This is hilarious I think partly because it's such a common theme in engineering or life in general. For some reason things that initially seem so benign and straight-forward end up becoming absolute rabbit-holes of startling complexity.
Typically only change the shape of the hopper in one direction at at time as you move down. This often leads to hoppers with an exit that is a slot and not round.
We've used these powder consultants before and I took a week long course on hopper design: http://powdernotes.com
Edit - another method we use to create empty-able hoppers: fluidization. Not sure if this fits with your processing strategy but it also mixes the powder somewhat which prevents size segregation of the particles. And this video is pretty cool:
Start with a simple question like: what kind of model do you use with bulk materials. Obviously it's not a liquid, but as a solid it has tons of weird properties- No tensile strength at all. Strength depends on history of compaction. The list goes on...
I’ve been in bed sick all day with a terrible cold and my sinuses are packed solid.
I had a headache and so out of bordeum tried using my black and decker buffer to massage my head and relieve my headache (I use the buffer as an awesome massager and modded it with a variable speed switch).
To my surprise it worked on the headache and also liquified my sinuses.
A quick google search turned up a few other people playing with vibrators for congestion and at least one patent.
Funny to come across this after experimenting with getting solids to behave at liquids via vibration all day.
Don't give in to temptation and stop too early and blow your nose! Keep going till you have full air flow, only then blow your nose (otherwise the pressure of blowing your nose closes things up again).
After that, consciously keep the nostril on the same side as your headache open, and let the other side close.
The closure is blood vessels in your nose swelling, it's not compacted material. When you exercise your body recognizes the need for more air and reverses the swelling. You don't usually notice, but it's normal to breathe with only one nostril at a time (and the body opens both when there is great demand for air). https://en.wikipedia.org/wiki/Nasal_cycle
Anyway, since there is no actual material compaction, your vibration did not work for the reason you think, rather it acted as a massage for the swollen (irritated) blood vessels.
I think the logical next step is to put a boxing glove on a sawzall.
They make it sound fancier than just vibrations though
But then I found an old Lutron floor dimmer switch in a drawer and it worked perfectly.
The black and decker is a 2 prong plug.
This is seriously an awesome tool / toy.
I’ve seen other massagers for like $700 that are basically the same thing rebranded.
Black & Decker WP900 Buffer
Lutron Credenza Dimmer TT-300
Painful, but effective.
Compare that to PV solar which is around 18% in a form that humans can use. Of course electricity is more difficult to store than ethanol and hydrogen but there's a big efficiency advantage that has to be made up.
Much better would be to use organic waste. People have to pay to get rid of that stuff so if you can make it your fuel there's money to be made. Hydrothermal gasification or liquification both seem promising for that.
PV certainly wins on efficiency compared to crops, but it's also relatively expensive (an acre of PV vs an acre of perennial crops). Also PV is quite unremarkable at removing CO2 from the atmosphere :]
Good work! Grasses are the best energy crops, but a serious pain to gasify (or burn, for that matter). Silica plus alkali metals => glass.
How much geological sequestration capacity exists, how long term is the sequestration, and what is the cost of securing it at the necessary scales? Is feedstock local to sequestration formations, and if not, has the transport been factored in?
Why not biogas as a turbine feedstock and sell carbon neutral electricity on the grid (offsetting extracted hydrocarbon)?
What about hydrogen being (my understanding) an indirect plastic byproduct?
What was the drawback of monetizing bio char volatiles while selling the "waste" as a soil amendment products?
I only ask these because I very much want this to succeed and I'm glad to see this here. I get the feeling that the point is very much finding an economic basis for sequestration.
1. In North America alone we have 32,000 gigatons of geological sequestration storage capacity... about 900 years of global carbon dioxide emissions.
2. We looked at generating electricity, and many others have built and operated biomass-to-electricity plants. The economics don't work out... electricity is very cheap. Most of the biomass-to-electricity plants in California are closing up shop now.
3. Hydrogen may be a byproduct of some plastics manufacturing processes, but not nearly on the scale consumed.
4. Yes, hydrogen is a (cleaned up) biochar volatile! We consume most of the biochar itself as the energy source for heating the gasifier. Any excess biochar will be sold as soil amendment.
