INTERNATIONAL CLEANER PRODUCTION INFORMATION CLEARINGHOUSE

CASE STUDY #49


1.   Headline: Conversion of pig effluent into energy and
     fertilizer

2.  Background: For many years the owners of Charles I.F.E.
had problems with disposal of the waste from their 1200-head
pig farm. The piggery produces a daily average of 210 000
liters of slurry with organic solids content of 1.7 per cent.
This is comparable to the sewage output of a town with a
population of 30 000-40 000 people.

     Liquid manure, composed of a suspension of faecal and
     urinary waste including spilled feed, hair and bedding,
     was size segregated by screening. The retained solids were
     spread over the farm land and the liquids were held in a
     large reservoir for summer irrigation.

     The company received many complaints about this disposal
     method which was far from odor-free and which wasted a
     potentially valuable resource.

3.  Cleaner Production Principle: New technology

4.   Description of Cleaner Production Application: To resolve
     the problem, the company decided to introduce the process
     of anaerobic digestion in which organic waste, in this
     case pig effluent, is broken down by bacteria in the
     absence of oxygen and at an optimum temperature of 35 C.
     The bacteria produce biogas and their dead bodies provide
     an excellent odorless organic soil conditioner that has
     resulted in dramatic improvements to the farm's cropping
     programme. Charles I.F.E. was assisted financially by an
     interest-free loan from the Victorian Government's Cleaner
     Production Grant Scheme.

    Enabling technology: The new technology involved:
     - an automatic flushing system to clean the effluent from
     the pig sheds;
    - a grit removal machine
     - a high-rate dissolved air flotation unit to concentrate
     the solids and produce biogas;
    - a cogeneration plant to produce electricity and hot
water; and
     - the development of an organic soil conditioner called
     Perma Fert.

    The technology base was of Italian origin but Charles
I.F.E. developed some significant and unique modifications to
the system during construction and commissioning stages,
especially in the digestion phase which is two stage but also
continuous, enabling it to cope with all wastes, including
excess non-digested feed

5.  Economics:
                                    $Aus/year

        Savings and electricity         100 000
        Improvements to cropping,
        sales of Perma Fert            300 000
        Running costs                   2 500

        Capital investment             1 800 000
        Payback period                5 years


6.   Advantages: No longer does the farm have to dispose of
     210 000 liters per day of noxious high strength pig waste.
     The farm sells `grit', which it separates from the
     effluent, to a local worm farmer. The farm now uses 70 per
     cent less water because it recycles water that is
     separated by the high rate dissolved air flotation unit.
     The plant produces 1700 m3 of biogas per day which is
     converted to:
    - 3840 kWh of electricity per day;
     - 28 800 megajoules per day of energy in the form of hot
     water.

     The plant produces approximately four tons of humus solids
     per day which it uses to increase crop yields or to
     produce a fertilizer called Perma Fert. The plant produces
     100 000 liters/day of nutrient rich liquor for irrigation
     or fertilization. The Environment Protection Authority
     buffered zoning, requiring the owners of the farm not to
     spread effluent in certain areas, has been removed. There
     are far fewer flies and rodents around the farm. The
     neighbors are much happier as the odor has almost totally
     disappeared.

7.  Constraints: N/A

8.  Contacts:Scott Charles
            Construction Engineer Consultant
            Charles I.F.E. Pty Ltd
            Berrybank Farm
            Windermere R.S.D
            Ballarat 3352
            Victoria
            Australia
            Tel: +61 53 432344
            Fax: +61 53 432443

9.             Keywords:Australia, pig farming, new
               technology, meat processing, pork slurry, air
               flotation, manure, biotechnology, soil
               conditioner

10. Reviewer comments: This case study was originally
published in the UNEP IE document "Cleaner Production in the
ASIA and Pacific Economic Coorporation (APEC) Region. In the
process of preparing the document the case study underwent a
technical review.