recycling

100 Articles

Disposable Vape Batteries Power EBike

November 7, 2024 by 11 Comments

There are a lot of things that get landfilled that have some marginal value, but generally if there’s not a huge amount of money to be made recycling things they won’t get recycled. It might not be surprising to most that this is true of almost all plastic, a substantial portion of glass, and even a lot of paper and metals, but what might come as a shock is that plenty of rechargeable lithium batteries are included in this list as well. It’s cheaper to build lithium batteries into one-time-use items like disposable vape pens and just throw them out after one (or less than one) charge cycle, but if you have some spare time these batteries are plenty useful.

[Chris Doel] found over a hundred disposable vape pens after a local music festival and collected them all to build into a battery powerful enough for an ebike. Granted, this involves a lot of work disassembling each vape which is full of some fairly toxic compounds and which also generally tend to have some sensitive electronics, but once each pen was disassembled the real work of building a battery gets going. He starts with testing each cell and charging them to the same voltage, grouping cells with similar internal resistances. From there he assembles them into a 48V pack with a battery management system and custom 3D printed cell holders to accommodate the wide range of cell sizes. A 3D printed enclosure with charge/discharge ports, a power switch, and a status display round out the build.

With the battery bank completed he straps it to his existing ebike and hits the trails, easily traveling 20 miles with barely any pedal input. These cells are only rated for 300 charge-discharge cycles which is on par for plenty of similar 18650 cells, making this an impressive build for essentially free materials minus the costs of filament, a few parts, and the sweat equity that went into sourcing the cells. If you want to take an ebike to the next level of low-cost, we’d recommend pairing this battery with the drivetrain from the Spin Cycle.\

Thanks to [Anton] for the tip!

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Recycling Tough Plastics Into Precursors With Some Smart Catalyst Chemistry

October 8, 2024 by 33 Comments

Plastics are unfortunately so cheap useful that they’ve ended up everywhere. They’re filling our landfills, polluting our rivers, and even infiltrating our food chain as microplastics. As much as we think of plastic as recyclable, too, that’s often not the case—while some plastics like PET (polyethylene terephthalate) are easily reused, others just aren’t.

Indeed, the world currently produces an immense amount of polyethylene and polypropylene waste. These materials are used for everything from plastic bags to milk jugs and for microwavable containers—and it’s all really hard to recycle. However, a team at UC Berkeley might have just figured out how to deal with this problem.

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Lasers Could Help Us Recycle Plastics Into Carbon Dots

July 18, 2024 by 17 Comments

As it turns out, a great deal of plastics are thrown away every year, a waste which feels ever growing. Still, as reported by Sci-Tech Daily, there may be help on the way from our good friend, the laser!

The research paper  from the University of Texas outlines the use of lasers for breaking down tough plastics into their baser components. The method isn’t quite as simple as fire a laser off at the plastic, though. First, the material must be laid on a special two-dimensional transition metal dichalcogenide material — a type of atomically-thin semiconductor at the very forefront of current research. When the plastics are placed under the right laser light in this scenario, carbon-hydrogen bonds in the plastic are broken and transformed, creating new chemical bonds. Done right, and you can synthesize luminescent carbon dots from the plastic itself!

“By harnessing these unique reactions, we can explore new pathways for transforming environmental pollutants into valuable, reusable chemicals, contributing to the development of a more sustainable and circular economy,” says Yuebing Zheng, a leader on the project. “This discovery has significant implications for addressing environmental challenges and advancing the field of green chemistry.”

Sure it’s a bit trickier than turning old drink bottles into filament, but it could be very useful to researchers and those investigating high-tech materials solutions. Don’t forget to read up on the sheer immensity of the world’s plastic recycling problems, either. If you’ve got the solution, let us know!

Recycling Of Portland Cement And Steel In Electric Arc Furnaces

May 27, 2024 by 25 Comments

The use of concrete and steel have both become the bedrock of modern-day construction, which of course also means that there is a lot of both which ends up as waste once said construction gets demolished again. While steel is readily recyclable, the Portland cement that forms the basis of concrete so far is not. Although the aggregate from crushed concrete can be reclaimed, the remainder tends to end up in a landfill, requiring fresh input of limestone to create more cement. Now a team of researchers from the University of Cambridge claim to have found a way to recycle hydrated Portland cement by using it as flux during steel production in electric arc furnaces (EAFs).

