Boots and Oil Blog: If I have Volts, and I need eV, how do I get that?...: Originally posted in 2011, updated 2.1.18 : Watching some welding work being done today reminded me of a post about electron volts. The l...
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Just running some numbers, and my calculations could be wrong. In the post, I noted that the hydrogen boron fusion reaction ( aneutronic ) yields approx 8 million electron volts. Sounds like a lot, but a joule has a trillion times that much. Not to worry. A gram of hydrogen has 10 billion joules of energy, if my calculations are correct. ( My calculations could easily be wrong, but it is indeed a lot of energy ). How much is 10 billion joules? Over 2.7 gigawatt hours. Remember how Doc Brown went berserk in the movie "Back to the Future", when he realized he need gigawatts of energy?
It may not be that much, though.
Well, the idea is that you won't need much hydrogen in order to produce a bunch of energy. But we knew all of that already, did we not?
Incidentally, I read somewhere that a fusion space engine might have an ISP of a million. Now, running the numbers on that one yields some really interesting observations. For instance, in a chemical rocket, 98 percent or more of the rocket's mass is for fuel. However, if a rocket had an ISP of 1 million, 99 percent of the rocket ship could be devoted to things other than fuel. Wow.
Friday, March 22, 2019
Thursday, March 21, 2019
NASA's Big Mistake?
Notice the question mark?
The big mistake may have been in cancelling the program. Composite tank problems was the reason given for the cancellation, but aluminum tanks were built as a backstop. In other words, the thing could have flown. Eventually, the composite tank issues were solved, but the project was suppressed "at the highest levels". Political decision in spite of the facts? Why would it be anything else? Considering what has been happening in this country in recent times, a political decision can not be ruled out.
The big mistake may have been in cancelling the program. Composite tank problems was the reason given for the cancellation, but aluminum tanks were built as a backstop. In other words, the thing could have flown. Eventually, the composite tank issues were solved, but the project was suppressed "at the highest levels". Political decision in spite of the facts? Why would it be anything else? Considering what has been happening in this country in recent times, a political decision can not be ruled out.
Thorium news
So, what's been happening with the project to bring Thorium energy to the world?
There doesn't appear to be as much going on as before. The Thorium Energy Alliance hasn't had a meeting in over a year. There isn't one planned for this year, or if there is, it isn't mentioned on their website.
Kirk Sorensen still has his Flibe Energy company going. Flibe is working on something fairly recently, but the results haven't been discussed on Sorensen's Twitter feed. There is this one tidbit:
There is something on Flibe Energy on its website, and it is dated from October of last year. The video describes an opportunity to do what they wanted to do, and was won in a competitive bid for the Energy Dept. funding. Sorensen will report on the results by the end of the year, he says.
Well, that's something. It is all I have for now.
There doesn't appear to be as much going on as before. The Thorium Energy Alliance hasn't had a meeting in over a year. There isn't one planned for this year, or if there is, it isn't mentioned on their website.
Kirk Sorensen still has his Flibe Energy company going. Flibe is working on something fairly recently, but the results haven't been discussed on Sorensen's Twitter feed. There is this one tidbit:
Our @PNNLab #NuclearEnergy team is partnering with Flibe Energy on advanced reactor R&D funded by @Energy. https://t.co/NTb9ocmpZa Our research looks at using nitrogen trifluoride to remove uranium from a #MoltenSalt fuel mixture. pic.twitter.com/t1Uj5C5g0o— Energy at PNNL (@energyPNNL) July 18, 2018
There is something on Flibe Energy on its website, and it is dated from October of last year. The video describes an opportunity to do what they wanted to do, and was won in a competitive bid for the Energy Dept. funding. Sorensen will report on the results by the end of the year, he says.
Well, that's something. It is all I have for now.
Wednesday, March 20, 2019
LOP-G or Gateway
The LOP-G ( Lunar Orbital Platform-Gateway ) architecture involves putting a space station in orbit around the moon.
