Sept 13 Discussion

September 16, 2007 at 9:59 pm Leave a comment

Present: Jordan Kohn, Laura Mulshine, Laura Bradley, Look Tobin, Kassi Dallavis, Erin McCowen, Emily Justusson, Cameron Kellett, Alan Shusterman

We had a short discussion regarding upcoming events in the Portland area and how to gain access with only limited funds. Ideas varied, practical and impractical. Later in the day I discovered and posted information about Reed’s Opportunity Grants for students.

We also talked about bicycling in Portland. Two parts of the Springwater Corridor bike trail run really close to campus.

  • Johnson Creek – Springwater Corridor. This trail runs east (to Gresham and beyond) and west (to the Sellwood neighborhood) on the south edge of the Eastmoreland neighborhood. It is very easy to get to. Ride south on Reed College Ave to the end (about a mile). Turn left and ride a few blocks to SE 37th. Turn right and go two blocks to the trailhead. The last two blocks are not paved, but they are short and the entrance to the trailhead is obvious (and it has finally been paved), but it is steep. For safety sake, walk your bike down to the bike trail.
  • Springwater Corridor – East Bank Esplanade. This trail runs south (to the Sellwood Bridge) and north (to the Steel Bridge) on the east bank of the Willamette river. It is a little harder to find from Reed (about a 2 mile ride) and one (rather long, but nice) way to get there is to go west on the Johnson Creek trail to the Sellwood neighborhood and wander westward (and a little north) until you find yourself under the Sellwood Bridge.
  • Map and Online Info. Info about the east-west and south-north sections of the Springwater Corridor bike trail (actually a mixed use trail) and other Portland area bike trails is available online.

Jordan and Laura then guided a discussion of several articles relating to biogas. When organic materials (like pig manure or dead plants) break down anaerobically they release methane, CH4. Methane is a potent greenhouse gas, but it can also be used as a fuel (it is the major component of natural gas).

When methane is burned, it releases energy and makes another greenhouse gas, carbon dioxide. This raises an important question, from a global climate perspective, is it better for farms and sewage plants to release methane into the atmosphere directly or try to collect it and burn it for energy? A number of factors need to be considered. First, when burned, one methane molecule makes one carbon dioxide molecule. Second, that methane molecule creates a larger greenhouse effect than the carbon dioxide molecule. This suggests that we are better off extracting energy from the methane molecule by using it as a fuel than just releasing it directly into the atmosphere. One more thing, methane is naturally converted to carbon dioxide in the atmosphere by photochemical reactions involving atmospheric oxygen. So it is only a question of “when” the methane turns into carbon dioxide and whether we derive any benefit from it (such as not using another fossil fuel in its place).

Laura and Jordan led us through two papers that examined means for enhancing methane production from organic material. The first paper showed that adding colonies of “hydrogen-producing bacteria” to the sludge led to enhanced methane formation. The second paper showed that shining (visible) light on a fermenting system could also enhance methane production.

Reading:

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Entry filed under: Meeting notes.

Attend a Conference Next meeting Sept 20, Th, noon

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