This invention relates to a liquid fuel composition, comprising distilled biofuel components as one of the components in its formulation.
The biosphere is presently overburdened by carbon emissions produced from fossil fuels. The burning of fuels presently contributes to an annual release of 4 billion metric tons of carbon dioxide into the atmosphere and the injection of 2 billion metric tons of carbon dioxide into the world's oceans. It has been well documented that these carbon emissions negatively impact living organisms in the oceans as well as on land.
There is presently intense interest in producing liquid fuels derived from renewable resources. Fuels that are derived from biomass, also called biofuels, represent a particularly attractive replacement for fossil fuels. Biofuels can be derived from a wide variety of feedstocks. Biomass feedstocks are much less expensive than liquid fossil fuel feedstocks.
Approaches discussing liquid fuel compositions include US Patent Publication 2010/0218417, titled “Liquid Fuel Compositions” to Bauldreay et al., which teaches a liquid fuel composition comprising one or more C4 compounds derived from biomass using a special process called aqueous phase reforming. In this process the biomass is first converted to sugars which are then subjected to hydrogenolysis and hydrogenation. The latter two processes produce C2-C6 oxygenates and sugar alcohols, which are typically subjected to Pt/Ru catalysts in order to form gasoline precursors. A method for producing a fuel composition is disclosed in U.S. Pat. No. 7,888,540 to Deluga et al. from a bio-oil feedstock utilizing a hydro-treatment process for the bio-oil. No specific details on the fuel composition were provided. International Patent Application WO 2009/004652 to Nair et al, titled “A Biofuel Composition, Process and Preparation and a Method of Fueling Thereof”, discloses distilled cashew nut shell liquid as one of the components for biofuel as well as methods for production and formulation of said biofuel.
The above methods do not disclose a fuel composition containing a biomass fuel component obtained via a novel process that utilizes ramps of temperatures under pressure.
a-5c show gas chromatograms (GC) of biofuel prior to distillation with no dehydration step(5a), a biofuel fraction collected in the temperature range 73° C.-105° C. during the biofuel distillation between 0° C. and 188° C., no dehydration step (5b), and biofuel component containing all combined collected fractions, no dehydration step (5c).
a-6c show gas chromatograms (GC) of biofuel prior to distillation with no dehydration step (6a), a biofuel fraction collected in the temperature range 73° C.-105° C. during the biofuel distillation between 0° C. and 188° C., with dehydration step (6b), and biofuel component containing all combined collected fractions, with dehydration step (6c).
A flow diagram for the basic steps of the present invention is shown in
As used herein, the term ‘biomass’ includes any material derived or readily obtained from plant sources. Such material can include without limitation: (i) plant products such as bark, leaves, tree branches, tree stumps, hardwood chips, softwood chips, grape pumice, sugarcane bagasse, switchgrass; and (ii) pellet material such as grass, wood and hay pellets, and iii) crop products such as corn, wheat and kenaf. This term may also include seeds such as vegetable seeds, fruit seeds, and legume seeds.
The term ‘biomass’ can also include: (i) waste products including animal manure such as poultry derived waste; (ii) commercial or recycled material including plastic, paper, paper pulp, cardboard, sawdust, timber residue, wood shavings and cloth; (iii) municipal waste including sewage waste; (iv) agricultural waste such as coconut shells, pecan shells, almond shells, coffee grounds; and (v) agricultural feed products such as rice straw, wheat straw, rice hulls, corn stover, corn straw, and corn cobs.
An embodiment featuring a biofractioning process is shown in
Referring now to
Embodiments feature dispensation onto a biomass chamber that is much wider and longer than it is thick. In some cases, biomass is dispensed into thin sheets whose total thickness is 1 to 30 times the biomass particle size. A preferred thickness for the chamber for uncompressed biomass (which is ground or chopped to ⅛″ or smaller) is approximately ¾″ in thickness. As the biomass is heated and further pulverized (as discussed below), the emerging BMF char quickly condenses to a layer about 1/10″ thick. This aspect ratio ensures mild pyrolyzing conditions that allow the collection of useful chemical compounds known as bio-intermediary compounds as well as the production of BMF char. A person of skill in the art will appreciate that these biomass chambers can be sized in width and length along with the diameter of their corresponding drive disc to any such size as appropriate for the desired throughput for the biomass fractionator, without departing from the scope if the invention.
