8 ms·

Producing industrial hydrogen from biomass

247 points by grantlmiller 8y ago

ars 8y ago
This article is about getting chopped up grass to flow through a hopper (so that it can be gasified for fuel). 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.)
- caymanjim 8y ago
  > 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.
  - iso1337 8y ago
    Looks like they forgot to proof read their website too. "If you are want to consume carbon-neutral hydrogen, please reach us at sales@charmindustrial.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.
    - ars 8y ago
      Hydrogen is a mistake anyways, they should make syngas instead. https://en.m.wikipedia.org/wiki/Syngas https://en.m.wikipedia.org/wiki/Syngas and then Substitute natural gas (SNG) https://en.m.wikipedia.org/wiki/Substitute_natural_gas https://en.m.wikipedia.org/wiki/Substitute_natural_gas 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.
    - pkrein 8y ago
      Charm co-founder here... thanks for the typo find, fixed! 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.
- pkrein 8y ago
  Charm co-founder here... Two quick notes: (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 ;)
ada1981 8y ago
My initial thought was vibration, so I was happy to see that was the solution! 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.
- ars 8y ago
  Another thing to try is running up and down stairs, while holding a tissue. 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 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.
- bbernoulli 8y ago
  Saw this thing in a sappy movie that had a character with cystic fibrosis: https://www.afflovest.com/ https://www.afflovest.com/ They make it sound fancier than just vibrations though
  - ada1981 8y ago
    Since I had a chest cold I also tried it on my lungs thinking it might help loosen things up. Less sure that worked (it felt nice), but I do feel much better today.
cwkoss 8y ago
I was just talking with a coworker about how we could theoretically modify our espresso machine hopper to avoid blockages. This is a great survey of bulk material handling options.
SubiculumCode 8y ago
I wonder what dampening the grass might do, as this might reduce the volume of the grass (increase density).
- saagarjha 8y ago
  I feel like this might make the grass harder to vibrate into a "fluid".
- rtkwe 8y ago
  First guess is it'd make it mat together worse by adding surface tension into the mix.
kazinator 8y ago
> Naively, we assumed that grass would flow somewhat like an ideal fluid, 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.
- warent 8y ago
  This is one of my favorite comments so far this year.
- dsfyu404ed 8y ago
  >Perfect sustenance for spherical cows. Engineering students discover that real world specialized solutions are in fact optimized for what they do. Water is wet. More breaking news at 11.
throwaway5752 8y ago
So many questions. 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.
- pkrein 8y ago
  One of the Charm co-founders here. Great questions, and you're correct the point is to find an economically profitable 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. https://en.wikipedia.org/wiki/Carbon_capture_and_storage https://en.wikipedia.org/wiki/Carbon_capture_and_storage 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.
  - hanniabu 8y ago
    What's the flow rate you guys want to achieve and what's the allowable variance?
    - pkrein 8y ago
      Flow rate of biomass or hydrogen? Per unit we expect roughly 10-20 tons per day of biomass, and 0.5-1 ton per day of hydrogen. Allowable variance is low, but depends on the customer.
jacknews 8y ago
"With the addition of geological carbon dioxide sequestration it becomes carbon-negative." 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
- chimere 8y ago
  (Charm Co-founder here) Certainly - you're effectively describing biochar (https://en.wikipedia.org/wiki/Biochar https://en.wikipedia.org/wiki/Biochar) which historically has been used as both an energy source and a soil amendment. Using it as a sequestration method has gained some attention recently, though I have reservations. 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).
  - marvindanig 8y ago
    Did you try blowing air through the mass from bottom up? It can help loosen the grass chips, reduce moisture and prevent agglomeration and is useful as long as the air flux doesn't prevent the grass from funneling down.
    - chimere 8y ago
      Certainly we considered it. The problem is that on this prototype system we were operating with a sealed hopper. Thus any gas injected into the hopper would travel through the system and dilute our output gas stream. Also any oxygen in the injected gas would result in combustion rather than gasification.
      - marvindanig 8y ago
        The inside of the funnel can be lined with a tube punchered uniformly and use pneumatic nitrogen piped from above and outside of the sealed hopper? I’m getting these weird ideas in my head.
zawerf 8y ago
I remember seeing a video demoing how to make sand flow like water by bubbling air into it: https://youtube.com/watch?v=My4RA5I0FKs https://youtube.com/watch?v=My4RA5I0FKs
- crossman 8y ago
  That was my first thought too.
- chimere 8y ago
  (Charm co-founder here) I love that video! That fluidization phenomenon is commonly used in large-scale gasification or combustion processes, see: https://en.wikipedia.org/wiki/Fluidized_bed_reactor https://en.wikipedia.org/wiki/Fluidized_bed_reactor
  - mojomark 8y ago
