Is the Cornucopian Promise of Algae Soon to be Realised?

Algae can be far more productive -- in terms of yield per acre -- than other energy crops. But up until now, too much energy has been required to process algae into fuel. If Unitel's new fuel-from-algae process is as energy-efficient as the company claims, we may be entering an entirely new era of biofuels sooner than expected.

Here are comparative bioenergy crop yields from MSU Bioenergy:

Table 1. Compartive productivity of selected biofuel crops.

Crop

Productivity (Ton/ha.year)

Energy (GJ/ha.year)

---

Wheat (seed + straw)	11	170
Miscanthus	16	270
Switchgrass	10	180
Microalgae (optimized)	60	1200
Microalgae (Theoretical)	120	2400

And here is what Unitel is saying about its new process for producing fuels and co-products from algae:

In the Unitel process, the feedstock—a slurry or “soup” of water and cultivated algae (1% to 20% by weight) is continuously treated in a special hydrolysis reactor to yield:

a fatty acid product;
a “sweet” water stream containing glycerol and other solubles; and
de-oiled algal biomass.
A small fraction of the fatty acid product is fed back into the reactor as catalyst. The nutrient rich “sweet water” is recycled into the algae propagation tanks, where the carbon in the glycerol serves to promote the growth of phytoplankton. The de-oiled biomass (consisting primarily of proteins and carbohydrates) is dried as a food ingredient for animal consumption.

The algal fatty acid product is catalytically decarboxylated and converted into paraffinic hydrocarbons (alkanes), followed by mild hydrocracking and hydroisomerization to make biojet fuel comprised of C10-C15 branched paraffins.

Some of the features included in our technology can be traced back to the nineties when we designed and built several first-of-its-kind slurry-based coal liquefaction and supercritical CO2 extraction demo units. The slurry pump loop and the depressurization module are two examples. The high-efficiency heat interchange system was developed in 1994 when I was Chairman of Xytel-Bechtel in Houston.

—Serge Randhava

Unitel has built up a diversified portfolio technology programs. In addition to the new algal process, its current agenda includes:

HarvestGas – oxyblown/pressurized fluidized bed gasifier for making synthesis gas from biomass
Bio-ammonia – fertilizer from biomass
Dimethylether (DME) – two options: methanol dehydration and direct synthesis
Cellulosic bio-alcohols – thermochemical conversion of renewable resources into liquid fuels
Cornex for the dry corn ethanol industry
Synthesis gas and hydrogen from infrastructure fuels
Neogen – beneficial harvesting of low grade waste heat
Catalyst test system (The Octave/CTS) – screening and evaluating catalysts for the future _GCC

Unitel Technologies, Inc. announced that the company has filed a patent application for a new technology for making biofuels from microalgae. The process involves minimal dewatering, and completely bypasses the energy intensive drying and oil extraction steps.

Currently, most of the proposed methods in the biofuels-from-algae space require the extraction of immobilized oil from algal biomass. However, regardless of the oil extraction technique used, and some are more efficient than others, getting to the oil is usually very expensive in terms of capital and energy costs. In some instances, the amount of energy consumed to extract the oil can actually exceed the energy value of the end product. _FP

Unitel is not dependent upon its algal processes to make a profit. Here are the future bio-energy technologies which Unitel is touting on its website: Synthesis gas from renewable biomass using pressurized, oxygen-blown fluidized bed gasification, Anhydrous ammonia from agricultural wastes, Dimethylether (DME) from biomass and brown coal, Cellulosic bio-butanol, bio-ethanol and bio-methanol, Fischer-Tropsch products from biomass, Synthesis gas and hydrogen from natural gas, LPG and gasoline, Rescue options for the struggling corn ethanol industry.

Unitel's lack of dependency on algae for profits is crucial to its chances for developing its agal fuels processes to the point where they are profitable on their own. It gives Unitel credibility and staying power.

Because of the serious economic and technological challenges involved, most observors of bioenergy do not expect algal and microbial fuels to breakthrough to full competitiveness with petro-fuels before 2020. But if companies such as Uniteltech can push the envelope by a few years, it could change the dynamics of the energy transformation appreciably.