Tag Archives: energy

Sailors, boaters, and motor sailing at the hull speed.

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I’ve gone sailing a few times this summer, and once again was struck by the great difference between sailing and boating, as well as by the mystery of the hull speed.

Sailors are distinct from boaters in that they power their boats by sails in the wind. Sailing turns out to be a fairly pleasant way to spend an afternoon. At least as I did it, it was social, pleasant, and not much work, but the speeds were depressingly slow. I went on two boats (neither were my own), each roughly 20 feet long, with winds running about 10-15 knots (about 13 mph). We travelled at about 3 knots, about 3.5 mph. That’s walking speed. At that speed it would take about 7 hours to cross Lake St. Clair (25 miles wide). To go across and back would take a full day.

Based on the length of the boats, they should have been able to go a lot faster, at about 5.8 knots (6 mph). This target speed is called the hull speed; it’s the speed where the wave caused by the bow provides a resonance at the back of the boat giving it a slight surfing action, see drawing.

This speed can be calculated from the relationship between wave speed and wavelength, so that Vhull = √gλ/2π where g is the gravitational constant and λ is the water line length of the boat. For Vhull in knots, it’s calculated as the square-root of the length in feet, multiplied by 1.34. For a 20 foot boat, then,

Hull speed, 20′ = 1.34 √20 = 1.34 x 4.5 = 6.03 knots.

While power boats routinely go much faster than this, as do racing skulls and Americas cup sailboats, most normal sailboats are designed for this speed. One advantage is that it leads to a relatively comfortable ride. There is just enough ballast and sail so that the boat runs out of wind at this speed while tipping no more than 15°. Sailors claim there is a big increase in drag at this speed, but a look at the drag profile of some ocean kayaks (12 to 18 feet, see below) shows only a very slight increase around this magical speed. More important is weight; the lowest drag in the figure below is found for the shortest kyack that is also the lightest. I suspect that the sailboats I was on could have gone at 6 knots or faster, even with our current wind, if we’d unrolled the spinnaker, and used a ‘screecher’ (a very large jib), and hung over the edge to keep the boat upright. But the owner chose to travel in relative comfort, and the result is that we had a pleasant afternoon going nowhere.

Data from Vaclav Stejskal of “oneoceankyacks.com”

And this brings me to my problem with power boating. Th boats are about the same length as the sailboats I was in, and the weight is similar too. You travel a lot faster, 20 to 25 knots, and you get somewhere, but the boats smell, and provide a jarring ride, and I felt they burn gas too fast for my comfort. The boats exceed hull speed and hydroplane, somewhat. That is, they ride up one wave, fly a bit, and crash down the other side, sending annoying wakes to the sailboaters. We crossed lake St. Clair and rode a way down the Detroit river. This was nice, but it left me thinking there was room for power -assisted sailing at an intermediate speed, power sailing.

Both sailboats I was on had outboard motors, 3 hp, as it happened, and both moved nicely at 1 hp into and out of the harbor, even without the sail up. Some simple calculations suggest that, with I could power a 15 to 20 foot sailboat or canoe at a decent speed – hull speed – by use of a small sail and an electric motor drawing less than 1 hp, ~400 W, powered by one or two car batteries.

Consider the drag for the largest, heaviest kayak in the chart a move, the Cape Ann Double, going at 6.5 knots. At 6 knots, the resistance is seen to be 15 lbs. To calculate the power demand, convert this speed to 10 fps and multiply by the force:

Power for 6 knot cruising = 10 fps x 15 lbs = 150 ft lbs/s = 202 W or 0.27 hp.

Outboard motors are not 100% efficient, so let’s assume that you need to draw more like 250 W at the motor, and you will need to add power by a sail. How big a battery is needed for the 250 W? I’ll aim for powering a 4 hour trip, and find the battery size by multiplying the 250 W by 4 hours: that’s 1250 Hrs, or 1.25 kWh. A regular, lithium car battery is all that’s needed. In terms of the sail, I’m inclined to get really invovative, and use a Flettner sail, as discussed here.

It seems to me that adding this would be a really fun way to sail. I’d expect to be able to go somewhere, without the smell, or the cost, or being jarred to badly. Now, all I need is a good outboard motor, and a willing companion to try this with.

Robert Buxbaum, Sept. 9, 2024

How I size heat exchangers

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Heat exchange is a key part of most chemical process designs. Heat exchangers save money because they’re generally cheaper than heaters and the continuing cost of fuel or electricity to run the heaters. They also usually provide free, fast cooling for the product; often the product is made hot, and needs to be cooled. Hot products are usually undesirable. Free, fast cooling is good.

So how do you design a heat exchanger? A common design is to weld the right amount of tubes inside a shell, so it looks like the drawing below. The the hot fluid might be made to go through the tubes, and the cold in the shell, as shown, or the hot can flow through the shell. In either case, the flows are usually in the opposite direction so there is a hot end and a cold end as shown. In this essay, I’d like to discuss how I design our counter current heat exchangers beginning a common case (for us) where the two flows have the same thermal inertia, e.g. the same mass flow rates and the same heat capacities. That’s the situation with our hydrogen purifiers: impure hydrogen goes in cold, and is heated to 400°C for purification. Virtually all of this hot hydrogen exits the purifier in the “pure out” stream and needs to be cooled to room temperature or nearly.

