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Coconut oil jet fuel matches kerosene's efficiency in engine tests

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Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests

#131

Post by bluebarbet »

runako wrote: post #74
toomuchtodo wrote: post #51

Earlier quoted context omitted.

The last high speed rail I was on was Fuxing Hao series in China, ~200mph. If we can go faster, go faster. Shanghai Maglev can do ~260mph. Japan’s Shinkansen tops out at ~199mph, a bit higher than the TGV in France (~186mph during commercial operations, but has achieved speed records as high as ~360mph). Within the scope of land travel, it’s clear it can be built. If it isn’t built, of course, that’s a choice. But it…

Obviously a choice, but also at 200mph it's obviously a vastly slower experience in a lot of way for many of the most-trafficked US domestic routes. Even at 300mph, which IIRC is much faster than normal operations on existing system, transcontinental travel becomes "too slow." The opposition would be insurmountable to making it take 12+ hours to travel from NYC to LA, for example. Effectively would split the continen…

First, 300 mph (480 kmh) is not on the cards. It's feasible technically but the energy usage rises exponentially, so it's quickly less attractive. (Obviously planes are even more inefficient for exactly the same reason, but wind resistance is at least reduced at altitude.) This is why speeds tend to top out at around 300 kmh, with only a very few prestige services (in China mainly) going marginally faster.

The good news is that 300 kmh is really fast, and rail is usually much more time-efficient at the endpoints (i.e. stations are more central and there's less waiting). In China, Shanghai-Beijing (approximately LA to San Francisco) is now possible in 4h30. Given the endpoint advantage, that is more than competitive with plane travel, and much more pleasant.

As of this year, China also has a high-speed capsule sleeper that gets you from Beijing to Guangzhou (CORRECTION: 1875 km) in 12 hours at an average speed of 180 kmh. It's still night travel, not every American would be interested. But it shows what's possible.

Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests

#132

Post by xp84 »

runako wrote: post #74
toomuchtodo wrote: post #51

Earlier quoted context omitted.

The last high speed rail I was on was Fuxing Hao series in China, ~200mph. If we can go faster, go faster. Shanghai Maglev can do ~260mph. Japan’s Shinkansen tops out at ~199mph, a bit higher than the TGV in France (~186mph during commercial operations, but has achieved speed records as high as ~360mph). Within the scope of land travel, it’s clear it can be built. If it isn’t built, of course, that’s a choice. But it…

Obviously a choice, but also at 200mph it's obviously a vastly slower experience in a lot of way for many of the most-trafficked US domestic routes. Even at 300mph, which IIRC is much faster than normal operations on existing system, transcontinental travel becomes "too slow." The opposition would be insurmountable to making it take 12+ hours to travel from NYC to LA, for example. Effectively would split the continen…

What’s creepy is how little the people arguing for this kind of thing seem to care that the policy would be hated by a majority, and experienced as cruel oppression. They just say “this is the right thing to do.” Climate/degrowth people seem to be the most anti-democratic politically. It seems they NEED to install a monarchy to get their way, because any system of government that allows the people to have any say will never accept the massive sacrifices that they religiously believe are necessary.

Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests

#133

Post by Retric »

WalterBright wrote: post #98
Retric wrote: post #93

Earlier quoted context omitted.

> cheaper than heather options Due to spoilage concerns grocery stores price food based on shelf stability not just production costs. Processed foods are generally shelf stable enough for this not to be a major concern. Similarly economies of scale apply in many situations. Slow cooking beans takes more energy the smaller the batch size due to surface area to volume ratios etc. Combined with the opportunity costs ass…

I bought over a pound of steak the other day for $5. (Yes, it was on sale. But it is frequently on sale.) Along with a potato for 50 cents, that's cheaper than a bag of Doritos. Oh, and I bought a banana for $.22. Cooking a steak takes about 10 minutes. Microwaving a TV dinner ($7.50) takes more time.

Potatoes have a long shelf life and even then it’s not a clear win.

