Environmental Engineering Reference
In-Depth Information
001/02 (CBP, 2005) will then apply. Technical regulations of the DVGW
dealing with safety and interoperability standards or the design, installation
and operation of biogas network connection facilities are listed in Table
16.1.
16.3 Design and operation of injection utilities
The design and operation of biogas injection equipment depend on the
operating conditions of the natural gas grid (pressure, gas composition and
combustion characteristics of the locally distributed natural gas, length of
the pipeline connecting to the supply network) and the type of biogas
upgrading facility. The design of an injection facilitiy is primarily dependent
on the natural gas grid; that is, if it is a distribution grid (low pressure of 30-
100mbar), a regional distribution network (medium pressure of 4-16 bar) or
a supra-regional gas transmission network (high pressure, between 32 and
120 bar).
16.3.1 Basic design of a biomethane gas feed-in station
The feed-in station is the link between the upgrading facility and the public
gas network (Fig. 16.1). At that point, the network operator accepts the
upgraded biogas (biomethane) and is responsible that the gas fed into the
network conforms to the required quality, feed-in pressure and volume of
the gas network. As a general rule, an injection facility consists of the
following components and sub-systems, derived from DVGW VP 265
(DVGW, 2008c).
Compression of the biomethane to the target pressure in the gas
network, or gas pressure regulation (expansion) when fed into a low-
pressure distribution grid.
.
Process control - measuring, monitoring and regulation of all parts and
parameters of the facility.
.
Monitoring the safety of the feed-in station by means of instruments and
mechanical guards (filters, safety shut-off valves, gas backflow guard,
gas pressure regulator, automatic shut-off valves with gas backflow to
the biogas treatment facility, gas mixer, flow regulation), including
protection of the upstream and downstream equipment in terms of
pressure, temperature and composition of the gas.
.
Measuring the gas characteristics, including monitoring the heating
value/Wobbe index of the biomethane and calibrated heating value
measurement. (The Wobbe index is an indicator of the interchange-
ability of fuel gases and is named after Goffredo Wobbe. The Wobbe
.
Search WWH ::
Custom Search