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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 Solvent 2. It depends on what is happening in the solvent? Alkaline/Saponifier Water/Emulsion Organic Solvent Reacting w/Soils Accumulating 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 Feed, Make-up Parts Mist-Evaporative And Drag-Out Losses w/soils Fluid Tank Recycling System Cleaning System Waste Cleaning Fluid With Soils Sewer or Disposal Identify & Understand Your Recycling Method 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 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 Organic Non-flammable Used Recommend Used Not Used H2O IPA Cool Prec. Recommend NPB Organic Combustible Recommend Used Used Not Used Organic Flammable Recommend Used Used Not Used 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 nonflammable, 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 FilterMΏ GAC Mixed Carbon Turbine 1g/m 1g/m 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 Incoming Tap/RO water Feed to fill tanks Initial and Make-up Operational .Flow @120F= 3gal/hr estimated Dryer DI Rinse Power Rinse Chem Isolation Wash Chem pump Filter MΏ GAC Carbon Mixed Turbine High Alarm High Alarm Add Add Low Alarm Low Alarm 1g/m 1g/m ~25gallons ~40gallons Gravity Drain Inline Cleaner - closed loop wash and Rinse Back View - Plumbing diagram 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? 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) 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 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) ?????????? ???????? ???????? 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 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 Building the Cost Model 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 Cleaning Cost Estimates 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) 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 Attending Questions ????????