A medium potato is around 110 calories. 15 * 150 calories servings = 5$ that’s 20.45 medium potatoes for 5$ or 24.4c per medium potato. https://www.walmart.com/ip/Doritos-Nacho-Cheese-Tortilla-Sna...

The potato requires prep, 10 minutes in the microwave ~= 1/4 kWh, and presumably a little salt and butter. A microwave meal is a more complete nutrition source and takes less time, making them more complex point of comparison.

Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests

#134

Post by spaceywilly »

pfdietz wrote: post #128
fy20 wrote: post #99

Earlier quoted context omitted.

I'm in Northern Europe and am in that situation. I have an electric heat pump, so would need around 3 MWh over the winter period. Apparently that would need a tank around 4m3 at 700 bar (typical pressure of hydrogen vehicle tanks). Plus the fuel cell actually generate heat, so that could be used for heating too. Doesn't seem terribly unrealistic.

I'm skeptical of any application for hydrogen where electricity could be used directly. In your case, I think hydrogen would better be used in a more centralized power plant as a backup for renewable sources (perhaps with the waste heat then used for district heating), and the power used to drive your heat pump.

The issue is long term, high capacity storage. To store enough energy to last an entire winter using batteries just isn’t practical today. I think you’d need around 100 power walls at today’s capacity to make a house completely off grid, meaning you store excess solar from the summer and draw it down in the winter. With hydrogen stored in pressurized tanks, a 20 m3 tank could be enough to last the whole winter, which seems much more practical than 100 powerwalls.

I think this could be a solution if you wanted a fully off grid, solar powered house, or perhaps if we collectively decide to generate more electricity at home and not rely so much on the grid.

Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests

#135

Post by WalterBright »

Retric wrote: post #133
WalterBright wrote: post #98

Earlier quoted context omitted.

I bought over a pound of steak the other day for $5. (Yes, it was on sale. But it is frequently on sale.) Along with a potato for 50 cents, that's cheaper than a bag of Doritos. Oh, and I bought a banana for $.22. Cooking a steak takes about 10 minutes. Microwaving a TV dinner ($7.50) takes more time.

Potatoes have a long shelf life and even then it’s not a clear win. A medium potato is around 110 calories. 15 * 150 calories servings = 5$ that’s 20.45 medium potatoes for 5$ or 24.4c per medium potato. https://www.walmart.com/ip/Doritos-Nacho-Cheese-Tortilla-Sna... The potato requires prep, 10 minutes in the microwave ~= 1/4 kWh, and presumably a little salt and butter. A microwave meal is a more complete nutrition…

Potato ------

Prep: 5 seconds under the faucet, 10 seconds to quarter it

Cook: 3 min 40 sec in the microwave

TV Dinner: 10 min in the microwave, $7.69 price

Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests

#136

Post by runako »

triceratops wrote: post #79
runako wrote: post #74

Earlier quoted context omitted.

Obviously a choice, but also at 200mph it's obviously a vastly slower experience in a lot of way for many of the most-trafficked US domestic routes. Even at 300mph, which IIRC is much faster than normal operations on existing system, transcontinental travel becomes "too slow." The opposition would be insurmountable to making it take 12+ hours to travel from NYC to LA, for example. Effectively would split the continen…

> The opposition would be insurmountable to making it take 12+ hours to travel from NYC to LA, for example. It already takes 6 hours to fly. Add in security, checked bags, getting to and from the airport and it's close to 10 hours. Also you waste a day or ruin a night's sleep on the redeye. Compared to that an overnight train with a bed sounds delightful. People could do almost-day-trips, coast-to-coast, with no ill…

> It already takes 6 hours to fly. Add in security, checked bags, getting to and from the airport and it's close to 10 hours.

10 hours is still significantly faster than a hypothetical HSR. Remember that it would also have to stop along the way. Secon, not everyone lives/is traveling to a place that is near a hypothetical train station; you have to keep in mind that American cities tend toward sprawl. HSR leaving from e.g. downtown LA would still be less convenient for e.g. the folks who live in the Valley. It's definitely not a 10-hour excursion for many people to transit the country (source: I did this for years for work).

