This weekly roundup thread is intended for all culture war posts. 'Culture war' is vaguely defined, but it basically means controversial issues that fall along set tribal lines. Arguments over culture war issues generate a lot of heat and little light, and few deeply entrenched people ever change their minds. This thread is for voicing opinions and analyzing the state of the discussion while trying to optimize for light over heat.
Optimistically, we think that engaging with people you disagree with is worth your time, and so is being nice! Pessimistically, there are many dynamics that can lead discussions on Culture War topics to become unproductive. There's a human tendency to divide along tribal lines, praising your ingroup and vilifying your outgroup - and if you think you find it easy to criticize your ingroup, then it may be that your outgroup is not who you think it is. Extremists with opposing positions can feed off each other, highlighting each other's worst points to justify their own angry rhetoric, which becomes in turn a new example of bad behavior for the other side to highlight.
We would like to avoid these negative dynamics. Accordingly, we ask that you do not use this thread for waging the Culture War. Examples of waging the Culture War:
-
Shaming.
-
Attempting to 'build consensus' or enforce ideological conformity.
-
Making sweeping generalizations to vilify a group you dislike.
-
Recruiting for a cause.
-
Posting links that could be summarized as 'Boo outgroup!' Basically, if your content is 'Can you believe what Those People did this week?' then you should either refrain from posting, or do some very patient work to contextualize and/or steel-man the relevant viewpoint.
In general, you should argue to understand, not to win. This thread is not territory to be claimed by one group or another; indeed, the aim is to have many different viewpoints represented here. Thus, we also ask that you follow some guidelines:
-
Speak plainly. Avoid sarcasm and mockery. When disagreeing with someone, state your objections explicitly.
-
Be as precise and charitable as you can. Don't paraphrase unflatteringly.
-
Don't imply that someone said something they did not say, even if you think it follows from what they said.
-
Write like everyone is reading and you want them to be included in the discussion.
On an ad hoc basis, the mods will try to compile a list of the best posts/comments from the previous week, posted in Quality Contribution threads and archived at /r/TheThread. You may nominate a comment for this list by clicking on 'report' at the bottom of the post and typing 'Actually a quality contribution' as the report reason.
Jump in the discussion.
No email address required.
Notes -
No, any methane in a normal natural gas pipeline is not liquid and will never be a liquid. The critical temperature of methane is -82 C and actual liquid natural gas as made is much colder. It takes special built terminals and a ton of refrigeration and a ton of very expensive insulation. Any methane in a transmission pipeline is either gas or supercritical
Iran-Contra? Manhattan Project? US bombing Cambodia? I mean I generally agree with you that complicated conspiracies' are hard to keep secret. But at least you have to admit that maybe your perception is flawed as you have no idea what the success rate is by definition, as they remain a secret and you only hear about the ones that are revealed.
Supercritical in this case -- the series of engineering case studies of NS 1 linked by @sansampersamp above are frikkin fascinating:
Transportation of Natural Gas in Dense Phase – Nord Stream 1
Part 2: Nord Stream Pipelines – Multiple Parallel Paths to Success or Failure?
Nord Stream Long Distance Gas Pipeline – Part 3 Application of Basic and AGA equations for estimating maximum gas flow in a long‐distance pipeline
It's quite a thing actually -- they are (were) pumping the gas with no booster stations, compressing it to 3190 psi (using a mere half-million horsepower) and having it arrive in Germany still at 1500 psi, enough to distribute it a little ways from the pipeline terminus.
AIUI hydrates are less likely to form in dense phase natural gas, which is one of the advantages of this kind of pipeline -- is that right?
No, that would seem to be a disadvantage of a high pressure pipeline based on the methane hydrate phase diagram you linked, looking at the chart as pressure goes up so does methane hydrate formation.
Supercritical methane: above -82 C and 46 bar
NS1/2 Operating from your first link: 2 to 6 C and 220 to 106 bar
Methane hydrate from the phase diagram you linked elsewhere in the thread: NS1/2 is pretty much exclusively operating in the methane hydrate range, at 2 - 6 C it looks like you need to be under maybe 20 bar to be out of the methane hydrate zone.
So if NS 1 has been operating in the methane hydrate zone for 20+ years why has it not had any issues until now? Well if no water is in the gas stream then no methane hydrate can form. And going off of steam tables and partial pressures at the injection state of 220 bar and 6 C the water content is 43 ppm, which does not leave much water at all for methane hydrate formation. Even less if they stuck the gas stream through a final dehydration step.
Given the above I really question the methane hydrate theory, especially in NS2. I could see at least being possible over time in NS1 as a build up they ignored. But still very doubtful, you'd have to assume that the Russians and Germans both ignored it. For NS2 which hasn't ever been sending gas through, any methane hydrate would be forming out of at most 43 ppm of water that was originally in the pipe when pressurized. Which is a very small amount of methane hydrate.
Above is also assuming that the Russians were not adding any kind of methane hydrate inhibitor to their gas. Or doing any further dehydration after compressing and cooling. Either way the gas is very dry to begin with, so there is not much water to form into methane hydrate, so there won't be much methane hydrate.
https://upload.wikimedia.org/wikipedia/commons/b/b4/Methane_Hydrate_phase_diagram.jpg
https://www.engineeringtoolbox.com/methane-d_1420.html
https://www.thermopedia.com/content/1150/
More options
Context Copy link
More options
Context Copy link
More options
Context Copy link