I suspect that is a tendentious estimate, considering no indicative amount of CO2 has yet been geologically sequestered and observed for effects. The wikipedia article has a graphic with CO2 being pumped into a "deep aquifer".
Biomass-derived syngas has to be substantially better in energy density and efficiency than any kind of hydrogen.
The leading industrial use for hydrogen is in oil refining, so if you outcompete conventional steam reformed hydrogen on price, you're just going to make gasoline cheaper.
Also note that the largest use of hydrogen (~50%) is actually for ammonia production as fertilizer, which alone is responsible for 1-2% of global CO2e emissions. Decarbonizing that industry would be fantastic.
US annual hydrogen production is approximately 10 million metric tons (1.0E+10 kg), 68% of which is used in petroleum processing.
Given that worldwide production of hydrogen-derived ammonia is 140 million tons in total, compared with hydrotreated gasoline coming in at about 2000 million tons worldwide, it doesn't appear that the U.S. is an outlier.
Decarbonizing the fertilizer industry would be fantastic. Wind-powered and solar-powered electrolyzers are already starting to do that job, perfect uses for intermittent energy sources. I'm skeptical that your process can realistically make more fertilizer than it consumes.
I find it a little disturbing that you boast "Hydrogen's quite easy" with this little public documentation to back up your claims. Be real careful here: you don't want to be the next Theranos.
You have lightning trapped in a bottle because of your luck in landing a YC slot. I encourage you to consider pivoting technologies away from anything involving hydrogen. Since you're such a big fan of ammonia, why not just go straight for that? Getting your nitrogen from the plant instead of from the air might stand a better chance to beat Haber-Bosch.
(1) electrolysis is much more expensive than steam methane reformation, so unfortunately I don't think it's gaining much steam as a real hydrogen production method.
(2) typical ammonia fertilizer application is 0.125 tons/acre/year at a price of $500/ton = $62.50/acre/year. Our grass and gasification process yields $1,750/acre/year worth of hydrogen... so roughly a 28:1 financial return on the fertilizer input which is probably pretty close to the EROI (Energy Return on Investment)
(3) To clarify "hydrogen is quite easy"... not on an absolute basis (which is quite hard), but relative to other products that could be produced. For example, you mention ammonia, but ammonia production has enormous economies of scale benefits from complex compression systems and pressure chambers... if you run the math it doesn't work out as favorably as hydrogen, and it's substantially more complex and difficult.
(4) We are funded by an amazing group of angel investors, but that does not include YC.
(2) I'd love to see your math, but assuming it's not available, let me show you my math: Assume 6000 pounds per acre per year yield of wet grass. Say that's 5000 pounds dried. Model grass as 100% cellulose, which is 6% by weight hydrogen. Assume 100% process efficiency, where you get all the hydrogen out, and it's magically compressed. 300 pounds of hydrogen sounds like a lot, but according to wikipedia, is only worth about 32 cents a pound at the pipe. So my numbers show $100/acre/year. The value goes way up at the "pump", but that's because of transportation infrastructure that neither you nor your competition provide. That also assumes free injection of low-pressure waste CO2, which is not only a fantasy, but presumably ties your process to a location far away from your target market for the H2.
(3) Ammonia solves your hydrogen storage and transmission problem, so my math shows it's way favorable, especially since you're triply tied to a CO2 injection site, fertile acreage to grow your grass, and an H2 consumer. Picking ammonia makes cost-effective transportation to the consumer possible. Realistically, you'd react the ammonia with CO2 to make urea, which is way better than ammonia for both transportation costs and market demand.
(4) Didn't say YC funded you, but you were in their demo day, hence my mention of the YC slot.
(2) 6000 dry lbs/acre/year = 3 dry tons/acre/year which is an extremely low yield. Even miscanthus and switchgrass get over 10 dry tons/acre/year, energy cane gets to 20 dry tons/acre/year and our grass gets to 25+ dry tons/acre/year. So that brings your $100/acre/year up to $800+/acre/year. Then for the chemistry it's important to note that much of the hydrogen gas produced is actually coming from H2O that reacts with carbon in the cellulose to produce 2 H2 + CO2. So, stoichiometrically you get significantly more than the elemental hydrogen content of the grass itself. That gets you another factor of 2 or so... and then we're at the $1750/acre/year mentioned in the parent comment.