Typical shell and tube heat exchanger design, Black Hills inc.

For our typical designs the hot flows in one direction, and an equal cold flow is opposite, I will show the temperature difference is constant all along the heat exchanger. As a first pass rule of thumb, I design so that this constant temperature difference is 30°C. That is ∆THX =~ 30°C at every point along the heat exchanger. More specifically, in our Mr Hydrogen® purifiers, the impure, feed hydrogen enters at 20°C typically, and is heated by the heat exchanger to 370°C. That is 30°C cooler than the final process temperature. The hydrogen must be heated this last 30°C with electricity. After purification, the hot, pure hydrogen, at 400°C, enters the heat exchanger leaving at 30°C above the input temperature, that is at 50°C. It’s hot, but not scalding. The last 30°C of cooling is done with air blown by a fan.

The power demand of the external heat source, the electric heater, is calculated as: Wheater = flow (mols/second)*heat capacity (J/°C – mol)* (∆Theater= ∆THX = 30°C).

The smaller the value of ∆THX, the less electric draw you need for steady state operation, but the more you have to pay for the heat exchanger. For small flows, I often use a higher value of ∆THX = 30°C, and for large flows smaller, but 30°C is a good place to start.

Now to size the heat exchanger. Because the flow rate of hot fluid (purified hydrogen) is virtually the same as for cold fluid (impure hydrogen), the heat capacity per mol of product coming out is the same as for mol of feed going in. Since enthalpy change equals heat capacity time temperature change, ∆H= Cp∆T, with effectiveCp the same for both fluids, and any rise in H in the cool fluid coming at the hot fluid, we can draw a temperature vs enthalpy diagram that will look like this:

The heat exchanger heats the feed from 20°C to 370°C. ∆T = 350°C. It also cools the product 350°C, that is from 400 to 50°C. In each case the enthalpy exchanged per mol of feed (or product is ∆H= Cp*∆T = 7*350 =2450 calories.

Since most heaters work in Watts, not calories, at some point it’s worthwhile to switch to Watts. 1 Cal = 4.174 J, 1 Cal/sec = 4.174 W. I tend to do calculations in mixed units (English and SI) because the heat capacity per mole of most things are simple numbers in English units. Cp (water) for example = 1 cal/g = 18 cal/mol. Cp (hydrogen) = 7 cal/mol. In SI units, the heat rate, WHX, is:

WHX = flow (mols/second)*heat capacity per mol (J/°C – mol)* ∆Tin-out (350°C).

The flow rate in mols per second is the flow rate in slpm divided by 22.4 x 60. Since the driving force for transfer is 30°C, the area of the heat exchanger is WHX times the resistance divided by ∆THX:

A = WHX * R / 30°C.

Here, R is the average resistance to heat transfer, m2*∆T/Watt. It equals the sum of all the resistances, essentially the sum of the resistance of the steel of the heat exchanger plus that of the two gas phases:

R= δm/km + h1+ h2

Here, δm is the thickness of the metal, km is the thermal conductivity of the metal, and h1 and h2 are the gas-phase heat transfer parameters in the feed and product flow respectively. You can often estimate these as δ1/k1 and δ2/k2 respectively, with k1 and k2 as the thermal conductivity of the feed and product, both hydrogen in my case. As for, δ, the effective gas-layer thickness, I generally estimate this as 1/3 the thickness of the flow channel, for example:

h1 = δ1/k1 = 1/3 D1/k1.

Because δ is smaller the smaller the diameter of the tubes, h is smaller too. Also small tubes tend to be cheaper than big ones, and more compact. I thus prefer to use small diameter tubes and small diameter gaps. in my heat exchangers, the tubes are often 1/4″ or bigger, but the gap sizes are targeted to 1/8″ or less. If the gap size gets too low, you get excessive pressure drops and non-uniform flow, so you have to check that the pressure drop isn’t too large. I tend to stick to normal tube sizes, and tweak the design a few times within those parameters, considering customer needs. Only after the numbers look good to my aesthetics, do I make the product. Aesthetics plays a role here: you have to have a sense of what a well-designed exchanger should look like.

The above calculations are fine for the simple case where ∆THX is constant. But what happens if it is not. Let’s say the feed is impure, so some hot product has to be vented, leaving les hot fluid in the heat exchanger than feed. I show this in the plot at right for the case of 14% impurities. Sine there is no phase change, the lines are still straight, but they are no longer parallel. Because more thermal mass enters than leaves, the hot gas is cooled completely, that is to 50°C, 30°C above room temperature, but the cool gas is heated at only 7/8 the rate that the hot gas is cooled. The hot gas gives off 2450 cal as before, but this is now only enough to heat the cold fluid by 2450/8 = 306.5°. The cool gas thus leave the heat exchanger at 20°C+ 306.8° = 326.5°C.

The simple way to size the heat exchanger now is to use an average value for ∆THX. In the diagram, ∆THX is seen to vary between 30°C at the entrance and and 97.5°C at the exit. As a conservative average, I’ll assume that ∆THX = 40°C, though 50 to 60°C might be more accurate. This results in a small heat exchanger design that’s 3/4 the size of before, and is still overdesigned by 25%. There is no great down-side to this overdesign. With over-design, the hot fluid leaves at a lower ∆THX, that is, at a temperature below 50°C. The cold fluid will be heated to a bit more than to the 326.5°C predicted, perhaps to 330°C. We save more energy, and waste a bit on materials cost. There is a “correct approach”, of course, and it involves the use of calculous. A = ∫dA = ∫R/∆THX dWHX using an analytic function for ∆THX as a function of WHX. Calculating this way takes lots of time for little benefit. My time is worth more than a few ounces of metal.

