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Bioplastic Made from Poop, for a Profit

Here's a profitable product that can solve two environmental problems at once. It involves a secret formula of bacteria, raw sewage, and an M.B.A.

Sometimes you can take two problems, add them together, and get a win-win solution. In this case, here are the two problems: First, as cities expand we create more waste and more sewage, and we don’t have any really good plan for it. And second, we keep making more and more plastic that never goes away, filling landfills or swimming in oceanic garbage patches. So, what’s the natural solution? Why not turn the poop into plastic that biodegrades? Simple, right? Actually, yes. It turns out it is.

Ryan Smith is CTO of Micromidas, and he turns poop into plastic for a living. “We take raw sewage from a waste water treatment plant and we convert it to biodegradable plastic.” He says it is “just a series of tanks, nothing complicated or fancy about it. Nothing that is technically too difficult.” That’s because he gets bacteria to do the hard work for him, and that’s the novelty of his product. Finding the bacteria, and mixing them up into the right combination, that’s a different story.

Right now, most plastic comes from petroleum. So as you tear open that new SD card from its packaging, or toss out the packing foam from your last Amazon order, you are, in essence consuming oil. There are various sugar- or corn-based bioplastics on the market already. (You can even follow this You Tube video and try to make your own.) These starch-based plastics solve the problem of living forever in a landfill or garbage patch, but if produced at the volume of petro-plastic, they would significantly drive up the price of corn or sugarcane. So a better solution, and the innovation here, is that Micromidas’ bioplastic adds sewage treatment to the enviro-benefits, and leaves corn out of the mix. It just so happens that’s also good for the bottom line.

(Dane Anderson Micromidas Engineer at work)

Here’s how it works, as explained to GOOD by Smith, who is a Pop!Tech Social Innovation Fellow. They take sewage and feed it to bacteria. “The bacteria store the organics as a bio-polymer … little plastic granules, or inclusions, inside their bodies … they are creating it.” Just like when we eat sugar and, through a series of metabolic processes, turn that into a fat, those little micro-buggers turn sewage into plastic in their bodies.

Then Micromidas uses a proprietary process that "disrupts" the cells and takes the plastic out. After they get it all cleaned up, the end product is a high-value, low­-cost plastic resin ready to be sold off, and it biodegrades in under 18 months once disposed of.

Lest you go try this at home, the bacteria are no ordinary bottom-of-your-tub household contagions. Ryan Smith says, “we actually have bug hunters, or ecological microbiologists. They actually go out into nature, they grab a soil sample, a sample of pond water, a sample of waste water” and then through a series of screening mechanisms they pick out just the right microbes that are particularly good at consuming sewage and making bio-plastic.

The company then breeds and combines the best of these and now has a library of 50-60 bacteria with different traits for different kinds of sewage chomping and plastic pooping depending on the needs of the “feed source.” Yes, that’s another way of saying, there is a secret formula of bacteria that eat poop and poop plastic, and it varies depending on the sewage you want to feed them—that’s the business in a nutshell.

Technically speaking, what the bacteria create inside their bodies is a resin powder. Its not a final product by a long shot. Micromidas then has to sell that to a plastics processor. Smith concedes, “we are not currently at a point where we know for certain what application makes the most sense.” Over the past couple months they have developed enough of the plastic resin to send to testing labs to explore options. Possible final products currently being prototyped and tested could be foams, fibers, films, injection molds and lots of other fancy words that mean plastic packaging that doesn’t get anywhere near food. “Something you don’t eat with, but is a packaging material, and ecologically beneficial,” Smith says.

If he can prove his resin does the job, the economics are in his favor. For most plastics, the “feed stock” is about 50 percent of the production cost, whether it's petroleum or bioplastic, but in this case Micromidas actually gets paid to take the sewage off the hands of local processing plants. That’s starting production with a negative unit cost. Not a bad sign for sustainability.

Right now they are still paying for the heavy load of research, testing, and other start-up costs, but Smith says he’s expecting to make his bioplastic at competitive market prices for other disposable plastics when they finalize the formula.

They plan to build out their operation to a commercial scale (right now it is prototype scale) within the next six to twelve months he says. Then the money, and the poop will roll in.

Images courtesy of Micromidas.

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