(3) Agreed the transportation costs are better for ammonia, but we aren't actually transporting the hydrogen except over a feeder pipe into a refinery or ammonia plant. It's cheaper and simpler to transport the grass as opposed to the hydrogen, mostly because you get to avoid the pre-transport compression energy and losses. Again, as in (1) the issue with ammonia is the heavy capex based around Haber-Bosch pressure vessels and compressors... we didn't have any good ideas for reducing those costs, so there's no sense in competing there.
(4) We weren't at YC's demo day... not sure what you're referring to ¯\_(ツ)_/¯
(2) If these numbers are accurate, you're doing yourself a disservice by burying them. 25+ dry tons/acre/year is amazing. And I thought the crab grass on my lawn grew fast.
I seriously doubt your chemistry, however. Let's look at your three possible approaches (2b sounding the most like what you're claiming to do):
(2a). Charring: Hopefully using all that free low-grade heat from the refinery you colocate with, the cellulose cooks until all the hydrogens join with the ample oxygens in the cellulose and you end up with a char and steam. No hydrogen this way.
(2b). Steam Reforming: This tech works with natural gas because the C:H ratio is so low, and no oxygen is introduced that doesn't bring its own "dates". Because the C=O bond in carbon monoxide is so strong, you can leach off some of the H2. However, as soon as you raise that C:H ratio, or up the available oxygen, steam reforming fails and just becomes combustion. C:H in cellulose is 6:10 vs. methane's 1:4. And that's before the 5 oxygens (vs. methane's 0) ruin it further. No hydrogen this way.
(2c). Fischer-Tropsch (the original Hans and Franz): In a chamber about as expensive as your Haber-Bosch capex, you somehow convert dried grass and catalyst to a mix of H2 and CO, the latter of which you can convert into more H2. Doesn't sound like you're using this approach, though it could technically work if pressure cooking your grass didn't require ridiculous amounts of energy, and you had a way to separate the H2 from the syngas. How many MJ of energy is that? So, maybe Hydrogen this way.
(2d) What'd I miss?
(3) Ok, so your co-founder's protestations about making gasoline cheaper were unnecessary, and you co-locate with oil refineries. Instead of downplaying it, own it: grassoline is trademarked but not for the type of product you'd make. Makes sense to leverage someone else's existing capex, as long as they let you. Those oil guys are flush with cash, why are you distancing yourself from them? They'd love to have your CO2 if it's at high enough pressure.
(4) My mistake. Your timing was highly coincidental with Demo Day, technology looked like it could have been part of it, and the faulty assumption was mine.
Don't mean to rain on the parade, but I am skeptical
If a less energy-intensive ammonia process is used, perhaps a simpler hydrogen-generating process would be a better fit. ie, if the heat can't be used directly, is this process an economically viable way to generate hydrogen?
Steam reforming the natural gas and then injecting the CO2 can't be any harder than charring the grass clippings and then injecting the CO2.
At least corn-derived ethanol is a decent motor fuel, for all its limp efficiency numbers and carbon-positive growth cycle. If you're willing to overlook the warts of this hydrogen technology, I don't see why you're not instead advocating for corn-based ethanol.
And if making green industrial hydrogen is your goal, PV-powered electrolyzers can outperform this in process efficiency, complexity, scalability, and deployment cost, all without consuming fertilizer, (as much) water, or depleting soil.
If you want to read it don't get stuck at the top (the start makes it seem like the article is about gasification instead), keep going till the images start.
Side note: From read this article they desperately need some experts. They are re-solving solved problems, and not working on what their startup is actually about. (I should add that them seem to be aware of this.)
That was my thought as well. These guys may have a viable business idea, but they don't appear to have any engineering experience at all, nor do they appear to understand that one can research for existing solutions, or hire/consult with experts. It doesn't bode well for the entire enterprise.
