Advanced tech without electricity/internal combustion?

Belial666 wrote:Once you got liquid air, LOx is as easy as opening the container and letting the nitrogen boil off. We did that in the university. We did not get pure LOx but we did get a good enough mixture to be usable as oxidant. So the problem is essentially getting liquid air, which was done back in 1883.




Any engineering problem is an issue of how many man-hours you put into it, once the base tech is discovered and refined. Have a high enough production and cost is going to fall rapidly because in the modern world "cost" is merely a function of supply vs demand rather than objective technological difficulties.

Yes it was done in 1883, but not in industrial quantities, which is what you are going to have to have to make much use of it outside of a laboratory oddity.

TN4994 wrote:

Draken wrote:So what about using kerosene or other light fraction of oil as fuel, when Merlin will show them the most efficient way to get cracking running, oil shouldn't be a very big problem.

It was written about kraken oil for lamps, and firevine oil for lubricants.

Yes, and the son of the largest kraken oil supplier studying other oils to replace it and thus become an oil company.

Since Safehold has coal, it would seem to be logical to invest in the Fischer–Tropsch process and convert the already available coal into a substitute petrochemical fuel and feedstock. Fuels created by the F-T process are chemically similar to diesel fuel.

The Fischer–Tropsch process was invented in 1925, and can be tweaked to use iron as a catalyst, which makes many of the issues of cost and availability go away.

Coal isn't the only possible feedstock, charcoal or even garbage can be pyrolized (burnt in a low or no oxygen environment) to provide the CO feedstock, which makes this rather flexible. The main limitation would be to provide industrial supplies of Hydrogen, but there have been several threads discussing that possibility already.

fallsfromtrees wrote:

Belial666 wrote:Once you got liquid air, LOx is as easy as opening the container and letting the nitrogen boil off. We did that in the university. We did not get pure LOx but we did get a good enough mixture to be usable as oxidant. So the problem is essentially getting liquid air, which was done back in 1883.




Any engineering problem is an issue of how many man-hours you put into it, once the base tech is discovered and refined. Have a high enough production and cost is going to fall rapidly because in the modern world "cost" is merely a function of supply vs demand rather than objective technological difficulties.

Yes it was done in 1883, but not in industrial quantities, which is what you are going to have to have to make much use of it outside of a laboratory oddity.

Yes, it is done in industrial quantities in most heavy industrial sites that need either nitrogen or oxygen in large quantities but the evaporation is done in a distillation column (usually embedded in a cold box). The biggest problems are water and carbon dioxide because they freeze in awkward places if not scrubbed out (LNG plants have the same problems). Not hard - just a real power hog.
A little LN2 is useful if you want to fit bushes into fine machinery and even moderate purity oxygen has a massive impact on steel making.

Belial666 wrote:Once you got liquid air, LOx is as easy as opening the container and letting the nitrogen boil off. We did that in the university. We did not get pure LOx but we did get a good enough mixture to be usable as oxidant. So the problem is essentially getting liquid air, which was done back in 1883.




Any engineering problem is an issue of how many man-hours you put into it, once the base tech is discovered and refined. Have a high enough production and cost is going to fall rapidly because in the modern world "cost" is merely a function of supply vs demand rather than objective technological difficulties.

fallsfromtrees wrote:Yes it was done in 1883, but not in industrial quantities, which is what you are going to have to have to make much use of it outside of a laboratory oddity.

AirTech wrote:Yes, it is done in industrial quantities in most heavy industrial sites that need either nitrogen or oxygen in large quantities but the evaporation is done in a distillation column (usually embedded in a cold box). The biggest problems are water and carbon dioxide because they freeze in awkward places if not scrubbed out (LNG plants have the same problems). Not hard - just a real power hog.
A little LN2 is useful if you want to fit bushes into fine machinery and even moderate purity oxygen has a massive impact on steel making.

It is done TODAY in industrial quantities. It was not done in 1883, with 1883 tech in industrial quantities. As you pointed out, the requirements to get water and CO2 out are real power hogs, and TODAY that means electricity, which is something Safehold is not going to have for a considerable period of time.

fallsfromtrees wrote:It is done TODAY in industrial quantities. It was not done in 1883, with 1883 tech in industrial quantities. As you pointed out, the requirements to get water and CO2 out are real power hogs, and TODAY that means electricity, which is something Safehold is not going to have for a considerable period of time.

