Biogas Safety first!

Specific requirements
14. Requirements for fittings and safety devices exposed to gas
Biogas plants have various fittings and safety devices
that are exposed to gas, including:
Overpressure and underpressure
protection devices
flame arrester
gate valve
sampling tap
shut-off valve
dirt separator
etc.
Technical protective measures
Organisational protective measures
Valves and fittings must be easily worked by an operator
adopting a safe stance. Fittings used for gas
withdrawal must be secured against unauthorised
and unintentional opening, for example by locking
the handle.
The work instructions/operating instructions must
state that safety devices are to be checked after an
operational disruption and at regular intervals in normal
operation, taking account of the manufacturer’s
instructions.
Fittings, safety devices and plant parts exposed to
gas must be installed to be frost-proof in accordance
with national guidelines and must be checked
for leaks. They must also be sufficiently resistant to
media, corrosion and pressure.
15. Requirements for gas flares
In order to prevent climate-damaging methane from
being released, various national guidelines require
biogas plants to have alternative gas-consuming
facilities (thermal utilisation). Flare systems are
often used for this purpose. There are different
types of flare, which can essentially be divided into
three categories: open flares; enclosed flame flares
(>850°C) and high-temperature enclosed flame
flares (>1,000°C).
Technical protective measures
Gas flare systems intended for use as alternative gasconsuming
facilities must be continuously ready for
operation and be capable of accepting the maximum
volume of biogas production. The gas flare system
is usually driven by the fill level of the gas storage,
either pressure-controlled or via an external signal.
The length of the ignition intervals must be ensured
by approved control technology. Every gas flare system
must have a safety valve (slow opening/rapid
closing, normally closed) that reliably prevents the
uncontrolled flow of air into the gas system of the
biogas plant. The rapid closing function is executed
in less than one second. The gas flare system must
meet the general requirements for plant parts exposed
to gas (in particular technically leak-tight,
corrosion-resistant and frost-proof – including the
condensate discharge pipe – in accordance with the
explosion protection requirements). Gas flares must
be equipped with a flame arrester
(DIN EN ISO 16852).
This should be fitted as close
as possible to the end-use
equipment.
The heat resistance of the
materials used must be taken
into account, for which for example
manufacturer’s notifications
or a type examination
certificate must be presented.
The necessary minimum gas
supply pressure (flow pressure)
for the gas flare must be
agreed between the manufacturer
and the operator for each
gas flare system. Insufficient
gas supply pressure can lead
to extinguishing of the flame,
especially if it is windy or in
Gas flare
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