Patent Issued for Removal of Bound Water from Bio-Oil

By a News Reporter-Staff News Editor at Journal of Engineering -- From Alexandria, Virginia, VerticalNews journalists report that a patent by the inventors Lin, Ronny W. (Sugar Land, TX); Bartek, Robert (Centennial, CO), filed on August 26, 2010, was cleared and issued on December 4, 2012.

The patent's assignee for patent number 8323456 is KiOR, Inc. (Pasadena, TX).

News editors obtained the following quote from the background information supplied by the inventors: "The present invention relates generally to the treatment of bio-oil. More specifically, the invention concerns processes and systems for reducing residual and bound water in bio-oil.

"With its low cost and wide availability, biomass has increasingly been emphasized as an ideal feedstock in alternative fuel research. Consequently, many different conversion processes have been developed that use biomass as a feedstock to produce useful biofuels and/or specialty chemicals. Existing biomass conversion processes include, for example, combustion, gasification, slow pyrolysis, fast pyrolysis, liquefaction, and enzymatic conversion. One of the useful products that may be derived from the aforementioned biomass conversion processes is a liquid product commonly referred to as 'bio-oil.'

"Despite recent advancements in biomass conversion processes, many of the existing biomass conversion processes produce low quality bio-oils containing high amounts of bound water. 'Bound water' is water that is physically and/or chemically bound within the bio-oil so that it does not naturally separate from the bio-oil. Bio-oils containing high amounts of bound water are not readily miscible with hydrocarbons due to their high polarity and, thus, require extensive secondary upgrading in order to be utilized as transportation fuels, petrochemicals, and/or specialty chemicals. Additionally, the bound water in these low quality bio-oils tends to increase the amount of organic acids present in the bio-oil, thus increasing its corrosive nature and diminishing its ability to be stored over long periods of time. Furthermore, these low quality bio-oils tend to readily degrade over time due to polymerization of the bio-oil caused by its highly corrosive nature.

"Bio-oils may be subjected to various separation processes in order to remove bound water. These processes, which have utilized distillation columns and/or molecular sieves, expose the bio-oil to unfavorable conditions in order to extract bound water. Such conditions facilitate polymerization of the bio-oil, thus increasing its viscosity and lowering its usefulness as a fuel. Consequently, previous separation processes have degraded bio-oils in the attempt to remove bound water.

"Accordingly, there is a need for an improved process and system for removing bound water from bio-oil."

As a supplement to the background information on this patent, VerticalNews correspondents also obtained the inventors' summary information for this patent: "In one embodiment, the present invention is directed to a bio-oil treatment process comprising the steps of (a) combining a bio-oil comprising bound water with an azeotrope agent to thereby provide a treated bio-oil, wherein the azeotrope agent comprises one or more C.sub.6-C.sub.10 water-insoluble hydrocarbons, and (b) subjecting the treated bio-oil to azeotropic distillation in an azeotropic distillation column to thereby provide a water-rich overhead stream and a water-depleted bio-oil stream. The water-rich overhead stream comprises at least 75 weight percent of the bound water originally present in the bio-oil.

"In another embodiment, the present invention is directed to a bio-oil treatment process comprising the steps of (a) separating a biomass conversion product into a free water phase and a bio-oil phase, wherein the bio-oil phase comprises at least 1 weight percent of bound water; (b) removing the free water phase from the bio-oil phase; combining the bio-oil phase with an azeotrope agent to thereby provide a treated bio-oil; (d) subjecting the treated bio-oil to azeotropic distillation in an azeotropic distillation column to thereby provide a water-rich overhead stream and a water-depleted bio-oil stream; and (e) recovering at least a portion of the azeotrope agent from the azeotropic distillation column and recycling at least a portion of the recovered azeotrope agent for use in step . During step (d), the azeotropic distillation is carried out at a top column pressure below atmospheric pressure and a bottom column temperature below 140.degree. C.

"In a further embodiment, the present invention is directed to a bio-oil producing system comprising a biomass feedstock source for providing solid particulate biomass; a conversion reactor for thermally converting at least a portion of the biomass feedstock into a conversion product comprising condensable vapors; a condenser for condensing at least a portion of the condensable vapors into a free water phase and a bio-oil phase comprising bound water; a separator for removing at least a portion of the free water phase from the bio-oil phase; an azeotrope injector for introducing an azeotrope agent into at least a portion of said bio-oil phase to thereby produce a treated bio-oil; an azeotropic distillation column for separating the treated bio-oil into a water-depleted stream and a water-rich overhead stream; and an azeotrope agent transport mechanism for transporting at least a portion of the azeotrope agent from the azeotropic distillation column to the azeotrope injector."

For additional information on this patent, see: Lin, Ronny W.; Bartek, Robert. Removal of Bound Water from Bio-Oil. U.S. Patent Number 8323456, filed August 26, 2010, and issued December 4, 2012. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=89&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=4414&f=G&l=50&co1=AND&d=PTXT&s1=20121204.PD.&OS=ISD/20121204&RS=ISD/20121204

Keywords for this news article include: KiOR Inc, Chemicals, Chemistry.

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