Reducing waste generation in sugar milling and refining Philippines 1993-1996 Full scale

MANUFACTURE OF FOOD PRODUCTS AND BEVERAGES # 36

Background:

The Industrial Environmental Management Project (IEMP) of the Philippine Department of Environment and Natural Resources (DENR),  funded by the United States Agency for International Development (USAID), was initiated in 1992 in response to growing concern for environmental protection. IEMP's goal is to encourage sustained economic growth while reducing pollution and improving workers' health. To achieve its goals, IEMP has three components:

capacity building;
policy studies;
a pollution reduction initiative.

IEMP provides assistance to small - and medium - sized Philippine industrial enterprises, in conducting pollution management appraisals (PMAs). PMA is a tool that identifies financially sound opportunities for waste reduction at the source of pollution, rather than end-of-pipe treatment.

Between 1993 and 1996, IEMP had conducted over 50 workshops and trained over 100 participants from government, the private sector, and NGOs in compliance audits and monitoring, environmental impact assessment, environmental risk assessment, data collection and sampling, and pollution management appraisal.

In addition, IEMP completed policy studies and action plans on areas including market based instruments (MBI), characterization and standards for hazardous waste, environmental impact statement system.

IEMP has conducted over 80 of the planned 150 PMAs to be completed by the end of the project in the following targeted industrial subsectors.

Sugar milling/refining - Pulp and paper
Vegetable/animal oils - Tanneries
Food and beverages - Fish canning
Industrial chemicals - Metal finishing
Piggeries - Meat processing
Cement and
Wood products - Metals/mining

It is expected that pollution prevention measures implemented by 50 % of the PMA firms will result in a 5 - 10 % reduction in production costs (savings), and a similar decrease in pollution.

One of the factories where the PMA was carried out under the IEMP was the Central Azucarera Don Pedro (CADP) established in 1927.  This factory is the leading raw sugar factory in the Luzon Island of the Philippines. It produces about 1 075 tons raw sugar at a rated capacity of 10 000 TCD. Enormous investments for the facility's Total Improvement Plan began in the 1987-88 crop year, with the acquisition of a Skoda mill from Czechoslovakia, capable of processing 8 000 tons of cane per day. CADP is now operating its new refinery, with a capacity of 550 tons of sugar per day.

At this factory raw sugar is processed as follows:

  1. Sugar cane arrives at the mill;
  2. The stalks are cut into small pieces by turning knives;
  3. The cane pieces are then passed through heavy rollers which squeeze out the juice;
  4. The juice is treated with lime, causing impurities to settle to the bottom;
  5. Impurities are removed by filtration;
  6. The clear juice is pumped to the multiple effect evaporator to concentrate the juice solids from about 12% to 65%. 
  7. Crystallization follows through further evaporation under carefully controlled conditions in vacuum pans.
  8. Sugar crystals are separated by centrifugation.

Cleaner Production Principle:

Recovery, reuse and recycle; Housekeeping; Process modification

Cleaner Production Application:

The Pollution Management Appraisal (PMA) at CADP, conducted by the Industrial Environment Management Project (IEMP) in March 1993, focused on reduction in water use and wastewater generation. CADP significantly reduced its wastewater generation by adapting the IEMP recommended low cost / no cost waste minimization options. These included:

waste segregation to enable dry handling of fly ash;
recycling bagasse for use in absorbing grease and oil spills;
recycling clarified water from ash settling pond and condensate tank overflow for cleaning purposes;
housekeeping measures such as monitoring oil spills, repair of leaking pumps, removing debris from canals.

Considering that water is a critical concern of the facility, CAD requisitioned an ultrasonic flowmeter. Such efforts allowed them to monitor sudden surges in the volume of the wastewater, immediately identify the cause of the rise in volume, and implement remedial measures.

CADP continues to study and implement waste minimization options. Each department now functions as an independent PMA team, investigating waste streams, checking pollution load, and recommending workable waste minimization options.

CADP's chemical control and laboratory department reduced their consumption of lead sub-acetate, a toxic chemical used in the analysis of sugar content. CADP is hoping to totally eliminate lead sub-acetate by shifting to analytical instruments.

CADP's PMA team recognized the importance of tracking not only the process raw materials, but also the waste generation. The combat against toxic chemicals was initiated by reducing the volume of samples per analysis from the Mill Department to 100ml from 250ml, and from the Boiling House to 75g from 150g. Consequently, this reduced use of lead sub-acetate.

Environmental and Economic Benefits:

Through waste minimization, CADP reduced wastewater volume from 18,000 m3 per day to 1 500 m3 per day. As a result, CADP's abstraction from the surface water source (a river) has reduced thus conserving   water resource. CADP now easily complies with government regulations on effluent discharge. With regard to reduced consumption of lead sub-acetate, the benefits from reduced lead pollution are significant. The wastewater generation and lead sub-acetate consumption before and after the implementation of the CP options is as follows:

  Before After
Wastewater (m3/day) 18 000 1 500
Lead sub-acetate (kg/day) 4.5 2-2.5

The costs for the ultrasonic flowmeter that was used for implementing the water conservation options are as follows:

Capital investment - P500 000 

Operating costs - P915 000

Cost savings - approx. P990 000

Payback period - 9 months

Savings can be attributed to the avoided treatment and compliance costs, and other liability costs. CADP was not able to fully quantify the corresponding savings.

Constraints:

None reported.

Contacts:

Mr Ramon Picornell Jr
Vice President / Resident Manager
Central Azucarera Don Pedro
Nasugbu, Batangas, Philippines
 
David L. Wadsworth, Chief of Party
Industrial Environmental
Management Project (IEMP)
9th Flr.,JMT Corporate Condominium
ADB Avenue, Ortigas Complex
Pasig. Metro Manila, Philippines
Tel: +632 634 1617-21; Fax: +632 634 1622
 
Dr Ronald S. Senykoff, Chief, NDR-USAID
Ramon Magsaysay Center
1680 Roxas Boulevard, Manila, Philippines
Tel: +632 521 5226; Fax: +632 522 2512

Review Status:

This case study was originally published in the UNEP IE document "Cleaner Production Worldwide", Volume II. In the process of preparing the document the case study underwent a technical review. Subsequently in September 1998 a second technical review was done by Dr. Prasad Modak, Environmental Management Centre, Mumbai, India.