In the past week, two separate efforts to turn waste into energy have crossed the wires. First, there’s this story from MSNBC that looks at how the Magic Hat Brewing Company is using an anaerobic methane digester from PurposeEnergy to turn leftover hops, barley and yeast into methane, which the brewery then uses to process the wastewater from the facility.
From the article:
PurposeEnergy says its digester is the first in the world to extract energy from the spent grain and then re-use it in the brewery, and all in one place. At Magic Hat, the big brown silo is located about 100 feet from the main complex….
“Over the years, we looked at ways of reducing it, and the strain on South Burlington’s system, and we came up with ideas ranging from using women’s pantyhose to filter solids while flushing the brew kettle to having the spent grains hauled off to a local farm to be used for feed,” said Steve Hill, social networking manager for North American Breweries, which owns Magic Hat.
“They (PurposeEnergy) laid out what we could save . and how the digester could benefit things from a ‘green’ standpoint, and it was too good to pass up,” Hill said in an e-mail.
A similar double-whammy was announced last week at the Rochester Institute of Technology, where researchers have developed a way to use algae to first clean wastewater and then use the algae itself to make biodiesel.
From a writeup about the project in Wired:
The process holds some appeal over conventional feedstocks like corn because algae is easy to grow, doesn’t require vast tracts of land to raise and uses photosynthesis to convert sunlight into energy.
“Algae — as a renewable feedstock — grow a lot quicker than crops of corn or soybeans,” researcher Eric Lannan said in a statement. “We can start a new batch of algae about every seven days. It’s a more continuous source that could offset 50 percent of our total gas use for equipment that uses diesel.”
Lannan and chemistry major Emily Young worked with Jeff Lodge, associate professor of biological sciences, to isolate and extract lipids from algae and produce biodiesel. They are growing Scenedesmus, a single-cell organism, using wastewater from a treatment plant in Irondequoit, New York.
“Algae will take out all the ammonia [and] 88 percent of the nitrate and 99 percent of the phosphate from the wastewater — all those nutrients you worry about dumping into the receiving water,” Lodge said in a statement. “In three to five days, pathogens are gone. We’ve got data to show that the coliform counts are dramatically reduced below the level that’s allowed to go out into Lake Ontario.”
Companies ranging from Chevron to Continental Airlines have been looking to algae as a promising feedstock for energy sources, and last year Marc Gunther profiled Solazyme, one of many companies working to create oil or oil replacements from algae.