The only times that I do the correct analysis is with flame boilers, with major mismatches between the hot and cold flows, or when the government requires calculations. Otherwise, I make an H Vs T diagram and account for the fact that ∆T varies with H is by averaging. I doubt most people do any more than that. It’s not like ∆THX = 30°C is etched in stone somewhere, either, it’s a rule of thumb, nothing more. It’s there to make your life easier, not to be worshiped.

Robert Buxbaum June 3, 2024

Ferries make more sense than fast new trains.

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Per pound mile of material, the transport cost by ship is 1/4 as much as by train, and about 1/8 as much as by truck. Ships are slower, it is true, but they can go where trucks and trains can not. They cross rivers and lakes at ease and can haul weighty freight with ease. I think America could use many more ferries, particularly drive-on, fast ferries. I don’t think we need new fast rail lines, because air travel will always be faster and cheaper. The Biden administration thinks otherwise, and spends accordingly.

Amtrak gets $30 Billion for train infrastructure this year, basically nothing for ferries.

The Biden administration’s infrastructure bill, $1.2 Trillion dollars total, provides $30 Billion this year for new train lines, but includes less than 1% as much for ferries, $220 million, plus $1B for air travel. I think it’s a scandal. The new, fast train lines are shown on the map, above. Among them is a speed upgrade to the “Empire Builder” train running between Chicago and Seattle by way of Milwaukee. I don’t think this will pay off — the few people who take this train, takes it for the scenery, I think, and for the experience, not to get somewhere fast.

There is money for a new line between Cleveland and Detroit, and for completion of the long-delayed, and cost-over-run prone line between LA and San Francisco. Assuming these are built, I expect even lower ridership since the scenery isn’t that great. Even assuming no delays (and there are always delays), 110 mph is vastly slower than flying, and typically more expensive and inconvenient. Driving is yet slower, but when you drive, you arrive with your car. With a train or plane, you need car rental, typically.

New Acela train, 150 mph max. 1/4 as fast as flying at the same price.

Drive-on ferries provide a unique advantage in that you get there with your car, often much faster than you would with by driving or by train. Consider Muskegon to Milwaukee (across the lake), or Muskegon to Chicago to Milwaukee, (along the lake). Cleveland to Canada, or Detroit to Cleveland. No land would have to be purchased and no new track would have to be laid and maintained. You’d arrive, rested and fed (they typically sell food on a ferry), with your car.

There’s a wonderful song, “City of New Orleans”, sung here by Arlo Guthrie describing a ride on the historic train of that name on a trip from Chicago to New Orleans, 934 miles in about one day. Including stops but not including delays, the average speed is 48 mph, and there are always delays. On board are, according to the song, “15 restless riders, 3 conductors, and 25 sacks of mail.” The ticket price currently is $200, one way, or about as much as a plane ticket. The line loses money. I’ve argued, here, for more mail use to hep make this profitable, but the trip isn’t that attractive as a way to get somewhere, it’s more of a land-cruise. The line is scheduled for an upgrade this year, but even if upgraded to 100 mph (14 hours to New Orleans including stops?) it’s still going to be far slower than air travel, and likely more expensive, and you still have to park your car before you get on, and then rent another when you get off. And will riders like it more? I doubt it, and doubt the speed upgrade will be to 100 mph.

Lake Express, 30 mph across Lake Michigan

Ferry travel tends to cost less than train or plane travel because water traffic is high volume per trip with few conductors per passenger. At present, there are only two ferryboats traveling across Lake Michigan, between Michigan and Wisconsin, Milwaulkee to Muskegon. They are privately owned, and presumably make money. The faster is the Lake Express, 30 mph. It crosses the lake in 2.5 hours. Passenger tickets cost $52 one way, or $118 for passenger and car. That’s less than the price of an Amtrak ticket or a flight. I think a third boat would make sense and that more lines would be welcome too. Perhaps Grand Haven to Racine or Chicago.

Route of the Lake Express. I’d like to see more like this; St. Joseph to Milwaukee say, and along Lake Erie.

Currently, there are no ferries across Lake Erie. Nor are there any along Lake Erie, or even across Lake St. Clair, or along the Detroit River, Detroit to Toledo or Toledo to Cleveland. These lines would need dock facilities, but they would have ridership, I think. New York’s Staten Island ferry has good ridership, 35,000 riders on a typical day, plus cars and trucks. In charge are roughly 120 engineers, captains and mates, one employee for every 300 passengers or so. By comparison, Amtrak runs 300 trains that carry a total of 87,000 passengers on an average day, mostly on the east coast. These 300 trains are run by 17,100 employees as of fiscal year 2021, one employee for every 4 passengers. Even at the slow speeds of our trains the cost is far higher per passenger and per passenger mile.

