In article , John
Rumm wrote:
Natural gas as supplied for fuel is about 90% methane CH4, most of the
rest being ethane C2H6 and a little CO2 and N2.

Is the natural gas we have piped naturally in that mixture or is it
blended that way for a reason?

MOST natural gases contain significant ethane mixed with the
methane, though the proportions do vary. (Exception - natural gas produced
by the biological decomposition of organic matter can be essentially pure
methane. But practical gas sources in Western Europe are the result of
natural catalytic cracking, so produce a spread of output compounds
depending on the feedstock and the conditions of cracking.) Ethane is
readily available onshore (and offshore in many cases, from co-processing
of other parts of the field), so mixing to produce the desired blend for
the consumer network is not a major problem.
What happens with re-gasifying LNG (at places like Milford Haven),
I don't know. I could see real arguments going both ways for keeping the
gases pure, or for keeping the gases blended.
--
Aidan
Aberdeen, Scotland
Written at Wed, 11 Jul 2007 00:43 +0100, but posted later.