Dispensation as thin sheets assures an environment similar to laboratory scale mild pyrolysis conditions. In practice, the environment is scalable in that it can be expanded in two dimensions to any practical working throughput while retaining a constant thickness for heat treatment of incoming materials. The biomass may be dispensed in pre-dried form, or it may be dried after dispensation. Biomass may be loaded piecemeal onto a plurality of movable biomass reaction chambers which are movable using conventional drive mechanisms such as gear drives, chain drives, ratcheting sprockets, etc. In addition to linear displacements, the reaction chambers may also be arranged on a disc that rotates continuously or in a stepwise fashion.
The dispensed biomass is subjected to a novel biofractioning process 420 described in detail in co-owned patent application Ser. No. 13/103,905 entitled “Method for Biomass Fractioning by Enhancing Thermal Conductivity” and co-owned patent application Ser. No. 13/019,236 entitled “System and Method for Biomass Fractioning”. This process subjects the biomass to decomposition that produces volatile gas streams 423 using discrete temperature increments under pressure. The pressure serves to increase the thermal conductivity of partially carbonized biomass and accelerates the decomposition.
In some embodiments, the temperature profiles are linear ramps ranging from 0.001° C./sec to 1000° C./sec, and from 1° C./sec to 100° C./sec. Processing heating station 68 may be heated by electrical heating elements, direct flame combustion, or by directed jets of heated working gas or supercritical fluid. For a given n, the heating profile and the pressure compaction profile may be linked via a feedback loop, or may be applied by the same agent simultaneously. Compacting station 69 may be controlled by electrically driven devices, air compressed devices, or any other form of energy that serves to impact load the biomass. A given volatile component or set of volatile components 423 of the decomposed biomass are collected after each application of a temperature ramp and pressure profile. BMF char 425 remains after these processing steps. BMF char is then ready for sequestration process 80.
The selective pyrolysis of the biomass arises out of the interplay between the applied pressure pulses, applied temperature and resultant pressures and temperatures experienced by the biomass. The process is illustrated diagrammatically in
With continued reference to
The compressional memory of carbon has been indirectly demonstrated in studies of commercial carbon resistors as low pressure gauges. See Rosenberg, Z. et al International Journal of Impact Engineering 34 (2007) 732-742. In these studies, metal discs were launched from a gas gun at high velocity and impacted an epoxy or Plexiglas target in which a carbon resistor was embedded. Resistance changes were measured as a function of time after impact. It was noted that the resistance decreased rather rapidly in less than a microsecond, and stayed low for several microseconds, in some cases over 10 microseconds, until it began to increase gradually to pre-impact levels. There is essentially a memory effect or a slow relaxation after the impact. As electrical resistance and thermal conductivity are inversely correlated for carbon as for metals (See, for example, Buerschaper, R. A. in Journal of Applied Physics 15 (1944) 452-454 and Encyclopedia of Chemical Technology, 5th edition), these studies reveal a compression memory on the part of the carbon. This compression memory is at least partly utilized in embodiments of the invention.
Embodiments of the invention also utilize the increase in thermal conductivity as carbon is compressed. The change in electrical resistance with pressure in carbon microphones is a well-known effect utilized by carbon telephones and carbon amplifiers. U.S. Pat. No. 203,216, U.S. Pat. No. 2,222,390 and U.S. Pat. No. 474,230 to Thomas Edison, describe apparatus that transform sound compressions (vibrations) to changes in electrical resistance of carbon granules. Carbon is even more sensitive than most metals in its inverse relationship between electrical resistance and thermal conductivity.
Below are data indicating the thermal conductivity of various substances (CRC Handbook of Chemistry and Physics, 87th edition) in comparison to the measured thermal conductivity of BMF char:
As the thermal conductivity of the formed carbon within the biomass increases due to pressure shocks, it becomes consequently easier to attain mild pyrolysis conditions within the biomass. As higher temperatures are reached, the fact that carbon is a better heat transfer agent than water enables higher boiling compounds to become volatile. Pressure shocks serve to compress these higher boiling compounds and contribute to fracturing cell walls within the biomass. The process is illustrated by
A variety of pressure profiles ΔPn are effective in increasing the carbon thermal conductivity. The magnitude of the pressure can vary from 0.2 MPa to 10 GPa and may be applied via a number of different technologies, including air driven pistons, hydraulically driven pistons, and explosive driven devices. The duration of the pressure application can vary from 1 microsecond to 1 week. It is understood that pressure pulses of different magnitudes and different time durations may be admixed to yield optimum results.