    You probably know, but don't forget that compressing air is energy intensive. I'm not saying that the extra expense can't be marginalized - especially if you can dramatically increase production, I'm just pointing out that it's far from free. Just another fun engineering problem to tackle:)
stevespang 8y ago
Grass biochar or bamboo (a fast growing wooden grass) biochar would seem very useful as biochar is a proven beneficial amendment for high value horticultural soils, - - - and the highest value horticulture right now is probably cannabis farming.
NoblePublius 8y ago
Where is the evidence that carbon sequestration works?
- pkrein 8y ago
  Stanford Prof. Sally Benson's talk here is a great overview: https://youtu.be/lIVwbSnD0AI?t=127 https://youtu.be/lIVwbSnD0AI?t=127 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 https://youtu.be/lIVwbSnD0AI?t=1199
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  - NoblePublius 8y ago
    Still seems like this is a big guess that sequestration works over long periods, or at all at the scale necessary to be industrially significant. I’m inherently sceptical of anything hydrogen related due to the fuel’s association with delay tactics from the carbon industry. Chevron would prefer we all not buy electric cars in hopes of HFC becoming a real thing which, obviously, is just a farce to keep paying them to produce, transport, and sell solid fuel. I think we are better off as a society not burning carbon at all, not looking for places to put carbon polution.
    - pkrein 8y ago
      Charm co-founder here... We are not betting on hydrogen fuel cell cars. There is an existing $120B/year market for hydrogen used in the production of ammonia fertilizer and oil refining. That hydrogen is currently produced from fossil natural gas, and we are replacing that. 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.
metalgearsolid 8y ago
I would have loved to be there the moment they first tried a funnel and failed. Bulk material handling seems pretty interesting to solve.
ggm 8y ago
what % of the generated H2 is currently consumed by the sequestration? If no other energy source is available, does this % change?
snappr_ 8y ago
Can the ash be used as a concrete additive? https://precast.org/2010/05/using-fly-ash-in-concrete/ https://precast.org/2010/05/using-fly-ash-in-concrete/
- pkrein 8y ago
  Charm co-founder here... possibly, but it's likely more valuable being sold as potash.
  - deleted 8y ago
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torpfactory 8y ago
Looks like they've got some bad Funnel Flow in the hopper. Mass flow is probably the desired flow regime. Using a non-conical hopper is probably a better idea and would negate the vibration, which can fail. 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 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: https://www.youtube.com/watch?v=My4RA5I0FKs https://www.youtube.com/watch?v=My4RA5I0FKs
- utexaspunk 8y ago
  Could the grass be blown in? Leaf blowers move grass pretty easily...
  - whatshisface 8y ago
    I would imagine that leaf blowers operate at a much lower density of grass, in an open area where there's nothing for a grass blade to stick on.
  - MisterTea 8y ago
    First thing I thought about was fluidizing the grass via forced air. Plenty of bulky stuff is handled fluidized. One good example is the hydraulic french fry maker where potatoes are fluidized using water and pushed through a slicing grate using the pressure and velocity of the flow. The water carries the french fries out of the other side just as easily.
  - torpfactory 8y ago
    You can probably blow it in just fine. The problem is really getting bulk materials out of hoppers. A whole world of research and engineering unto itself. 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...
dosy 8y ago
you want to mix the grass with air so you have grass suspended in a flow of air just like a fluid. since you need to avoid oxygen blow this grass nitrogen suspension through some pipes and into your gassifier.
williesleg 8y ago
So the oceans aren't rising enough we need to make more water? I'm scared for my life! Gonna have to vote now for sure!
malloryerik 8y ago
If you want to have the grass flow like water, could you take a stream of water and add grass to it? The water could carry it down a wide pipe for example, you filter the grass from the water at the destination, then send the water back to get more grass?
- torpfactory 8y ago
  Things start happening to grass when you put it in water. That might be OK depending on your other processing steps. A similar idea is pneumatic transport, where you add material to an air stream and then use a cyclone to separate the air and the grass.
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warent 8y ago
"Obviously we just needed a steeper cone angle, so we fabricated one at 75° but it still jammed. Perplexed, we increased the angle to 82.5°—practically a straight pipe—and it still jammed. Thus began our surprise introduction to the field of bulk material handling, where entire books have been written and companies have been founded solely to solve this issue known as ‘bridging’, and the frequently-associated ‘hammer rash’." 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.
naringas 8y ago
why not blow the grass?
thinkcontext 8y ago