The Staten Island ferry is slow, 18.5 mph, but folks don’t seem to mind. The trip takes 20 minutes, about half as long as most people’s trips on Amtrak. There are also private ferry lines in NY, many of these on longer trips. People would take ferries for day-long trips along our rivers, I think. Fast ferries would be nice, 40 mph or more, but I think even slow ferries would have ridership and would make money. A sea cruise is better than a land cruise, especially if you can have a cabin. On the coal-steam powered, Badger, you can rent a state-room to spend the night in comfort. Truckers seem to like that they cover ground during their mandatory rest hours. The advantage is maximized, I think, for ferry trips that take 12 hours or so, 250 to 350 miles. That’s Pittsburgh to Cincinnatti or Chicago to Memphis.

New York’s Staten Island ferry leaves every 15 minutes during rush hour. Three different sizes of boat are used. The largest carry over 5000 passengers and 100 cars and trucks at a crossing.

A low risk way to promote ferry traffic between the US and Canada would be to negotiate bilateral exemption to The Jones Act and its Canadian equivalent. Currently, we allow only US ships with US crews for US travel within the US.* Cabotage it’s called, and it applies to planes as well, with exemptions. Canada has similar laws and exemptions. A sensible agreement would allow in-country and cross-country travel on both Canadian and US ships, with Canadian and/or US crew. In one stoke, ridership would double, and many lines would be profitable.

Politicians of a certain stripe support trains because they look futuristic and allow money to go to friends. Europeans brag of their fast trains, but they all lose money, and Europe had to ban many short hop flights to help their trains compete. Without this, Europeans would fly. There is room to help a friend with a new ferry, but not as much as when you buy land and lay track. We could try to lead in fancy ferries going 40 mph or faster, providing good docks, and some insurance. Investors would take little risk since a ferry route can be moved**. Don’t try that with a train.

In Detroit we have a close up of train mismanagement involving the “People Mover.” It has no ridership to speak of. Our politicians then added “The Q line” to connect to it. People avoid both lines. I think people would use a ferry along the Detroit river, though, St. Claire to Wyandotte, Detroit, Toledo — and to Cleveland or Buffalo. Our lakes and rivers are near-empty superhighways. Let’s use them.

Robert Buxbaum, January 2, 2024. *The US air cabotage act (49 U.S.C. 41703) prohibits the transportation of persons, property, or mail for compensation or hire between points of the U.S. in a foreign civil aircraft. We’ve managed exemptions, though, e.g. for US air traffic with Airbus and Embraer planes. We can do the same with ferries.

** I notice that it was New York’s ferries, and their captains, that rescued the people on Sullenberger’s plane when it went down in the Hudson River — added Jan. 6.

Hydrogenation, how we’ve already entered the hydrogen economy

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The hydrogen economy is generally thought to come in some distant future, where your car (and perhaps your home) runs on hydrogen, and the hydrogen, presumably, is made by clean nuclear or renewable solar or wind power. This is understood to be better than the current state of things where your car runs on dirty gasoline, and your home runs on coal or gas, except when the sun is shining bright and the wind is blowing hard. Our homes and cars can not run on solar or wind alone, although solar cells have become quite cheap, because solar power is only available in the daytime, basically for 6 hours, from about 9AM to 3PM. Hydrogen has been proposed as a good way to store solar and wind energy that you can’t use, but it’s not easy to store hydrogen — or is it? I’d like to suggest that, to a decent extent, we already store green hydrogen and use it to run our trucks. We store this hydrogen in the form of Diesel fuel, so you don’t realize it’s hydrogen.

Much of the oil in the United States these days comes from tar sands and shale. It doesn’t flow well at room temperature, and is too heavy and gooey for normal use. We could distill this crude oil and use only the light parts, but that would involve throwing away a huge majority of the oil. Instead we steam reform it to gasoline, ethylene and other products. The reaction is something like this, presuming an input feed of naphtha, C10H8:

C10H8 + 2 H2O –> C7H8 + C2H4 + CO2.

The C2H4 component is ethylene. We use it to make plastics. The C7H8 is called toluene. It is a component of high octane gasoline (octane rating about 114). The inventor of the process, Eugene Jules Houdry claimed to have won WWII for the allies because his secret process (Houdryflow catalytic cracking) allowed high production of lots of gasoline of very high octane, giving US and British planes and trucks higher mpg than the Germans or Japanese had. It was a great money maker, but companies can make even more by adding hydrogen.

Schematic of the hydrocracking process, from the US energy information agency

Over the last 2-3 decades, refineries have been adding catalytic hydrogenation processes. These convert high octane aromatic products, like toluene to low -octane diesel and jet fuel. These products sell for more. Aromatic toluene is exposed to hydrogen at about 500°C and 300 psi (20 bar) to produce heptane, an excellent diesel fuel with about 7% more energy content than toluene per gallon.

C7H8 + 4H2 –> C7H16.

Diesel fuel sell for about 20% more than gasoline per gallon, in part because of the higher energy content, and because Diesel engines are more efficient than gas engines. What’s more, toluene expands as it’s converted to heptane. One gallon of toluene converts to 1.16 gallons of heptane. As a result hydrogenation adds about 40% to the sales price per molecule. Refineries have found that they can make significant money this way if they can buy cheap hydrogen. Over the last few years, several refineries in Norway and Texas (high sun and wind areas) have added hydrogenators along with electrolysis units to produce the cheap hydrogen when no one needs the unwanted electricity generated when supply exceeds demand. Here is an analysis of the thermodynamics of this type of hydrogen generation.

