Молодой учёный Международный научный журнал

33
“Young Scientist”
. 
# 24.2 (158.2)
. 
June 2017
Спецвыпуск
excess of fat leads to inhibition of the process of biological 
gas formation and even to its complete stop. Therefore, the 
composition of raw materials should be regularly monitored. 
60 percent of methane makes biological gas valuable fuel. 
Methane has no color and smell, it is lighter than air. Does 
not have toxicity. Steam and carbon are produced when it is 
burned. In biological gas plants of a single-stage type, the 
decomposition of raw materials is carried out in one fermenter, 
so biological gas is a gas mixture. Therefore, biological gas is 
a gas mixture. Installations of a two-stage type allow at the 
first stage to remove insignificant gases. And at the second 
get gas with a large percentage of methane.
In addition to methane and carbon dioxide, the 
composition of the biological gas includes hydrogen sulphide, 
which has an aggressive effect on equipment, cylinders, 
burners. Chlorine, fluorine are also aggressive. This is why 
a technology for the removal of hydrogen sulphide and 
hydrocarbons containing halogens is provided on bio-units. 
Biological gas without sulfur has practically no characteristic 
odor. And the absence of hydrocarbons containing chlorine 
and fluorine in it makes the gas less aggressive. To transport 
biological gas, it should be compressed and liquefied. Before 
liquefaction or compression, the gas is completely purified 
from impurities, hydrogen sulphide, carbon dioxide.
The biological gas composition makes it possible to use 
it as an unconventional source of energy, and its production 
prevents the increase of methane content in the atmosphere, 
which is important from the ecological point of view.
The principle of biological exhaust gas cleaning is based 
on microorganisms converting the contents of exhaust gas 
into harmless products. As the process always has to take 
place in a more aqueous phase than is available in the 
microorganisms» habitat, the microorganisms are either 
grown in a film of moisture on a substrate or suspended in an 
aqueous solution. The microorganisms are aerobic bacteria 
that oxidize the contents when oxygen is present.
The degradation performance of the micro-organisms is 
highly dependent on the environmental conditions: not only 
must enough oxygen and nutrients be available, but the 
temperature, pH and moisture levels also have a key role 
to play. Unlike a bio-filter, the advantage of a bio-scrubber 
is that it can control microbiological contamination on the 
exchange surface and keep this at a sufficiently low level.
Biogas is a biofuel produced from the anaerobic 
fermentation of carbohydrates in plant material or waste (e. 
g. Food peeling of manure) by bacteria.
It is mainly composed of methane, with some carbon 
dioxide and other trace gases. However, the proportion 
of methane within the biogas can vary between 50 % and 
80 % depending whether some oxygen is able to enter at 
the beginning or during the process. If some oxygen is 
present the bacteria will respire aerobically and will produce 
a gas with a higher proportion of carbon dioxide and a lower 
proportion of methane.
Biogas can be produced on a small scale in a biogas 
generator, which can be made of simple materials.
The carbohydrate — containing materials are fed in, and 
a range of bacteria anaerobically ferment the carbohydrate 
into biogas. The remaining solids settle to the base of the 
digester and can be run off to be used as fertilizer for the land. 
These types of biogas generator are most commonly used in 
the developing world to satisfy the needs of a small family.
The optimum temperature for biogas production is 
between 32 C and 35 C. temperatures above and below this 
optimum can result in less biogas being produced, which can 
be a problem in hotter and cooler countries (see table below).

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