I'm skeptical of most bioenergy projects that involve growing things in a field. The best by far I've seen is seen is Brazilian sugarcane to ethanol. Sugarcane is around 8% efficient at converting light into biomass, for comparison corn which the US uses for ethanol is 1-2%. Of course you then have to process those into something else to allow us humans to make use of that energy, so real efficiency is lower. 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.
- driverdan 8y ago
  You're ignoring the energy and materials costs for building solar panels. Land is not the problem so the difference between 8% and 18% is negligible.
  - thinkcontext 8y ago
    This is a good point, I debated whether to express things as EROI instead of efficiency. Brazilian ethanol is estimated to be about 8:1, corn ethanol is less than 2:1. According to a Wikipedia a 2015 metastudy for solar PV found between 8:1 and 40:1. https://en.wikipedia.org/wiki/Energy_returned_on_energy_invested https://en.wikipedia.org/wiki/Energy_returned_on_energy_inve...
- chimere 8y ago
  (Co-founder at Charm) Fair points. I'm not going to defend corn ethanol - our process yields 10x more saleable energy per acre than corn ethanol. The energy crop we're currently field trialing is similar to sugarcane, with extremely high yields (and our process uses the entire plant, unlike ethanol). Of course, energy crops are only required at large scale. At small scale, there's plenty of agricultural waste available for cheap, as you mentioned. 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 :]
hourislate 8y ago
Couldn't they use a manure spreader to throw the grass onto a conveyor belt at a steady rate? Manure spreaders come with variable flow rate and beaters to shred the manure. If you threw a bale of hay in there it would tear it up and throw it nicely. Here is an example: https://www.youtube.com/watch?v=YhvMMK91P-8 https://www.youtube.com/watch?v=YhvMMK91P-8
mrfusion 8y ago
So how does the sequestration work?
mchannon 8y ago
I get the desire to turn biomass into vehicle fuel. I don't get the desire to involve hydrogen. 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.
- chimere 8y ago
  (Charm Co-founder here) Ultimately our goal is large-scale CO2 removal and sequestration with biomass. This process produces an excess of energy which we can sell in various forms to fund the process. We chose to start with Hydrogen simply because it's quite easy and has a large industrial market. 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.
  - jacknews 8y ago
    There's this https://www.nextbigfuture.com/2018/11/nanomembrane-based-tech-can-replace-haber-bosch-process-that-feeds-world.html https://www.nextbigfuture.com/2018/11/nanomembrane-based-tec... Don't mean to rain on the parade, but I am skeptical
    - thinkcontext 8y ago
      That advance is for combining hydrogen and nitrogen in order to make ammonia. This company is talking about production of hydrogen, so the technologies complement one another.
      - jacknews 8y ago
        Indeed, but they're also touting that the energy component of haber-bosch can come from complete combustion of the charcoal, which is where some (much?) of the economic incentive comes from to pay for 'geologic sequestration'. 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?
gus_massa 8y ago
How advanced is the hydrogen production prototype? Looking at the Wikipedia page https://en.wikipedia.org/wiki/Steam_reforming 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.
vlizz 8y ago
Is there a reason you need to make it flow as opposed to simply conveying it mechanically? It seems like you came up with a complicated solution (making solids behave like liquids) when there are plenty of simpler solids handling techniques that could be used. For example a belt or screw conveyor.
trickstra 8y ago
wouldn't it be easier to pelletize the grass before feeding it?
deleted 8y ago
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L_226 8y ago
I like this. Slightly related, I am planning on building a house eventually and I really want to incorporate a domestic biogas generator for cooking. Something like https://www.homebiogas.com/ https://www.homebiogas.com/
vixen99 8y ago
'Charm’s mission is to return the atmosphere to 280 ppm CO2 profitably'. i.e., 2,130,000,000 metric tons of CO2 (= 1ppm) * (410ppm - 280ppm) or some 276 giga tons. Evidently a modest goal.
mojomark 8y ago
In case anyone is curious as to how bio-gassification compares to electrolysis (or a hybrid process), I found this 2009 paper [1] that sums it up decently (at least with the technology available at the time): (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. 1.) https://www.sciencedirect.com/science/article/pii/S0360319908014481 https://www.sciencedirect.com/science/article/pii/S036031990...
- chimere 8y ago
  Interesting question - I'm not sure I know the answer but happy to speculate. Electrolysis certainly is a much tidier process than gasification, but everyone seems to assume it's powered by 100% renewable energy. What incentives exist to make H2 production decarbonize faster than the rest of the electricity grid? I'd expect electrolysis to only be fully carbon-neutral when the rest of the grid is, which will take some time. 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 :]
gdpgreg 8y ago
Looks like the issue is the feed stock, non-uniform particle size distribution and significant differences in aspect ratio. All the different pieces are clumping up because of the particle interlocking. Maybe consider a grill sorter on the outlet of your size reduction system, allow <1cm particles through and rehandle larger particles back into whatever is chopping, or add secondary size reduction.

