Patent Application
20180298294
The diminishing availability of high-quality crude oils, increasing worldwide energy demand, and associated environmental issues of fuel production and use make oils from nonfood, biomass-derived resources an attractive hydrocarbon fuel feedstock option. Biofuel production from processing pure biomass-derived (bioderived) materials and/or co-processing these materials with petroleum-derived feedstocks has the potential to significantly reduce greenhouse gas emissions (GHG) through the entire fuel production process chain. However, many technical difficulties still exist before biofuels can be technically and economically viable. Thus, there remains a need for improved technological solutions for producing fuels and fuel intermediates from biomass-derived materials.
An aspect of the present disclosure is a liquid composition that includes an alkane concentration between 40 wt % and 55 wt %, and an alkene concentration between greater than 0 wt % and 20 wt %, where cyclopentenone accounts for greater than 65 wt % of the alkane concentration. In some embodiments of the present disclosure, the liquid composition may further include phenol. In some embodiments of the present disclosure, at least a portion of the liquid composition may be bioderived.
An aspect of the present disclosure is a liquid composition that includes a concentration of single ring aromatics of less than 40 wt %, a concentration of two ring aromatics of less than 60 wt %, and a concentration of oxygenates of less than 20 wt %. In some embodiments of the present disclosure, greater than 70 wt % of the oxygenates may include at least one of butanone and/or butenone. In some embodiments of the present disclosure, greater than 25 wt % of the oxygenates may include pentenone. In some embodiments of the present disclosure, about 20 wt % of the oxygenates may include a methyl phenol, and about 20 wt % of the oxygenates may include an alkyl phenol. In some embodiments of the present disclosure, about 55 wt % of the oxygenates may include benzene diol. In some embodiments of the present disclosure, at least a portion of the liquid composition may be bioderived.
An aspect of the present disclosure is a method that includes thermally reacting a biomass to produce a bio-oil and upgrading the bio-oil to produce a liquid product, where the thermally reacting is performed in a pyrolysis reactor, and the upgrading is performed an upgrading reactor. In some embodiments of the present disclosure, the liquid product may include a concentration of single ring aromatics of less than 40 wt %, a concentration of two ring aromatics of less than 60 wt %, and a concentration of oxygenates of less than 20 wt %. In some embodiments of the present disclosure, the upgrading reactor may be a fluidized bed reactor. In some embodiments of the present disclosure, the pyrolysis reactor may be a catalytic fast pyrolysis reactor. In some embodiments of the present disclosure, the biomass may include at least one of a wood and/or a grass.
In some embodiments of the present disclosure, the method may further include, prior to the upgrading, combining the bio-oil with a second oil, where the upgrading further includes the second oil. In some embodiments of the present disclosure, the second oil may include at least one of a vacuum gas oil, a light cycle oil, and/or a naphthenic. In some embodiments of the present disclosure, the combining may include mechanically mixing the bio-oil and the second oil to form a suspension. In some embodiments of the present disclosure, the method may further include, before the upgrading, phase separating the suspension to form a light phase oil and a heavy phase oil. In some embodiments of the present disclosure, the upgrading may be performed on the heavy phase oil.
An aspect of the present disclosure is a method that includes thermally reacting a biomass to produce a bio-oil, mixing the bio-oil with a second oil that includes at least one of a vacuum gas oil, a light cycle oil, and/or a naphthenic to form a suspension, phase separating the suspension to form a light phase oil and a heavy phase oil, and upgrading the heavy phase oil to produce a liquid product, where the thermally reacting is performed in a pyrolysis reactor, and the upgrading is performed an upgrading reactor.
Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than limiting.
The present disclosure may address one or more of the problems and deficiencies of the prior art discussed above. However, it is contemplated that some embodiments as disclosed herein may prove useful in addressing other problems and deficiencies in a number of technical areas. Therefore, the embodiments described herein should not necessarily be construed as limited to addressing any of the particular problems or deficiencies discussed herein.
