Tag Archives: REB Research

What’s Holding Gilroy on the Roof

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We recently put a sculpture on our roof: Gilroy, or “Mr Hydrogen.” It’s a larger version of a creepy face sculpture I’d made some moths ago. Like it, and my saber-toothed tiger, the eyes follow you. A worry about this version: is there enough keeping it from blowing down on the cars? Anyone who puts up a large structure must address this worry, but I’m a professional engineer with a PhD from Princeton, so my answer is a bit different from most.

Gilroy (Mr Hydrogen) sculpture on roof of REB Research & Consulting. The eyes follow you.

Gilroy (Mr Hydrogen) sculpture on roof of REB Research & Consulting. The eyes follow you. Aim is that it should withstand 50 mph winds.

The main force on most any structure is the wind (the pyramids are classic exceptions). Wind force is generally proportional to the exposed area and to the wind-speed squared: something called form-drag or quadratic drag. Since force is related to wind-speed, I start with some good statistics for wind speed, shown in the figure below for Detroit where we are.

The highest Detroit wind speeds are typically only 16 mph, but every few years the winds are seen to reach 23 mph. These are low relative to many locations: Detroit has does not get hurricanes and rarely gets tornadoes. Despite this, I’ve decided to brace the sculpture to withstand winds of 50 mph, or 22.3 m/s. On the unlikely chance there is a tornado, I figure there would be so much other flotsam that I would not have to answer about losing my head. (For why Detroit does not get hurricanes or tornadoes, see here. If you want to know why tornadoes lift things, see here).

The maximum area Gilroy presents is 1.5 m2. The wind force is calculated by multiplying this area by the kinetic energy loss per second 1/2ρv2, times a form factor.  F= (Area)*ƒ* 1/2ρv2, where ρ is the density of air, 1.29Kg/m3, and v is velocity, 22.3 m/s. The form factor, ƒ, is about 1.25 for this shape: ƒ is found to be 1.15 for a flat plane, and 1.1 to 1.3 a rough sphere or ski-jumper. F = 1.5*1.25* (1/2 *1.29*22.32) = 603 Nt = 134 lb.; pressure is this divided by area. Since the weight is only about 40 lbs, I find I have to tie down the sculpture. I’ve done that with a 150 lb rope, tying it to a steel vent pipe.

Wind speed for Detroit month by month. Used to calculate the force. From http://weatherspark.com/averages/30042/Detroit-Michigan-United-States

Wind speed for Detroit month by month. Used to calculate the force. From http://weatherspark.com/averages/30042/Detroit-Michigan-United-States

It is possible that there’s a viscous lift force too, but it is likely to be small given the blunt shape and the flow Reynolds number: 3190. There is also the worry that Gilroy might fall apart from vibration. Gilroy is made of 3/4″ plywood, treated for outdoor use and then painted, but the plywood is held together with 25 steel screws 4″ long x 1/4″ OD. Screws like this will easily hold 134 lbs of steady wind force, but a vibrating wind will cause fatigue in the metal (bend a wire often enough and it falls apart). I figure I can leave Gilroy up for a year or so without worry, but will then go up to replace the screws and check if I have to bring him/ it down.

In the meantime, I’ll want to add a sign under the sculpture: “REB Research, home of Mr Hydrogen” I want to keep things surreal, but want to be safe and make sales.

by Robert E. Buxbaum, June 21, 2013

New hydrogen generator from REB Research

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Here’s the new, latest version of our Me150 hydrogen generator with our wonder-secretary, Libby, shown for scale. It’s smaller and prettier than the previous version shown at left (previous version of Me150, not of secretary). Hydrogen output is 99.9999% pure, 9.5 kg/day, 75 slpm, 150 scfh H2; it generates hydrogen from methanol reforming in a membrane reactor. Pricing is $150,000. Uses about 7 gal of methanol-water ($6 worth) per kg of H2 (380 ft3). Can be used to fill weather balloons, cool electric dynamos, or provide hydrogen fuel for 2-10 fuel cell cars.

New REB Research hydrogen generator 150 scfh of 99.9999% H2 from methanol reforming

New REB Research hydrogen generator 150 scfh of 99.9999% pure H2 from methanol-water reforming against metal membranes.

Dr. Robert E. Buxbaum

Some people have noticed that I’m wearing a rather dapper suit during the recent visit of the press to my lab. It’s important to dress sharp, I think, and that varies from situation to situation. Fashion is an obligation, not a privilege; you’ve got to be willing to suffer for it, for the greater good of all.

Do you think Lady Gaga finds her stuff comfortable?

Do you think Lady Gaga finds her stuff comfortable? She does it for the greater good. 

R.E. Buxbaum. You are your own sculpture; Be art.

 

Robert Buxbaum is now on the board of a new charity

I’m now on the board of directors for two non-profits (lucky me), plus for my own hydrogen company, REB Research. My first charity seat is for The Jewish Heritage Foundation; it’s really one rabbi who takes donations to make tapes about topics he finds interesting. He then gives away or sells the tapes. We meet once a year to go over the finances and decide what his salary ought to be — basically we rubber stamp.

The second board seat, one I’ve been elected/appointed to just this week, is with a group call “The First Covenant Foundation” they’re semi-religious, trying to get people to behave decently. The first covenant is the one with Noah — God won’t destroy the earth but we have to behave sort-of OK. It’s certainly worthwhile to get people to keep to this minimal standard: no murder, no bestiality, don’t eat the limbs off of living creatures… Then again, if God has trouble keeping folks to this standard, I’m not sure how effective the 1st covenant will be. So far they’ve done nothing illegal or immoral that I’ve seen, so that’s good. Unlike with my first my board position, my contract with first covenant includes a sanity clause. They’re more inclusive that way; as expected, the Jewish heritage group didn’t believe in any sanity clause.

