The following case studies show how a range of industries have implemented projects or overall corporate strategies that profit from the synergies of energy efficiency, pollution prevention, process efficiency, and increased productivity.
AAP Saint Mary's
Aluminum Recycling
AAP Saint Mary's (AAP) produces original and after-market aluminum automotive wheels. The process takes raw aluminum ingots and melts, casts, machines, and polishes finished aluminum wheels. During the machining process, up to 40 percent of a wheel's aluminum is lost, resulting in 6,000 tons of aluminum shavings per year. Traditionally, these chips were trucked to a third-party recycler, who cleaned, re-melted and reformed them into ingots, which were returned to AAP where they were re-melted and reused.
With the help of Ohio Department of Development (ODOD) and a $300,000 grant from DOE's NICE3 program, AAP moved chip reclamation in-house, eliminating the need to transport and re-melt their waste aluminum chips. AAP's advanced furnace improves the recovery of aluminum and produces fewer pollutants than the equivalent off-site melting process.
Achievements:
- Reduced transportation and melting the aluminum once instead of twice reduces energy use by 15.6 billion Btus.
- Aluminum waste was reduced to 1.5 percent from the old process's 8 percent waste rate.
- Cuttings oils are now also recycled.
- Cost savings are $1.60 per wheel — more than $1.9 million per year — for a payback of around 18 months.
Contacts: Dan Hosek at AAP St. Mary's, or Susan Covey or John Greenway at ODOD
Source: DOE 1997
A. Finkl & Sons Co. is one of the largest custom die steel forgers in
the U.S., with $80 million in sales and 400 employees as of 1995. This fully
integrated steel production facility in Chicago produces die blocks for the
closed die forging industry, plastic mold and die casting die steels, custom
open die forgings, and forge shop and steel mill repair parts.
Finkl's long-term program to reduce costs and improve productivity include:
upgrading and computerizing equipment and building new, more efficient furnaces,
including a Vacuum Arc furnace, and solid-waste recycling. All of the steel
made is produced from premium scrap metal.
Achievements:
-
Energy use has declined 36 percent from 165 therms to 105 therms per ton.
-
99.7 percent of solid waste is reused or recycled.
-
Production efficiency (in terms of man-hours worked) has doubled.
-
Partly because of its success in pollution prevention and energy efficiency,
the City of Chicago and Finkl have created a new urban manufacturing campus
adjacent to an affluent residential neighborhood, preserving 10,000 jobs
in the city.
Source: DOE 1997
In response to rising fuel prices in the late 1970s, Anheuser-Busch looked
for ways to gain control over energy and other utility costs. The company
began exploring anaerobic treatment of organic nutrients in wastewater, in
which bacteria consume organic compounds under water, releasing biogas that
bubbles to the top of the tank. The biogas (mostly methane) is collected
and used for fuel (bio-energy recovery), and solid waste is reduced. In addition,
constructing and using a bio-energy recovery system requires less capital
and operating expenses than expanding conventional treatment facilities.
Anheuser-Busch plans to be using this process in eight of its facilities
by 2000.
Achievements:
-
The process produces a renewable source of energy that provides 10-15 percent
of a brewery's fuel needs.
-
The process reduces wastewater by about 80 percent, allowing municipal plants
that treat the remaining wastewater to use 80 percent less electricity to
accomplish this task, reducing emissions by 80 percent and enhancing regional
air quality.
-
Solid waste is reduced by 50 percent, freeing up capacity at local municipal
treatment plants, and increasing brewery capacity.
-
By the year 2000, it is estimated that eight facilities with bio-energy recovery
systems will save more than $40 million annually.
Contact: Bill Sugar, Anheuser-Busch, phone: (314) 577-3730
Source: Sugar 1997
Bowater
Inc.
Mechanical Vapor Recompression Heat Pump Recaptures
Steam
Bowater Inc., a Climate Wise
Partner, manufactures market pulp, newsprint, and coated magazine paper.
