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A new clean technology process has been developed for harvesting algae to produce formulated feedstocks from biomass and cleaning oil and gas water.
OriginOil, developer of a new clean technology process for harvesting algae to produce formulated feedstocks from biomass as well as for cleaning oil and gas water, recently announced the US Department of Energy, Idaho National Laboratories (INL), has ordered two test-scale energy appliance units for testing under a research agreement.
The units will be incorporated into process demonstration units that can be used by industry and researchers to validate the units for various industrial and environmental applications.
How it works
The Model 4 algae dewatering unit delivered to the INL will treat a little over 1 gal/minute (4 liters/min) of liquid. This unit will be tested for the capacity to produce feedstocks from biomass. The Model 4 sells for approximately US $35,000 as a test unit. The company recently has shipped the first Model 4 Algae Appliance harvester production unit to Ennesys in Paris, France, for water management in the La Defense complex.
The unit provides a low-energy (total energy less than 1 kilowatt-hour/cubic meter), chemical-free “west harvest” system to efficiently dewater, compromise cell walls, and concentrate dilute microalgae in suspension. A production unit would be typically located near or at the algae growth facility. When the algae are ready for harvesting, the dilute microalgae culture is fed directly into the unit without any prior pretreatment or concentration.
Each unit is equipped with an integrated SCADA control system and sensors to monitor various characteristics of the input and output streams. The SCADA system manages the operational system for the algae aggregation (flocculation). The dilute suspension is bombarded by tuned electromagnetic pulses as is passes through the Model 4 algae dewatering unit.
The algae dewatering system consists of two mandatory phases and a third optional phase:
• First phase: low-energy, chemical-free flocculation;
• Second phase: concentration to remove up to 90% of the water; and
• Third phase (optional): compromising the cell wall (“cracking”) for downstream availability.
Current methods for extracting oils from oil/water mixtures are to apply an immiscible solvent, for example, hexane, that is oil soluble and non-polar. Usually, some oil remains with the water, especially if the mixture contains organic acid or hydroxyl groups.
Benefits in oil extraction, hydraulic fracturing
If successful and applicable on a practical scale, the use of OriginOil’s dewatering unit could reduce the cost of extracting oil from algae. Algae biofuels are possible replacements for petroleum-based fuels and algae fuels are compatible with current energy infrastructure. Growing algae does not require the use of arable land. Burning oil from algae produces no sulphur dioxide or heavy metals and consumes carbon dioxide.
Deborah T. Newby, molecular biologist at INL’s Biofuels and Renewable Energy Department, said, “We are anxious to test OriginOil’s new equipment in our algal dewatering research. This system appears to have the potential to significantly reduce the algal dewatering barrier, allowing us to dewater large quantities of algae for use in applications, including the production of formulated feedstocks blended from algal and terrestrial biomass.”
The second unit delivered to INL for testing, a Solids Out of Solution (SOS) Model 2K, can process first-stage cleaning of 2,000 gal/day (7,570 liters/day) of hydraulic frac flowback water. Produced water (water that is pumped out of oil and gas wells) is generated from almost all of the approximately one million actively producing wells in the US. More than 98% of the produced water from onshore wells is injected back underground. Some produced water and water from other sources also is used for hydraulic fracturing operations to either initiate production or enhance production from oil and gas wells.
Fracturing operations usually are performed during the first few months of well production and later (usually years or tens of years) when well production declines. Approximately 50% to 80% of the water injected for fracturing remains underground and approximately 20% to 50% of the water returns to land surface as frac flowback water. This flowback water contains hydrocarbons with varying specific gravities, brine water, and many other organic and inorganic compounds.
The US Environmental Protection Agency estimated in 2010 that 70 billion gal to 140 billion gal of water are used to fracture 35,000 oil and gas wells in the US each year. Flowback water remediation is expensive, and according to Greentech Media, the current market for treating produced water is estimated to exceed $4.3 billion over the next five years, and that market will continue to expand “whether or not regulations increase.”
In recent independent testing, OriginOil’s process removed 98% of the hydrocarbons from a sample of West Texas oil well frac flowback water in the first stage alone. This result potentially is a valuable and cost-effective application of the company’s core water processing technology originally applied for algae harvesting. Riggs Eckelberry, president and CEO of OriginOil, explained that production versions of the SOS process can process hundreds of thousands of gal/day of frac flowback water.
In the SOS process during the first stage, electrical pulses are emitted from tubes that neutralize the electrical charge of suspended solids or colloids, allowing these materials to come out of solution. In the second stage, similar electrical pulses push the solids to the surface using a bubble flotation method. At the surface, the solids can be raked off and processed further.
Currently, produced water is transported to offsite water treatment facilities, disposed in settling ponds, disposed in wells, and treated on site for recycling. Deborah Newby of INL noted that the group also is interested in testing OriginOil’s system for processing frac flowback water. “The boom in hydraulic fracturing is urgently forcing new practices in water conservations, and OriginOil’s system may be a key part of the answer,” she said.