247 points by grantlmiller 8y ago

ars 8y ago

This article is about getting chopped up grass to flow through a hopper (so that it can be gasified for fuel). 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.)

caymanjim 8y ago
> 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.
- iso1337 8y ago
  Looks like they forgot to proof read their website too. "If you are want to consume carbon-neutral hydrogen, please reach us at sales@charmindustrial.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.
  - ars 8y ago
    Hydrogen is a mistake anyways, they should make syngas instead. https://en.m.wikipedia.org/wiki/Syngas https://en.m.wikipedia.org/wiki/Syngas and then Substitute natural gas (SNG) https://en.m.wikipedia.org/wiki/Substitute_natural_gas https://en.m.wikipedia.org/wiki/Substitute_natural_gas 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.
  - pkrein 8y ago
    Charm co-founder here... thanks for the typo find, fixed! 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.
pkrein 8y ago
Charm co-founder here... Two quick notes: (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 ;)

ada1981 8y ago

My initial thought was vibration, so I was happy to see that was the solution! 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.

ars 8y ago
Another thing to try is running up and down stairs, while holding a tissue. 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 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.
bbernoulli 8y ago
Saw this thing in a sappy movie that had a character with cystic fibrosis: https://www.afflovest.com/ https://www.afflovest.com/ They make it sound fancier than just vibrations though
- ada1981 8y ago
  Since I had a chest cold I also tried it on my lungs thinking it might help loosen things up. Less sure that worked (it felt nice), but I do feel much better today.

cwkoss 8y ago

I was just talking with a coworker about how we could theoretically modify our espresso machine hopper to avoid blockages. This is a great survey of bulk material handling options.

