Liquid Waste Solutions
Introduction
The following Case Studies represent a series that showcase successful projects, undertaken by companies committed to Environmental Waste Management.
Case Study 1:
Background
GlaxoSmithKline, being a manufacturer of pharmaceutical products, requires very high purity water as an addition for many of its products. The high purity water is obtained by passing normal tap water through a filter to remove solids, and water "hardness" - then passed through a reverse osmosis unit.Sketch of the Reverse Osmosis Process: Pores in the reverse osmosis membrane are so small that only water molecules pass through. The contaminants are rejected and drained away.
As part of this process of producing high purity water, the impurities that have been removed become part of a waste stream of what is classified as relatively impure water. However even this impure water is in many ways better than what is received straight from the tap (due to the earlier filtering). In the past this waste stream was sent to the sewer.
The Initiative
The potential to reuse this water within the operations at GSK had been discussed for several years, but required a 10,000 litre storage tank and considerable new piping - which made the project hard to cost justify. However they kept this opportunity in "the back of their minds", and later a storage tank became available, and other building changes allowed for piping to be put in as part of other changes.
Achievements and Savings
As part of stage 1 of this project, the waste water from the Reverse Osmosis system is now being used for flushing toilets and vacuum pumps.The saving is approximately 10kl per day, which equates to about 3-4 megalitres pa, which is approximately $6,000pa.
There is still some RO wastewater being sent to sewer, and it is planned in stage 2 to use this water for cleaning of compactor bins and for makeup to the cooling towers and water for gardens.
One important lesson from this project was that the time scale from initial idea to implementation was several years - this will not be unusual where cost justification is difficult. In this case it was the persistence of interested staff, and the grasping of an opportune time that lead to success.
Case Study 2:
BackgroundLuxfer Gas Cylinders has grown to become the world leader in the development, production and supply of seamless, extruded aluminum and composite high-pressure cylinders for the storage of gases.
Luxfer serves customers in major gas markets, including medical, life support, beverage, fire, scuba and specialty gases. Luxfer has six manufacturing sites, spread over Europe, North America and Australia and has over 30 million gas cylinders in service worldwide in more than 50 countries.
The Australian manufacturing plant at Kings Park, New South Wales, produces 300,000 cylinders annually for local and overseas markets. A major export success is the supply of cylinders for the SCUBA diving industry in Japan. Luxfer have met the challenge to supply high quality gas cylinders to this very demanding market.
Waste minimisation has been identified as a strategic priority for Luxfer, who see it equally as an environmental obligation, a good manufacturing practice and a vehicle for cost reduction.
The Process
As part of the Waste audit undertaken in conjunction with the AMC Waste Minimisation program Luxfer identified an annual water usage in excess of 100,000kl, costing over $200,000. The largest consumption of water in the Luxfer manufacturing process was found to be the lube line process.
The lube line process is used to wash, rinse, etch and lubricate aluminum billets prior to extrusion into cups, which form the body of the cylinder. The process includes 4 rinse baths.The Initiative
The goal of this project was to reduce water usage and disposal. This would provide the twofold effect of cost reduction and the protection of a precious commodity. Investigation of current practices, found that when the baths were refilled, or topped up, that taps were left on and the baths overflowed. This overflow then went to Luxfer's waste treatment plant and then safely into the sewer.
The reason that this practice was in place was that the operators were unaware of the cost of the water. The cost being $0.95/kl to buy the water in and even more, $1.03/kl, to dispose of down the sewer. Also the location of the taps, at the rear of the baths were inconvenient to access.
Following suggestions from employees, the rinse tanks were re-plumbed to relocate the taps to the front of the baths. Solenoid valves and 4 minute timers were also installed. The filling operation is now activated, by pressing a button. The filling time for each bath is limited by the timer. If further water is required, the operator presses the button again.
Achievements and Savings· The new system was installed at the start of September 2001, at a cost of $8,500.
· During September, daily water consumption fell from 350kl to 230kl. This equates to the contents of 2 large back yard swimming pools every day of the year.
· The cost benefit is approximately $240 a day, which will provide annual savings to Luxfer of $55,000 to $60,000. Pay back on the initial investment is estimated at less than 2 months..
· Electricity consumption is also expected to decrease due to the reduced water usage and subsequent loading on the pumps in the waste treatment plant.Lessons Learned
· The Waste Audit proved the old maxim, 'If you don't measure you can't improve'
· The actual amount of water usage came as a surprise
· Simple improvement activities often yield major results
· Improvement projects need not be capital intensive
Further Information on the AMC Industry Waste Minimisation Program and Additional Case Studies may be obtained by:
Phone: (02) 9209 4051
Fax (02) 9209 4470
