Environmental Engineering Reference
In-Depth Information
Table 19.2 Overview of biomethane transport mechanisms regarding mode of
transport, separation of gas types and back tracing
Physical identity
Mass balancing
'Book and claim',
trading certificates
Biomethane transport inside
closed vessel, e.g. tank truck
or separated grid
Transport e.g. inside
natural gas grid
No physical transport
necessary
.
.
.
No mixing with other gas
types allowed, not even with
other biomethane types
Mixing of
biomethane with
natural gas or other
biomethane types is
possible
Separation of
commodity (natural
gas) and 'biogas
properties' both have
tradable value
.
.
.
The originally produced
molecules are applied
Back tracing from
source to application
is possible
No back trace
possible
.
.
.
electricity from biomethane in CHP plants. Upgrade and feed-in is
supported by special bonuses is these countries.
Three options for regulating transport and balancing mechanisms are
presented in Table 19.2. If physical identity is required to be preserved,
transport needs to be done in a way that prevents mixing with other types of
gas, even with other types of biomethane, for example from different
feedstock (see Table 19.2). Therefore only delivery within closed vessels (e.g.
inside a special tanker or a separate grid) is applicable. At the moment of
feed-in into the public grid, physical identity can no longer be provided.
A mass balancing system is reasonable, if mixing with other (fossil)
commodities is allowed, but the path from application back to the source
needs to be traceable (see Table 19.2). In this way, conventional means of
transport can be used as long as mass balancing is operated in parallel as
well. Mass balancing is defined in the EU directives 2009/28/EC and 2009/
30/EC.
A certificate system ('book and claim') makes sense if only promotion of
the special (green) product is desired and the transport chain to the customer
can be neglected (see Table 19.2). In this case, the green properties are
separated from the gas, which is then treated as natural gas. The green
properties are traded separately, and tracing back to source is usually
impossible. On application, the certificate is recombined with natural gas
and afterwards regarded as biomethane again. The guarantee of origin
system is (vaguely) defined in directives 2001/77/EC (repealed) and 2004/8/
EC for the European electricity market: the corresponding certificate, for
example, guarantees the renewable origin of a certain amount of (electric)
energy.
The topic and claim option is the more simple and more flexible. It is
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