Robert Buxbaum, May 11, 2023

Germany is the biggest loser in a long Ukraine war

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Early in the Ukraine War with Russia, Poland sent 200 T-72 battle tanks to Ukraine. Most other NATO members joined in, sending tanks, missiles, guns, supplies and technology. Germany sent nothing and have continued to avoid helping Ukraine as much as possible while the war dragged on for a year. Germany seems to have hoped for a quick Russian victory leading to a quick return to the pre-war, state of affairs. That’s not likely. Even early on, the war looked like a slow, long slog. Reluctantly, this month, Germany promised to send 18 Leopard tanks to Ukraine, requesting as replacements, mothballed tanks from Switzerland.

Germany is currently the 4th largest economy in the world, just behind Japan, and ahead of India (for now). They also have the 3rd oldest population. Their place as the leading economic and political power in Europe rests on a close relationship with Russia that is fading, bringing Russian goods west and manufacturing with them. Before the war, Germany imported most of its oil and 65% of its natural gas from Russia. Much of the gas came via two direct pipelines, Nord Stream, that bypassed the rest of Europe. Well into the war, while the rest of Europe disengaged, Germany is still buying from Russia and funneling it west: steel, aluminum, titanium, ammonia and platinum. Germany is still buying some Russian natural gas by way of Poland. The German economy is based on turning these materials into cars, high tech machines, and chemicals for export to the US, the EU, and China. Despite the very old population, Germany counts on cheap labor from low wage EU nations. These transient, long term. workers do not get citizenship or retirement benefits. The current war has presented Germany with more potential workers, Ukrainian refugees, but far fewer Russian supplies. The German economy is shrinking, and so far, the Ukrainian refugees have been mostly left unemployed.

Ex German Chancellor, Gerhard Schroeder, with Putin. He’s now head of Nordstream and Rosneft.

German industrial production is down by about 4% this year leaving its GPD at about $4T/year, about where it was in 2018. The US economy and the rest of Europe has grown. For an explanation, consider Germany’s ex-chancellor, Gerhard Schroeder, shown at left with Putin. Schroder remains a leader in the ruling SDP party, the party of Ms Merkel and of the current chancellor. He is also the chairman of the board for Nord Stream AG and of Rosneft, (Russian aerospace). He also sits on the board for Gasprom (Russia’s energy conglomerate), Rothschild, a prominent International bank, and is chairman of the board of the Hannover 96 football club. He is symbolic of Germany’s attachment to Putin and Russia. But the rest of the EU, along with the rest of the developed world, has come to hate Putin and Russia (they’re not too fond of Rothchild either). Europe is unlikely to tolerate Germany’s Russian imports, including titanium (65% of Airbus titanium comes from Russia) or natural gas. Germany has asked for a titanium exception (and been denied). What’s more, three of the four Nord Stream pipelines have been blown up (by whom?) leaving Germany to buy natural gas from its NATO allies: Norway, Britain, France Holland, and the US. Gas purchases are expensive for Germany while helping its NATO neighbors — Germany has asked to be subsidized for energy too (unlikely, imho). It has also restarted old coal-burning power plants, an insult to the EU given how hard Germany pushed them on climate change.

Germany is now near recession. Much of Europe is close, but Germany is worse-off since they are buying from the rest.

Percent of population over 65, CIA Factbook.

Much of the EU can sell gas and food to Germany, and Russia can export to China, India, and Iran. German inflation averaged 8.5% last year (9.2% in January). That is not hyperinflation, but a shock for a country that’s averaged 1% inflation over the last 25 years. US inflation, by comparison was 7.5% last year — due to excess spending by the Democrats (imho), the so- called “inflation reduction act,” but at least the US economy grew, along with the US population. It seems to me that, without Russian supplies, Germany will continue to slip versus the world and versus the EU.

Excess mortality for European countries has been very high for the last 6 months, especially in Germany. Death rates are up by 25% or so. Much of it is heart-related. Perhaps it’s COVID, or long COVID, or air pollution, or vaccines, or depression.

The German population is dying too. They too among the highest percent population over 65, see map. The death rate has spiked 25% over the last 6 months, too. Europe and much of the EU saw similar spikes earlier in the pandemic, partially from COVID, the rest is alcoholism, drugs, the vaccine, pollution, or a psycho-somatic response to isolation and the war. Sweden has largely avoided these problems so far.

Germany has been propping up its inefficient industries with low cost loans. The idea, presumably, is that things will go back to normal soon, and the companies will make good. So far, the war goes on, and the loans discourage competition and modernization. It becomes ever more likely that these inefficient German companies will default. If so, they could take down their lenders as happened in Japan in the 90s, and as happened to Lehman Bros. in the US. The same seems likely for China.

It becomes ever more likely that these inefficient German companies will default.

Even if the war ended tomorrow, it’s not clear that Germany could go back to its pre-war status. The blown Nord Stream pipelines will need a year or more to repair. And may never restart, as sanctions might remain long after the fighting ends, as with Cuba or North Korea. Russia seems to have recognized this possibility, and has begun sending titanium, gas, and oil elsewhere, mostly to Iran, India, and China. Iran has become a major customer of Russian aluminum, and food, and is a major supplier of drones and consumer goods to Russia. In the last two years, the Iranian GDP has doubled to about $2T/year. It is now nearly half the size of Germany’s GDP and growing while Germany shrinks.

