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As a bit of a New Year’s resolution this year, I’ve been trying to do my part to recycle what I can and keep trash to a minimum. After boiling a big pot of grains for the first step of my new beer homebrewing hobby, I had a bag full of wet grain, which would create nasty methane if hauled off to a landfill, so I took a couple of minutes to see what else could be done with it. A beer blogger informed me that some brewpubs have reused these grains in rustic breads or pizza dough, though the majority of the spent malted barley grains end up as dinner for lucky livestock.

Kate Dixon

February 17, 2009

2 Min Read
Old materials offer new alternatives for petroleum-free products


Coors Brewing, just down the road from me in Golden, CO, partnered with Merrick & Co. to produce a petroleum alternative by turning spilled beer and waste grains into commercial fuel ethanol. A second plant opened in 2005 to meet the growing demand for the product, which is distributed by Valero Energy Corp. to Diamond Shamrock fuel stations around Denver. I didn’t realize my car may have been running on beer byproducts, but the next application was an even bigger surprise – bioplastics. In Japan, the Akita Research Institute of Food & Brewing developed a technology for turning these spent grains into polylactic acid at a reduced cost for use in biodegradable plastics.

While the fuel vs. food debate continues as to whether or not turning acres of corn or other food crops into ethanol or bioplastics is really a sustainable option, other options exist for converting nonfood into energy, and even plastics.

Algae cells can contain up to 60% oil, and for photosynthesis they use carbon dioxide, solar energy, and water, whether it’s freshwater, seawater, or even polluted water. Exploring algae production for energy is not new, but finding a scalable, affordable way to produce enough for the potential demand has been difficult.

Luckily for the plastics industry, it takes plastic to make algae, and lots of it. A patent application for GreenFuel Technologies claims that the process would be able to produce 45,000 gal/acre/year, but to some energy experts, the numbers don’t add up, especially when considering the cost to get started. The ideal growing setting has been using polycarbonate (PC) tubes, as the material excels at transmitting photosynthetically active radiation (PAR) used in photosynthesis, while it blocks out unwanted UV more than acrylic or glass.

But with estimated installed costs of around $150-190/m2 for the PC tubing, along with all the other operating costs, one expert estimates that oil would have to be priced at greater than $240 a barrel to make the cost of the operation competitive, and at that price, the PC cost would be much higher. At current prices it would take 50 years to break even on the investment, and the PC tubes would need to be replaced every 10-15 years due to UV damage.

But finding energy alternatives, and petroleum-free bioplastics, are areas that will certainly grow. And plasticstoday.com will inform you about these advances along the way. [email protected]

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