The present disclosure relates to thermochemical biomass conversion with a focus on ex-situ upgrading of biomass pyrolysis vapors, also called vapor-phase upgrading (VPU), as an efficient and economical route to pyrolysis-based fuel precursors and potentially fuels and chemicals depending on catalyst choice, feedstock choice, and process conditions. In some embodiments of the present disclosure, biomass vapors were generated via fast pyrolysis (FP) and destabilizing vapor components (char, inorganics, tar aerosols) were removed by hot gas filtration with the conditioned vapors more amenable to catalytic upgrading. A Davison Circulating Riser (DCR), a petroleum industry standard for fluid catalytic cracking (FCC) catalyst evaluation, was coupled with a custom pyrolysis reactor system designed to produce consistent pyrolysis vapors as feed to the DCR. Baseline DCR tests with an equilibrium catalyst (E-Cat) and vacuum gas oil (VGO—see Table 2 for a list of physical properties) showed that the system operated reproducibly to produce gasoline. VGO is that portion of crude oil that has an initial boiling point of 340° C. or higher at atmospheric pressure and an average molecular weight ranging from about 200 to 600 or higher. In addition, pure hardwood or softwood vapors were upgraded using a variety of catalysts comprising zeolites and modified zeolites. Oils were condensed from the upgraded vapors and analyzed with 31P and 13C nuclear magnetic resonance (NMR) spectroscopy, TGA based simulated distillation (SIM DIST) boiling point curve analysis, two-dimensional GC time-of-flight mass spectroscopy (2D GC TOFMS), carbonyl and ultimate analysis (CHNO) to assess oil chemistry, process induced changes, and to identify the best conditions for producing fungible product liquids. Critical oil parameters evaluated include oxygenate content and composition, carbon content and composition, carbon conversion efficiency from biomass to products, and catalyst coking rates. In some embodiments of the present disclosure, zeolite catalysts produced oils with <12% oxygenate content. These vapor phase upgrading results demonstrate the feasibility of producing refinery compatible hydrocarbon fuel intermediates entirely from biomass derived fast pyrolysis vapors using a DCR system.
Some of the embodiments described herein reduce process issues such as catalyst coking, pyrolysis oil age-induced chemical changes, and enhanced light gas production by co-feeding biomass pyrolysis liquids with VGO to produce fuels, by using modified FCC zeolite catalysts and a Davison Circulating Riser reactor to upgrade biomass fast pyrolysis vapors directly. Additionally, in some embodiments of the present disclosure, a hot gas filter may be used to remove alkali and residual char particles from raw pyrolysis vapors to produce a cleaner, stabilized feedstock for subsequent catalytic upgrading. In some embodiments of the present disclosure, the resultant condensed liquid products may be suitable as a fuel blend-stock material and/or as a liquid fuel and/or may be suitable for insertion into refining operations with oxygen contents of 10 wt % or less depending on the upgrading catalyst choice.
Referring again to
The vapor phase components of the pyrolysis vapor 135 may include various cellulose, hemicellulose, and/or lignin degradation products with examples including acids, alcohols, carbonyls, aldehydes, alkenes (C3-C10+), alkanes, aromatics (1-3 ring), esters, furans, ketones, oxygenates, methoxies, phenols, sugars, and nitrogen containing compounds. Specific examples of organic pyrolysis vapor compounds include acetic acid, propionic acid, ethylene glycol, hydroquinone, glyoxal, tetradecene, benzene, toluene, styrene, indene, methylindene, naphthalene, methylnaphthalene, butyrolactone, furfural, furfuryl alcohol, 1-(2-furanyl)ethanone, 4-methyl-3-penten-2-one, 2-cyclopenten-1-one, 2-methyl-2-cyclopenten-1-one, 2,3-dimethyl-2-cyclopenten-1-one, 3-methyl-2-cyclopenten-1-one, 3,4-dimethyl-2-cyclopenten-1-one, 2-hydroxy-3-methyl-2-cyclopenten-1-one, 3-ethyl-2-cyclopenten-1-one, 