Biofuels’ 10 Scariest Challenges: Part 2 of 2

by Jim Lane (Biofuels Digest) Upstream, downstream, processing, policy, finance – opportunities and challenges abound in the bioeconomy – but which challenges are the most intractable and daunting of them all? In today’s part 2, #5 through #1.
5. The blend wall ...Solutions? Here sayeth the Center for Agricultural and Rural Development at Iowa State University, “the ethanol blend wall” can be overcome and Renewable Fuel Standard (RFS) requirements can be met in 2014 and beyond through increased use of attractively-priced E85.”
4. Affordable Aggregation of Feedstock ... The problem? The impossibly high cost of sourcing sufficient biomass within, say, a 50-mile radius. After 50 miles or so – a little less, if small trucks are used, a little more if barges or rail are used — the economics of transporting raw biomass become impossible. Too much oxygen, too much water — the weight is a killer.
That’s one of the primary reasons why refineries in the bio-space rarely exceed 25 million gallons for projects based on agricultural residues, 50 million gallons for woody biomass, and 250 million gallons for waste or crop-based oils.
An interesting work-around that has gained currency in recent years has been the production of biofuels in what transport mavens call the hub-and-spoke system. In these scenarios, smaller biomass projects manufacture refinery intermediates rather than finished fuels. They are then shipped in a highly densified form to massive refineries where they are converted to finished fuels and chemicals.
...
The hottest category is renewable sugars, which has attracted companies like Virdia, Blue Sugars, Proterro, Renmatix and Sweetwater Energy. Their challenge? Produce low-cost, high-performance renewable sugars that can be sold to synthetic biology companies like LS9, Virent, or Gevo, who convert sugars into an array of useful end products ranging from surfactant alcohols, base chemicals like isobutanol, or diesel, jet or alcohol fuels. ...
3. Watering & dewatering ...
2. Oxygen content ... Here’s the oxygen issue, biomass has it – as much as 60 percent by weight. But hydrocarbon fuels have none. So, in converting biomass to hydrocarbons, you lose an awful lot of biomass in the process. ...
There are the alcohol fuels, which do utilize oxygen, but there are infrastructure issues. ...
1. Photosynthetic limits ... There are two basic paths to meet the challenge. One, addressing photosynthetic efficiency through genetic engineering.
...
Another route? Bypass photosynthesis altogether. Solazyme and others are going that route with heterotrophic microorganisms that derive their energy from consuming sugar — though ultimately, the sugar is photosynthesis dependent.
One alternative? Electrofuels. READ MORE and MORE and MORE and MORE and MORE and MORE and MORE (Part 1)