Alternative energy often means the better-known sources like solar, wind power, or biofuels. A new form of alternative fuels recovers energy from post-consumer or post-industrial plastic wastes that cannot be recycled efficiently. Technologies for creating these fuels attempt to solve two big problems: the overabundance of unrecycled plastic in landfills, and the creation of domestic energy sources. Several of these plastics-to-fuel (PTF) conversion processes are on the verge of commercialization in the US.
The waste-to-energy (WTE) industry began by approaching polymer wastes as a problem to be eliminated, but failed to come up with financially feasible methods, Jay Schabel, CEO of PolyFlow, told us. Previously, the only purpose for creating fuels was burning them for heat, but the quality and selling price of those fuels is low. Schabel says:
You can't sort your way to financially sustainable success. With a toothbrush made of different plastics, for example, the materials you can recover can never justify the effort it takes to sort them. So if a technology had a high cost of sorting on the front end, and produced a product with a cheap selling price, it couldn't survive.
Common household items made of mixed plastics, whether clean or contaminated, can serve as a feedstock for PolyFlow's pyrolysis-based plastics-to-fuel conversion process. (Source: PolyFlow)
Plastics-to-fuel energy recovery methods offer a different approach by creating technologies that can become profitable. These technologies are aimed at the non-recycled plastics (NRPs) that would otherwise go into landfills, since the highest-BTU waste stream available is polymer.
In conventional WTE plants, municipal solid waste (MSW) is burned and the heat is used to produce steam in a closed-loop process, Jeff Wooster, global sustainability leader for Dow Performance Plastics, told us. That steam either produces process heat for operations like paper mills or utilities, or it's converted to electricity. This produces lots of energy from plastic and a fair amount from paper and wood, but very little energy from other sources.
WTE processes are the least efficient for plastic, said Greg Wilkinson, past president of the Canadian Plastics Industry Association. "Recovered fuel is more selective. Here, you take some components of the waste stream and turn them into fuel for narrower uses."
Ann, I am not aware of anyone using this method. It just popped into my head that since both heat and ultraviolet attack the bonds in polymers, that a combination should be even more effective. OThers are certainly welcome to use the concept as long as I get credit for coming up with it. It will be a nice addition to my resume, and it may be of some benefit to humanity as well.
Ann, No, the idea that I had was using solar energy, both light and heat at the same time, to break the large molecules up. Essentially a solar furnace with ultraviolet as well..
Leaving the plastic out in the sun does break it down, but it would be a very long time for anything useful to be created.
So the big deal is putting in the right amount of energy, to cause just enough decomposition. The process would indeed be a form of pyrolysis, but with the UV as well, it would be more effective, I think.
While the smallest Blest units may be "too large" for home use their capacity is about right for use by small groups of people in a neighborhood, or a strip mall of stores, as Jerry suggests and as is currently done in Japan. When the company finishes developing the solar-powered version for use on TOP's boats, that one might be small enough for home use.
William, if you mean just letting plastic sit out in the sun without further treatment, the problems with that method of decomposition are: a) it takes way too long, and b) while it's taking way too long to decompose, particles get into the ecosystem and consumed by fish and birds, and poison water and soil. This is well-known by everyone involved in various forms of WTE and PTE. Or did you mean something else?
How about using the sun's energy directly to break apart the plastic molecules so that they can be reassembled into fuel. The benefit of directly driven solar decomposition is that it would not affect the power grid at all, and it would have fewer conversion losses. Just add enough energy to push the plastics back to the original petroleum stock, or something like that. After all, ultraviolet does break plastics bonds when we don't want it to, why not utilize that process when it could be useful.
The 100-percent solar-powered Solar Impulse plane flies on a piloted, cross-country flight this summer over the US as a prelude to the longer, round-the-world flight by its successor aircraft planned for 2015.
GE Aviation expects to chop off about 25 percent of the total 3D printing time of metallic production components for its LEAP Turbofan engine, using in-process inspection. That's pretty amazing, considering how slow additive manufacturing (AM) build times usually are.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This radio show will show what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.