3-ethyl-2-hydroxy-2-cyclopentene-1-one, 2,3-dihydroxy-1H-inden-1-one, 2,2,6,6-tetramethylpiperidone, benzylnitrile, pyridinol, indole, methylindole, hydroxyacetaldehyde, acetol, 1-hydroxy-2-butanone, 4-hydroxy-4-methyl-2-pentanone, 2,3-dihydrobenzofuran, guaiacol, 2-methoxy-4-methylphenol, 4-ethyl-2-methoxyphenol, 2-methoxy-4-vinylphenol, 2-methoxy-4-vinylphenol, eugenol, isoeugenol, 2,6-dimethoxyphenol, phenol, o-cresol, 2,5-dimethylphenol, p-cresol, m-cresol, 2,4-dimethylphenol, 3,5-dimethylphenol, 4-ethylphenol, 3-ethylphenol, 2-ethylphenol, 4-ethyl-3-methyl phenol, 4-(1-methylethyl)phenol, 2-me-1,4-benzenediol, 2,3-anhydro-D-mannosan, 1,4:3,6-dianhydro-α-D-glucopyranose, and/or levoglucosan. In addition, lower molecular weight pyrolysis compounds may react with each other to produce higher molecular weight compounds, e.g. tars, multi-ring compounds like naphthalenes, and/or char. Char is a condensed carbon solid material obtained from thermochemical conversion of biomass in an oxygen-limited environment. Biochar can be used for a range of applications as an agent for soil improvement, improved resource use efficiency, remediation and/or protection against particular environmental pollution and as an avenue for greenhouse gas (GHG) mitigation. In addition, to be recognized as biochar, the material has to pass a number of material property definitions that relate both to its value (e.g., H/Corg ratios relate to the degree of charring and therefore mineralization in soil) and its safety (e.g., heavy metal content). In addition, the pyrolysis vapor 135 may include alkali and/or alkaline earth elements where alkali and alkaline earth elements include K, Na, Mg, and Ca. Alkali and alkaline earth materials play essential roles in plant metabolism and occur in organic structures or very mobile, inorganic forms. Potassium and calcium are the most common examples. These species can vaporize during pyrolysis and deposit on cooler surfaces including reactor walls and catalyst surfaces. They also can induce gas phase polymerization reactions among reactive biomass pyrolysis species. Thus, in some embodiments of the present disclosure, alkali and/or alkaline earth elements may be removed from pyrolysis vapors via hot gas filtration to provide a cleaner, stabilized vapor for catalytic upgrading. Forms can include inorganic oxides and carbonates.
The components/compounds making up the pyrolysis vapor 135 made in the pyrolysis reactor 130 can depend significantly on the type of biomass 125 used (e.g. switchgrass versus hardwood) and on the type of pyrolysis reactor 130 used. Fast pyrolysis reactors within the scope of the present disclosure include vertical and/or horizontal fluidized-bed pyrolysis reactors, where the reactors may or may not use a solid catalyst such as olivine. A biomass pyrolysis reactor system may include at least one of a feed hopper, a lock hopper, a dosing screw/hopper, and/or a fast feed screw that introduces biomass (1-2 mm particle size, 0.5-1.5 kg dose up to 5 kg/hr) into the pyrolysis reactor. The pyrolysis reactor 130 used for the work described herein included a 2″ inside diameter×40″ long stainless-steel pipe located between the biomass inlet and the reactor outlet. In some embodiments of the present disclosure, operating conditions were as follows: nitrogen fluidization to achieve about a 2 second biomass residence time in the pyrolysis reactor, a pyrolysis reactor temperature of about 500° C., a pyrolysis reactor pressure of 35 psig, and a biomass to nitrogen feed ratio to the pyrolysis reactor of about 0.5. A ceramic hot gas filter removed alkali and residual char particles from the produced pyrolysis vapor of which a slipstream (at 400° C.) was sent to the DCR. The primary flow of pyrolysis vapors was condensed in a spray tower with dodecane at about 25° C. and separated from the resultant liquid mixture in a horizontal phase separator. In some embodiments of the present disclosure, water and/or steam may be provided to the pyrolysis reactor 130 such that the water and/or steam react with the biomass 125 to form the pyrolysis vapor 135.
