• A biochar of spent coffee grounds.

    Not coffee grounds.

    If you don’t know what biochar is, it’s high carbon material that’s left over after burning organic matter (think:wood) slowly under low-oxygen conditions.

    Biochar requires energy and emitting gases.

    It seems unfair to say that we’re saving on CO2 and methane from decomposition without also counting the cost of the biochar combustion.

    • I wish they had a bit about that in the article itself, but they did link another article about biochar creation and its byproducts. I linked it in another comment here.

      I feel there’s a lot of assumptions here that no one actually reads articles.

      •  norbert   ( @norbert@kbin.social ) 
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        10 months ago

        Most of us are from reddit and unfortunately that “jump to the comments to argue” mentality seems to have followed a lot of us.

        For example, I haven’t read the article. Just clicked into the comments to see what it was, found out it was coffee.

        I’ll go read it now.

        I’m back, the other linked USDA article about pyrolysis is fascinating. It’s not really clear on how much energy the process takes but they did mention it could (possibly) be self-sustaining. Really cool stuff!

  • For anyone who came here without reading the article to comment about the impending effects of climate change on coffee yields, do note that this proposes using spent (i.e. already used) coffee grounds. SCG currently end up in landfills and eventually get turned into carbon dioxide and methane.

    • The article they link about pyrolysis is worth a read too. The main source of CO2 emissions from cement production is cooking down limestone into lime IIRC. I was curious how much energy is used to turn the biomass into the end product and what waste is generated. It’s a bit too detailed for me to understand, but the process ends up with 15-25% biochar (the stuff they’re promoting in this article), some potentially useful byproducts, and some regular combustion pollution.

    •  sundrei   ( @sundrei@lemmy.sdf.org ) 
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      110 months ago

      I guess this means I’ll need yet another, different colored wastebin just for coffee now. I mean I’ll do it if it helps, but I can only fit so many receptacles in my kitchen. Meh, I’ll just put the rest in the twins’ room.

    • I worked on some undergrad research examining the potential to use spent coffee grounds for biodiesel. SCG has residual oil that can be extracted and refined. I wonder if this could be combined with biochar, getting multiple commodities from a waste product.

  •  anon6789   ( @anon6789@beehaw.org ) 
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    10 months ago

    I’m glad to see research into this. Sand for concrete is a specific type of sand (nice and bumpy so it likes to lock together like a jigsaw puzzle) and people get killed by what are basically sand cartels. This was the “legitimate” mob business in the last season of Barry.

    Portland cement is about 2/5 sand, so we’ll need to start drinking more coffee! I was glad to see they’re testing other organic matter since coffee is very susceptible to climate change, ironically caused in a large part by cement production. Unless you believe the reader comment on the article begging people to realize climate change is a hoax…

  • The disposal of organic waste poses an environmental challenge as it emits large amounts of greenhouse gasses including methane and carbon dioxide, which contribute to climate change,

    I mean, yeah, but isn’t it carbon neutral? The coffee comes from the earth, returns to the earth. And couldn’t coffee also be used for biogas?

    natural sand as the particulate’s rough exterior provides more surface area for water and cement to bind

    What further puzzles me is how they decided to use coffee. Surely there are many other waste products that have the required structure. Is coffee the first thing they tried?

    • Methane is produced by methanogens in landfills, methane is not really part of the carbon cycle. The cycle itself isn’t self contained, so all the carbon dioxide and methane join all the rest in the atmosphere. We want to reduce any greenhouse gas sources as much as possible, whether it’s “carbon neutral” or not.

      They can’t just use any type of sand for construction, beach sand is out of the question as it’s not rough enough. It’s coming to the point that it’s hard to find sources of sand that don’t have negative ecological impacts, so replacing that component with something else is a good idea.

      I’d be willing to guess that they already tested using bio char as a replacement and saw that it worked well in concrete, then started looking at waste sources of starting material that had sandy texture, then boom coffee grounds.

    • I mean, yeah, but isn’t it carbon neutral? The coffee comes from the earth, returns to the earth. And couldn’t coffee also be used for biogas?

      Yes you’re right, the overall process of a plant growing and then the plant dying and breaking down is carbon neutral. Sequestering the carbon would interrupt this process and make it carbon negative. This is generally speaking a Good Thing since so many other processes are carbon positive.

      There are currently many efforts around the world looking to ramp up biochar production and use in remediating agricultural soils. For example, in many places after harvest time, leftover wheat stalks are gathered up and burned to get rid of the waste. This creates a lot of smoke and air pollution. Some companies are instead picking up the waste, transforming them into biochar and then tilling it back into the soil. https://farmland.org/biochar/

      A Spent Coffee Ground project could be analogous to this.

      What further puzzles me is how they decided to use coffee. Surely there are many other waste products that have the required structure. Is coffee the first thing they tried?

      Could probably also use other sources of biochar. Since you’re replacing sand, it may be an advantage that the coffee grounds are already ground up very finely. I’d imagine something like wheat stalks or corn cobs might be too large to replace sand and require further processing.

  • I know sand is actually a precious resource when you really learn about how much concrete we make and what kinds of sand there are and which are needed for concrete.

    But still, it’s strange to think that this exotic bean which will only grow in certain climates can actually be easier to get than fucking sand.