Very long time ago, when excrements called «night gold» (and nightmen, respectively, золотарями), in the name it there were 99 % of irony. And it besides that then on these most золотарях and brought by them from the big city on the village fertilizer kept production so necessary for this nearest city of greens, vegetables and other agricultural production. 
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If to look from the point of view of a science – that after all and really! Subjecting «these fossils» to anaerobny gasification, from a waste we receive almost pure gold. If it is so possible to call net renewable energy.
Alas, in Russia it treat, to put it mildly, carelessly. St. Petersburg until quite recently lowered the sewer drains to the Gulf of Finland, poisoning waters – even Finns complained!
And after all if «this most» to subject to processing in methane tanks, the station of processing serving the city with the population of about 100.000 people, will give 2500 m3 biogases that is equivalent to two tons of gasoline in day!
Using such stations, say, in Moscow, in day we will receive to 200.000 m3 biogases – so the most part of public and city transport of Moscow could work at biogas, saving the same Moscow more than 150.000 liters of oil products (diesel fuel and gasoline) per day. The large regional cities, such as Novosibirsk, Irkutsk, Tula, would receive about 10.000 liters of fuel per day. St. Petersburg could have in day of 80.000 liters. And it – only on the sewerage!
Considering the area of all ranges for a waste (in popular speech – simply "dumps") if to take on the country, and considering that from 1 hectare of such range within a year it is possible to collect 1.000.000 m3 biogases (in the West and collect), the general production of biogas in the country could reach 15 billion m3 a year! However, for this purpose it is necessary to sort at first garbage, then to prepare garbage burials, then there to drill wells, to select being allocated gas…
Potentially (for Russia – potentially, in Europe for a long time it do) a large source of biogas – poultry farming. From one ton of a chicken dung receive the amount of biogas equivalent to 800 liters of gasoline. So on large integrated poultry farms, at a livestock of a bird approximately in 500.000 heads, the biogas exit per day will make of a dung about 100.000 m3 per day that it is enough for work of gas power plant in capacity in 6 MWt.
Cattle – too a powerful source not only milk, but also biofuel. Anaerobnym a sbrazhivaniye from 1 ton of manure receive 350 m3 biogases. One cow in a year can "make" about 900 m3 biogases. And if to count an equivalent in gasoline, it turns out that from one cow it is possible to receive not only milk, but also about 700 liters of gasoline a year.
It is necessary to notice that biogas – it is far not pure methane. Besides about 65 % of methane, in it about 30 % of carbon dioxide, and other about 5 % – nitrogen, hydrogen and oxygen. For cleaning of impurity biogas, for example, pass through water, freeze or at low temperatures subject adsorptions. Biomethane, in which 95-98 % of CH4 as a result turns out. Its warmth of combustion makes 50-55 MDZh/kg that exceeds warmth of combustion of the gasoline, equal 44 MDZh/kg, and its octane number is equal 110 – as it is known, automobile gasolines at us have smaller octane number.
Research was abroad made – gasoline replacement in engines how influences biomethane. Results turned out magnificent, emissions of harmful substances in the atmosphere decreased in comparison with gasoline in times. Thus emissions of a smoke and emissions of an oxide of carbon (carbon monoxide) decreased approximately in 10 times! Plus – absence of liquid fractions improves a smazyvayemost of cylinders of the engine, and therefore its wear considerably decreases.
Now in one only China over 5.000.000 family biogas reactors in which 1.3 billion m3 of biogas are developed annually are maintained, providing with it over 35 million people. Except them some honeycombs of the large biogas stations using for production of biogas an organic waste of animal husbandry and poultry farming work, for processing of a waste of the Chinese cities over 24.000 biogas cleaning reactors function and about 200 biogas power plants work. Thus the total amount of biogas production in China is estimated at 33*1015 J.
Small Denmark annually takes from an organic waste of 4*1015 J, overworking at the 18 biogas plants of 75 % of a waste of animal husbandry and 25 % of other organic waste (at plants about 45 million m3 of biogas are annually made).
In the USA works to 20 large biogas plants one of which, processing a waste from three large feeding complexes, provides with gas the gas-distributing Chicago network. Besides in the USA, Canada and Europe installations on processing of a waste of averages and small cattle breeding farms – to 150 heads of cattle were widely adopted. They regularly develop to 200 m3, providing farms with heat and an electricity in the summer for 100 %, and in the winter – for 30-50 %.
When processing a firm household waste in Sweden receive 5 · 1015 J, in Japan – 6 · 1015 J, in the USA 9 · 1015 J, in Germany – 14 · 1015 J.
Still long ago, about 15 years ago, I was dumbfounded by information that Italy at the expense of processing of the… a biowaste makes 10 % of the natural gas necessary to it!
Generally, all biogas is good, here only for its receiving it is necessary to make efforts and to enter into business a big banknote which will return far not at once. Where as it is simpler to call in on filling and to fill in a full tank of gasoline.