Thus, in some embodiments of the present disclosure, the pyrolysis vapor 135 produced in the pyrolysis reactor 130 may be purified to include substantially only the organic vapor-phase components by passing the pyrolysis vapor 135 through one or more separation units. For example, referring again to
The purified pyrolysis vapor 154 may then be directed to the upgrading reactor 160 such that the purified pyrolysis vapor 154 reacts in the upgrading reactor 160 to form a liquid product 172. In some embodiments of the present disclosure, the upgrading reactor 160 may be a batch reactor, a continuous reactor, and/or a semi-continuous reactor. Further, the upgrading reactor 160 may include at least one of a packed-bed reactor and/or a fluidized-bed reactor. In some embodiments of the present disclosure, the upgrading reactor 160 may include a Davison Circulating Riser (DCR). Thus, an upgrading reactor 160 may contain a solid catalyst (not shown) that promotes the reaction of the feed materials (e.g. at least one of the purified pyrolysis vapor 154, the oil 115, and/or the liquid recycle 174) to produce the final liquid product 172.
Examples of suitable solid catalysts for use in the upgrading reactor 160 include aluminosilicates. As used herein, “aluminosilicate” refers to materials containing aluminum, silicon, and oxygen. Examples of aluminosilicates include clay minerals and zeolites. Examples of clay minerals include kaolin, smectite, illite, chlorite, sepiolite, and attapulgite. A zeolite is a microporous crystalline aluminosilicate, composed of TO4 tetrahedra, wherein T is a silicon or aluminum atom, with oxygen atoms connecting neighboring tetrahedral. The extra-framework cations in zeolites and molecular sieves are ion exchangeable. The amount of aluminum within the framework can vary over a wide range, with silicon to aluminum ratios varying from 1 to 1 to infinity to 1 for the case where the zeolite contains no aluminum, the completely siliceous form of SiO2. As the amount of trivalent aluminum is increased in a zeolite's framework, the zeolite's physical properties may change. Cations may be placed (or deposited) onto the surfaces and/or within the pores of a zeolite and/or a molecular sieve. Examples of such ion-exchangeable cations that may be deposited onto a zeolite crystalline surface include monovalent cations such as H+, Li+, K+, Rb+, Cs+, Ag+, and Tl+, divalent cations such as Cd2+, Ca2+, Sr2+, Cu2+, Pe+, and Ba2+, rare earth ions such as La3+, transition metal ions such as Cr, Mo, W, Mn, Fe, Ni, Cu, Zn, Ag, Al, and Ga, having a variety of valence charges, noble metals such as Pt and Pd in the form of Pt(NH3)42+ and Pd(NH3)42+ respectively, inorganic ions such as ammonium (NH4+), tetramethylammonium ion (TMA), tetraethylammonium ion (TEA), tetrapropylammonium (TPA), benzyltrimethylammonium (BTMA), and C1-C4 mono-n-alkylammonium, and/or di-n-alkylammonium (MA, EA, PA, BA, M2A, E2A, P2A, B2A) ions.
In some embodiments of the present disclosure, the solid catalyst used in the upgrading reactor 160 may include a molecular sieve, where the term “molecular sieve” refers to crystalline aluminosilicate materials (e.g. zeolites) that incorporate other elements instead of or in addition to silicon and aluminum. For example, aluminophosphates (AlPOs) have strictly alternating AlO2− and PO2+ units, and the framework is neutral, organophilic, and nonacidic. The alternation of aluminum or phosphorus leads to structures lacking in odd-numbered rings. Substitution of phosphorus by silicon leads to silicoaluminophosphates (SAPOs), with cation-exchange abilities. Some molecular sieves may also include one or more elements and/or compounds as catalytic active sites, as described above for zeolites.
