Weekly/monthly (prophylactic) maintenance work
• clean gas appliances;
• lubricate movable parts (slides, guiding frame of floating drum plants, taps etc.);
• servicing of biogas-driven engines within the prescribed time intervals;
• maintenance of pressure relief valves and under pressure valves;
• maintenance of slurry agitator / mixer;
• control gas appliances and fittings on tightness and function
Control of functions
Control
Mistakes
water separator
non-automatic water separator is
full;
piping system
no water is collected in the water
separator; gradient of the pipes is
wrong;
pressure relief and
under pressure non-functioning
valves
Removal
empty the water separator;
Reinstall pipes in a way that
condensation flow leads to the
water separator;
clean valves or renew them
Annual maintenance work
• Check the plant in respect of corrosion and, if necessary, renew protective coating
material;
• Check the gas pipes for gas tightness (pressure check). If necessary, search the
leakage and repair the parts concerned. Note: minor gas leakage is usually
undetected during normal operation as it is ’compensated’ by gas production
Monitoring
Monitoring subsumes all activities of data collection regarding an individual biogas unit or
biogas programs. Collecting data on the performance of biogas units is necessary to
• detect problems in the unit’s performance;
• to have a base for economic evaluation;
• to have a base for comparing different models and different modes of operation
Measurements and other data which become necessary for the optimization of the existing
biogas unit should be recorded by the owner or by a person appointed by him/her. The
records should include the following data:
• The amount and type of substrate, incl. the amounts of mixing water.
• The substrate temperature, if necessary at various stages of the substrate flow
(heated plants). By measuring the substrate temperature, faults in the heating system
can be detected.
• Gas production: measurements are carried out with a gas meter between the digester
and the gas-holder (gas production) or between the gas-holder and the points of
consumption (gas consumption). In simple plants, the gas production can be
estimated during times of no consumption. Changes in gas production and the speed
by which these changes occur give valuable hints on the nature of the problem.
• Electricity and heat production from co-generation units;
• pH-value (monthly); recorded substrate intake;
• content of hydrogen sulfide in the gas (monthly);
• analysis of the fertilizing value of biogas slurry (annually or seasonally) to determine
the optimal amount of slurry to be spread on the fields.
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