In Situ Recycling of Cleaning and Rinsing Fluids to Meet Lean and Green Cleaning Process Targets

By Steve Stach

President Austin American Technology

Outline

• 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

Setting Cleaner Recycling Targets

• 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

Potential Savings

• Water Saving – up to 99% reduction

• Chemical Savings – 50-99% reduction

• Energy Saving – 10-50% reduction

• Waste Disposal – 50-90% reduction

What Cleaning Fluids Can be Recycled?

Just about everything!• Water

– 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

Choosing the Right Recycling Technology

1. It depends on the Solvent2. It depends on what is happening in the solvent?

Alkaline/SaponifierWater/EmulsionOrganic Solvent

Reacting w/SoilsAccumulating Soils

Evaporation

Getting StartedLook at your “Mass Balance”

• Mass Balance analysis looks at all materials entering and leaving the cleaning process.

• Shows where you are loosing or gaining fluids/ingredients

Cleaning Mass Balance Diagram

Fluid Tank

Recycling System

CleaningSystem

Waste

Fluid Feed,Make-up

Mist-EvaporativeAnd Drag-Out Losses

w/soils

Parts

Cleaning Fluid With SoilsSewer or Disposal

Recycle Method

Type Used with Waste stream Waste disposal handler

System Complexity

level

Safety concern

Chemical addition

Additive

Key Ingredient

1) Reactive

Aqueous

Mixtures

(saponifiers)

Soil loaded tank dump

Company Technician Medium

Ion Exchange Subtractive

Adsorption

Rinse water

Alcohols

Glycols

Esters

Depleted DI resins

Third party Operator Low

Carbon Adsorption

Subtractive

Adsorption

Rinse water Carbon media with organics

Third party Operator Low

Zeolite

Absorption

Subtractive

Adsorption

NPB

CFC’s

HCFC’s

Zeolite with adsorbed contaminate

Third party Operator Low

Chelation Subtractive

Adsorption

Water with heavy metals

Chelation media with heavy metals

Third party Operator Low

Distillation Subtractive

Distillation

NPB

CFC’s

HCFC’s

Non volatile residues

Company Technician High

Filtration Subtractive

Filtration

All fluids Filters with contaminate

Company Technician Medium

Reverse Osmosis

Subtractive

Filtration

Rinse water Reject fluid stream

Company Technician Medium

Identify & Understand Your Recycling Method

Cleaning Fluid Recycling Choices

Cleaning/Rinsing Agent Adsorption Distillation Filtration Replenish Ingredient

Water Only Recommend Not Used Used Not Used

Water Neutral Not Used Not Used Used Recommend

Water Alkaline Not Used Not Used Used Recommend

Organic Non-flammable Used Recommend Used Not Used

Organic Combustible Recommend Used Used Not Used

Organic Flammable Recommend Used Used Not Used

H2OIPA

CoolPrec.

NPB

Additive Recycling Technologies

• Key Ingredient Replacement– Common in aqueous mixture to replace

drag out or reactive losses• Saponifing agents• Degreasing stabilizers

Subtractive Recycling Technologies

• 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

Fluid Filtration

• 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

Fluid Distillation• Boiling fluid is vaporized and

condensed

• High boiling soils are left behind for disposal

• Recommended for non-flammable, single solvents or azeotropic solvent blends

• Not usually recommended for water or flammable solvents

Ion Exchange• 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

Carbon Absorption• 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

Carbon Absorption

• 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

Carbon Absorption VS Compound

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

Closed Loop Inline Cleaning System

TurbineMixedGACCarbon

1g/m 1g/m

FilterMΏ

Reverse Osmosis (RO)

• RO is most commonly used for feed water generation to closed loop cleaners

• RO typical removed ~90% of dissolved solids from tap water

Reverse Osmosis

• Molecular sized microscopic pores block large molecules and allow smaller molecules to pass