During the processing of green wood chips, which are half water and half
fiber, the water is converted to steam as the fibers are separated, processed,
and pumped to paper machines to be converted to paper stock. The company
wanted to capture the energy lost in this low-pressure steam it vented from
its seven thermomechanical pulping (TMP) refiner lines.
To convert the steam to energy, Bowater installed two mechanical vapor
recompression (MVR) heat pumps that efficiently converted the 19-psig steam
at 250oF to 57-psig steam at 470oF. The converted steam could then be used
to power the drying stage of the paper production operations. The MVR compressor
also has a turndown of 50 percent, allowing it to adapt to changing amounts
of steam, which optimizes energy use.
Achievements:
-
Annual energy savings of $1 million paid back the $1.5 million investment
in 1.5 years.
-
About 200 gallons of turpentine (a TMP byproduct) is recovered daily for
re-sale, reducing atmospheric emissions and providing additional income.
-
By preventing steam from escaping, 100 gallons of water per minute is saved,
which saves about $144 per day.
-
Controlling the steam vapor once it is released into the atmosphere reduces
the plant's noise level.
Contact: EPRI Pulp and Paper Office, Atlanta, Georgia, phone: (404) 853-9511
Source: DOE 1996
Chaparrel Steel Company
Waste Re-use
Each year, Chaparrel Steel uses more than 700,000 used cars as scrap in the
production of 1.6 million tons of steel, using electric-arc furnace technology.
The company generates wastes in the form of electric-arc furnace slag, mill
scale, and baghouse dust from its air pollution control systems. Because
the mill scale was rich in iron oxide, Chaparrel had no problem finding a
buyer for it. Chaparrel had been selling the slag mixed with baghouse dust
for a low price to highway construction firms, however, they believed there
might be a more lucrative use for the slag. Chaparrel created an internal
task force (STAR, Systems and Technology for Advanced Recycling) that teamed
with a neighboring cement plant to create a patented process called CemStar,
which adds slag to the raw material cement mix. CemStar processes the crushed
slag through a magnetic separation system to recover valuable metallic substances
that are then cycled back into the electric-arc furnaces. The remaining
lower-grade slag is used in the cement kilns as a substitute for limestone
in the manufacturing process.
Achievements:
-
Cement manufacturing energy requirements were reduced almost 15 percent (five
million Btus saved for every ton of slag substituted for limestone).
-
Existing kiln capacity increased 9 percent for a low capital investment,
which was paid back in the first year of operation.
-
The value of the slag increased 20 times over the previous market price offered
by road contractors.
The STAR task force also introduced a cleaning and source separation system
to reduce landfill-destined waste. The sale of recovered non-ferrous metals
(primarily aluminum and magnesium) is expected to recoup the capital investment
within one year. The sale of clean plastics (non-chlorinated) from the separation
system will generate additional annual revenues of $500,000. Recycling plastics
lowers the demand for petrochemical feedstocks used to make virgin plastic.
Contact: Andrew Mangan, Business Council for Sustainable Development —
Gulf of Mexico. Phone: (512) 794-8813; fax: (512) 794-8815; e-mail:
andy_mangan@radian.com
Source: World Business Council for Sustainable Development and the International
Chamber of Commerce 1997
The Colorado State University Industrial Assessment Center (CSU IAC) conducted
an energy efficiency/waste minimization audit at a company that manufactures
screw machine products for hydraulic systems. The company has 140 employees
who produce about 38 million parts per year, creating gross sales of $8.5
million. Energy expenses amount to about 2.5 percent of gross sales. The
major hazardous waste is spent ion exchange resins from the wastewater treatment
area.
CSU IAC made eight energy-saving and waste minimizing recommendations to
the manufacturer, who implemented four recommendations: (1) High-efficiency
lamps and ballasts replace the present ones as they burn out (IAC recommended
replacing all existing standard lamps and ballasts with high-efficiency lamps
and electronic ballasts). (2) High-efficiency motors and insulating of hot
tanks in the brazing area and plating lines save energy. (3) Installation
of a spring-loaded lid on the parts washer reduces the potential for leaving
the lid open, which, in turn, reduces the evaporation of cleaning solvents.