Zeolites and molecular sieves may be characterized as small, medium, or large pore types. Non-limiting examples of these zeolites/molecular sieves include the small pore zeolites/molecular sieves, AEI, AFT, APC, ATN, ATT, ATV, AWW, BIK, CAS, CHA, CHI, DAC, DDR, ED1, ER1, GOO, KFI, LEV, LOV, LTA, MON, PAU, PHI, RHO, ROG, THO, and substituted forms thereof; the medium pore zeolites/molecular sieves, AFO, AEL, EUO, HEU, FER, MEL, MFI, MTW, MTT, TON, and substituted forms thereof and the large pore zeolites/molecular sieves, including BEA, EMT, FAU, and substituted forms thereof. Other zeolites/molecular sieves include ANA, CFI, CLO, DON, GIS, LTL, MER, MOR, MWW, SOD, faujasites, pentasils, mordenite, beta, VPI, MCM, SAPO, MeAPO, ELAPO, and ELAPSO, zeolite X, zeolite Y, VPI-5, MCM-41, ZSM-5, ZSM-11, ZSM-14, ZSM-17, ZSM-18, ZSM-20, ZSM-31, ZSM-34, ZSM-41 and ZSM-46.
A zeolite may contain pores formed from 6-membered ring, 8-membered ring, 10-membered ring, 12-membered ring, 18-membered ring, and/or a larger membered ring of silicon (or aluminum) and oxygen pairs. For example, the term “8-membered ring” refers to a closed loop that is built from eight tetrahedrally coordinated silicon (or aluminum) atoms and 8 oxygen atoms. These rings form pores with characteristic diameters. By way of example 8-membered ring ZK-5 (KFI) has a characteristic pore size of about 4 Å, 10-membered ring ZSM-5 has a characteristic pore size of about 5.5 Å, and 12-membered ring beta (BEA) zeolite has a characteristic pore size of about 7.5 Å.
Solid catalysts, including zeolites and molecular sieves, may be incorporated in another material referred to herein as a “matrix” or “binder”. Such matrix materials may include synthetic or naturally occurring substances as well as inorganic materials such as clay, silica and/or metal oxides. The latter may be either naturally occurring or in the form of gelatinous precipitates or gels including mixtures of silica and metal oxides. Naturally occurring clays which can be composited with zeolite and/or molecular sieves include those of the montmorillonite and kaolin families, which families include the subbentonites and the kaolins commonly known as Dixie, McNamee, Georgia and Florida clays or others in which the main mineral constituent is halloysite, kaolinite, dickite, nacrite or anauxite. Such clays can be used in the raw state as originally mined or initially subjected to calcination, acid treatment or chemical modification. In some cases, a matrix or binder may also act as a catalyst. Equilibrium catalyst (E-Cat) is a mixture of FCC catalyst material of various age and level of activity which as whole best represents the level of activity of the average catalyst mass in the reactor. Typical FCC catalyst is composed mostly of Y zeolite with or without cation exchange bound in a matrix of clay and/or metal oxides. Other FCC catalyst components, additives or promoters maybe found in the E-Cat solid mixture. These additives may include ZSM-5 zeolite containing particles that contribute to the overall catalytic activity.
Table 1 below summarizes a catalyst used in the upgrading reactor, according to some embodiments of the present disclosure. Other suitable examples include P-doped HZSM-5 zeolites, and/or metal modified zeolites (for example at least one of Ni, Ga, Cu, Pt, and/or Ru).
Referring again to
Table 2 provides a summary of typical VGO physical properties. Other “VGOs” may also be used in some embodiments of the present disclosure, as well as other petroleum fractions include light cycle oil (LCO) and/or kerosene.
Final liquid product from the upgrading reactor will typically have at least reduced carbonyl and/or phenol contents, with an aggregate weight percent of oxygenates of less than 10 wt %. The liquid product 172 produced in the upgrading reactor 160 may initially exit the upgrading reactor 160 as a vapor product 162, which may be subsequently condensed in a condenser 170 to produce the liquid product. In some embodiments of the present disclosure, up to 100% of the vapor product 162 may be condensed, with non-condensables venting (not shown) from the condenser.