Turbine

Gravity Drain

High Alarm

Add

Low Alarm

High Alarm

Add

Low Alarm

Inline Cleaner - closed loop wash and Rinse Back View - Plumbing diagram

Mixed

Dryer DI Rinse Power Rinse Chem Isolation Wash

GACCarbon

Chem pump

Incoming Tap/RO waterFeed to fill tanks

Initial and Make-upOperational .Flow @120F=

3gal/hr estimated

1g/m 1g/m

Filter MΏ

~25gallons ~40gallons

Problem Heavy Metals in DI/GAC media

• 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

Molecular Sieve Absorption

• 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

Molecular Sieve Absorption

• Useful in removing water, flux residues, and most ions from organic cleaning solvents

35X 700X 4,500X

Use of Molecular Sieve

• Molecular Sieve filters to remove contamination from– Degreasing

Solvents– Organic solvents

The impact of the recycling location

The impact of the recycling location

Here, There or Anywhere?

TurbineMixedGAC

Carbon

Chem pump

1g/m1g/m

FilterMΏ

~25gallons

In Situ(in the cleaner)

Plant System(in the factory)

Third party(bonded & licensed)

Off-site Treatment of Cleaning Materials

• 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

In-plant Recycling of Cleaning Fluids

• Distillation and Evaporation– Check with local air quality

authorities– A permit may be required

• Central DI Plant– What materials are use?

• Source, new or regenerated?

In Situ Recycling of Cleaning Fluids• Built in, or Next to the Cleaner

– No transfer logistics– Minimizes heat loss– Fewer Parts

• Local Control– Requires training

• Operator• Maintenance

• Costs less to Operate– Equipment costs less than stand

alone– Lowest operating costs

The Cost of Cleaning

Building the Cost Model

Indep Inline Cleaner Cost ModelProcess Data  Inline Open Loop

 Closed Loop Central System

 In Situ Closed Loop

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

7 year equipment amortization      

6 Run time per Shift      

300 Shifts per year      

  Process Costs ($'s/hr)      

  Absorbtive capacity (mg CaCO3 or Succinate) ?????????? ???????? ????????

  Bed Life (hrs of operation)

Capacity of Close Loop Absorptive Beds

• Depends on the Ion– Molecular weight & valance

• Tank Absorptive Capacity (Abtotal)– Bed Volume (Vab)– Absorptive Capacity (Abcap)

(Abtotal) = (Abcap) X (Vab)

Estimating the Life of Absorptive Beds

• Contamination Feed Rate

– Mass Flow Rate (MFrate)

Bedlife = (Abtotal / MFrate)x %factor** %factor is % available in begining + % remaining at exhaustion

US map showing water hardness

Building the Cost Model

Indep Inline Cleaner Cost ModelProcess Data  Inline Open Loop

 Closed Loop Central System

 In Situ Closed Loop

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

7 year equipment amortization      

6 Run time per Shift      

300 Shifts per year      

  Process Costs ($'s/hr)      

  Absorbtive capacity (mg CaCO3 or Succinate) 1,680,000 7,900,000 7,900,000

  Bed Life (hrs of operation) 3.7 219.4 219.4

Cleaning Cost Estimates

 Inline Open Loop

 Closed Loop Central System

 In Situ Closed Loop

  Annual Cost of beds OL DI, CL DI+GAC $144,642.86 $4,101.27 $4,101.27

  Hourly Cost of beds $80.36 $2.28 $2.28

  Hourly cost of tap water $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

 

Total Equipment + Water + Power ($/hr) $114.79 $36.02 $28.56

Summary

• Government and industry are driving recycling

• Cost and environmental benefits provide the rewards for conversion

• Cleaning mass balance analysis provides data to start

Summary

• All cleaning solvents can be recycled

• There are many methods of recycling

• Your clean solvent guides you recycling method

Summary

• Recycling reduces process costs

• The location of the recycling system can affect cost.

• In situ recycling is the most cost effective

Conclusions

• If you are not recycling your cleaning fluids, you should be!

“In Situ Recycling of Cleaning and Rinsing Fluids to Meet Lean and Green Cleaning Process

Targets”by

Steve Stach

Thank You for AttendingQuestions????????