Environmental Engineering Reference
In-Depth Information
16.2 Gas mixture examples with their heating values H
s
in kWh/m
3
as a
function of the biogas upgrading level and propane addition (source:
Urban, 2010)
fluctuation margin of H-gas, southern region of Germany (11.416-
11.513 kWh/m
3
)
.
fluctuation margin of H-gas, North Sea region of Germany (11.783-
11.89 kWh/m
3
)
.
gas with a heating value of 12 kWh/m
3
(in the figure)
.
maximum upper heating value of H-gas, north Germany (12.8 kWh/m
3
)
.
upper heating value limit of H-gas (13.0 kWh/m
3
).
.
In addition to the DVGW set of codes and DIN standards for LPG, other
regulations such DIN 51624 Automotive fuels (DIN, 2008) define standards
for the permitted admixture of LPG to natural gas. In the case of a natural
gas filling station, the permitted molar fraction of propane/butane in the
total mixture may be limited to 6 and 2mole% respectively. DIN 51624 also
requires a methane number higher than 70.
Technically, conditioning gases can also be admixed before the
biomethane is compressed to the required feed-in level. High operating
pressure has no effect on the technical concept of the conditioning facility.
Independent of the network pressure, the limiting factors for conditioning
are only the highest possible mole fractions of the gases for conditioning the
gas mixture.
Considering the gas grades distributed in Germany (Table 16.2) it should
be noted that the injection of biomethane fulfilling all legal requirements is
physically not possible if the natural gas has a heating value higher than
12.0 kWh/m
3
(43.2MJ/m
n
3
) when LPG is used for conditioning.
Injection of biomethane into pipelines with highcalorific value natural
gases can only be achieved under one of the following conditions.
Search WWH ::
Custom Search