(4) Floor dry was replaced by absorbent pads and a wringer, eliminating solid
waste.
Achievements:
-
Installing high-efficiency lamps and
ballasts as replacement is needed saves $4,460 annually.
-
High-efficiency motors and insulated
hot tanks save $3,500 per year, with an 11-month payback.
-
Reduced solvent evaporation resulting from the spring-loaded lid on the parts
washer reduces solvent air emissions by more than 20,000 pounds and saves
$5,400 in solvent costs annually.
-
Replacing floor dry with absorbent pads and a wringer saves $800 and reduces
plant waste by 48,500 pounds annually.
-
Total annual savings equal $14,250
Source: DOE 1996
Cominco America, Inc.
Re-engineered Fertilizer Production
Cominco produces ammonia for fertilizer, which uses water and gas fuel to
generate steam. Process condensate is generated as wastewater, which is managed
by a holding pond and injection wells. Cominco retained an engineering
consultant, M.W. Kellogg Co., to re-engineer its ammonia plant to reduce
fuel and make-up water consumption.
Fuel consumption was reduced by replacing existing plant parts with newer
material that improved heat transfer. Convection section and heating coil
modules were replaced with more efficient units that reduced heat and improved
heat transfer, which reduced NOx emissions and fuel consumption. The ammonia
converter reactor was modified with new equipment to reduce steam consumption.
These new designs not only reduced fuel consumption but also increased
productivity. New equipment installed in the new convection section allows
wastewater to be recovered for conversion to steam, reducing both make-up
water and fuel consumption.
Achievements:
-
Natural gas consumption declined 22 percent (1 billion ft3 per year), saving
over $1.7 million per year.
-
NOx emissions declined 35 percent.
-
Average annual water usage for steam production was reduced by more than
110 million gallons, saving $65,000 per year.
-
Additional savings came from reduced disposal costs of wastewater into injection
wells.
-
$16 million in capital costs are anticipated to be recovered in approximately
six years.
Contact: Larry Wood, Cominco, phone: (806) 274-5204
Source: EPA 1996
Dana Corporation is the largest original equipment manufacturer of automotive
and heavy equipment axles, transmissions, and brakes for the North American
automotive industry. Dana, and an estimated 4,500 facilities in the U.S.,
use a heat-treating (carburizing) process that hardens and increases the
wear resistance of steel surfaces on products such as gears, bearings, drive
shafts, piston rings, universal joints, hand and machine tools, gas turbine
blades, and steel fasteners. Conventionally, the carburizing process treats
parts in a 1750o (F) atmosphere composed of carbon monoxide, hydrogen, and
nitrogen, which are discharged when the process is completed. New federal
standards will soon require these facilities to purchase air emission permits
and install discharge monitoring equipment.
In 1995, with support from
NICE3, Dana began testing
a full-scale prototype of a membrane-based technology developed by Atmospheric
Recovery, Inc. (ARI). The technology recovers and reuses discharged furnace
atmosphere gas rather than exhausting it to the air. The process is economically
advantageous because it allows a facility to avoid installation of expensive
pollution control equipment, reduces operating expenses, and increases
productivity.
Achievements:
-
Emissions were reduced 90 percent.
-
Operating expenses reduced by two thirds.Energy use was reduced at least
25 percent.
-
Increased productivity.
-
Reduced furnace downtime and fewer part rejects.
Contact: Paul Koehn, Dana Corp., phone: (612) 559-6233
Source: Koehn 1997
Decatur Foundry, Inc.