As for REB Research, our aims are simpler: to make and sell good hydrogen-related products, to make money, to pay our workers and creditors, and to develop our workers through training associated with the making and selling of good hydrogen products. Simple enough. My board meets 3 or 4 times a year over pizza; the salary of board members is the pizza. So far we haven’t done anything illegal either, that I know of — and we’re even making money.

A visit to the Buxbaum laboratory from Metromedia

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It’s a slow news day in Detroit, so the folks from Metromedia came to visit my laboratory at REB Research. You can visit too. We’re doing cool stuff most of the time, we’re working on a hydrogen-fueled plane that stays aloft for weeks (not that cool, actually, the Hindenberg did it in the 30s). On this particular day I’ve got a cool hat on, and a beige suit. I’m putting hydrogen in my car. Hydrogen increases the speed of combustion, and so it adds to milage — or it has when we’ve added it from electrolysis sources.buxbaum-003

The fun thing about science is that there are always surprises.

Adding hydrogen to a Malibu at REB Research

Adding hydrogen to a Malibu at REB Research

REB Research periodic table cup

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Some 20 years ago I designed this periodic table cup, but with only the 103 named elements that existed then. In part this was done because I wanted a good, large, white coffee cup, in part because I often found I needed a periodic table, and didn’t like to have to look one up, and in part to people how much more area you get on a cylinder than on a flat sheet (roughly 3.14 times more area). To show that, I put all the side elements (rare earth lanthanides, and actinides) where they belonged, and not off on the side. I also put hydrogen in twice, once as a metal (HCl) and once as a non metal (NaH). The color I chose was Tryian Blue, a key color of Biblical Tyre, what you get from male purpura mollusks (the females give a shade of red that I also try to associate with REB Research).

I’ve updated the cup to add more elements: I think it’s great. You can buy it for $30 through our web-site, or for $25 by e-mailing me (reb@rebresearch.com/blog/). Or if you do something really cool, I may send you one for free.

REB Research, Periodic table coffee cup

REB Research, Periodic table coffee cup

By the way, I only use 4 digits for the atomic weight; I can think of no application where a normal person needs more.

 

 

How and why membrane reactors work

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What follows is a shorter, easier version of my old essay on how membrane reactors work to get you past the normal limits of thermodynamics. Also, I’m happy to say, our membrane reactors designs have gotten simpler, and that deserves an update.

At left, is our current, high pressure membrane reactor design, available in one-tube to  72 tube reactor assembly; high pressure, or larger, I suppose. Typically, the area around the shell is used for heat transfer. One needs to add heat to promote endothermic reactions like methanol reforming CH3OH + H2O –> 3H2 + CO2, or ammonia cracking 2NH3 –> N2 + 3H2. You need to take away heat from exothermic reactions, like the water gas shift reaction, CO + H2O –> CO2 + H2. Generally you want to have some heat transfer to help drive the reaction.

The reactor is a shell containing metallic tubes that filter gas. Normally the idea is for hydrogen to be formed in the shell area, and leave by diffusion through the tube walls and down the tubes, leaving as pure hydrogen (only hydrogen can go through metals). We typically suggest to have the reactor sit this way, with the tubes pointed up, and the body half-filled or more with catalyst. According to normal thermodynamics, the extent of a reaction like ammonia cracking will be negatively affected by overall pressure, and the extent of the WGS reaction is only affected by operating temperature. The membrane reactor allows you to remove hydrogen while the reaction progresses, and allows you to get good conversion at higher pressures too. That’s because hydrogen removal shifts the equilibrium so the reaction goes further. The effect is particularly significant at higher pressures. By combining the steps of reaction with separation, we can operate a higher pressures, delivering ultra high purity, avoiding the normal limitations of thermodynamics.

The water-gas reaction, CO + H2O –> CO2 + H2, deserves special mention since it’s common and exothermic. In a normal reactor, your only option to drive the reaction to near completion is by operating at low temperature where the catalyst barely works, 200 °C, or lower. You also have to remove the heat of reaction. In a membrane reactor, you can operate at a much higher temperature, especially if you work at higher pressure. At higher temperature the catalysts work better, and you don’t have to work so hard to remove heat.

At our company, REB Research, we sell membrane reactors; and catalysts, membrane tubes, and consulting.

Healthcare thoughts

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I offer healthcare to keep workers working for me — it’s an employee retention benefit that helps cover the cost of training. As it is now, if they quit, covered workers will have to pay for their own heathcare or find another company that’s willing to pay for it.

Perhaps that’s mean to think this way, but it’s really my only means to keep people from jumping shop at the first higher-paying opportunity. Anyway, that’s what I do/did. When congress gave free healthcare to everyone as of this year, they not only raised my taxes, and my company taxes, they also removed a key tool I have for keeping people on the job. In return, I suppose my healthcare fees are supposed to go down, but I have no faith they will, in part because I worked for the government and have no faith in their ability to be efficient or fast moving; in part because my ability to pay for healthcare comes from my ability to keep trained workers.

Though I’m not too happy about the change, I imagine (hope) that my employees are happy. Their  taxes will go up a bit, but they will be more free to jump ship at will. I imagine that the unemployed are especially thrilled, though I don’t know why that was not implemented through an increase in Medicare and Medicaid. In a sense I’m surprised it took congress this long to give everyone “free” healthcare without forcing them to work for it.