Russia’s trade with India and China has grown too. They are working to improve the Trans-Iranian railroad that would allow easy shipments from Russia to India and China via the port of Tehran. The first direct shipment of this sort was completed in July 2022– Caspian Sea containers to an Iranian train to ship to India and China. If the war goes on, Iran, India, and China will benefit at the expense of Germany, it seems. India, in particular. India’s economy is already approaching the size of Germany’s, and will probably pass it with the help of Russia’s energy and raw materials. Meanwhile, Germany is left with an aging population and aging industries; with few suppliers, and no obvious competitive advantages. Europe is almost as badly positioned, but they can still sell to Germany. As for Ukraine, it seems to be doing well, despite the war — or because of it. They still grow and export food and energy, and they are holding their own in the war, for now. There is destruction in the east, but Ukraine might come out stronger, as happened with South Korea and Vietnam. Russia too seems to have found new customers and might come out OK. It is hard to see how Germany comes out well. This, at least, is how I see things today.

Robert Buxbaum, March 8, 2023.

Plans to Raise-the-Dead-Sea

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The Dead Sea in Israel is a popular tourist attraction and health resort-area. It is also the lowest point on the planet, with a surface about 430m below sea level. Its water is saturated with an alkaline salt, and quite devoid of life, and it’s shrinking fast, loosing about 1 m in height every year. The Jordan river water that feeds the sea is increasingly drawn off for agriculture, and is now about 10% of what it was in the 1800s. The Dead Sea is disappearing fast, a story that is repeated with other inland seas: the Aral Sea, the Great Salt Lake, etc. In theory, one could reverse the loss using sea water. In theory, you could generate power dong this too: 430m is seven times the drop-height of Niagara Falls. The problem is the route and the price.

Five (or six) semi-attractive routes have been mapped out to bring water to the Dead Sea, as shown on the map at right. The shortest, and least expensive is route “A”. Here, water from the Mediterranean enters a 12 km channel near Haifa; it is pumped up 50m and travels in a pipe for about 52 km over the Galilean foothills, exiting to a power station as shown on the elevation map below. In the original plan the sea water feeds into the Jordan river, a drop of about 300m. The project had been estimated to cost $3 B. Unfortunately, it would make much of the Jordan river salty. It was thus deemed unacceptable. A variation of this would run the seawater along the Jordan in a pipe or an open channel. This would add to the cost, and would likely diminish the power that could be extracted, but you would not contaminate the Jordan.

A more expensive route, “B”, is shorter but it requires extensive tunneling under Jerusalem. Assuming 20 mies of tunnel at $500 MM/mile, this would cost $10B. It also requires the sea water to flow through the Palestinian West Bank on its way to the sea. This is politically sensitive and is unlikely to be acceptable to the West Bank Palestinians.

Vertical demand of the northern route

Two other routes, labeled “C” and “D” are likely even more expensive than route B. They require the water to be pumped over the Judaean hills near Bethlehem, south of Jerusalem. That’s perhaps 600m up. The seawater would flow from Ashkalon or Gaza and would enter the Dead Sea at Sodom, near Masada. Version C is the most politically acceptable, since it’s short and does not go through Palestinian land. Also, water enters the dead sea at its saltiest point so there is no disruption of the environment. Route D is similar to C, somewhat cheaper, but a lot more political. It goes through Gaza.

The longest route, “E” would go through Jordan taking water from the Red Sea. Its price tag is said to be $10 B. It’s a relatively flat route, but still arduous, rising 210m. As a result it’s not clear that any power would be generated. A version of this route could send the water entirely through Israel. It’s not clear that this would be better than Route C. Looking things over, it was decided that only routes that made sense are those that avoided Palestinian land. An agreement was struck with Jordan to go ahead with route D, with construction to begin in 2021. The project has been on hold though because of cost, COVID, and governmental inertia.

In order to make a $5-10B project worthwhile, you’ll have to generate $500MM to $1B/year. Some of this will come from tourism, but the rest must come from electrical power generation. As an estimate of power generation, let’s assume that that the flow is 65 m3/s, just enough to balance the evaporation rate. Assuming a 400 m power drop and an 80% efficient turbine, we should generate 80% of 255 MWe = about 204 MWe on average. Assuming a value of electricity of 10¢/kWh, that translates to $20,000/ hour, or $179 million per year. This is something, but not enough to justify the cost. We might increase the value of the power by including an inland pond for water storage. This would allow power production to be regulated to times of peak load, or it could be used for recreation, fish-farming, or cooling a thermal power station up to 1000 MWe. These options almost make sense, but with the tunnel prices quoted, the project is still too expensive to make sense. It is “on hold” for now.

It’s not like the sea will disappear if nothing is done. With 10% of the original in-flow of water to the Dead Sea, it will shrink to 10% its original size, and then stop shrinking. At that point evaporation will match in-flow. One could add more fresh water by increasing the flow from the sea of Galilee, but that water is needed. When more water is available, more is taken out for farming. This is what’s happened to the Arial Sea — it’s now about 10% the original size, and quite salty.

Elon Musk besides the prototype 12 foot diameter tunnel.