Infrared Drying
Decatur Foundry, a Climate Wise
Partner, is a small-run jobbing
foundry in Decatur, Illinois,
which specializes in iron castings for electric-motor frames and parts as
well as pump components. The castings industry has been moving away from
quick-drying, solvent-based coatings to slow-drying, environmentally safer
water-based coatings, creating a bottleneck in the production process. At
the same time, Decatur's customers were moving to just-in-time inventory
systems, placing pressure on suppliers to provide quick turnaround on orders.
A third variable putting pressure on turnaround time was Decatur's short
production runs, which require molds to be formed and made ready for casting
as quickly as possible.
With the help of Illinois Power (now Illinova Corp.) and
EPRI's Center for Materials Production,
Decatur identified the infrared/forced air unit as a replacement for the
conventional electric-resistance ovens. Instead of warming the air in contact
with the mold's surface, the new short-wavelength infrared systems radiate
heat directly to the surface of the mold, quickly driving out moisture. In
addition, the system requires no warm-up time, so it is only on when in use.
The new system was also equipped with precision instrumentation, which allows
more control in the drying process. All of these advantages resulted in
decreasing drying time by 85 percent.
Achievements:
-
Replacement on the first production line (cost: $12,000) reduced annual energy
consumption by 120 MWh, or $9,000. New infrared units were subsequently installed
on two new lines.
-
Organic solvents were eliminated.
-
Improved product quality virtually eliminated the need for additional polishing.
-
Mold failure rates fell.
-
New units freed up floor space.
-
Eliminating the drying bottle neck reduced labor costs and increased
productivity, allowing Decatur to offer a very competitive turnaround time.
-
Enhanced efficiency and productivity allowed Decatur to add two new lines,
increase employment by 13 percent, and increase sales from $5.9 million to
$10 million.
Contact: Terry Young, Decatur Foundry, phone: (217) 429-5261
Source: DOE 1996; 1997
Ilco Unican Corporation
Aqueous Cleaning System
The Ilco Unican facility in Rocky Mount, North Carolina, produces over 1.5
million blank keys daily. The facility had been using 1,1,1, trichloroethane
in a vapor degreaser to remove a medium-grade residue from the keys, but
designed an aqueous cleaning system to eliminate the use of the organic solvent.
The chemical-free, aqueous cleaning system uses a high-pressure, hot-water
spray to wash the keys and high-pressure air to dry them. The water in the
system is recirculated and cleaned by an oil skimmer.
Achievements:
-
The plant's water usage has been reduced 50 percent.
-
Energy used in the cleaning phase was reduced by almost 95 percent ($25,000
savings/year).
-
Unican's annual consumption of almost 200,000 pounds of 1,1,1, trichloroethane
was completely eliminated ($60,000 savings/year).
-
$25,000/year savings from reduced water and labor.
-
The $120,000 investment in the new washer was repaid in a little over a year
with $110,000 in annual cost savings.
-
Reduced liability from elimination of chemical treatment.
Contact: Brian Wells, Project Engineer, phone: (919) 725-1331
Source: DOE 1996
Nisshinbo, California, Inc.
Variable Speed Drives
Nisshinbo, California, Inc. is a textile manufacturer that produces yarns
and threads from the initial spinning process to finishing. With
performance-based financing from Energy Capital Partners, Nisshinbo installed
variable-speed drives (VSDs) throughout
their manufacturing facility as part of the textile spinning and weaving
processes. The VSDs allow for energy consumption to more adequately track
energy requirements, adjusting for varying load requirements, using less
energy more efficiently.
Achievements:
-
Measured energy reductions of 1,314 MWh save about $140,000 annually.
-
VSDs improve spinning and weaving process performance, which enhances product
quality and increases productivity.
-
Payback of 1.3 years on investment, or 70 percent rate of return.
Source: DOE 1997
Since Quad/Graphics started in 1971, the company has grown more than 20 percent
per year to become the largest privately held printing company in North America,
with annual revenues exceeding $1 billion, ten manufacturing sites, and over
8,000 employees. Quad provides full production services, including design,
photography, finishing, mailing, and distribution.