"If you are want to consume carbon-neutral hydrogen, please reach us at email@example.com"
I wish them the best of luck, but I've seen the first wave of biofuels fail and pivot to selling cosmetics or go under (Amyris, Solazyme, LS9). Sure, this is different, but the economics haven't really changed. It's damn hard to compete against something you can pump out of the ground and has no price tag on its externalities.
Personally, I think more effort put into lobbying and activism is better spent. I know we have the technology to make carbon-neutral fuels. I sincerely hope that we transition to using something like EVs for all ground-based transport and biofuels for applications like jet travel that need the energy density.
However, it's the market and the economics that don't work out. And they don't work in a way that prevents you from having easy stepping stones to scaling up. There's basically no-one who will buy this commodity at small scale for a much higher price. You have to succeed completely or fail.
You can even look at startups using conventional approaches and cheap feedstock (Siluria with methane). 10 years and still working on their tech. These big commodity markets have huge players who have huge competitive advantages.
And if you check the articles people already make those. I guess their "new thing" is using grass? switchgrass is usually considered the best plant for this.
I don't really understand why they are reinventing things that already exist.
People have been lobbying and protesting for years, I don't believe it's going to fix things on its own. Policy makers need legitimate technology options to put support behind, and that's what we intend to develop.
Thankfully you are simply incorrect that "no-one who will buy this commodity at small scale for a much higher price". We are in active sales conversations with a number of buyers who are very much willing to pay a premium for the commodity given its reduced carbon intensity.
(1) we agree wholeheartedly on the experts front — for the core technology around gasification we've been working with a variety of PhDs, national labs and companies with extensive previous gasification experience,
(2) the gasification technology we're developing is actually fairly novel and unfortunately in this industry that means patenting is in our future, which means that we're not going to blog about the core parts of our gasification system... instead we can blog about the surrounding systems that still represent interesting challenges. So that's why we blogged about grass flow. Rest assured 95% of our time is going into gasification ;)
(Note: SEK := Swedish Krone; currently ~$0.11USD and was roughly the same in 2009)
Abstract: "An integrated system for the production of hydrogen by gasification of biomass and electrolysis of water has been designed and cost estimated. The electrolyser provides part of the hydrogen product as well as the oxygen required for the oxygen blown gasifier. The production cost was estimated to 39 SEK/kg H2 at an annual production rate of 15 000 ton, assuming 10% interest rate and an economic lifetime of 15 years. Employing gasification only to produce the same amount of hydrogen, leads to a cost figure of 37 SEK/kg H2, and for an electrolyser only a production cost of 41 SEK/kg H2. The distribution of capital and operating cost is quite different for the three options and a sensitivity analyses was performed for all of these. However, the lowest cost hydrogen produced with either method is at least twice as expensive as hydrogen from natural gas steam reforming."
In addition to a dollar-to-dollar comparison, however, I think a Carbon-to-Carnon byproduct comparison is also warranted. If you don't have to pay for geo-sequestration (or the messy supply of grass compared to piped in water), is the small cost increase of electrolysis over bio-gas more than compensated for?
As an H2 advocate myself (as an industrial transportation battery alternative), actively looking to boost H2 fuel supply infrastructure, I would be interested to hear from Chimere (OP co-founder) on this point. I ask, because I don't know the answer.
On the other hand, our process is close to carbon neutral from day one (we've confirmed this with an external life cycle assessment), and will become significantly carbon negative when we begin sequestration. And as I mentioned elsewhere, sequestration is the primary mission and electrolysis is unremarkable at it :]
So, my point is that in the bio-gas process, you are generation H2 + CO2 and using some proceeds from H2 sales to sequester the CO2 you produce.
However, with electrolysis (from renewable elect. plants), you aren't generating any CO2, so any profit that you spend on Carbon sequestration (from somebody else's process) would be a much more Carbon negative proposition overall.
All this depends on the H2 production cost as to which is a mor effective Carbon sequestration scheme, right?
In the paper I cite (I convert SEK to $): bio-gas costs ~$4/kg H2 (let's say this produces 5 kg of CO2), and electrolysis ~$4.50/kg H2 (producing 0 kg Carbon).