Catalysts and feedstocks: Baseline DCR operations to produce gasoline were periodically verified with standard vacuum gas oil and an equilibrium catalyst (Y-type zeolite) with 2D GC TOFMS analysis of liquid product used to measure system reproducibility. Oak-derived pyrolysis vapors were co-fed with VGO to assess the impact of pyrolysis vapor on catalyst retention during DCR upgrading to a gasoline liquid product. These results were used to determine catalyst circulation rates for pure pyrolysis vapor feeding to the DCR. Several catalysts comprising E-Cat, ZSM-5, and a phosphorous stabilized ZSM-5 and CP758 zeolite were evaluated for pure pyrolysis vapor upgrading performance. Condensed liquid products were characterized for composition to understand catalyst induced changes. Some of the zeolite catalysts used in this study minimized oxygenated products to 12 wt % or less. Table 1 above lists typical catalyst properties.
In general, the FCC catalysts are fine, spray-dried powders having a bulk density of 0.80 to 0.96 g/cm3 and an average particle size of 60 to 100 Current FCC catalysts consist of three major components: crystalline zeolite, binder, and/or filler. Crystalline zeolite is the primary active component and can range from about 15 to 50 weight percent of the total catalyst (all three major components). Feedstocks used in this work were oak as a representative hardwood and pine as representative softwood. Their properties are shown in Table 3.
Biomass fast pyrolysis: Referring to
Vapor catalytic cracking and upgrading: Referring to
Table 4 lists ranges for the DCR parameters utilized in the experiments reported herein. For these experiments, the system pressure was set at 15 psig and the pyrolysis vapor feed rate between 170 g/hr and 240 g/hr (total feed rate of 1 kg/hr, N2 included). The regenerator, stripper, riser outlet, and the feed pre-heater temperatures were set to 600° C., 500° C., 550° C., and 150° C., respectively.
Product analysis: Condensed pyrolysis oils collected from the pyrolysis reactor and upgraded pyrolysis liquids collected from the DCR fractional condensation train were comprehensively analyzed for chemical composition with methods comprising moisture content, ultimate and proximate analysis, carbonyl content, carboxylic acid number (CAN), simulated distillation (SIM DIST), total acid number (TAN), 13C NMR, 31P NMR, and two dimensional gas chromatography time of flight mass spectrometry (2D GC TOFMS).
Moisture content was determined by titration with standardized Karl-Fisher reagent on a Metohm 701 KF Titrino automatic titrator. Hydranal® 5K was used as the titrant and was standardized against a NIST traceable water standard. Samples were vigorously shaken for 60 to 90 s to suspend any heavy material that had settled before aliquoting. Approximately 100 μL of oil was transferred to the KF vessel which was preconditioned to an anhydrous condition and titrated to the instrument end point. Each sample was measured in triplicate. Elemental compositions were determined by combustion analysis using a LECO TruSpec® CHN analyzer. Oxygen was determined by difference. Calibration of the CHN analyzer is with a known standard (EDTA).
The original carbonyl analysis method developed by Faix was modified to increase sample size and decrease reactant volumes. Samples were reacted with hydroxylamine hydrochloride in ethanol and the liberated hydrochloric acid was reacted with an excess triethanolamine solution. Unreacted TEA was then titrated with standardized hydrochloric acid to determine the amount of hydroxylamine hydrochloride originally consumed which was equivalent to the amount of carbonyl groups present. The estimated detection limit was near 0.1 mol carbonyl group/kg oil. The CAN was determined by pH titration with a Metrohm 842 Titrando automatic titrator using Nicolaides' method. Samples were weighed into titration cups, diluted to 40 ml with 80% ethanol/water and titrated to a pH of 13 with standardized NaOH. The acid end point was determined by the first derivative of the pH. The pKa of organic acids is not highly variable in different organic acids. Standard potassium hydrogen phthalate and salicyclic and anisic acid carboxylic acids of known concentration were used to validate the method.