Quad has an overall environmental mission to make the best possible use of
all resources, asking two questions when making business decisions: Is it
good for business? Is it good for the environment? Management feels that
its proactive environmental strategy gives Quad a competitive advantage.
Quad, which is a Climate Wise participant, has achieved much in the way of
cost-effective energy efficiency and pollution prevention.
Achievements:
-
Recycled over 146,000 tons of paper, saving $12.6 million in landfill fees
in 1995.
-
Reduced ink waste by almost 50 percent between 1989 and 1993, despite steep
increases in production. This ink conservation saved $400,000 over this four-year
period.
-
Recycled over 287 tons of plastic in 1995 by creating markets and uses for
the recycled material. Earned $33,000 from selling used plastic and saved
over $15,000 in landfill fees.
-
Repaired and reused 110,000 wooden pallets in 1995, saving $375,000 in new
pallet costs and saving $453,800 in landfill tipping fees.
-
Replaced 3 8-hour shifts with 2 12-hour shifts, resulting in one-third fewer
trips to work, and provided discounted bus service to employees.
-
Located a new facility in an existing structure, saving 50,000 MMBtu (energy
to build a new structure), and due to its more urban location, decreased
average commuting distance by 20 miles for each of its 700 employees, saving
20,000 MMBtu annually.
In addition, Quad's R&D division, Quad/Tech, with the assistance of the
Wisconsin Energy Bureau and a $400,000 NICE3 grant, developed and commercialized
a new technology that captures both energy savings and non-energy pollution
prevention benefits. This closed-loop ink-jet supply and printer solvent
recovery system captures 80 percent to 90 percent of methyl ethyl ketone
(MEK) vapor and condenses it for reuse instead of emitting it into the air;
and eliminates the need for ventilation systems and MEK production and
transportation, saving at least 2.3 trillion Btus by the year 2010.
Achievements:
-
Reduced the amount of ink and solvent used by at least 50 percent.
-
Reduced materials costs by $552,000 annually.
-
Reduced energy costs by $72,900 annually.
Contact: Tari Emerson, Quad/Graphics
Sources: DOE 1997; EPA/DOE 1997
Republic Engineered Steels, Inc.
Scrap Metal Recycling and Water Reuse
Republic Engineered Steels, a Climate Wise Partner, manufactures special
quality bars of carbon steel, stainless steel, tool steel, and various alloy
steels at ten plants in six states. Due to economic pressures, Republic was
forced to cut costs significantly, and began by soliciting suggestions from
all employees. Melt shop staff at the Canton, Ohio plant made two
recommendations: sorting scrap steel before remelting it, and changing from
live steam cleaning to a dip rinse system as well as other water-saving
recommendations.
Republic uses electric arc furnaces to melt scrap steel from various sources
(e.g., autos, appliances, steel plant scrap) and form it into new product.
Prior to this project, scrap of high and low quality (i.e., varying impurity
levels) were not sorted, resulting in the high-quality steel losing its value
when melted with the low-quality scrap. With sorting, Republic could now
sell an additional 90,000 tons of high-quality steel at $106 per ton rather
than at the scrap price of $85 per ton. In addition, by dedicating each melt
to different grade of steel, it is easier for metallurgists to remove impurities
from the melt, saving labor costs. Sorting also reduces the time it takes
to adjust the chemical composition, so less energy is required to keep it
hot.
Changing from a live steam cleaning to a dip rinse system reduced wastewater
and energy costs. After emerging from an acid pickle liquor that removes
scale and oxides, the steel bars are sprayed with recycled water, which is
returned to holding tanks and reused until it no longer cleans adequately.
Washwater life is extended with a chemical inhibitor, Kleanrite 50. Bars
are then rinsed with fresh water, which is subsequently used to dilute the
pickle liquor.
Achievements:
-
Sorting saved almost $1.9 million a year, and cost only what it took to train
employees for one week.
-
Wastewater was reduced 26 percent in the first year.
