Tuesday, August 27, 2013

Biosystems Engineering at the University of Minnesota

Last Wednesday, a friend twisted my arm to go see a demonstration of what the University of Minnesota was up to in the obscure world of Biosystems Engineering. It was being held at an agricultural extension station a short drive from my house so even though I am very skeptical of the claims made by the biotechnology crowd, I went.  Skeptical is probably an understatement—I believe that corn-based ethanol production is one of the worst ideas in human history (a category that includes a great many examples of human folly.)  Corn production uses premium fertilizers, causes extensive soil erosion and run-off that creates problems all the way to the Gulf of Mexico, and is so energy intensive, the resulting alcohol produced by ethanol conversion usually contains less energy than it took to produce that corn.  Dumb, DUMB idea!  And it is almost certain that stunningly bright folks at UM helped make corn-based ethanol happen on an industrial scale.

I drove onto the site and was confronted by THIS contraption.  As someone who has been around a lot of pre-production technology, I am pretty forgiving about what such things looks like, but this was sitting cockeyed on an old hay wagon, the best that could be said for the paint job was that it probably prevented corrosion, and there was metalfab that would get a ninth-grade metal-shop student sent to the principal for goofing off.

Roger Ruan, the man with his right arm extended in the picture below, is in charge of the UM's microwave-assisted pyrolysis micro-algae project and he stood in the hot sun enthusiastically describing all the things his contraption could do.  Pyrolysis is any technique that heats a substance in an oxygen-free environment—coke and charcoal are the two most famous materials made by the process.  His device loaded algae through that green tube at the left and is loaded into the grey tank where it gets heated by microwaves.  This reduces the algae into biofuels akin to diesel fuels, and natgas (methane) which can fuel the generator at the right which in turn powers the whole process.  The remaining char (like coke in that process) is carbon-dense from all the CO2 the algae sucks out of the atmosphere through photosynthesis, and best of all, if the algae has been grown in municipal waste water, it has captured the phosphorus introduced by detergents.  As phosphorus is notoriously difficult to remove from waste water, this feature alone makes microwave-assisted pyrolysis worth perfecting.  Captured phosphorus also means the char can be ground up for use as a high-quality fertilizer—at a time when there are growing shortages of ag-grade phosphorus.  What's not to like?  This is pretty much what I have in mind when I try to define Elegant Technology.

Algae grows VERY fast in wastewater—like a crop every 3-4 days.  According to our tour guides, an acre of soybeans converted to biodiesel yields about 50 gallons.  An acre of corn converts to 350 gallons of ethanol.  But an acre of algae trays yields between 4000 and 10,000 gallons of biofuels depending on the design and it doesn't require prime farmland.  As our guide cracked, "there's nothing wrong with the idea of biofuels, it just that we have been growing the wrong crops."

I wish Ruan and his gang of grad students a great deal of luck.  They're going to need it.  No matter how good these ideas are, they will only be sold to markets that are being squeezed.  I mean, how many municipalities are capable of rebuilding their waste-water treatment facilities?—most of the communities with existing systems are going broke and $4 gas has put a serious dent in urban sprawl so there are not many new systems being built.

As a side note on how the world is changing, when I was a student at the University of Minnesota, this sort of research would have been done by folks with Nordic and German surnames.  This kind of project is so right up our alley.  But Ruan and his students are all Chinese.  The big midwest land grant universities have benefitted greatly from the international students over the years but somehow I was a little bit surprised that Chinese engineers with these skills weren't working in China—especially in light of China granting "key industry" status to green technologies.  But to prove my instincts are not totally wrong, I have discovered a Norwegian company that is many steps beyond the haywagon stage in building microwave-assisted pyrolysis equipment.

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