Logan Byrd

This thread is a description of a process I've discovered and found very helpful, and a question for anyone that might have a tool suggestion!

I've been doing very small scale biochar production using the tin can method - remove one end of two cans, crimp one, poke a hole on the other, fill with materials and press the cans together to "seal" them, and toss the can into a fire or on a grill to convert the materials to biochar.

My goal has been to convert any paper-like home waste (paper towel, kleenex, paper plates, newspaper, non-glossy/bleached junk mail) into biochar, but the biggest constraint for me has been trying to be as efficient as I can with the biochar process, as I can't make a large fire or similar.

One tool that I've found very useful (after spending a long time trying to find something that worked) is a "rosin press". It's a metal tube, with a metal cap on one end, and a metal peg on the other end. I can put kleenex or other paper materials into the capped tube, put the peg in it, and then press it in a vice to produce a very compressed pellet of pre-biochar. Once turned into biochar, these still retain their pellet-like structure, and can be either crushed up or added to my compost piles as-is.

The only downside to this is that it's very physically intensive to bring small amounts of materials to a vice, tighten it as much as I can, and repeat until I'm out of materials.
Does anyone have any suggestions for a more efficient way to do this, or any hobbyist/home electric presses that would work for placing pressure on a small tube like that?

There are electric rosin presses, but they're all designed to heat up the tube as well, which is not something I want or need - I'm just looking for a way to put a lot of force into pressing the peg into the tube.

This is a very cool bundle! Lots of great learning material in there.

Anne Miller wrote:Why not try an experiment by trying to compost just a few of them to see what happens?

Please let us know what your findings are.

I'd be happy to give this a try, but is there a good way to determine whether it's actually composting or just breaking down into microplastics?

I have a small collection of PLA straws that I've collected over time from restaurants, and they've all been labelled "100% home compostable" and "meets ASM D6400".

But looking it up online, I'm getting mixed opinions about whether or not they can be home composted, and if so, how.

Does anyone have any advice on these, especially in terms of cold composting? I don't mind if they take 2-5 years to compost, but I want to make sure they're actually composting and not just making the soil worse.

Last spring/summer was a busy time for me, so I did not have much time to maintain my garden or do any work on it. There were quite a few volunteer tomato plants that appeared at the ground level, rather than in the barrels, although unfortunately the fruit did not mature before frost came. (either that, or the wildlife was eating them as they ripened)

I planted some mint, as well as some golden raspberries, and both of those are still alive and seem to be doing well! The wild horsetail, on the other hand, has become incredibly prolific. There are shoots appearing all throughout the garden, and even in all of the barrels, so I need to keep an eye on them to make sure I don't lose my planters to them.

Or maybe I could try just planting alongside them? I think they would let more than enough light through for anything I sow to get started, but I haven't tried that yet.

Douglas Alpenstock wrote:My understanding is that there is a worldwide cardboard shortage. Supply chains are messed up. Clean cardboard is highly recyclable; they just pulp it up and add it to the mix. And everybody demands as much post-consumer content as possible. So in my opinion, clean cardboard should always be recycled, not burned, wherever it is possible. The alternative is to cut and shred more living trees.

That said, I sometimes have cardboard that is not clean enough to recycle, or has grease stains, and doesn't belong in the recycling stream. It just causes problems. I certainly avoid sending it to the landfill. I have been known to slice it in thin strips down the channels for wood stove firestarter. If it has grease, all the better. It works well.

Or I guess you could char it in a closed retort. Problem is, it's high volume, low fibre stuff -- compared to, say, broken up sticks. So the amounts of char produced are relatively tiny. But I guess I might use charred cardboard on shelterbelts. Probably not on food growing areas though; there are just to many unknowns from my perspective.

Unfortunately, the only recycling service in my area seems to be one of those "take everything and dump it in a landfill for extra profit" types. They don't require any separation of materials, something like an empty jar of pasta sauce with sauce & mold still inside of it is fine, and any time I've tried to call to ask about what happens to the materials they take, I get vague answers and "let me have my boss call you back later" responses that never lead to anything.

The area I'm in, while rural, doesn't give me much freedom to go around and collect local materials - so even things like sticks are in short supply

As promised, here's a photo of my mixture of dehydrated food scraps and biochar - this is normally a light brown colour, but the biochar gives it a much darker colour as it gets ground up and mixed in.
Most of the larger pieces in this batch are eggshells, kumquat skins, and chicken bones - but the biochar seems well blended with the rest.

A bit off topic since it's not cardboard, but I think it might help show that I'm fine with a finer biochar - some of the biochar pieces I put in here were beef bone and stonefruit pits, and they all ground down well.

Nancy Reading wrote:I'm currently researching pfas in cardboard....about pfas
They are making me sad.
I've still got a lot of research to do, but hope to post a bit more about them in the next week.
My worry is that they have got into the paper recycling stream and hence could be in most cardboard for example. I don't think burning makes them go away.

I'm looking forward to seeing your post! I haven't heard about them before but it seems a bit alarming, although vague - I'll have to look into it more and see what happens (if anything) when they're combusted.

Timothy Norton wrote:I think my only thing that I can say as a negative (besides what is above) is that the biochar that you are producing is going to be on the more fine side than coarse. Cardboard is made up of essentially wood pump randomly laying on top of eachother dried into a sheet. If you are looking for the chunkier random sized biochar you get from a wood stock source it might not be what your looking for.

I'll see if I can grab a picture later, but what I've been doing with my biochar is putting it through the food scrap grinder/drier I have to produce a fine mixture of food scraps and biochar. I think it will provide increased surface area as well as solving the concern of non-activated biochar absorbing nutrients, since most of it will be covering food scraps once the composting action starts.

Timothy Norton wrote:I'd love to hear results from trying to do some grows supplemented with this biochar.

I think I might give this a try - I don't have much growing space, but I could try two indoor potted plants (maybe radishes?) with weighted amounts of biochar, dried food scraps, and potting soil. One would have biochar made purely from cardboard, and one would have biochar made purely from wood grown around here.

I think weighing them would balance out the two as much as I can.

J Hillman wrote:Because of all the news about micro plastics I am no longer a fan of using cardboard and newspaper as mulch and more.  I don't know what they use for ink or glue.  I don't know if those things go away in the process of making it into charcoal.

I personally burn un-recyclable cardboard and don't use the ashes from it in my garden.

My understanding is that the plastic and glue would burn off - that seems to be the case for my trial piece as well, as I can separate the three layers of the cardboard with minimal force. (although they're more likely to break as I try due to how thin they are)

In this case the cardboard didn't have any ink on it - I think soy-based ink would be fine, but heavy metal ink (is this still used?) would remain in the biochar.
I wouldn't want to test it, but I'm curious if whatever is printed on the cardboard would still be visible on the biochar if something used the less eco-friendly form of ink.