Corn Cobs: Fuel of Nightmares • Hacker News Board

Re: Corn Cobs: Fuel of Nightmares

#11

Post by ed » Thu, Jul 14, 2022, 3:34 PM UTC

So the ELI5 is they burn crop waste, harvest the heat and bury the carbon-rich ash. This process is called BECCS. (Not totally right - see 'pkrein’s comment below.)

The upper bound on capture is pretty good! Almost 70% of yearly CO2 emissions.

> Intergovernmental Panel on Climate Change (IPCC), suggests a potential range of negative emissions from BECCS of 0 to 22 gigatonnes per year [1]

> Human activities emit over 30 billion tons of CO2 (9 billion tons of fossil carbon) per year [2]

1 - https://en.m.wikipedia.org/wiki/Bioenergy_with_carbon_captur...

2 - https://en.m.wikipedia.org/wiki/Carbon_dioxide

Re: Corn Cobs: Fuel of Nightmares

#12

Post by liminvorous » Thu, Jul 14, 2022, 3:35 PM UTC

rexreed wrote: post #7

carbadtraingood wrote: post #6

Earlier quoted context omitted.

They discuss a bit in the article, but the material they had prototyped with was very different than the material they tried to scale up with. It sounds like their scaled up plant accepted a wide variety of materials, but this one specific input stream slowed them down. So they weren't shut down while they figured this out, they just processed the material they knew they could process until they had a solution here.

Why would you prototype with a material that's substantially different from the real-world item? I read the article and this bit puzzled me. The differences clearly matter, and the $300M bankruptcy they reference in the article even makes that point.

They want to be able to process both the material they prototyped with and the material they started with (straw) and the material they tried to scale up with (corn cobs), and probably any kind of plant matter that has less structural integrity than say, timber.

Re: Corn Cobs: Fuel of Nightmares

#13

Post by rexreed » Thu, Jul 14, 2022, 3:35 PM UTC

SV_BubbleTime wrote: post #9

carbadtraingood wrote: post #6

Earlier quoted context omitted.

They discuss a bit in the article, but the material they had prototyped with was very different than the material they tried to scale up with. It sounds like their scaled up plant accepted a wide variety of materials, but this one specific input stream slowed them down. So they weren't shut down while they figured this out, they just processed the material they knew they could process until they had a solution here.

I’m starting to believe the idea that long term zero percent rates have made MBAs in charge of almost everything completely careless to the historical realities of business where you have a product and process before investing tons into a system. It seems to me that with “endless free money” we miss things like “this one input stream will be a nightmare, let’s not do it”.

Absolutely agree. Also, how is this firm based in Silicon Valley / San Fran where the customers are primarily in the midwest? If they were serious about this problem, shouldn't they be where their customers or resources are? Building something in isolation and then "shipping" it to where it will be used seems very inefficient and they're clearly missing out on valuable on-the-ground information and experience. This seems more like a university research project than a serious concern?

Re: Corn Cobs: Fuel of Nightmares

#14

Post by pkrein » Thu, Jul 14, 2022, 3:36 PM UTC

rexreed wrote: post #7

carbadtraingood wrote: post #6

Earlier quoted context omitted.

They discuss a bit in the article, but the material they had prototyped with was very different than the material they tried to scale up with. It sounds like their scaled up plant accepted a wide variety of materials, but this one specific input stream slowed them down. So they weren't shut down while they figured this out, they just processed the material they knew they could process until they had a solution here.

Why would you prototype with a material that's substantially different from the real-world item? I read the article and this bit puzzled me. The differences clearly matter, and the $300M bankruptcy they reference in the article even makes that point.

Initial testing was in San Francisco, where corn stover is relatively tricky to come by because corn is not widely grown in California, and agricultural residues cannot be brought into the state because of the bugs. Wheat straw was much easier to procure in-state.

Since encountering the differences, we tracked down the rarer corn growers in California and now use corn stover for testing as well.

Re: Corn Cobs: Fuel of Nightmares

#15

Post by taneq » Thu, Jul 14, 2022, 3:38 PM UTC

rexreed wrote: post #4

How do you get so far into a project before you even realize that you have such a show-stopper problem? Move fast / fail fast works with software because iteration times are quick and penalty per iteration is low. But just building stuff and hoping it works and then realizing major problems doesn't work so well with real-world stuff. Couldn't they have "workshopped" this with non-functional item to see what the real…

Somehow you never quite get the real raw material when you ask for samples, no matter how careful you are.