In an earlier post, with respect to Zubrin, it would appear to be a useless and expensive effort. Compare that with nothing at all.
The LOP-G is expected to do science. Since it is mostly a political effort, this is about as good as it gets. It is a political effort because NASA has been political since its start. Besides that, it is international. Not only do you have to deal with American politics, you have to deal with the politics of international partners. This is like herding cats.
Of the most useful scientific efforts, human health and performance in space, should be of long term interest in going to Mars. It is out of the Earth's protective shadow, so we should be able to find out the long term effects of exposure to cosmic radiation.
NASA proposes to use this Gateway as a staging point for its Deep Space Transport craft. Which is probably another boondoggle, but this is government. That is the way it is.
Like it or not, NASA has a plan. I don't know if it should be ditched just because of some successes in the private spaceflight field. Over time, those successes may make the government effort seem rather timid, but until then, it is all we got.
The LOP-G is expected to do science. Since it is mostly a political effort, this is about as good as it gets. It is a political effort because NASA has been political since its start. Besides that, it is international. Not only do you have to deal with American politics, you have to deal with the politics of international partners. This is like herding cats.
Of the most useful scientific efforts, human health and performance in space, should be of long term interest in going to Mars. It is out of the Earth's protective shadow, so we should be able to find out the long term effects of exposure to cosmic radiation.
NASA proposes to use this Gateway as a staging point for its Deep Space Transport craft. Which is probably another boondoggle, but this is government. That is the way it is.
Like it or not, NASA has a plan. I don't know if it should be ditched just because of some successes in the private spaceflight field. Over time, those successes may make the government effort seem rather timid, but until then, it is all we got.
Going to Mars is a terrible idea
This guy is so negative that if you still like the idea to go to Mars, better stop here... and not watch this video!
Actually, you should watch. By the way, this is why we should continue to work in closer to Earth until we master the technologies first. This may take awhile. Getting a plausible way to getting there is just the first step.
BBC News - UK's air-breathing rocket engine set for key tests
Not ready for flight tests, it is a test of the pre-cooler systems. These tests have occurred earlier, but the upcoming tests are a bit more rigorous, if I am understanding the story correctly.
If it goes on a Skylon spaceplane, it will be a SSTO platform. Didn't someone ask the question of: do these "suck"?
The Skylon might be better than a flying gas can. That's what they said about the cancelled VentureStar SSTO program. The key is re-usability and a quick turnaround time. Smaller payloads could be justified if the turnaround time was shorter. The idea is cheaper operations. Lower cost to orbit.
BBC News - UK's air-breathing rocket engine set for key tests https://t.co/VjAWPzfoh8— Greg Meadows (@BootsandOilBlog) March 20, 2019
SpaceX's raptor engine
An explanation for the meaning of the term "full flow staged combustion cycle". Quite a mouthful there.
Just say "new design" that hasn't been on a flight yet. In other words, it is breaking new ground. It isn't really a new design. It is simply a design that hasn't flown yet. Say what???? There have been rocket engines on test stands like this one, but nobody has actually flown one. The video doesn't explain why.
Yep, and the now cancelled VentureStar aerospike engines were tested on a stand, but never flew either. Doesn't mean that they won't work, just means that for whatever reason, they never flew.
Tuesday, March 19, 2019
High temperature steam electrolysis
It is said to be more efficient than at lower temperatures. If a kilogram of hydrogen can be produced for 225 megajoules, and a gallon of gasoline ( which is equivalent to about a kilogram of hydrogen in terms of energy ) yields about 126 megajoules.
Obviously, you lose something in the conversion. Thus, you lose about 100 megajoules this way. To produce gasoline from the hydrogen thus obtained would not be very efficient at all.
The thought I had was not to make carbon based fuels, but ammonia instead. You might even do some cogeneration in order to make the energy conversions more efficient. Ammonia could be made this way, and can be used as a hydrogen carrier to boot.