SubiculumCode 8y ago

I wonder what dampening the grass might do, as this might reduce the volume of the grass (increase density).

saagarjha 8y ago
I feel like this might make the grass harder to vibrate into a "fluid".
rtkwe 8y ago
First guess is it'd make it mat together worse by adding surface tension into the mix.

kazinator 8y ago

> Naively, we assumed that grass would flow somewhat like an ideal fluid, 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.

warent 8y ago
This is one of my favorite comments so far this year.
dsfyu404ed 8y ago
>Perfect sustenance for spherical cows. Engineering students discover that real world specialized solutions are in fact optimized for what they do. Water is wet. More breaking news at 11.

throwaway5752 8y ago

So many questions. 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.

pkrein 8y ago
One of the Charm co-founders here. Great questions, and you're correct the point is to find an economically profitable 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. https://en.wikipedia.org/wiki/Carbon_capture_and_storage https://en.wikipedia.org/wiki/Carbon_capture_and_storage 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.
- hanniabu 8y ago
  What's the flow rate you guys want to achieve and what's the allowable variance?
  - pkrein 8y ago
    Flow rate of biomass or hydrogen? Per unit we expect roughly 10-20 tons per day of biomass, and 0.5-1 ton per day of hydrogen. Allowable variance is low, but depends on the customer.

jacknews 8y ago

"With the addition of geological carbon dioxide sequestration it becomes carbon-negative." 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

chimere 8y ago
(Charm Co-founder here) Certainly - you're effectively describing biochar (https://en.wikipedia.org/wiki/Biochar https://en.wikipedia.org/wiki/Biochar) which historically has been used as both an energy source and a soil amendment. Using it as a sequestration method has gained some attention recently, though I have reservations. 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).
- marvindanig 8y ago
  Did you try blowing air through the mass from bottom up? It can help loosen the grass chips, reduce moisture and prevent agglomeration and is useful as long as the air flux doesn't prevent the grass from funneling down.
  - chimere 8y ago
    Certainly we considered it. The problem is that on this prototype system we were operating with a sealed hopper. Thus any gas injected into the hopper would travel through the system and dilute our output gas stream. Also any oxygen in the injected gas would result in combustion rather than gasification.
    - marvindanig 8y ago
      The inside of the funnel can be lined with a tube punchered uniformly and use pneumatic nitrogen piped from above and outside of the sealed hopper? I’m getting these weird ideas in my head.

zawerf 8y ago

I remember seeing a video demoing how to make sand flow like water by bubbling air into it: https://youtube.com/watch?v=My4RA5I0FKs https://youtube.com/watch?v=My4RA5I0FKs

crossman 8y ago
That was my first thought too.
chimere 8y ago
(Charm co-founder here) I love that video! That fluidization phenomenon is commonly used in large-scale gasification or combustion processes, see: https://en.wikipedia.org/wiki/Fluidized_bed_reactor https://en.wikipedia.org/wiki/Fluidized_bed_reactor
- mojomark 8y ago
  You probably know, but don't forget that compressing air is energy intensive. I'm not saying that the extra expense can't be marginalized - especially if you can dramatically increase production, I'm just pointing out that it's far from free. Just another fun engineering problem to tackle:)

stevespang 8y ago

Grass biochar or bamboo (a fast growing wooden grass) biochar would seem very useful as biochar is a proven beneficial amendment for high value horticultural soils, - - - and the highest value horticulture right now is probably cannabis farming.

NoblePublius 8y ago

Where is the evidence that carbon sequestration works?

pkrein 8y ago
Stanford Prof. Sally Benson's talk here is a great overview: https://youtu.be/lIVwbSnD0AI?t=127 https://youtu.be/lIVwbSnD0AI?t=127 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 https://youtu.be/lIVwbSnD0AI?t=1199
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- NoblePublius 8y ago
  Still seems like this is a big guess that sequestration works over long periods, or at all at the scale necessary to be industrially significant. I’m inherently sceptical of anything hydrogen related due to the fuel’s association with delay tactics from the carbon industry. Chevron would prefer we all not buy electric cars in hopes of HFC becoming a real thing which, obviously, is just a farce to keep paying them to produce, transport, and sell solid fuel. I think we are better off as a society not burning carbon at all, not looking for places to put carbon polution.
  - pkrein 8y ago
    Charm co-founder here... We are not betting on hydrogen fuel cell cars. There is an existing $120B/year market for hydrogen used in the production of ammonia fertilizer and oil refining. That hydrogen is currently produced from fossil natural gas, and we are replacing that. 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.