I worked on a system once upon a time that fed steel balls into a ball mill. We tested it thoroughly in the workshop with the same steel balls used on the customer's site, but when we went to commission it, it jammed non-stop.

Turns out a hundred randomly selected balls won't contain most of the outliers that you'd get in even one tonne of balls, and when you're feeding 5 tonnes per hour, that's a lot of jams. We had balls with big craters in them, half-balls, balls with two halves offset by 50%, and everything in between. Not the kind of thing you could rely on rolling nicely.

Also, of course, when you ask a mill ball manufacturer for a sample, they might be inclined to send you the very nicest examples they can find, because they think you might buy their product...

Anyway, unless you're super careful about sourcing legitimate feed samples it's easy to think you're testing against the real product when you really aren't.

Re: Corn Cobs: Fuel of Nightmares

#16

Post by [deleted] » Thu, Jul 14, 2022, 3:38 PM UTC

rexreed wrote: post #7

carbadtraingood wrote: post #6

Earlier quoted context omitted.

They discuss a bit in the article, but the material they had prototyped with was very different than the material they tried to scale up with. It sounds like their scaled up plant accepted a wide variety of materials, but this one specific input stream slowed them down. So they weren't shut down while they figured this out, they just processed the material they knew they could process until they had a solution here.

Why would you prototype with a material that's substantially different from the real-world item? I read the article and this bit puzzled me. The differences clearly matter, and the $300M bankruptcy they reference in the article even makes that point.

[deleted]

Re: Corn Cobs: Fuel of Nightmares

#17

Post by rexreed » Thu, Jul 14, 2022, 3:38 PM UTC

pkrein wrote: post #14

rexreed wrote: post #7

Earlier quoted context omitted.

Why would you prototype with a material that's substantially different from the real-world item? I read the article and this bit puzzled me. The differences clearly matter, and the $300M bankruptcy they reference in the article even makes that point.

Initial testing was in San Francisco, where corn stover is relatively tricky to come by because corn is not widely grown in California, and agricultural residues cannot be brought into the state because of the bugs. Wheat straw was much easier to procure in-state. Since encountering the differences, we tracked down the rarer corn growers in California and now use corn stover for testing as well.

If corn stover is a critical importance to your business and business model, wouldn't it be more effective, efficient, and beneficial to your business to be where the critical resource and information and experience is? Basically why not move to Kansas instead of stay put in California?

Re: Corn Cobs: Fuel of Nightmares

#18

Post by 9dev » Thu, Jul 14, 2022, 3:40 PM UTC

pkrein wrote: post #14

rexreed wrote: post #7

Earlier quoted context omitted.

Why would you prototype with a material that's substantially different from the real-world item? I read the article and this bit puzzled me. The differences clearly matter, and the $300M bankruptcy they reference in the article even makes that point.

Initial testing was in San Francisco, where corn stover is relatively tricky to come by because corn is not widely grown in California, and agricultural residues cannot be brought into the state because of the bugs. Wheat straw was much easier to procure in-state. Since encountering the differences, we tracked down the rarer corn growers in California and now use corn stover for testing as well.

If you rely on material that is scarce in one location but widely available in another, wouldn't it make sense to test where the material is abundant..?

Re: Corn Cobs: Fuel of Nightmares

#19

Post by pkrein » Thu, Jul 14, 2022, 3:40 PM UTC

PaulHoule wrote: post #2

This is some kind of https://en.wikipedia.org/wiki/Bioenergy_with_carbon_capture_... ?

Academia has started referring to our category as Biomass Carbon Removal and Storage, or BiCRS (pronounced like “bikers”):

https://www.icef.go.jp/pdf/summary/roadmap/icef2020_roadmap....

Re: Corn Cobs: Fuel of Nightmares

#20

Post by thimkerbell » Thu, Jul 14, 2022, 3:41 PM UTC

Interesting post.

Is there a "mechanical engineering for dummies" educational path (Book? Software? Kit?) that would equip someone for doing like 90% of the mechanical design&prototyping work?

Interesting point: "when you solve one bottleneck you find a new one somewhere else."