-
Changing to a dip rinse system from a steam system reduced energy needs.
-
Water savings (primarily from rinse changes) reduced water costs by $20,000
per year.
Contact: Harold Kelly, Republic Engineered Steels, phone: (216) 837-6000
Source: DOE 1996
Sandia National Laboratories Microelectronics
Development Laboratory
Water-Use and Wastewater Reduction
Sandia National Laboratories (SNL) is a multi program laboratory operated
by Sandia Corporation, a Lockheed Martin Company, for the U.S. Department
of Energy. Sandia's Microelectronics Development Laboratory (MDL) in New
Mexico (NM) has over 30,000 ft2 of clean room space, with state-of-the-art
equipment for processing wafers up to 150 mm in diameter. MDL conducts R&D
in a range of micro technologies, including advanced packaging and
interconnection, micro sensors, compound semiconductors, advanced nonvolatile
memory, micro machining, and advanced materials and process development for
the semi-conductor industry. Many operations conducted at MDL require high
purity water. Incoming water from the City of Albuquerque (COA) and well
water obtained from Kirtland Air Force Base (KAFB) is processed through a
water treatment facility that includes: carbon absorption, reverse osmosis
(RO), vacuum degassing, and ion exchange.
Using a team approach, MDL sought to reduce water consumption and wastewater
discharges to the COA sewer system. The MDL water treatment system was modified
to meet this goal: new stainless steel control valves were installed for
precise control of water flow; a new manifold was added to the RO pump converting
it to a more efficient two-stage pump; high surface area RO membranes were
added; and the existing PVC piping was replaced with industrial, water production
piping.
Achievements:
-
SNL/NM reduced overall water usage by 8 percent and waste water by 11 percent
(143.6 m3/yr), for a cost savings exceeding $100,000 per year.
-
Annual energy savings of $22,000 resulted from the more efficient RO system
operating fewer hours.
-
Total project cost of $107,113 gives a payback of 0.8 years with a simple
ROI of 108 percent.
Contact: John Jewell and Javier Chavez at Sandia Labs, Albuquerque, NM
Source: Jewell and Chavez 1997
Shaw Industries
Automated Dyebath Reuse
Shaw Industries served as a test facility for a NICE3 project that showed
how carpet manufacturers can reduce pollution and save energy through automated
dyebath reuse. In the conventional batch dyeing process, water is pumped
into a dyeing machine, where fabric is placed and saturated with water. Chemicals
and dye are then added and the bath is heated and held at dyeing temperature
until dyeing is complete, at which point the bath is emptied, discharging
large quantities of water, chemicals and energy. The machine is then refilled
and the process is repeated for the next batch.
By automating the process, low-cost precision pumping systems allow a small
volume of dyebath chemicals to be reused for numerous dyeing operations.
Innovative monitoring instruments can analyze the dyebath and communicate
results to a computer which calculates the amount of chemicals that need
to be added for the next dyeing operation. This process could also prove
valuable for the textile industry.
Energy is saved by reducing the need to reheat dyebaths, eliminating the
energy used to produce additional dyes, chemicals and water, and reducing
energy needed to treat wastewater. If fully implemented nationally, throughout
the carpet and textile industries, an estimated seven trillion Btus could
by saved annually by 2010 — enough energy to supply the needs of 70,000
homes for a year.
Achievements:
-
Resource reuse: 6 percent of the dyes, 60 percent of the auxiliary chemicals,
and 42 percent of the water are reused and therefore removed from the waste
stream. Nationwide, waste would be reduced by 36 million pounds of chemical
per year.
-
Total cost of $833,000 (including NICE3 grant) is recovered in about six
months with savings of $1.6 million per year.
