🚀 go-pugleaf

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         *HEAT RECOVERY COMPOSTING PLANT  IN AN INTEGRATED PRODUCTION*
         *OF COMPOST, EARTHWORMS, FISH BREED, GREENHOUSE, AND OUTDOOR*
         *CULTURES: a demonstration project of VJ-Komposteringssystem*
         *AJ, sponsored by EC. Part I: The composting processes      *
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         1
         INTRODUCTION
         ============

         This project has the aim to achieve maximum  utilization  of
         the  organic  waste  projects  which  are a potential energy
         source and raw material for compost products.   The  compost
         products are tested for greenhouse and outdoor use before it
         is sold as a declared compost.  Also, the aim is to demonst-
         rate less-pollution problems with agricultural and other or-
         ganic wastes.

         The plant is built in the Danish parish of Aulum-Haderup  in
         an  area  of  10  hectares in the vicinity of the factory of
         Praeriemuld A/S.  Many fur and  poultry  producers,  with  a
         large surplus of animal manure, are located in the area, and
         they are very interested in the delivery of  manure  to  the
         plant.

         Most of the income will be brought by an eel breeding plant.
         The wastewater produced by this plant will be treated in the
         water-hyacinth greenhouses.  The sludge will be treated with
         the  separated  slurry  in an anaerobic filter.  Part of the
         effluent from the filter will  be  totally  treated  by  the
         water-hyacinths,  and  the  other part will be used for land
         application.

         2
         DESCRIPTION OF THE SOLID MATERIAL LINE
         ======================================

         2.1
         Receipt of the organic substrates
         ---------------------------------

         At the plant, the different substrates (poultry and fur  ma-
         nure,  straw,  chips,  bark, and peat, or the like), will be
         received and stored separately under a cover.

         2.2
         Substrate mixtures
         ------------------

         The substrates will be analyzed in a laboratory for relevant
         physical  and  chemical properties, and the desired mixtures
         will be formulated by means of a computer.  The  plant  will
         be  scaled  for  the treatment of ca.  2.630 tons of organic
         substrate per year, corresponding to ca.  7,2 tons (ca.   10
         cubic meters) per day.

         2.3
         Composting heat plant (CH plant)
         --------------------------------

         The substrate mixtures will be composted for 5 - 7 days in a
         composting  heat  plant.   The  main  characteristics of the
         plant are as follows:

         1) The composting process will be fully  controlled  with  a
         subsequent high rate of composting.  In 5 days, ca.  30 per-
         cent of the substrate solids will be converted  into  carbon
         dioxide and water.

         2) The plant will be a closed system, where the  whole  bio-
         mass  will be exposed to a temperature of 60 degrees  Centi-
         grade  for 5 days,  so that  the substrate will be sanitized
         for pathogens, parasites, and weed seeds.

         3) Ca.  70 percent of the biologically produced heat  energy
         can  be  exploited  by  the heat exchanger system, while the
         rest will be lost with the exhausted air.

         4) The exhausted air  will  have  an  increased  content  of
         carbon  dioxide,  and  after  a purification this air can be
         utilized for the heating and carbon  dioxide  enrichment  of
         the greenhouse atmosphere.

         5) Nitrogen loss during the process will be limited  due  to
         process  adjustment and the collection of evaporated ammonia
         to the water of the air scrubber in connection to  the  heat
         exchanger system.

         In this project, the heat produced by the CH plant  will  be
         used  for the heating of the greenhouse, eel culture, vermi-
         culture, and for the heating of the connected building  con-
         taining laboratory, packing equipment, administration, etc.

         The carbon dioxide formed will be utilized for the promotion
         of  plant  growth  in  the greenhouse, while the ammonia-en-
         riched water will be utilized as as a liquid fertilizer  for
         outdoor vegetables.

         When the CH plant will receive ca 7.2 tons of substrate  per
         day,  corresponding to ca.  10 cubic meters per day, and the
         plant will have the treatment time of 5 days, a plant volume
         of 50 cubic meters will be necessary.

         The plant will produce ca.  3.7 tons of  fresh  compost  per
         day  (1,350 tons per year), and the power will be 50 kW (ca.
         38 tons of oil equivalent per year).  Energy consumption  of
         the  plant  for the structuring and aeration of the material
         will be 6.5 kW (ca.  5 tons of oil equivalent per year).

         2.4
         Curing
         ------

         The fresh (raw) compost coming from the CH  plant  don't  be
         sufficiently  stabilized (mature) for use as a growth medium
         for plants, and it can cause damage to the plants  or  rest-
         raint of germination.  This compost must therefore be cured,
         partly by windrow composting and partly by vermicomposting.

         2.41
         Windrow composting

         One-third of the fresh compost (450 tons per year)  will  be
         stabilized in windrows.  The stabilization process will take
         place indoors in 4 - 8 weeks, depending on the wanted  matu-
         rity  index wanted for the compost.  In this period the com-
         post will be turned, structured, aerated and  moistened  se-
         veral  times by means of a turning machine.  Fresh and cured
         compost will be removed by means of a front-end loader.  The
         production of cured compost will be ca.  210 tons per year.

         2.42
         Vermicomposting

         Two-thirds of the fresh compost (ca.  900 tons/year) will be
         stabilized  by  means of vermiculture, which will take place
         in an insulated hall at 25 degrees Centigrade in a system of
         trays in 7 storeys.

         In the vermicomposting process, a tropical species from East
         Asia,  Perionyx  escavatus, will be used instead of the spe-
         cies Eisenia foetida (manure or dung worm), which is  common
         in Denmark, and until now the species mostly used for vermi-
         culture.  The two species are more or less  equal  according
         to  the  size, growth, and reproduction potential, but Peri-
         onyx excavatus doesn't - as in the case of Eisenia foetida -
         segregate  any  evil smelling secretion, which means that it
         can be utilized directly as a living fodder in fish  produc-
         tion.

         (To be continued)