1999 NH Pollution Prevention Program
Final Project Report
Intern:Greg GriffinHome: 603-778-1025
9 Vine StreetFax: 603-778-1025
Exeter, NH
Facility:HADCO Corporation
Tech Centers East
Rogers Road
P.O. Box 8240
Ward Hill, MA 01835
Contact:David Unger
E.H.S. Manager
Tel: (978) 556-6283
Fax: (978) 556-6400
EXECUTIVE SUMMARY
There are essentially five major projects that I have undertaken this summer. The first involves using Eco-Tec’s MicroPur acid purification system to recycle some of the nitric acid in the outerlayer stripper. The second project is using a RenoCell® from PAL Sales Inc. to recover the metal in the MicroPur’s waste stream. The third is using Lewis Environmental Services’ Enviro-Clean process to recycle some of our rinsewater. The fourth project is electrodialysis of electroless copper using equipment from J&M Associates. Tracking chemistry usage to make sure none is being wasted is the fifth and final project.
INTRODUCTION/BACKGROUND
Presently, 4840 gallons of solder stripper are used every year at a cost of $33,638. The spent solder stripper is currently treated on site at a cost of $9314.59/yr plus $2785.22 in waste disposal charges. Also, the present waste treatment of spent solder stripper generates lead in Tech East’s WWT sludge.
The MicroPur acid purification system by Eco-Tec is simply a packed bed filled with ion exchange resins which sorb strong acids but are unreactive to metallic salts of those acids in a waste stream. Acids are readily desorbed from the resins allowing for regeneration of the bed with water and recovery of the acid. The system has been successfully applied in over 500 installations worldwide. The manufacturer has estimated that a recovery of 95% of the nitric acid is possible.
RenoCell® uses a revolutionary three-dimensional porous carbon element to recover metals in elemental form through electrowinning. While the resin sorption unit recovers most of the nitric acid, electrowinning using a RenoCell® may be able to recover the rest. Electrowinning using a RenoCell® from PAL Inc. has the potential to remove lead from the MicroPur Acid Purification system waste stream, eliminating its discharge.
The Enviro-Clean process uses a activated granular carbon packed bed to physically remove metals from wastewater. The carbon is regenerated off site. It has the potential to recycle a large amount of wastewater.
The Electrodialysis unit uses a series of alternating concentrate and diluate cells to remove waste salts from the electroless copper-plating bath. This technology has been applied to numerous electroplating baths in the past.
GOALS/OBJECTIVES
First and foremost, a goal common to all of the projects is to decrease fresh chemistry usage, be it solder stripper, water or electroplating solution. In doing this there will be a corresponding decrease in the amount of chemicals needed for waste treatment. Less lead containing sludge and a decrease in waste disposal cost are other results.
APPROACH/METHODOLOGY
The first step was to determine the composition of the waste streams that were candidates for recycling. This information was then provided to vendors. After quotes were received, a cost analysis was performed. Wherever possible, bench scale units were obtained and evaluated.
CHEMICAL USAGE, EQUIPMENT NEEDS
The MicroPur Acid Purification System will be purchased through Eco-Tec. PAL Sales Inc. has provided us with a bench scale RenoCell® to evaluate. Most probably a RenoCell® will be purchased from them. J&M Associates has provided a pilot Electrodialysis unit for our evaluation. Lewis Environmental Services has been contracted to provide an Enviro-Clean pilot test unit and run it our waste treatment line for a few days.
There is no new chemical usage as a result of any of the aformentioned projects.
RELEASES/WASTES GENERATED AT THE FACILITY
It is not foreseeable that any of these projects will result in any new releases or wastes generated at the facility. To the contrary, releases and wastes will theoretically both be reduced.
DETAILS OF WORK ACCOMPLISHED/ PROJECT RESULTS
The MicroPur acid purification system has been sized and is being purchased.
The RenoCell® pilot scale unit was run from August 6 to August 9. A 1:1 mixture of spent solder stripper and DI water was circulated through the system. As suspected, the results were discouraging due mostly the corrosive nature of the solution. The results can be found below. A sample of spent solder stripper has been sent to Renovare so that they can determine the best way to treat it. The waste stream from the MicroPur acid purification system, on the other hand, is a good candidate for metal reclamation with this technology.