metalgearsolid 8y ago

I would have loved to be there the moment they first tried a funnel and failed. Bulk material handling seems pretty interesting to solve.

ggm 8y ago

what % of the generated H2 is currently consumed by the sequestration? If no other energy source is available, does this % change?

snappr_ 8y ago

Can the ash be used as a concrete additive? https://precast.org/2010/05/using-fly-ash-in-concrete/ https://precast.org/2010/05/using-fly-ash-in-concrete/

pkrein 8y ago
Charm co-founder here... possibly, but it's likely more valuable being sold as potash.
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torpfactory 8y ago

Looks like they've got some bad Funnel Flow in the hopper. Mass flow is probably the desired flow regime. Using a non-conical hopper is probably a better idea and would negate the vibration, which can fail. 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 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: https://www.youtube.com/watch?v=My4RA5I0FKs https://www.youtube.com/watch?v=My4RA5I0FKs

utexaspunk 8y ago
Could the grass be blown in? Leaf blowers move grass pretty easily...
- whatshisface 8y ago
  I would imagine that leaf blowers operate at a much lower density of grass, in an open area where there's nothing for a grass blade to stick on.
- MisterTea 8y ago
  First thing I thought about was fluidizing the grass via forced air. Plenty of bulky stuff is handled fluidized. One good example is the hydraulic french fry maker where potatoes are fluidized using water and pushed through a slicing grate using the pressure and velocity of the flow. The water carries the french fries out of the other side just as easily.
- torpfactory 8y ago
  You can probably blow it in just fine. The problem is really getting bulk materials out of hoppers. A whole world of research and engineering unto itself. 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...

dosy 8y ago

you want to mix the grass with air so you have grass suspended in a flow of air just like a fluid. since you need to avoid oxygen blow this grass nitrogen suspension through some pipes and into your gassifier.

williesleg 8y ago

So the oceans aren't rising enough we need to make more water? I'm scared for my life! Gonna have to vote now for sure!

malloryerik 8y ago

If you want to have the grass flow like water, could you take a stream of water and add grass to it? The water could carry it down a wide pipe for example, you filter the grass from the water at the destination, then send the water back to get more grass?

torpfactory 8y ago
Things start happening to grass when you put it in water. That might be OK depending on your other processing steps. A similar idea is pneumatic transport, where you add material to an air stream and then use a cyclone to separate the air and the grass.
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warent 8y ago

"Obviously we just needed a steeper cone angle, so we fabricated one at 75° but it still jammed. Perplexed, we increased the angle to 82.5°—practically a straight pipe—and it still jammed. Thus began our surprise introduction to the field of bulk material handling, where entire books have been written and companies have been founded solely to solve this issue known as ‘bridging’, and the frequently-associated ‘hammer rash’." 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.

naringas 8y ago

why not blow the grass?

thinkcontext 8y ago

I'm skeptical of most bioenergy projects that involve growing things in a field. The best by far I've seen is seen is Brazilian sugarcane to ethanol. Sugarcane is around 8% efficient at converting light into biomass, for comparison corn which the US uses for ethanol is 1-2%. Of course you then have to process those into something else to allow us humans to make use of that energy, so real efficiency is lower. 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.

