|Cleaner Production at a Toddy Distillery in Sri Lanka||Sri Lanka||1995||Full scale|
MANUFACTURE OF FOOD PRODUCTS AND BEVERAGES # 39
Seeduwa Distillery is part of Distilleries Company of Sri Lanka Ltd. And probably the largest coconut arrack distillery in the country. It is a member of the Stassens group of companies. The facility employs approximately 200 people and produces around 6,750 liters of absolute alcohol per day when enough toddy is available.
Cleaner Production Principle:
Housekeeping; Process modification; New technology.
Cleaner Production Application:
The production of coconut arrack harnesses the natural formation of alcohol in the nectar of the coconut flower. Toddy tappers climb the coconut trees to collect the toddy, in the traditional manner, in coconut plantations along the tropical shores of the Indian Ocean. Toddy is lowered to the ground, placed into traditional wooden barrels and transported to the distillery. The fermentation occurs due to naturally occurring yeasts that find their way into the toddy. By the time the toddy arrives at the distillery, the fermentation is complete. At the distillery, toddy is stored to form a suitable batch and then fed to one of a range of stills, depending on the quality and quantity of product required. Following distillation, the alcohol is aged in wooden (halmilla) vats to improve its flavor. Some high quality alcohol products require a double distillation. After aging, the product is blended and filtered prior to bottling and sale.
The cleaner production initiative came at an opportune time for the distillerys owners, as it capitalized on and focused the companys own progress in the area of production efficiency. A cleaner production study of the distillery and bottling hall highlighted the benefits of a number of potential changes. Cleaner production has allowed the company to attain more efficient production, reduce energy costs, reduce wastage and pollution and improve the quality of the product. Current modifications include improvements to the continuous French Patent Still, heat recovery from effluent, reduction in bottle breakage, more efficient bottle washing and reduction in extraneous matter in the delivered toddy.
A joint company/UNIDO cleaner production project team was formed to analyze the production process and equipment. A four-step approach was agreed upon to develop modifications and implement them without severely disturbing the production process. In the first phase, the operating practices and equipment were examined in detail. Designs were drawn up and implemented for upgrading the stainless steel still and optimizing its process parameters. Also, several housekeeping improvements could be implemented. These included sorting of bottles prior to washing and a reduction in handling breakages. In the second and third phases, the French Patent Still will be further enhanced. More new equipment, including a degassing column and a thermocompressor (for the recovery of heat) will be installed.
In the fourth and last phase, an effluent treatment facility will be built. The biogas produced in this facility will replace part of the fuel. The capacity will depend on how successful the plant has been in reducing its effluent stream by cleaner production methods. As the second stage has not yet ended, only the results from the first phase will be discussed.
Modifying the bubble caps and downcomers in the distillation column still optimized the mass transfer characteristics of the stainless steel. More accurate flowmeters were also introduced. Better housekeeping was instituted as well.
Environmental and Financial Benefits:
The improvements resulted in fuel savings of 22 percent, leading to a similar reduction in SO2 and CO2 emissions. The amount of alcohol leaving the process in the spent wash has been reduced by 95 percent, resulting in a 7 percent reduction in BOD load in the effluent stream. By avoiding the breakage of bottles, both resource requirements (glass) and the volume of solid waste were reduced.
On the basis of operating figures since implementation, the 22 percent fuel savings mentioned above has yielded a US$ 25,000 savings annually.
Reductions of 95 percent in alcohol loss to the drain saved US$ 34,000 worth of recovered alcohol annually. Reductions in breakage during handling, bottling and loading, saved US$ 22,600 annually.
Major quality improvements in the alcohol produced that reduce the aging time by two years will result in US$ 70,000 in savings on interest payments. (Alternatively, by not reducing the aging time, the company could market a better quality product and realize a higher margin.)
Not taking into account the potential for extra earnings or savings on product quality improvements, the financial gains are as follows: US$ 27,820 was invested and US$ 88,900 (on an annual basis) was saved, for a payback time of three months.
The cleaner production audit has generated a large number of other options that show potential economic benefits. These are being prioritized and implemented or further investigated. The current results of cleaner production initiatives have added to the benefits of other operational initiatives to the point where the production cost of arrack decreased from 132 to 92 Sri Lanka rupees per liter between 1992 and 1995 (that figure includes excise duty), i.e. a 30 percent reduction. In the same period, output from the plant increased by over 40 percent.
This case study is part of a UNIDO-funded demonstration project and was taken from UNIDO's booklet, Cleaner Industrial Production (see address above). It was edited for the ICPIC diskette in November 1998. It has not undergone a formal technical review by UNEP IE.
Subsequently, in March 1999 the case study underwent a technical review by Dr. Prasad Modak, Environmental Management Centre, Mumbai, India.