The Science of Cleaning Green

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

Process Targets

By Steve Stach

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 Solvent

2. It depends on what is happening in the solvent?

Alkaline/SaponifierWater/EmulsionOrganic Solvent

Reacting w/SoilsAccumulating Soils

Evaporation

Getting Started

Look 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

Identify & Understand Your Recycling MethodRecycle 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

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 azeotropicsolvent 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

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 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

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

TurbineMixedGAC

Carbon

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

Mixed

Dryer DI Rinse Power Rinse Chem Isolation Wash

GACCarbon

Chempump

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

Chempump

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 beginning + % 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