Basic Oxygen steel making is a massive step up from the Bessemer process and making liquid oxygen is technically feasible even with riveted pressure vessels (read steam boiler technology). Weather it is worth developing at Charis's current tech level with a war on is another question entirely. Possible yes, needed questionable. Electricity needed, emphatically no.
Water, H2S and CO2 can be readily separated with molecular sieves (like zeolites)using thermal regeneration quite easily. Pressure swing oxygen absorbers could be another possible technology to be exploited where liquid form or ultra high purity gas is not needed.

Another thought.
Would there be a better man transmission if we hadn't concentrated the effort toward the internal combustion engine?
The development of the diesel engine stalled because the internal combustion engine became more popular.
Just throwing it out there for debate.

TN4994 wrote:Another thought.
Would there be a better man transmission if we hadn't concentrated the effort toward the internal combustion engine?
The development of the diesel engine stalled because the internal combustion engine became more popular.
Just throwing it out there for debate.

Unfortunately Diesel is one of three main types of internal combustion engine, the others being otto cycle (primarily used with gasoline) and gas turbines.

Diesel development stalled due to Otto cycle working much better in small engines. I have read claims that early (ca. 19000) diesels used most of their power output, just keeping themselves running. Diesel develop did continue due to there being need for engines smaller than steam boilers and larger than Otto cycle. Early adopters of diesels were trains and factories where they ran powershafts. The first generation of Submarines used Otto Cycle engines, however they fairly quickly went to diesels due to the increased safety of diesel fuel compared to gasoline.

Much of what drove Earthly technology was a quest for high power to weight ratios. Diesel and Stirling engines were quite sufficient for many tasks, especially stationary engine tasks, and have many advantages over Otto or Brayton (or even Rankin) cycle engines, but the low power to weight ratio's of early Stirling and Diesel engines caused many people to overlook them, and the desire for high power to weight ratio's drove the development of competing engine designs farther and faster. (Jet engines in particular are a great example, despite being fuel thirsty and hogs at low RPM, their compact size and high thrust or shaft power easily trumps any other engine in aviation applications).

Only in specific applications where the advantages of Diesel or Stirling engines trump the advantages of power to weight do you see any concerted efforts to develop these alternatives. Fire safety helped the adoption of Diesel engines, and their superior fuel economy helped cement their position in many industrial and naval applications.

Stirling engines are still niche players (primarily used for AIP rigs on conventional submarines), but perhaps economic considerations might change to the extent that Stirling engines can move into other niches.

Because of the peculiar position of Safehold, Diesel and Stirling engines will be able to fill more niches than on Earth, and if/when electricity becomes available, these engines will have had many years of development and a large installed base of users, mechanics and infrastructure to support their use, making it difficult for Otto cycle engines to break in.

Thucydides wrote:...
Stirling engines are still niche players (primarily used for AIP rigs on conventional submarines), but perhaps economic considerations might change to the extent that Stirling engines can move into other niches.
...

Early Stirlings had indeed bad power/mass ratios because of lack of low-friction seals allowing to pressurize them at least 5 bars. This is a solved problem.

Modern Stirlings with 10/12 bars internal pressure are quite good, but the IC tech is so developed everywhere that it is much cheaper to produce. Stirlings are also the most efficient engine possible.

The main use nowadays of stirlings is for cryo generation (used as motor) or as generators either in solar applications or cogeneration. There is a renewed interest for small stirlings (a few cc) where IC and diesel are very inefficient.

In Safehold case, IC is no go because of the electrical problem, and if Diesel can be made without, you have launch problems. Stirlings on the other hand, can replace any steam engine with a better efficiency (fuel economy) for a lower mass and insurance against boiler explosion. So there is no reason that in Safehold, they cannot become the main engine if the seals can be made. Teflon and the like are out of question of course but textile seals highly charged with graphite, while onerous to make should work.

Another advantage of stirlings is that they are extremely reliable.