Biogas. Used in Ancient China, and then millennia later, once again “open” as “non-traditional, environmentally friendly energy source of the XXI century”, it attracts a growing attention in our country. The evidence may, in particular, to serve the steady increase in biogas-related publications. Including in the pages of “Modeller-designer” (see for example, № 1’87, 5’88). Confirmation of steady growth in popularity, as well as the immensity of the topic of technical solutions for the production and practical use of “valuable gaseous product vyrobni (i.e., occurring without oxygen) fermentation (re-Pravaya) of the organic substances, previously falling under the category of worthless garbage”, and it is this article.
Biogas is basically “hell” mix. Its main components: methane (55-70%) and carbon dioxide (28-43%); small amounts also present other compounds, including chemically aggressive. For example, hydrogen sulfide. And it is impossible not to take into account when you create an installation for the production of biogas, taking into account that on average 1 kg of organic substance, biodegradable to 70%, produces 0,18 kg of methane, 0,32 kg of carbon dioxide, 0.2 kg of water and 0.3 kg of an irreducible residue.
Since the decomposition of organic waste with the release of biogas is the result of certain types of bacteria, washing significantly it affects the environment. In particular, temperature. Is: the warmer, the higher the rate and extent of fermentation of organic material.
But we, as they say, Tashkent, means need to heat up the fermented mass. This task is easiest, perhaps, to solve, using the heat produced during the decomposition of manure. It’s the need to put “gazoprovodiv center” of the installation — the so-called “digester”, which can be done from 2…5-mm sheets of “stainless steel”, cooked twice: first by electric welding, and then (for safety) gas. Besides, include the refueling of biogas plant raw materials and also waste from the work area.
Biogas plant:
1 — aerobic fermenter (resistant to corrosion — for example, wood — box construction with a folding rear and front walls) 2 — flooring (wooden panels) 3 — filler neck of the digester (welded construction from 2.5 mm “stainless steel”), 4 — digester (of suitable dimensions tanks for storage of chemical fertilizers, petroleum products; or is welded from 2,5…5 mm “stainless steel”), 5 — mechanical mixer (welded construction of the “steel”), 6 — a branch pipe of selection of biogas 7 — insulating layer of expanded clay or foam, 8 — slatted floor (of timber 100×100 mm), 9 — drain valve 10 — technological channel, 11 —stand brick, 12 — bushing — guide Varna (100-mm pipe cut 32×5 “stainless”), 13 — blower (or bellows).
A device for removing condensate from bioresorbed:
1 — biohazard, 2 — U-shaped tube (the length of the free branches of the “X” must be greater than expressed in millimeters of water column the pressure of the biogas in the pipeline), 3 — condensate.
Some successful technical solutions others came. And here, nwco finally, the development took the form illustrated.
A cylindrical metal tank — methane tank — with filler neck, drain cock, mechanical stirrer and nozzle selection bogus combined in a compact design (see Fig.), for the manufacture of which is the best fit, for example, the container of chemical fertilizers, other parts and components of “steel”. And he “gazoprovodiv center” is located within the aerobic fermenter, which can sdelat rectangular (e.g., lumber).
Two side walls of the fermenter removable to facilitate the discharge of waste manure. The floor is made of lattice. Beneath it through the technological channel is run air. To do this, use a blower type bellows or a blower.
On top of the fermenter, it is recommended to close the wooden boards. And to reduce the loss of Tepl, walls and floor to comply with the insulation layer.In the digester through the pipe pour prepared manure with cow urine. Humidity “technology of materials” must be in the range of 88-92%. Moreover, the level of this slurry is controlled at the bottom of the filler neck. Same aerobic fermenter through the upper opening part is filled with a solid litter manure or a mixture of the latter with a loose dry organic litter (straw, sawdust) and humidity of 65-69%.
When applying the blower in the fermenter begins to decompose organic matter, heat is generated. It is enough for heating the digester, the contents of which is mixed (good in that there is a special mixer, also known each since high school physical phenomenon of convection). The result is the release of biogas. It accumulates at the top of the honor of maitnence. Through the special nozzle, the biogas is withdrawn in “highway” and use for household needs.
In the operation of this biogas plant (cake, however, and most other devices-nalogov) should be mindful of the need to ensure biochemical balance. Indeed, sometimes the rate of production of acids by bacteria participating in the process anvarovna.. fermentation is higher than the rate of their consumption by the bacteria of another group of participants. In this case, as noted already log in their earlier publications, the acidity of the mass increases and the biogas yield is reduced. The situation can be corrected either by reducing daily ration of raw materials, or an increase in its solubility (hot water), or, finally, by the addition of neutralizing substances (e.g. lime milk, washing or baking soda).
Biogas production can be reduced by estimates of violations of the ratio between carbon and nitrogen. The correct position, entering into the digester substance, containing nitrogen— urine or a small amount of ammonium salts commonly used as chemical fertilizers (50-100 g per cubic meter of raw materials).
We should not forget that the high humidity and the presence of sulfide (the content in the biogas can be up to 0.5%) stimulate increased corrosion of metallic parts of the installation. Therefore, the States of all other elements of the fermenter and maitnence should be controlled regularly. And any damaged parts carefully to protect (best lead minium — in one or two layers, with the subsequent coating with two layers of any oil paint).
The waste after processing in a biogas plant work disinfected. It is good to use as a high quality fertilizer. But beyond that, after all, produced and most importantly — gas. Moreover, in volume, sufficient for two plates.
This setup will pay for itself in a year only due to the recycling of waste in private households.
A. KOVALEV
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