There’s a now a new tunnel option though and perhaps these routes deserve a second look: Elon Musk claims his “Boring company” can bore long tunnels of 12 foot diameter, for $10-20 MM/mile. This should be an OK size for this project. Assuming he’s right about the price, or close to right, the Dead Sea could be raised for $1B or so. At that price-point, it makes financial sense. It would even make sense if one built multiple seapools, perhaps one for swimming and one for energy storage, to be located before the energy-generating drop, and another for fish after. There might even be a pool that would serve as coolant for a thermal power plant. Water in the desert is welcome, even if it’s salt water.

Robert Buxbaum, February 14, 2023.

Fusion advance: LLNL’s small H-bomb, 1.5 lb TNT didn’t destroy the lab.

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There was a major advance in nuclear fusion this month at the The National Ignition Facility of Lawrence Livermore National Laboratory (LLNL), but the press could not figure out what it was, quite. They claimed ignition, and it was not. They claimed that it opened the door to limitless power. It did not. Some heat-energy was produced, but not much, 2.5 MJ was reported. Translated to the English system, that’s 600 kCal, about as much heat in a “Big Mac”. That’s far less energy went into lasers that set the reaction off. The importance wasn’t the amount in the energy produced, in my opinion, it’s that the folks at LLNL fired off a small hydrogen bomb, in house, and survived the explosion. 600 kCal is about the explosive power of 1.5 lb of TNT.

Many laser beams converge on a droplet of deuterium-tritium setting off the explosion of a small fraction of the fuel. The explosion had about the power of 1.2 kg of TNT. Drawing from IEEE Spectrum

The process, as reported in the Financial Times, involved “a BB-sized” droplet of holmium -enclosed deuterium and tritium. The folks at LLNL fast-cooked this droplet using 100 lasers, see figure of 2.1MJ total output, converging on one spot simultaneously. As I understand it 4.6 MJ came out, 2.5 MJ more than went in. The impressive part is that the delicate lasers survived the event. By comparison, the blast that bought down Pan Am flight 103 over Lockerbie took only 2-3 ounces of explosive, about 70g. The folks at LLNL say they can do this once per day, something I find impressive.

The New York Times seemed to think this was ignition. It was not. Given the size of a BB, and the density of liquid deuterium-tritium, it would seem the weight of the drop was about 0.022g. This is not much but if it were all fused, it would release 12 GJ, the equivalent of about 3 tons of TNT. That the energy released was only 2.5MJ, suggests that only 0.02% of the droplet was fused. It is possible, though unlikely, that the folks at LLNL could have ignited the entire droplet. If they did, the damage from 5 tons of TNT equivalent would have certainly wrecked the facility. And that’s part of the problem; to make practical energy, you need to ignite the whole droplet and do it every second or so. That’s to say, you have to burn the equivalent of 5000 Big Macs per second.

You also need the droplets to be a lot cheaper than they are. Today, these holmium capsules cost about $100,000 each. We will need to make them, one per second for a cost around $! for this to make any sort of sense. Not to say that the experiments are useless. This is a great way to test H-bomb designs without destroying the environment. But it’s not a practical energy production method. Even ignoring the energy input to the laser, it is impossible to deal with energy when it comes in the form of huge explosions. In a sense we got unlimited power. Unfortunately it’s in the form of H-Bombs.

Robert Buxbaum, January 5, 2023

A simpler way to recycle the waste fuel of a SOFC.

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My favorite fuel cells burn hydrogen-rich hydrocarbon fuels, like methane (natural gas) instead of pure hydrogen. Methane is far more energy dense, and costs far less than hydrogen per energy content. The US has plenty of methane and has pipelines that distribute it to every city and town. It’s a low CO2 fuel, and we can lower the CO2 impact further by mixing in hydrogen to get hythane. Elon Musk has called hydrogen- powered fuel cells “fool cells”, methane-powered fuel cells look a lot less foolish. They easily compete with his batteries and with gasoline. Besides, Musk has chosen methane as the fuel for his proposed starship to Mars.

Solid oxide fuel cells, SOFCs, can use methane directly without any pre-reformer. They operate at 800°C or so. At these temperatures, methane reacts with water (steam) within the fuel cell to form hydrogen by the reaction, CH4 + H2O –> 3H2 + CO. The hydrogen, and to a lesser extent the CO is oxidized in the fuel cell to create electricity,, but the methane is not 100% consumed, generally. Unused methane, CO, and some hydrogen exits a solid oxide fuel cell along with the products of combustion, CO2 and water.

Several researchers have looked for ways to recycle this waste fuel to capture the energy value. Six years ago, I patented a membrane method to extract the waste fuel and recycle it, see a description here. I now see this method as too complex, and have applied for a patent on a simpler version, shown below as Figure 1. As before the main work is done by a membrane but here I dispense with the water gas shift reactor, and many of the heat exchangers of the previous approach.

Simple way to improve fuel use in a high temperature fuel cell, using just a membrane.

The fuel cell system of Fig. 1 operates at somewhat elevated pressure, 2 atm or more. It is expected that the majority of the exhaust going to the membrane will be CO2 and water. Most of this will pass through the membrane and will exhaust to the air. The rest is mixed with fresh methane and recycles to the fuel cell. Despite the pressure of the fuel cell, very a little energy is needed for recirculation since the methane does not go through the membrane. The result is a light, simple, and energy efficient process. If you are interested, please contact me at REB Research. Or you can purchase the silicone membrane module here. Alternately, see here for flux information and other applications.

Robert Buxbaum, December 8, 2022.

A new, higher efficiency propeller

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Elytron biplane, perhaps an inspiration.