Contact: Eric Hass, DOE, Golden Field Office, phone: (303) 275-4728
Source: EPA 1996
Sulzer Chemtech AG
Saving Energy in the Chemical Industry
Sulzer provides supplies and services to the chemical industry. One of its
more popular services is a "layer crystallization" process used to separate
and purify chemicals. The process is energy intensive, so to reduce operating
expenses, Sulzer spent 18 months developing a process to reduce energy intensity
while maintaining quality. The less energy-intensive approach used a crystallizer
under pressure, as both the condenser and evaporator of a cooling unit. The
new process has several improved features: no intermediate liquid heat-transfer
medium; no buffer vessels; fewer and smaller pumps, piping, and valves; lower
temperature differentials; and less space requirement.
Achievements:
-
Energy requirements were reduced 30 percent.
-
Solvent use and heat-carrier fluids were eliminated.
-
Space requirements were reduced 50 percent, which reduces demands on materials
and natural resources because it is more compact.
-
Capital costs were reduced more than 25 percent.
-
Operating expenses (e.g., utilities, materials) were reduced.
Contact: Peter Gebhardt, Sulzer Technology Corporation. phone: 0041-52-262-2088;
fax: 0041-52- 262-0022; e-mail: peter.gebhardt@sulzer.ch
Source: World Business Council for Sustainable Development and the International
Chamber of Commerce 1997
Trailblazer Foods, Inc.
Water Recycling and Treatment System
Trailblazer Foods, a small Portland, Oregon company, specializes in the
production of fruits, jams, and syrups. Employees proposed, designed and
installed one of the most innovative water recycling systems for heating
and cooling in the food process industry. The system uses recirculated water
to pasteurize and cool food products, using the heat capacity and thermal
integrity of water to control temperatures reliably. Recirculating water
reduced the need to heat and cool the water, cutting gas and electricity
used by the boiler and fans. After using the water many times, the water
is treated, and hazardous sludge is eliminated, discharging effluent that
meets environmental standards. The Water Treatment project cost $40,000.
Achievements:
-
Water use was reduced 50 percent — 1.5 million gallons per year.
-
Electricity use was reduced 50 percent.
-
Gas use was reduced 10 percent.
-
The release of hazardous sludge was eliminated.
Source: DOE 1997
Wacker Siltronic Corporation
Multi-Wire Saw for Silicon Slicing
Wacker Siltronic, in Portland, Oregon, manufactures silicon wafers used in
the semiconductor industry. Wacker has a history of commitment to proactive
environmental management. In the past 12 years, Wacker has reduced air emissions
by 89 percent, hazardous waste by 99 percent, toxic chemical use by 86 percent,
and overall chemical use by 47 percent. As a result, the company saves about
$2 million in operating expenses a year, and almost all projects help the
bottom line.
In 1996, Wacker installed a new multi-wire saw silicon slicing technology
that increased productivity and reduced wastewater. This new process, however,
created new waste streams, so Wacker developed alternative, recyclable cutting
fluids, and began reclaiming the cutting slurry from its wire saw operations.
Using a water-based cutting fluid instead of oil eliminated solvent cleaning
and reduced water-rinsing steps. The process has also significantly reduced
use of solvents, oils, and water.
On this particular project, Wacker was assisted by the Environmental Assistance
Project (EAP), a joint project between the Oregon Department of Environmental
Quality, the City of Portland Bureau of Environmental Services, and the Portland
business community. EAP evaluated environmental impacts and provided regulatory
guidance.
Achievements:
-
The new multi-wire saw increases silicon wafer production by 20 percent.
-
Water usage is reduced by 37 million gallons per year.
-
Water and sewage expenses are reduced by $400,000 per year.
-
Prevention of 2,400 barrels/year of used oil and solid waste disposal reduces
disposal costs by 75 percent ($640,000 per year).
-
Recovering usable materials from wastes (e.g., cutting fluid) saves $1.5
million annually.
-
Hazardous air emissions (solvents), created when changing cutting fluids,
were reduced by 36 tons per year.
-
Project investment ($2 million) is paid back in 1.4 years.
Contact: Tom McCue, Environmental Manager, Wacker
Source: DOE 1997; McCue 1997
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