When operation a biogas plant attention should be paid to the following:
• Inhalation of biogas in large quantities over a long period of time can cause poisoning as hydrogen sulphide, contained in biogas is quite poisonous. Unfiltered biogas smells of rotten eggs, but when filtered does not have any smell. Therefore all premises where household biogas appliances are located should be regularly ventilated. Gas pipes should be regularly checked for impermeability and protected from damage. Gas leaks should be located by using liquid soap or soapy water or special appliances. Using open fire to check for gas leaks is prohibited.
• Mixture of biogas and air in proportions of 5% to 15 % and presence of inflammation source with temperature of 600°C and above can lead to explosions. Open fire is dangerous when concentration of biogas in the air exceeds 12 %. Therefore, it is prohibited to smoke or make fire near the biogas plant. Welding works should not be conducted within 10 meters of biogas plant. After unload of substrate out of the digester for repair works digester should be ventilated as there is a danger of explosion of mixture of biogas and air.
• Pressure of gas in piping system that carries it to gas appliances should not exceed 0,15 МПа (1,5 kg/cm2), and in proximity of appliances should not exceed 0,13 kg/cm2. Digester should be fitted with catches and hydraulic hitches that could if necessary cut it off from the gas piping system. Digester should have a automatic safety valve that would release excessive pressure inside it when it exceeds the norm.
• Used electric appliances should be grounded. Ground lead resistance should not exceed 4 Ohm.
• Main sources of sanitary danger are helminth eggs, colon bacillus bacteria and other pathogenic micro flora that is present in the manure. Therefore it is necessary to observe preventive measures for averting infection. It is not recommended to eat in stables and in proximity of biogas plant.
• Digester and substrate storage tank should be designed in a way to avoid the danger of people falling in.
State technical control service requirements
Construction, exploitation and servicing of biogas plants should comply with the requirements of the “Rules of construction and safe exploitation of vessels operated under pressure” of State technical control service, if biogas plant design includes:
• vessels operation under pressure over 0,07 МПА (0,7 kg/cm2).
• balloons for transportation and storage of gases compressed under pressure above 0,07 МПА (0,7 kg/cm2).
• tanks and barrels for transportation of compressed gases pressure of which under temperature of under 50ºС exceeds 0,07 МПА (0,7 kg/cm2).
For servicing biogas plants and gas works only qualified personnel aged over 18 and possessing permission from the State technical control service of the Kyrgyz Republic in form of an id card of due form stating that they have a right to service biogas plants and gas works.