Biofuels’ 10 scariest challenges: Part 2 of 2

August 21, 2013 |

3. Watering & dewatering

Dewatering – the bane of low-cost algae. As we covered in Crazy 8s: Algae’s 8 crazy-fast cores of innovation, “once you have made optimized algae, you generally either have to get the water out of the algae or the algae out of the water. First step is to do some concentrating to get the algae to, say, a 20 percent concentration, up from the 0.1 percent mix it might naturally achieve on its own.”

The DAF )diffused air floatation) technology used in wastewater treatment is well-suited to Sapphire's cost goals

The DAF )diffused air floatation) technology used in wastewater treatment is well-suited to Sapphire’s cost goals

Now, Sapphire Energy revealed recently that it is producing crude oil daily from algae biomass cultivated and harvested at its Green Crude Farm.  Oil extraction is conducted through a patented method for converting wet algae to crude oil, which enables algae to be processed without the need for a timely and costly drying step.

In 2011, we highlighted 10 Hot Algae Extraction Technologies (and 5 Stealth Projects to keep an eye on)
But even if you discount the problem of dewatering, what about water itself? That is, water use — or, rather, freshwater. It can take quite a few gallons of rainfall to produce a bushel of feedstock — in cases where rainfall in insufficient, it will take groundwater.

So, what about getting beyond the challenges of freshwater availability?

groundwater-large

We looked at this last December when we reported that Norwegian company Yara had teamed with the Qatari government on the Sahara Forest project that will use solar power and sea water to produce food crops such as tomatoes, cucumber, melon, fodder crops, freshwater, clean energy, salt, algae and for biofuel.The metrics? A commercial scale project of 4,000 hectares would supply enough power for the project and export 325GWh a year in addition to 7,500 tonnes of algae oil, and hundreds of thousands of tonnes of food and fodder crops.

On a broader front, we looked at Aquadudes: 15 saltwater-based energy technologies here to save the day, here.

In today’s Digest, follow the page links below for each Scary Challenge – and potential solutions.

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