Sharrow Marine introduced a new ship propeller design two years ago, at the Miami International Boat show. Unlike traditional propellers, there are no ends on the blades. Instead, each blade is a connecting ribbon with the outer edge behaving like a connecting winglet. The blade pairs provide low-speed lift-efficiency gains, as seen on a biplane, while the winglets provide high speed gains. The efficiency gain is 9-30% over a wide range of speeds, as shown below, a tremendous improvement. I suspect that this design will become standard over the next 10-20 years, as winglets have become standard on airplanes today.

A Sharrow propeller, MX-1

The high speed efficiency advantage of the closed ends of the blades, and of the curved up winglets on modern airplanes is based on avoiding losses from air (or water) going around the end from the high pressure bottom to the low-pressure top. Between the biplane advantage and the wingtip advantage, Sharrow propellers provide improved miles per gallon at every speed except the highest, 32+ mph, plus a drastic decrease in vibration and noise, see photo.

The propeller design was developed with paid research at the University of Michigan. It was clearly innovative and granted design patent protection in most of the developed world. To the extent that the patents are respected and protected by law, Sharrow should be able to recoup the cost of their research and development. They should make a profit too. As an inventor myself, I believe they deserve to recoup their costs and make a profit. Not all inventions lead to a great product. Besides, I don’t think they charge too much. The current price is $2000-$5000 per propeller for standard sizes, a price that seems reasonable, based on the price of a boat and the advantage of more speed, more range, plus less fuel use and less vibration. This year Sharrow formed an agreement with Yamaha to manufacture the propellers under license, so supply should not be an issue.

Vastly less turbulence follows the Sharrow propeller.

China tends to copy our best products, and often steals the technology to make them, employing engineers and academics as spys. Obama/Biden have typically allowed China to benefit for the sales of copies and the theft of intellectual property, allowing the import of fakes to the US with little or no interference. Would you like a fake Rolex or Fendi, you can buy on-line from China. Would you like fake Disney, ditto. So far, I have not seen Chinese copies of the Sharrow in the US, but I expect to see them soon. Perhaps Biden’s Justice Department will do something this time, but I doubt it. By our justice department turning a blind eye to copies, they rob our innovators, and rob American workers. His protectionism is one thing I liked about Donald Trump.

The Sharrow Propeller gives improved mpg values at every speed except the very highest.

Robert Buxbaum, September 30, 2022

Biden stops fracking and gas prices go up 300% — Surprise!

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Natural gas prices for June 2022 as of May 6, 2022.

Natural gas prices have quadrupled in the last 17 months. It’s gone from $2.07 per million BTU in mid January 2021 when Joe Biden took office, to nearly $9 today. It’s a huge increase in the cost to heat your home, and adds to the cost of any manufactured product you buy. Gasoline prices have risen too, going from $2/gallon when Biden took office to about $4.40 today. Biden blames the war with Russia, but the rise began almost as soon as he took office, and it far outstrips the rise in the price of wheat shown below (wheat is grown in Ukraine — it’s their major export). The likely cause is Biden’s moratorium on fracking, including his decision to stop permitting oil exploration and drilling on federal land. In recent weeks Biden has walked back some of this, to the consternation of the environmentalists. On April 15, 2022, the Interior Department announced this significant change including its first onshore lease sale since the moratorium.

Biden also cancelled the Keystone XL oil pipeline that would have brought tar-sands oil from Canada and North Dakota to Texas for refining. Blocking the pipeline helped increase gas prices here and helped cause a recession in Alberta and North Dakota. The protesters who claimed to speak for the natives are not affected.

Another issue fueling price increases is that Biden is printing money. Bidenflation is running at 8%/year. It’s not hyperinflation, but it’s getting close. It’s money taken from your pocket and from your savings. Much of the money is given to friends: to groups that Biden thinks will use it virtuously, but inflation is money taken from us, from our pockets and savings. Another beneficiary are those who are rich enough to take no salary, but live by borrowing against their real estate and corporate equity. The richest people in the US do this, earning $1 per year or less, (here’s a list compiled by Bloomberg, it’s basically every rich person). They pay no taxes, as they have no income. The only way to tax them is by tariffs, taxing what they import, but the government is against tariffs.

What you can do, personally about energy-cost inflation is not much. I would recommend insulating your home. I plan to repaint the roof white, and put in a layer of roof insulation. I also have fruit trees: an apple tree and a peach tree, grapes and a juneberry. They provide summer shade, and you get a lot of fruit with minimal work. Curtains are a good investment. Another thought is to buy solar cells. A vegetable garden is fun too, but it’s unlikely to pay you back.

Winter wheat prices are up by about 40%, likely due to the loss of supply from Ukraine and Russia

Speaking of wheat prices, they are up. They increased 40% when Russian troops invaded Ukraine, and have held steady at that level since. This is far less increase than for natural gas. Corn and rice prices are up too, but nowhere near as much. Fertilizer prices are up 300%, though, and Biden has indicated he’d like to push for a sustainable alternative; is that poop? There is a baby formula shortage too. We can handle it, I think, unless Biden get involved, or starts a hot war with Russia.

Robert Buxbaum May 10, 2022. As a fun sidelight, here is Biden answering questions about Pakistan when someone in a Bunny costume grabs him and walks him away from the reporters. Who is that masked handler? What’s going on in Pakistan?