13C NMR analysis was conducted by dissolving standards, oil and upgraded products samples (200 μl) in CDCl3 (250 μl) with 1 mg/ml chromium (III) acetylacetonate as relaxation reagent. All 13C NMR spectral data were recorded with a Bruker 600 MHz NMR spectrometer. The quantitative 31P NMR measure the absolute amount of each reactive —OH group (aromatic —OH, aliphatic —OH and carboxylic —COOH) and was calibrated against known standards of reagent grade compounds. NMR frequency shift was used to identify each type of OH group.
Two-dimensional gas chromatography time of flight mass spectrometry (2D GC TOFMS) analysis was conducted with a LECO Pegasus unit equipped with a Gerstel autosampler. The non-polar configuration used was very similar to the non-polar column used for ASTM methods D6729, D2887, D3710, D5134 and D5443 but added a second polar column to provide separation of polar olefins, aromatics and oxygenates after the primary boiling point separation. For the 2D GC TOFMS analysis, the standards and samples (100 μl) were dissolved in acetonitrile for pyrolysis oil or dichloromethane for upgraded pyrolysis oils (900 μl) with added internal standards (0.3 μg/μl each α,α,α-trifluorotoluene, 2-fluoro-1,1′-biphenyl, and σ-terphenyl). This solution was then further diluted 200 μl diluted sample with 800 μl acetonitrile or dichloromethane before injection. Post-condensation product gases were analyzed using an Agilent Technologies 490 Micro gas chromatograph, using MS5A (10 m), PPQ (10 m), AlOx (10 m), and 5CB (8 m) columns.
Comprehensive chemical analysis of fast pyrolysis (FP) oils, catalytic fast pyrolysis (CFP) oils, and gasoline product from VGO was used to understand how oil composition varies with feedstock and catalyst. The aqueous phase from the CFP oils were also characterized as the biogenic carbon it contains is an upgradeable source of biomass-derived fuels and chemicals. Primary oil analysis was conducted with 2D GC TOFMS and 31P NMR to characterize individual species and carbon bond types, respectively. Simulated distillation (SIM DIST) was used to compare thermal behavior of the liquids. On-line gas chromatography provided permanent gas analysis of the vapor feed to the DCR and post-condensation product gas analysis. FP and CFP oils and the control gasoline product obtained from VGO and E-Cat showed significant differences as expected.
Analyzing the more than 400 compounds present in each of these samples is complex. Compound identification from software matching, peak size, and retention times for each spectrum were tagged with CAS registry numbers to generate a searchable Excel-based spreadsheet to 1) quantitate species in the samples and 2) group compound classes.
Carbon bond types as determined by 31P NMR are shown in
On-line analyses of the post-condensation gas phase products (permanent and light hydrocarbon gases) are shown in
Gas phase hydrocarbon species resulting from the upgraded CFP oils were predominantly C2 and C3 olefins with little difference observed between the various CFP feedstocks and upgrading catalysts used in the DCR. This result is consistent with the similar CFP spectra of
Miscibility and Characterization of Biomass Catalytic Fast Pyrolysis Liquids with Petroleum Vacuum Gas Oil (VGO): The experiments describe below investigate the miscibility of CFP oils with VGO, by mixing the two phases together and allowing them to phase separate. The mixtures were produced by mechanical mixing. In some embodiments of the present disclosure, a single liquid stream containing a first fraction of VGO and a second fraction of a CFP oil may be fed directly to an upgrading reactor, as described above, and described in more value below.
As shown in
VGO/CFP oil upgrading: Based on the miscibility results described above, variations of VGO, CFP/VGO mixtures and catalysts were fed to the DCR upgrading reactor to produce biogenic hydrocarbon fuels at a process relevant scale. Table 6 below lists these experiments; Run #s utilized in
Upgrading reactions were completed using either pure E-Cat or a combination of 10 wt % CP758 zeolite with the remainder (90 wt %) E-Cat. These catalyst choices were used to upgrade a 10 wt % CFP-90 wt % VGO feed. VGO upgraded with E-Cat was performed as a control experiment. VGO upgraded with the catalyst mixture of zeolite/E-Cat assessed the impact of the additional catalyst on VGP product. The mixed feed was upgraded with either E-Cat as a baseline experiment or the mixed catalyst to assess impact on product composition. CFP oils from pine were produced and mixed with VGO to produce a single liquid feedstock for DCR upgrading.
