[dbcurtis]

How is this an overall improvement over leaving the corn stalks in the field to decompose and return nutrients to the soil? This process moves soil nutrients away from point of origin. (Serious question from former Iowa farm boy who still owns corn ground operated by others. Should I let my tenants ship stover away? I want to be a good steward of the soil. )

[pkrein]

The process separates the biomass carbon into bio-oil, and the NPK in the biomass separates into the biochar/ash (2% of the N, 70% of the P, >90% of the K). That biochar/ash goes back into the soil. So we recover most of the nutrients, plus you get biochar which improves soil carbon, water retention, microbial health, etc.

https://charmindustrial.com/faq?question=how-do-you-sustaina...

[colechristensen]

Yes, but why is this better than leaving the biomass in the field and perhaps doing some soil building techniques?

You also need to hire some farm kids or pay for some scholarships to get interns. Some of the problems you described solving over months would have been trivially solved by someone with farm experiences.

You’d really benefit from going to farm auctions, finding one of these, taking it apart, and adapting the mechanisms to your purposes. https://youtu.be/aYv8aDRv998

[pkrein]

Leaving the biomass on the field results in the CO₂ going back into the atmosphere (~80% within 2 years): https://cdnsciencepub.com/doi/10.4141/cjss2010-055#T0002

By contrast, our process retains the nutrients, improves the soil health relative to the baseline of just leaving it, and you get permanent carbon removal.

Yes, we're hiring for great mechanical engineers with experience in these areas ;) Lots to do!

[jonstewart]

How does removing the biomass improve soil health?

[lazide]

Biochar helps avoid soil compaction and dramatically improves productivity of the soil.

[jonstewart]

I just did a quick search on impact of biochar on corn yield and the research seems mixed, at best. It seems to have the most impact on poor soil, but little impact on yield in good soil (e.g., the corn belt). A public benefit may be reduction of nitrate leaching—-so applied at scale that could help the Gulf. Water retention can be improved, too; it’d be interesting to see whether there’s impact on yield in drought years.

[pkrein]

Read two comments up. Biochar/ash made from the biomass goes into the soil.

[jonstewart]

So ideally one of your systems would be at the local elevator to make stover dropoff/biochar pickup easy? And then maybe someday combines would have a baler on them? And the biochar could go in a manure spreader for application?

Is there waste heat/syngas coming off the pyrolysis (beyond what's needed for sustaining it)? If so, have you looked into applying that to grain drying?

[Fomite]

Yeah, the West Coast Ag School professor in me in flinching at some of this.

[RosanaAnaDana]

Whatever their answer they'll need to account for the fuel cost of the trip to a facility, lifecycle cost of the instrumentation, and fuel cost of a return trip for where ever the whatever is going to go.

I can tell you right now having done experimental LCA previously, its not gonna pen out. The cost of moving massive amounts of 'stuff' to do 'something' with it when its an extremely low margin, low value add product; this will end up generating more CO2 than it sequesters.

If you can't do it in place, you likely can't do it.

[YeGoblynQueenne]

Couldn't the bio-oil generated by the process be used to power the transport and supply lines? Or don't the maths work out? I don't know any of the numbers here...

[RosanaAnaDana]

You have to drive the 'stuff' to 'somewhere' to turn it into 'whatever'.

The stuff costs more in CO2 to drive to the place than you get from turning it into 'whatever'.

[YeGoblynQueenne]

But is this a general and inescapable rule?

[RosanaAnaDana]

I think that would be a very interesting question to try and address in a meta-analysis.

[dreamcompiler]

That would defeat the purpose. Burning the bio-oil to extract energy from it would just pump CO2 into the atmosphere.

[YeGoblynQueenne]

Yes, I understand that, but I thought that most of the CO2 is bound to the ash that's supposed to be buried underground? So there would be a net reduction of CO2, even if the bio-oil was burned?

[dbcurtis]

Yes, that is my take. It only works economically if the soil nutrients come back to the field, and it costs no more (net) than adding a stalk chopper to the combine.

Extra trips over the field burn fuel, and something needs to pay for the dollar cost of that (in added fertilizer value or something) not to mention the net carbon emissions of burning diesel to go over the field again.

[colechristensen]

You usually have to have entirely renewable generated electric powered processes in order to actually sink meaningful amounts of carbon.

And even then, to actually sink carbon the correct thing to do would be to electrify the farm machinery for a much higher carbon ROI.

[jonstewart]

(Another former Iowa farm boy) This is a CO2 sequestration process, and one still in development. The carbon in the corn stalks is obviously pretty neutral—it’s the petroleum for tractors, drying, and fertilizer that are the CO2 emissions problem.

For soil health, I think you’d want your renter to go no-till (if isn’t already). And then for emissions, look into putting solar panels wherever, seeing whether there are electric/heat pump dryers available (???) if you have drying bins, and encouraging renter to use biodiesel.

[carbadtraingood]

Decomposing biomass releases almost all its mass back as CO2 into the atmosphere, very little is sequestered.

This approach removes carbon from the atmosphere permanently.

It's also (probably) a net energy producer and it doesn't require creating massive piles of decomposing plant matter everywhere.

[goda90]

This depends on the conditions the biomass is decomposing in. A lot of carbon can be captured in the soil if handled well. No till, no spray, cover crops, and managed grazing of the cover crops can create an environment where the soil is a carbon sink and a better base for future crops.

[carbadtraingood]

Yes. And also no. Practices like that are good, but the majority of your carbon sequestration will come in the form of the roots of plants. (This is part of why no till is good.)

Getting surface vegetation to deposit carbon in the soil long term is trickier. You aren't wrong, but it's also not as simple as some folks believe. Just cutting the corn stalks and cobs and leaving them on a field won't put much carbon back in the soil.

[ciphol]

Possibly the bacteria which decompose the corn emit CO2 as they "burn" the corn for their food?