One objection to fuel cells as a power source, in comparison with batteries, was the relatively lower efficiency rate. One reason for this was the necessity for compression or liquifaction of the hydrogen. To do this requires a lot of energy, and these losses degrades efficiency, thereby adding to the problem. Fuel cells are still more efficient than gasoline powered ICE engines.
To beat batteries, I suggest making ammonia, and then cracking it on an as-needed basis. The ammonia will be the hydrogen carrier, thus alleviating the necessity to achieve cryogenic temperatures, and high pressures. Ammonia crackers can possibly be put on a car, and the weight penalty might not be too bad. Less than that of batteries, I suspect. Batteries add a tremendous weight penalty.
Now, can we get the hydrogen source from a means that would increase efficiency so that the cost of operating a fuel cell car may be comparable to a gasoline powered ICE vehicle? Perhaps not, but it might not matter if the energy source is cheaper.
Let's go back to the production of hydrogen seen earlier. If it was to be produced with a molten-salt reactor, which is cheaper than coal to begin with, and if it utilized steam electrolysis to produce the the hydrogen and then ammonia, it would have to get back that 100 megajoules mentioned above in order to compete on efficiency. But, you could do that ( on the basis of price ) if the energy source is cheaper, as is the case with molten-salt reactors. With a higher efficiency than ICE engines, a fuel cell power source would get back more, if not all, of that efficiency penalty, and the rest could be made up by the lower price of the molten-salt reactor derived energy.
In the end, could it be cheaper than gasoline if you were to use this method? I think that it may be possible. Better than batteries? Maybe not in terms of efficiency, but once again, molten-salt reactor tech wins on price.
Update:
After digging in a little deeper, I found something that may throw a money wrench into this idea. If it takes 389 kilojoules of energy to break just one of the nh3 bonds, then that's the monkey wrench. In other words, the idea of using ammonia as a hydrogen carrier may be flawed. Too inefficient.
I'm gobsmacked.
Obviously, you lose something in the conversion. Thus, you lose about 100 megajoules this way. To produce gasoline from the hydrogen thus obtained would not be very efficient at all.
The thought I had was not to make carbon based fuels, but ammonia instead. You might even do some cogeneration in order to make the energy conversions more efficient. Ammonia could be made this way, and can be used as a hydrogen carrier to boot.
One objection to fuel cells as a power source, in comparison with batteries, was the relatively lower efficiency rate. One reason for this was the necessity for compression or liquifaction of the hydrogen. To do this requires a lot of energy, and these losses degrades efficiency, thereby adding to the problem. Fuel cells are still more efficient than gasoline powered ICE engines.
To beat batteries, I suggest making ammonia, and then cracking it on an as-needed basis. The ammonia will be the hydrogen carrier, thus alleviating the necessity to achieve cryogenic temperatures, and high pressures. Ammonia crackers can possibly be put on a car, and the weight penalty might not be too bad. Less than that of batteries, I suspect. Batteries add a tremendous weight penalty.
Now, can we get the hydrogen source from a means that would increase efficiency so that the cost of operating a fuel cell car may be comparable to a gasoline powered ICE vehicle? Perhaps not, but it might not matter if the energy source is cheaper.
Let's go back to the production of hydrogen seen earlier. If it was to be produced with a molten-salt reactor, which is cheaper than coal to begin with, and if it utilized steam electrolysis to produce the the hydrogen and then ammonia, it would have to get back that 100 megajoules mentioned above in order to compete on efficiency. But, you could do that ( on the basis of price ) if the energy source is cheaper, as is the case with molten-salt reactors. With a higher efficiency than ICE engines, a fuel cell power source would get back more, if not all, of that efficiency penalty, and the rest could be made up by the lower price of the molten-salt reactor derived energy.
In the end, could it be cheaper than gasoline if you were to use this method? I think that it may be possible. Better than batteries? Maybe not in terms of efficiency, but once again, molten-salt reactor tech wins on price.
Update:
After digging in a little deeper, I found something that may throw a money wrench into this idea. If it takes 389 kilojoules of energy to break just one of the nh3 bonds, then that's the monkey wrench. In other words, the idea of using ammonia as a hydrogen carrier may be flawed. Too inefficient.