The pilot scale electrodialysis unit was run on several occasions, but the composition of the treated samples is not yet available.
The 10-gallon sample that was sent to Lewis Environmental Services was treated with a 1 gallon per minute unit at their facility. The copper, lead and nickel in the treated sample were all well below the permissible discharge limits.
POLLUTION PREVENTION BENEFITS
The only project that is true pollution prevention is the tracking of chemistry usage. While the other projects are not necessarily pollution prevention per se, they all represent beneficial waste reduction measures:
Reduction in amount of fresh chemistry needed.
Reduction in usage of waste treatment chemistry.
Reduction in waste disposal costs.
Removal of lead from sludge.
Increased value of sludge.
RECOMMENDATIONS FOR FUTURE EFFORTS
Based on the current operating conditions, the MicroPurΤ/ RenoCell® combination is quite cost effective. Potential savings assuming a 75% recovery of the nitric acid and 100% recovery of the metal can be found below.
Eco-Tec MicroPur Unit:
Recovery:
95% of the free acid with 46% of the metal removed
Current chemical usage
16.13 gallons of chemistry as makeup every day
Potential chemical usage savings based on 75% acid recovery:
0.75 * $6.95/gal * 16.13 gal/day = $84.08/day
$25,475.52/yr
Note:The addition of a proprietary agent may be necessary, which will decrease this savings.
Current waste treatment of spent solder stripper:
16.7 gallons of 50% NaOH for 50 gal of spent stripper
Potential waste treatment savings based on 75% acid recovery:
0.75 * 16.7/50.0 * 16.13 gal/day * 3.786 L/gal * 15.220 kg/L * $0.1/kg NaOH = $23.28/day
$7,054.72/yr
Potential waste disposal savings:
$0.19 worth of sludge for every liter of spent solder stripper
0.75 * .19/.35 * $0.19/L * 16.13 gal/day * 3.786 L/gal = $4.72/day
$1,430.39/yr
Total savings:$25,475.52
$7,054.72
$1,430.39
$33,960.63/yr
RenoCell® Unit:
Recovery:
Assuming an 100% recovery of the metals in the MicroPur waste stream:
50 g/L * 3.786 L/gal * 16.13 gal/day * 0.001 kg/g * $1.00/kg = $3.06/day
$925.14/yr
This would represent an additional savings as far as waste disposal:
0.75 * .16/.35 * $0.19/L * 16.13 gal/day * 3.786 L/gal = $3.98/day
$1205.94/yr
Total savings: $925.14
$ 1205.94
$2,131.08/yr
Total savings of both projects = 33,960.63 + 2,131.08 = 36,091.71/yr
Total price of equipment = $52,500
Simple payback period = 52,500/36,092 = 1.45 years
Enviro-Clean process:
All told, the Enviro-Clean process represents a yearly saving of $48,420. The IRR is 24%, which is above the 15% requirement for discretionary projects.
Based on the above financial figures, the MicroPur/ RenoCell® combination and the Enviro-Clean process are both quite cost effective and worth pursuing. Actually, both the MicroPur and the Enviro-Clean process are scheduled to be purchased and implemented in the coming months.
APPENDICES
Jim Jablonsky
J & M Associates
1610 Hedgewood Road
Hatfield, PA 19440-2146
Tel: (215) 368-6822
Fax: (215) 362-0413
Paul Pajunen
Eco-Tec Inc.
1415 Squires Beach Rd.
Pickering, Ontario L1W 3T9
Tel: (905) 427-0077
Fax: (905) 427-4477
Lou Guertin
PAL Sales Inc.
145 Flanders Road
Bethlehem, CT 06751
Tel: (203) 266-7616
Fax: (203) 266-7614
Paul Fecsik, CEF
Hughes Missile Systems Company
Bldg. 826, Old Nogales Highway
Tucson, AZ 85735
Tel: (520) 794-4105
Fax: (520) 794-9463
Tom Lewis, III
Lewis Environmental Services, Inc.
550 Butler Street
Etna, PA 15223
Tel: (412) 799-0959
Fax: (412) 799-0958
George Kniazewycz
Tel: (925) 945-7576
Fax: (925) 945-0131
Ben Quarles
Commercial Manager
MacDermid Incorporated
245 Freight Street
Waterbury, CT 06702
Office & Fax: (978) 456-3570
Pager: (800) 838-9785