How to Generate Power from Garbage
(Page 5 of 12)
May/June 1970
By the Mother Earth News editors
A trap should be placed at the low point in the gas line to permit the escape of any water caused by moisture condensation. The trap can be placed in a pit next to the tank or at some other place where the low point of the line can be conveniently located.
RELATED CONTENT
If the gas is burned in an engine, removal of hydrogen sulfide (which will also be generated) is sometimes desirable to prevent corrosion. This can be accomplished by passing the gas through an absorption tank containing ferric oxide. The oxide will remove very small concentrations of hydrogen sulfide and can be regenerated by exposure to the air.
MATERIALS AND COSTS
Complete plants, either prefabricated or built of concrete at the site, may be purchased in several countries. I would suggest Germany, Switzerland and Japan as sources, if for some reason you just can't build one from local materials. The prefabricated plants may use steel or concrete digestion tanks with metal covers and gas-holders.
You can reduce installation costs if you build most of the plant yourself. The digestion tanks and gas-holder base can be constructed of concrete or masonry. If masonry is used, the tanks should be lined with plaster to prevent leakage of gas or liquid.
The gas-holder cover usually has to be purchased since it is most satisfactory when made of metal. It must be gas tight, not easily deformed and built with sufficient accuracy to avoid binding in the guides as it adjusts to varying volumes. The piping valves and burners must also be purchased. Unless you're skilled in pipe fitting, the pipes should be installed by an experienced craftsman.
The initial cost of a methane plant may seem rather high, particularly if you do not do a great deal of the work yourself. When this cost is amortized over a period of several years, however, you'll find that such a plant will provide a cheap source of fuel and a sanitary method of waste treatment.
The operating and maintenance costs are relatively insignificant. Loading and removal of material is a matter of labor, part of which would be expended in the normal handling of manure from the barns to a stack or compost pile. The maintenance of equipment amounts to painting the metal parts with the same paints used in sewage plants, to prevent corrosion. One of these generators, if well built and protected, should last over 25 years.
CHOICE OF CONSTRUCTION MATERIALS
Most of the materials required for the construction of a manure-gas plant can usually be found locally: Sand and gravel for making concrete, and stones or bricks for masonry. Concrete structures are preferred because they can be made water and gas tight. When built above ground, they can also be reinforced to resist inside water pressure. Concrete does require construction forms, reinforcing steel and more cement than is needed for masonry-built tanks, however. In some areas, this may constitute a serious disadvantage.
Page:
<< Previous 1 |
2 |
3 |
4 | 5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
Next >>