> Also you waste a day or ruin a night's sleep on the redeye.

Highly dependent on the individual & service class. But the point of this is you're actually physically there in less time.

> Leave LA tonight, shop/sightsee/eat all day in NYC, take in a show, hop on the late train back to LA the following day. This is pretty near impossible today unless you have a private jet.

You're going to get a lot of pushback from people who have been to weddings on the other side of the continent, since they will have done this. Most of them do not have private jets, it's just a common thing Americans do.

Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests

#137

Post by xp84 »

triceratops wrote: post #79
runako wrote: post #74

Earlier quoted context omitted.

Obviously a choice, but also at 200mph it's obviously a vastly slower experience in a lot of way for many of the most-trafficked US domestic routes. Even at 300mph, which IIRC is much faster than normal operations on existing system, transcontinental travel becomes "too slow." The opposition would be insurmountable to making it take 12+ hours to travel from NYC to LA, for example. Effectively would split the continen…

> The opposition would be insurmountable to making it take 12+ hours to travel from NYC to LA, for example. It already takes 6 hours to fly. Add in security, checked bags, getting to and from the airport and it's close to 10 hours. Also you waste a day or ruin a night's sleep on the redeye. Compared to that an overnight train with a bed sounds delightful. People could do almost-day-trips, coast-to-coast, with no ill…

You still need all those things for a high speed train. The only reason it’s a little less today is that almost nobody takes passenger rail.

Keep in mind these old downtown stations built in 1900 won’t be able to handle the kind of passenger counts that would “need” to be shifted from the airports, so don’t delude yourself into thinking you wouldn’t need big train stations built in the outskirts, crowded and irritating to get to, like we have with modern airports.

Your day trip thing sounds even more confusing. That itinerary that’s “near impossible” with fast flight becomes more impossible with trains that take 2-3x longer. Also, sleeper train tickets are incredibly expensive compared to coach, because of how much space they take up and the cost of upkeep for these little suites. They’re always going to be expensive, like the redeye flight on a lie-flat bed. So again, no different than what we have today, just much, much slower and less accessible to the masses.

Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests

#138

Post by WalterBright »

tolien wrote: post #106
WalterBright wrote: post #98

Earlier quoted context omitted.

I bought over a pound of steak the other day for $5. (Yes, it was on sale. But it is frequently on sale.) Along with a potato for 50 cents, that's cheaper than a bag of Doritos. Oh, and I bought a banana for $.22. Cooking a steak takes about 10 minutes. Microwaving a TV dinner ($7.50) takes more time.

This canard again [0]? You're comparing one piece of beef with a massive bag of Doritos. The banana's irrelevant, but last time you compared it to an enormous block of chocolate [1]. From experience a microwave meal should take about 3 minutes to cook so I don't know how you're taking more than 10 minutes unless, like your food item comparisons, you're cooking enough of them to feed an entire town. 0: https://news.yc…

Stouffers Spaghetti & Meatballs:

1. Cut film to vent

2. cook 6 1/2 mins on high

3. Let stand 1 min

A frozen pot pie is 10.5 min.

I don't know any frozen dinners for 3 min.

Re: Coconut oil jet fuel matches kerosene's efficiency in engine tests

#139

Post by andriy_koval »

xp84 wrote: post #124
fc417fc802 wrote: post #66

Earlier quoted context omitted.

> If trains were more effective Well they're more convenient by virtue of being faster. The well off will inevitably pay for convenience if allowed. > If California has taught us anything it's that implementation of high speed rail is a joke. The only thing California stands as an example of in that regard is political dysfunction. A hypothetical benevolent dictator could have built out high speed rail there on time…

You’ve got the answer with CAHSR. The only form of government that can build high-speed rail well is one like the CPC: a dictatorship which doesn’t need the consent of the governed. If we put them in charge of CAHSR they would have the job done in a couple years, but we would have to allow them to nationalize every single property in their way, by force if necessary, and cities, towns, unions, etc. would have no righ…

How US builds new highways in this situations, which are not different from rail in context of land use
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