Monthly Archives: September 2026

It was better in Dubai before Iran attacked

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Dubai is a gorgeous, clean, modern city in the Emirates state of Abu Dhabi. As such it is Abu Dhabi’ as it were, Abu Dhabi’s gateway into being a modern Islamic Republic. All religions are respected in the city of Dubai, though not elsewhere in the Emirates. Alcohol and nightclubs are permitted, even encouraged, along with western books, movies, and music. There’s fast Internet, low taxes, free newspapers, and great plane connections via Emirates Air, along with premiere hotels, Ferraris, lots of them, and villas on peninsulas shaped like palm trees. Dubai is promoted with the phrase, “It’s better in Dubai,” Other promotions included having the Sex in the City movie filmed there and hosting the 2022 FIFA World Cup. And then Iran attacked with 5000 drones and missiles, hitting hotels, below and oil shipping. Three Emirates oil ships struck in the last week alone, leaving one crew member dead, 20 injured. Some rich people are fleeing, while others are staying. The airport is still open, as are the eyes of some rich folks in the US and Europe. It’s not so great in Dubai, but not that bad either. I don’t think Dubai is going away, and expect it to grow, slowly.

Photos from Dubai after an attack last week.

A similar pattern is playing out in Qatar’s western-style area of Doha. This is a section of the capital city that allows alcohol, and has fast internet, air-conditioning, western religion, movies, and books. I’d written, with wonder about Qatar, with its rich citizens and indentured, workers. I would have thought Doha would be safe from Iranian missiles since Qatar is Shia Mulsim, like Iran. It too is being hit, and not only in the western areas. Iran also destroyed Qatar’s largest natural gas and oil facilities, and their helium plant. The problem for Iran is that Qatar isn’t Shia Islamic enough to make them happy. Alternately, Qatar is rich, and Iran is jealous. Destruction is the answer, but the city endures, and I expect it will grow.

Saudi Arabia was in the process of building the beginnings of its own, modern gateway city, NEOM. It’s more conservative religiously than Dubai, but more technically advanced, envisioned with robots, solar energy, and zero cars. It’s in the early stages, but already attacked by Iran. The motivation, I expect, is to insure that the king doesn’t sign the Abraham accords with Israel and Abu Dhabi. The king has slowed construction, but not stopped, or stopped working with the US.

While these attacks are clearly a setback for these western-enclaves, I don’t expect Saudi Arabia, Qatar, and Abu Dhabi will shut them down. Dubai, Doha, and Neom are attractive, and seen as a necessary part of a post oil future. I suspect the attacks only bring resentment of Iran and its mullahs, plus a desire for increased spending on defense. The attacked countries may ally with each other, something unlikely before the attacks perhaps through expended Abraham accords, or via some other defense cooperation. I also imagine that the gateway cities will grow, allowing conservative Muslims to become more comfortable with Western ideas and behaviors.

I don’t expect Iran to change, nor copy these cities, nor do I expect their influence to weaken much. They have oil and a powerful ally, China, who depends on Iranian oil. China benefits by Iran fighting China’s western rivals, or it did before sanctions. I expect Iran to make more trouble for us and their neighbors, especially when Democrats win congress in a few months. I’m not totally sure why Democrats are sanguine about a nuclear Iran as negotiated by Obama, or seem OK with Iran bombing their neighbors for no good reason. Then again, I don’t quite understand “Queers for Palestine.” Most liberals are unhappy, and my guess is that the Iran leadership is too. Both are happy seeing Dubai and Doha bombed. Even with the bombs falling, I see these cities as a gate to a more peaceful, more tolerant Middle East.

Robert Buxbaum September 14, 2026

Hydrogen stripping by membrane extraction

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We occasionally make hydrogen stripper systems where the goal is to strip the hydrogen, and sometimes other gases from a mixed gas leaving everything else in place. We use metal membranes, coiled as shown below, if the gas to be removed is hydrogen. For other gases H2S, siloxanes, we use polymeric membranes. In either case, it’s not a product we advertise, but it’s worthy of a blog post.

A typical customer was a Cambridge researcher using gas chromatography with hydrogen as the carrier gas to separate a series of compounds. He now wanted to recover the separated compounds without the hydrogen.

A hydrogen extractor during manufacture.

To minimize the amount of membrane needed, I like to create a plug flow. If the flow is low, or there isn’t much hydrogen, we use a single coiled membrane. If the flow is high or there is a lot of hydrogen, we use several straight membranes in parallel, typically with baffles; we even have a patient for this. Some customers want to recover the hydrogen. If so, we extract it with a vacuum pump. Other customers just want the hydrogen gone. For these oxidation works well. The reaction H2 + 1/2 O2 –> H2O is essentially irreversible, and quite fast on a palladium surface.

A basic analysis is to assume that flux is proportional to hydrogen pressure in the gas, and calculate the hydrogen pressure as total pressure, P, times the fraction of hydrogen in the mixed gas, H/(H + inerts) .

Then, for any small amount of membrane area, dA, the small amount of hydrogen removed per second, dH equals the area, dA, times the permeance of the membrane, P, times P, times H/(H + inerts): dH = -PP (H/(H+Inerts)) dA.

We now rearrange the above: dH(H+Inerts)/H = -PP dA, and integrate:

∫ dH ( H+Inerts)/H = ∫(1 + inerts/H) dH = ∫ -PP dA. It’s found that

Hi – Hf , + inerts • ln (Hi)/(Hf) = PPA. Thus,

A = (Hi – Hf )/PP + (Inerts/PP) ln (Hi)/(Hf).

where A is the total area of membrane needed, inerts = the inert gas flow per second, and and Hi and Hf ate the hydrogen flow rates in the mix at the beginning and end of the extraction. Hi – Hf equals the total amount of hydrogen removed per second.

Note that the first term dominates in the beginning of the extraction process, or where there is a lot of hydrogen content, ln 1 =0), and the pressure of hydrogen is essentially P. The logarithmic term dominates in latter (final) stages, where the inert content is the majority and hydrogen content changes fast. In these later stages, very little hydrogen removal decreases the partial pressure by half, but a significant area of membrane is needed to remove every successive 50% since the hydrogen pressure is continuously decreasing by 50%.

You can derive similar equations for normal distillation, as used to make liquor or refine gasoline. You can also modify the above expression because permeation isn’t always proportional to pressure but to the difference of Pressure to some power, the 1/2 power, or so. I should also mention that, in membrane distillation and liquor it is important to continuously remove components that can build up in the still. For membrane- based hydrogen stripping, we do this using a back-pressure controller, or a flow controller. Thus, if you know you have a feed of 95% hydrogen, 5% desirable inerts, you want a to maintain a suitable back-pressure and you want a flow controller that lets mostly inerts out of the process with minimal H2.

She was only the moonshiner’s daughter, but he lover her still.

Robert Buxbaum, September 6, 2026.