The efficient heat energy transfer executed by embodiments of the present invention can be enhanced by the addition of supercritical fluids in the reaction chamber. It is known that supercritical fluids can improve heat transfer as well as accelerate reaction rates. Certain embodiments can operate with supercritical carbon dioxide, supercritical water, supercritical methane, supercritical methanol, or mixtures of the above. It is possible that supercritical conditions are created internally with some pressure and temperature profiles.
A system capable of embodying the methods of the present invention is described in co-owned, co-pending U.S. Patent Application No. 2010/0180805 entitled “System and Method for Biomass Fractioning,” the content of which is incorporated herein by reference in its entirety. This system comprises a biomass load and dump station, a heated pulverizing processing station for compressing the biomass, a biochar dumping station for removing residual biochar, and a plurality of biomass reaction compartments able to carry the biomass from station to station.
The volatile gas streams are transformed to fuel compounds via a catalyst conversion process. These fuel compounds are typically termed renewable fuels and can be components in any combustible fuel, such as gasoline, diesel, aviation fuel and other fuel blend stocks such as BTX, derived from biomass and useful for transportation or other purposes. Numerous catalyst systems may be selected to effect this conversion depending on the nature of the volatile gas streams and desired fuel component properties. The catalysts that can be used in the conversion include aromatization catalysts, gas-upgrading catalysts and dehydration catalysts. The aromatization catalysts can be comprised of MFI type zeolites and metal modified MFI type zeolites, where the metal is selected from the group consisting of: Group VIB metals, Group VIIB metals, Group VIII metals, Group IB metals, Group IIB metals, Ga, In, and all combinations thereof. The gas-upgrading catalyst can be comprised of metal modified MFI type zeolites, where the metal is selected from the group consisting of: Ga, Zn, In, Mo, W, Cr, Pt, Pd, Rh, Ru, Au, Ir and combinations thereof. The dehydration catalyst can be any acid catalyst, such as heterogeneous solid acid catalysts.
Volatile components can be recirculated to at least one of the following: a) one or more processing stations b) the dehydration catalyst, c) the aromatization catalyst, and d) the gas-upgrading catalyst in order to create fuels.
In one embodiment, a first fuel component can comprise one or more C4+ compounds derived from biomass conversion using ramps of temperature under pressure, wherein the fuel component has a component initial boiling point of in the range of 0° C. and 70° C. and a component final boiling point in the range of 85° C. and 225° C., a component density at 20° C. in the range of 600 to 990 kg/m3, a component sulfur content of at most 10 mg/kg, a component RON in the range of 80 to 120 and a component MON in the range of 75 to 110. The C4+ compounds can comprise compounds primarily with 4 to 16 carbon atoms.
In some cases, the gasoline composition contains a first fuel component, comprising one or more C4+ compounds derived from biomass conversion using ramps of temperature under pressure, wherein the fuel component has a component initial boiling point of in the range of 0° C. and 70° C. and a component final boiling point in the range of 85° C. and 225° C., a component density at 20° C. in the range of 600 to 990 kg/m3, a component sulfur content of at most 10 mg/kg, a component RON in the range of 80 to 120 and a component MON in the range of 75 to 110. The gasoline composition has an initial boiling point in the range of 0° C. and 70° C., a final boiling point at most 225° C., a RON number in the range of 80 to 120 and a MON number in the range of 75 to 110. The amount of first fuel component in a gasoline composition is at least 0.1% volume, based on total volume of gasoline.
Dehydration of the biofuels can be performed with a drying agent such as magnesium oxide or molecular sieves. This prevents azeotropic distillation and is expected to change the composition of the distillate. When the pre-distillation material is subjected to dehydration with 3A zeolite,
According to some embodiments of the invention, the aviation fuel composition contains a second fuel component, comprising one or more C4+ compounds derived from biomass conversion using ramps of temperature under pressure, wherein the fuel component has a component final boiling point in the range of 110° C. and 250° C., a component density at 20° C. in the range of 600 to 990 kg/m3, a component sulfur content of at most 10 mg/kg, a component RON in the range of 80 to 120 and a component MON in the range of 75 to 110. The C4+ compounds can comprise compounds primarily with 4 to 16 carbon atoms. The aviation fuel composition of the present invention has a final boiling point of at most 250° C., a Lean Mixture MON number of 75 or more, and a Rich Mixture Octane number of 85 or more. In some cases, the amount of second fuel component in an aviation fuel composition is at least 0.1% volume by total volume of aviation fuel.
