More on biofuels

The Agricultural wastes and those of the food industry are energy resources, in whose utilization is obtained useful energy while saving the cost of disposal in WWTPs.

There are two main types of waste:

Cellulose which are containing materials: straw, cornstalks, wood:

They are made of natural and biologically stable binopolimers -- cellulose, hemicellulose, lignin. The cellulose and hemicelluloses are polysaccharides which give monosaccharides (glucose, etc.) during its chemical degradation. They are adopted by the animals (ruminants only)too difficult. The ligninat is polyphenols, no nutritional value - it serves to the plant for "cementing" of its tissues. The materials containing cellulose are characterized by large volumes and а fire hazard during the storage.

Wastes from livestock farms:

Faeces, litter (a mixture of faeces with straw), flush water, food wastes. These materials have a diverse composition. They contain inorganic and organic substances, and therefore they are a good environment for all (including pathogenic) microorganisms. The materials are distinguished by high content of organic and inorganic nitrogen. They are a serious problem for farmers as they accumulate in large quantities and pollute the environment, creating poor conditions for both humans and farm animals. Most often the wastes are used to produce methane.

In the natural fermentation of animal feces and other wastes, there is  released methane, which is a "greenhouse gas" and represents  7-10% of global methane pollution. On the other hand, if the  methane is captured and do not fly freely in the atmosphere, it is ecofuel that during its burning pollute the environment minimally. And in the case of incineration of extracts hydrogen from methane there is produced only water.

Energy content of biogas - 22 600 KJ/m3 or 5 400 ccal/m3 (1 KJ = 4.185 ccal). 1 kilograms of methane corresponds to 1.18 kilograms of oil, ie 1 m3 = 1 l fuel oil. From a kilogram of biomass (waste - such as dry matter) is receive 200 - 1200 liters biogas (depending on the composition of biomass and fermentation conditions);