Now say it costs $0.50/kg for CO2 sequestration). In the biogas process, because of the cost to sequester the CO2 byproduct, your actually spending ($0.5×$5)+$4 = $6.50/kg H2 produced just to get Carbon Neutral. However, for electrolysis (without the mess) you're only spending $4 to be Carbon Neutral, and if you want you can spend $2.50 (which you avoided by chosing elect. over gas), to go Carbon negative.
These are rough numbers I guessed at based on a little googling. Am I far off on the real numbers?
I'm really not trying to be a pain. What you're proposing is still light years better than the greedy bastards reforming natural gas and pocketing 100% of the profits without giving a second thought to the environment. I'm just wondering if there might be a way for you guys to do even more good, more easily.
Electrolysis also typically costs more than you'd expect as soon as you add the requirement of renewable energy supply. Usually the renewable energy supply is solar, which has a ~30% duty cycle. So 70% of the time your electrolyzer is sitting idle. This crushes your economics and makes solar-powered electrolysis untenable in all of the analyses I've seen. We didn't have any clever ideas for how to change that situation, so after looking at it ~1.5 years ago we decided to look elsewhere.
Working very peripherally in this sector, I applaud your efforts, not only for the ingenuity, but also for the guts to consider environmental impact as opposed to stock-holder happiness from a profit margins perspective.
Honestly, it would be cool if on your site you showed a side-by-side comparison on your profit model compared to a competing natural gas reforming competitor's profit structure to demonstrate to customers how you are sacrificing some profit for environmental benefit, whereas the competition simply pockets the profit and turns a blind eye to the environment. For me, that would help me decide to buy potentially higher cost H2 from you, just like I choose to pay a higher premium for energy I know is renewable sourced.
The world needs more innovators like you folks. Good luck!
Looking at the Wikipedia page https://en.wikipedia.org/wiki/Steam_reforming this looks like a difficult process, even when using methane that is a very small molecule and is easy to purify. Big molecules in grass are more eager to produce soot that would block the machine, and grass also has other elements like Nitrogen and Phosphorus that may react with the catalyzer, and there is the ash problem.
Is using a grass more efficient that burning the grass and use the energy to produce Hydrogen with the standard method?
What about producing ethanol from the grass and then using the ethanol to make the Hydrogen? (Both parts are somewhat proven technology.) And ethanol is easy to move and purify than grass.
LOL, easy peasy then
Can you make "grass charcoal"? If so, just pile the grass high and cover in a layer of clay before burning, as is done with wood. Then bury the charcoal, which also improves the soil
For one, biochar is typically produced in small, low-efficiency reactors without proper emissions control (though this is solvable). The bigger issue is the high energy content of biochar (~30MJ/kg). Simply burying all of this energy isn't economical - it makes much more sense to store carbon in its oxidized state, and sell the energy that's released in the process (in various forms - we're starting with Hydrogen).
The latest research seems to show that done properly, biochar can improve crop yields substantially, so that could be a way to pay for the process, but the other aspect is that it can be produced in a very low-tech manner, which is almost certainly the situation in many or most parts of the world.
How are you planning 'geological carbon dioxide sequestration'? I'm not sure of the chemistry/process, but is burning the charcoal completely actually necessary to produce hydrogen? It seems not, to me. The cynical view of course is that you will omit the costly sequestration step, which makes this just another biofuel endeavor, with the attendant pros, and, mainly (IMHO), cons...
Specifically, she talks about the results of the Sleipner Project in the North Sea, where they've measured leakage rates, etc: https://youtu.be/lIVwbSnD0AI?t=1199
The Sleipner Project for geological carbon sequestration has been ongoing for 20 years with extremely rigorous measurement. We also know that natural gas is stored in geological deposits for millions of years, and in vast quantities. I don't see a strong reason to be skeptical of long-term sequestration a slightly different gas in those same geological formations.
Here is an example:
i.e., 2,130,000,000 metric tons of CO2 (= 1ppm) * (410ppm - 280ppm) or some 276 giga tons. Evidently a modest goal.
If no other energy source is available, does this % change?
Perfect sustenance for spherical cows.
> allowing us to use a simple, funnel-like hopper.
But, since that one didn't vibrate, it could hardly be called a grasshopper.
Engineering students discover that real world specialized solutions are in fact optimized for what they do. Water is wet. More breaking news at 11.