I'm gobsmacked.
Sunday, March 17, 2019
Off-grid post, 2.18.19--- Next step
Updated,
3.17.19:
It may be better to check out the possibility that of simply turning right toward to the cabin site, instead of making all those turns. If there isn't any impediment to that, that would be the best bet.
2.18.19:
After only 3 hours out there, and nothing else done, I am now regretting that I couldn't do
more. Besides drilling a hole, and filling it back in, I did scout around a bit in the
immediate area for a possible cabin site.
This is like everything else in this project--- easier said than done. Sure, I stepped out
a possible turnaround zone for the trailer, but after examining the waypoints, it doesn't
appear to be large enough without some clearing of vegetation. That is what is needed
next.
An idea came to me to put the cabin in another spot which I had marked in an earlier trip.
This spot is just to the east of a "plowed" region that has since disappeared. The deep
rows are now worn down, and it may be easier to use that as a drive way as opposed to clearing
out a spot from this other place. The distances are okay, so it is just a matter of which
of these two spots that I will end up picking. The one with the least amount of work
should win. It may sound pretty lazy, but there are no real advantages of one over the other.
Or, I should say, no advantages except by ease of access. The area I contemplated on this
last trip would require a turnaround. This area that I am reconsidering will require no
turnaround. I would just pull straight in, after a right turn. The other would require
several turns. A right turn, then a left turn, then a circle around before pulling in.
Therefore, the simplest procedure would be to pull straight in. So, the next trip would
involve checking out this other alternative location.
After this has been decided, the next step would be to clear out the vegetation.
3.17.19:
It may be better to check out the possibility that of simply turning right toward to the cabin site, instead of making all those turns. If there isn't any impediment to that, that would be the best bet.
2.18.19:
After only 3 hours out there, and nothing else done, I am now regretting that I couldn't do
more. Besides drilling a hole, and filling it back in, I did scout around a bit in the
immediate area for a possible cabin site.
This is like everything else in this project--- easier said than done. Sure, I stepped out
a possible turnaround zone for the trailer, but after examining the waypoints, it doesn't
appear to be large enough without some clearing of vegetation. That is what is needed
next.
An idea came to me to put the cabin in another spot which I had marked in an earlier trip.
This spot is just to the east of a "plowed" region that has since disappeared. The deep
rows are now worn down, and it may be easier to use that as a drive way as opposed to clearing
out a spot from this other place. The distances are okay, so it is just a matter of which
of these two spots that I will end up picking. The one with the least amount of work
should win. It may sound pretty lazy, but there are no real advantages of one over the other.
Or, I should say, no advantages except by ease of access. The area I contemplated on this
last trip would require a turnaround. This area that I am reconsidering will require no
turnaround. I would just pull straight in, after a right turn. The other would require
several turns. A right turn, then a left turn, then a circle around before pulling in.
Therefore, the simplest procedure would be to pull straight in. So, the next trip would
involve checking out this other alternative location.
After this has been decided, the next step would be to clear out the vegetation.
Saturday, March 16, 2019
The Truth about hydrogen
This is a fairly comprehensive critique of energy efficiencies of hydrogen versus battery electric.
Sure, battery electric appears more efficient, but they are using grid electricity, not solar panels or wind turbines.
Believe me, I've studied the topic. The best combination in terms of efficiency might well be nuclear and battery electric. But battery electric has its issues as well. It's too darned heavy and too darned slow to charge. The author is probably a bit biased in favor of battery electric.
Note: There is a plug on the video for skillshare. That is an interesting idea in itself.
Sure, battery electric appears more efficient, but they are using grid electricity, not solar panels or wind turbines.
Believe me, I've studied the topic. The best combination in terms of efficiency might well be nuclear and battery electric. But battery electric has its issues as well. It's too darned heavy and too darned slow to charge. The author is probably a bit biased in favor of battery electric.
Note: There is a plug on the video for skillshare. That is an interesting idea in itself.
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