cleaner)
Plant System (in the factory)
Third party (bonded & licensed)
The Local Sewer Plant Check with local water authorities A permit may be requires
The DI Guy What materials do they use? ▪ Source, new or regenerated? How do they dispose of the waste?
Solvent Recycler/Disposal Use EPA licensed & bonded company Cradle to grave responsibility
Indep
Process Data
Inline Open Loop
Closed Loop Central System
Varib
Equipment cost
$200,000
$200,000
$200,000
DI system system cost
$25,000
$35,000
$5,000
Shipping
$5,000
$5,000
$4,000
Water consumption rate gph (operating)
300
10
10
Cost of water $'s/gal
$0.01
$0.01
$0.01
Cost to regenerate DI (1.5Ft3)
$300.00
$500.00
$500.00
Water purity (dissolved solids) mg/gal
250
20
20
Final rinse rate GPM
5
5
5
Power cost $s/Khr
$0.10
$0.10
$0.10
Operating KW (KV*A)
100
110
75
Inline Cleaner Cost Model
7
year equipment amortization
6
Run time per Shift
300
In Situ Closed Loop
Shifts per year Process Costs ($'s/hr) Absorbtive capacity (mg CaCO3 or Succinate) Bed Life (hrs of operation)
1,680,000
7,900,000
7,900,000
3.7
219.4
219.4
Depends on the Ion
Molecular weight & valance
Tank Absorptive Capacity (Abtotal) Bed Volume (Vab) Absorptive Capacity (Abcap) (Abtotal) = (Abcap) X (Vab)
US map showing water hardness
Contamination Feed Rate Mass Flow Rate (MFrate) Bedlife = (Abtotal / MFrate)x %factor*
* %factor is % available in begining + % remaining at exhaustion
Inline Open Loop Annual Cost of beds OL DI, CL DI+GAC
Closed Loop Central System
In Situ Closed Loop
$144,642.86
$4,101.27
$4,101.27
$80.36
$2.28
$2.28
$3.00
$0.10
$0.10
Power costs/hr
$15.00
$16.50
$11.25
Total Power and water cost $/hr
$98.36
$18.88
$13.63
Equipment Amortization cost per hr
$16.43
$17.14
$14.93
$114.79
$36.02
$28.56
Hourly Cost of beds Hourly cost of tap water
Total Equipment + Water + Power ($/hr)
Saves $85/hr
All cleaning solvents can be recycled There are many methods of recycling Your clean solvent guides you recycling method
Government and industry are driving recycling Cost and environmental benefits provide the rewards for conversion The savings are easy to estimate with a good mass and energy balance diagram
The location of the recycling system can affect cost. In situ recycling is the most cost effective
If you are not recycling your cleaning fluids, you should be!
"Cleaning Fluid Recycling Options for Green Manufacturing” by
Steve Stach
Thank You for Attending Questions ?