According to further embodiments, a third fuel component of present invention can comprise one or more C4+ compounds derived from biomass conversion using ramps of temperature under pressure, wherein the third fuel component has a T95 (temperature at which 95% volume has evaporated) in the range of 220° C. to 400° C., a density at 20° C. is between 600 to 990 kg/m3 and a sulfur content is at most 10 mg/kg. In some cases, a diesel composition may include a third fuel component that comprises one or more C4+ compounds derived from biomass conversion using ramps of temperature under pressure, wherein the third fuel component has a T95 in the range of 130° C. to 400° C., a density at 20° C. is between 600 to 990 kg/m3 and a sulfur content is at most 10 mg/kg. The C4+ compounds can comprise compounds primarily with 4 to 16 carbon atoms. The diesel composition has an initial boiling point in the range of 130° C. to 230° C., a final boiling point of at most 420° C., and a cetane number in the range of 35 to 120. The amount of third fuel component in a diesel composition can be at least 0.1% volume by total volume of diesel.
In some embodiments of the invention, a fourth fuel component can comprise one or more C4+ compounds derived from biomass conversion using ramps of temperature under pressure, wherein the fourth fuel component has an initial boiling point in the range of 120° C. to 220° C., a final boiling point in the range of 220° C. to 320° C., and a sulfur content of at most 10 mg/kg. In one implementation, a kerosene composition contains a fourth fuel component, comprising one or more C4+ compounds derived from biomass conversion using ramps of temperature under pressure, wherein the fourth fuel component has an initial boiling point in the range of 80° C. to 220° C., a final boiling point in the range of 220° C. to 320° C., and a sulfur content of at most 10 mg/kg. The C4+ compounds can comprise compounds primarily with 4 to 16 carbon atoms. The kerosene composition may have an initial boiling point of at least 80° C., a final boiling point of at most 320° C., and a flash point is in the range of 35° C. to 65° C. The amount of fourth fuel component in kerosene composition is at least 0.1% volume by total volume kerosene.
According to an embodiment of the invention, the fuel components can be optionally blended in a gasoline formulation, diesel formulation, aviation fuel formulation, and kerosene formulation. It may also be co-blended with methanol, ethanol, propanol, butanol, butanediol, isobutanol, and vegetable oil. It may also be co-blended with any products from a fluidized catalytic cracking process, such as light naphtha, heavy naphtha, light cycle oil, heavy cycle oil, and kerosene. In some embodiments, additives may be added to the fuel or fuel blends. Additives such as detergents, combustion improvers, cetane improvers, emulsifiers, antioxidants, antifoam agents, corrosion inhibitors, wax crystal modifiers, distillate flow improvers, lubricity agents, icing inhibitors and antistatic agents may be added.
The steps set forth hereinabove with respect to
Although the invention is described above in terms of various exemplary embodiments and implementations, it should be understood that the various features, aspects and functionality described in one or more of the individual embodiments are not limited in their applicability to the particular embodiment with which they are described, but instead can be applied, alone or in various combinations, to one or more of the other embodiments of the invention, whether or not such embodiments are described and whether or not such features are presented as being a part of a described embodiment. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments.
Terms and phrases used in this document, and variations thereof, unless otherwise expressly stated, should be construed as open ended as opposed to limiting. As examples of the foregoing: the term “including” should be read as meaning “including, without limitation” or the like; the term “example” is used to provide exemplary instances of the item in discussion, not an exhaustive or limiting list thereof; the terms “a” or “an” should be read as meaning “at least one,” “one or more” or the like; and adjectives such as “conventional,” “traditional,” “normal,” “standard,” “known” and terms of similar meaning should not be construed as limiting the item described to a given time period or to an item available as of a given time, but instead should be read to encompass conventional, traditional, normal, or standard technologies that may be available or known now or at any time in the future. Likewise, where this document refers to technologies that would be apparent or known to one of ordinary skill in the art, such technologies encompass those apparent or known to the skilled artisan now or at any time in the future.
The presence of broadening words and phrases such as “one or more,” “at least,” “but not limited to” or other like phrases in some instances shall not be read to mean that the narrower case is intended or required in instances where such broadening phrases may be absent. Additionally, the various embodiments set forth herein are described in terms of exemplary block diagrams, flow charts and other illustrations. As will become apparent to one of ordinary skill in the art after reading this document, the illustrated embodiments and their various alternatives can be implemented without confinement to the illustrated examples. These illustrations and their accompanying description should not be construed as mandating a particular architecture or configuration.
This application claims priority to U.S. Provisional Patent Application No. 61/507,799, filed on Jul. 14, 2011, the content of which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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61507799 | Jul 2011 | US |