Not only does this save a lot of space in landfills, it also stands to reduce a lot of the carbon dioxide produced during cement and steel production, which is primarily from the use of limestone for cement and lime-dolomite for steel. The details can be found in the open access paper in Nature by [Cyrille F. Dunant] and colleagues. Essentially reclaimed cement paste is mixed with some fresh material to form the flux that shields the molten steel in an EAF from the atmosphere. The flux creates the slag layer that floats on top of the molten steel, with this slag after cooling down being ground up and turned into cement clinker, which is then mixed to create fresh cement.

The process has been patented by Cambridge, who call the product ‘Cambridge Electric Cement‘, with the claim that if using low-carbon power sources for the EAF like hydro and nuclear, it would constitute ‘no emissions’ and ‘no landfill’ cement. We have to see how this works out on an industrial scale, of course, but it would definitely be nice to keep concrete and cement in general out of landfills, while cutting back on limestone mining, as well as questionable practices like adding heavy metal-laden fly ash as filler to concrete.

Thanks to [cscott] for the tip.

An Umbrella Can Teach A Thing Or Two About Product Longevity

May 10, 2024 by 30 Comments

This time of year always brings a few gems from outside Hackaday’s usual circle, as students attending industrial design colleges release their final year projects, The worlds of art and engineering sit very close together at times, and theirs is a discipline which sits firmly astride that line. This is amply demonstrated by the work of [Charlie Humble-Thomas], who has taken an everyday object, the umbrella, and used it to pose the question: How long should objects last?

He explores the topic by making three different umbrellas, none of which we are guessing resemble those you could buy. The first is not particularly durable but is completely recyclable, the second is designed entirely with repairability in mind, while the third is hugely over-engineered and designed for durability. In each case the reader is intended to think about the impact of the umbrella before them.

What strikes us is how much better designed each one is than the typical cheap umbrella on sale today, with the polypropylene recyclable one being flimsy by design, but with a simplicity missing from its commercial counterpart. The durable one meanwhile is full of CNC parts, and carbon fiber.

If you’re hungry for more student work in this vein, we recently brought you this toasty typewriter.

Common Enzyme Breaks Down PLA Fast

February 4, 2024 by 50 Comments

The global issue of plastic waste has prompted scientists to seek innovative solutions for recycling. Single-use plastics, notorious for their environmental impact, require new methods for efficient and sustainable management. For some common plastics, though, salvation could be at hand, with researchers identifying a common enzyme that can be used to break them down fast.

Researchers at King’s College London have discovered an enzyme used in laundry detergents that can break down PLA plastics within 24 hours, using a little heat as an aid. Normally, this is achieved via composting methods that take weeks or months. This method transforms the plastics back into their original chemical components, offering a rapid and eco-friendly recycling process. The monomers can then be reused for manufacturing new plastic items.

One wonders if this could also be used in another way – perhaps in a multimaterial printer, allowing PLA to be used for supports and then broken down. It’s probably not that necessary, given other degradable materials exist, but it’s something to think about.

This project is a significant leap forward in recycling technology, showcasing the potential for enzymes to revolutionize how we handle plastic waste. It could also be a great way to recycle all those errant deformed Pikachus that keep ending up in your hackerspace’s 3D-printing waste basket. In any case, plastic waste is a problem the world needs to solve, and quickly, because it’s not going anywhere any time soon. Video after the break.

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3D Printing With Plastic Cutlery

December 25, 2023 by 18 Comments

How many plastic spoons, knives, and forks do you think we throw away daily? [Stefan] noted that the compostable type is made from PLA, so why shouldn’t you be able to recycle it into 3D printing stock? How did it work? Check it out in the video below.

[Stefan] already has a nice setup for extruding filament. However, unsurprisingly, it won’t accept spoons and forks directly. A blender didn’t help, so he used an industrial plastic shredder. It reduced the utensils to what looked like coarse dust, which he then dried out. After running it through the extruder, the resulting filament was thin and brittle. [Stefan] speculates the plastic was set up for injection molding, but it at least showed the concept had merit.

In a second attempt, he cut the ground-up utensils with fresh PLA in equal measures. That is, 50% of the mix was recycled, and half was not. That made much more usable filament. So did a different brand of compostable plasticware.

The real test was to take dirty plasticware. This time, he soaked utensils in tomato sauce overnight. He cleaned, dried, and shredded the plastic. This time, he used 20% new PLA and some pigment, as well. We aren’t sure this is worth the effort simply on economics, but if you are committed to recycling, this might be worth your while.

It always seems like it should be easy to extrude filament. Until you try to do it, of course. Recycling plastic bottles is especially popular.

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