driverdan 8y ago
You're ignoring the energy and materials costs for building solar panels. Land is not the problem so the difference between 8% and 18% is negligible.
- thinkcontext 8y ago
  This is a good point, I debated whether to express things as EROI instead of efficiency. Brazilian ethanol is estimated to be about 8:1, corn ethanol is less than 2:1. According to a Wikipedia a 2015 metastudy for solar PV found between 8:1 and 40:1. https://en.wikipedia.org/wiki/Energy_returned_on_energy_invested https://en.wikipedia.org/wiki/Energy_returned_on_energy_inve...
chimere 8y ago
(Co-founder at Charm) Fair points. I'm not going to defend corn ethanol - our process yields 10x more saleable energy per acre than corn ethanol. The energy crop we're currently field trialing is similar to sugarcane, with extremely high yields (and our process uses the entire plant, unlike ethanol). Of course, energy crops are only required at large scale. At small scale, there's plenty of agricultural waste available for cheap, as you mentioned. 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 :]

hourislate 8y ago

Couldn't they use a manure spreader to throw the grass onto a conveyor belt at a steady rate? Manure spreaders come with variable flow rate and beaters to shred the manure. If you threw a bale of hay in there it would tear it up and throw it nicely. Here is an example: https://www.youtube.com/watch?v=YhvMMK91P-8 https://www.youtube.com/watch?v=YhvMMK91P-8

mrfusion 8y ago

So how does the sequestration work?

mchannon 8y ago

I get the desire to turn biomass into vehicle fuel. I don't get the desire to involve hydrogen. 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.

chimere 8y ago
(Charm Co-founder here) Ultimately our goal is large-scale CO2 removal and sequestration with biomass. This process produces an excess of energy which we can sell in various forms to fund the process. We chose to start with Hydrogen simply because it's quite easy and has a large industrial market. 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.
- jacknews 8y ago
  There's this https://www.nextbigfuture.com/2018/11/nanomembrane-based-tech-can-replace-haber-bosch-process-that-feeds-world.html https://www.nextbigfuture.com/2018/11/nanomembrane-based-tec... Don't mean to rain on the parade, but I am skeptical
  - thinkcontext 8y ago
    That advance is for combining hydrogen and nitrogen in order to make ammonia. This company is talking about production of hydrogen, so the technologies complement one another.
    - jacknews 8y ago
      Indeed, but they're also touting that the energy component of haber-bosch can come from complete combustion of the charcoal, which is where some (much?) of the economic incentive comes from to pay for 'geologic sequestration'. 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?

gus_massa 8y ago

How advanced is the hydrogen production prototype? Looking at the Wikipedia page https://en.wikipedia.org/wiki/Steam_reforming 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.

vlizz 8y ago

Is there a reason you need to make it flow as opposed to simply conveying it mechanically? It seems like you came up with a complicated solution (making solids behave like liquids) when there are plenty of simpler solids handling techniques that could be used. For example a belt or screw conveyor.

trickstra 8y ago

wouldn't it be easier to pelletize the grass before feeding it?

deleted 8y ago

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L_226 8y ago

I like this. Slightly related, I am planning on building a house eventually and I really want to incorporate a domestic biogas generator for cooking. Something like https://www.homebiogas.com/ https://www.homebiogas.com/

vixen99 8y ago

'Charm’s mission is to return the atmosphere to 280 ppm CO2 profitably'. i.e., 2,130,000,000 metric tons of CO2 (= 1ppm) * (410ppm - 280ppm) or some 276 giga tons. Evidently a modest goal.

mojomark 8y ago

In case anyone is curious as to how bio-gassification compares to electrolysis (or a hybrid process), I found this 2009 paper [1] that sums it up decently (at least with the technology available at the time): (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. 1.) https://www.sciencedirect.com/science/article/pii/S0360319908014481 https://www.sciencedirect.com/science/article/pii/S036031990...

chimere 8y ago
Interesting question - I'm not sure I know the answer but happy to speculate. Electrolysis certainly is a much tidier process than gasification, but everyone seems to assume it's powered by 100% renewable energy. What incentives exist to make H2 production decarbonize faster than the rest of the electricity grid? I'd expect electrolysis to only be fully carbon-neutral when the rest of the grid is, which will take some time. 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 :]

gdpgreg 8y ago

Looks like the issue is the feed stock, non-uniform particle size distribution and significant differences in aspect ratio. All the different pieces are clumping up because of the particle interlocking. Maybe consider a grill sorter on the outlet of your size reduction system, allow <1cm particles through and rehandle larger particles back into whatever is chopping, or add secondary size reduction.