In some embodiments of the present disclosure, other feedstock combinations than VGO and CFP oils may be used. Other petroleum feedstocks that may be co-processed via the upgrading reactions described herein with fast pyrolysis (FP) and CFP liquids include light cycle oil (LC) and hydrocracked naphthenics. Additionally, hydrotreated FP and CFP liquids may be co-processed with these petroleum feeds. Compositionally, the most abundant constituent in LCO is aromatic compounds, especially the multi-ring aromatics. Selective hydrogenation and subsequent catalytic cracking of light cycle oil (LCO) from a fluid catalytic cracking unit is expected to produce more high-octane-number gasoline. In this process, the multi-ring aromatics are selectively hydrogenated and transformed to naphthenic aromatics, which are further converted into the gasoline fraction through cracking reaction. Naphthenic acids (NAs) are a mixture of several cyclopentyl and cyclohexyl carboxylic acids with molecular weight of 120 to well over 700 atomic mass units. The main fraction are carboxylic acids with a carbon backbone of 9 to 20 carbons. Naphthenic acids are represented by a general formula CnH2n-z O2, where n indicates the carbon number and z specifies a homologous series. The z is equal to 0 for saturated, acyclic acids and increases to 2 in monocyclic naphthenic acids, to 4 in bicyclic naphthenic acids, to 6 in tricyclic acids, and to 8 in tetracyclic acids.
In summary, regarding CFP Oil compositions:
In summary, regarding CFP/VGO miscibility:
Regarding co-feeding CFP oils with VGO as a mixture to an upgrading reactor:
Thus, for the first time, biomass derived fast pyrolysis vapors were catalytically upgraded to >liter quantities of liquid hydrocarbon fuels, termed catalytic fast pyrolysis oils (CFP), using varied industrial zeolite catalysts (E-Cat and HZSM-5 variants), biomass feedstocks (pine and Miscanthus), and pilot scale FCC processing.
Produced CFP liquids contain significantly less oxygenate content (20%) compared with analogous fast pyrolysis liquids (50%) with oxygenates of interest comprising >70% buta/enone (butanone and/or butenone) in pine CFP oils and 25% pentenone in Miscanthus CFP oil. Other compositional differences are due to zeolite catalyst composition (varied HZSM-5 content). These compounds may be useful as feedstocks for biogenic chemicals production. CFP oils additionally contained 1-ring aromatics (benzene, toluene, xylene), which are not in FCC petroleum vacuum gas oil (VGO). Enhanced biogenic xylene is a significant feedstock for “green” PET polymer production.
The CFP oil composition (reduced oxygenates, enhanced aromatics) was shown to be miscible with VGO with simple mechanical mixing. Settling of the 50/50 vol % mixture formed a 25% volume enhanced light VGO layer and an analogous reduced volume CFP layer. Settled layer compositions were strikingly different with oxygenates remaining in the residual CFP layer. Additionally, no benzene remained in the residual Miscanthus CFP layer. Some toluene and xylene remain in this layer suggesting that sequential extraction with VGO would further increase their concentration in the enhanced VGO layer.
Co-processing single feed mixtures of 90 vol % 10 vol % VGO with the CFP oils and enhanced VGO layers produced gasoline with slightly higher light aromatics content. This result is significant because current state of the art uses two independent nozzles for co-feeding VGO with FP liquids to produce biogenic carbon containing fuels. Single liquid feeding is significant process intensification that likely will result in both capital and operating costs in a refinery setting. Demonstrating that CFP oil can be processed with VGO using refinery upgrading is significant in that the gasoline composition did not contain oxygenates and only slight enhancement of aromatics and alkanes. Further work with catalyst compositions and biomass feedstocks should provide “tunable i.e. enhanced olefins per refinery request” CFP feedstocks for petroleum co-processing. Further work with the residual CFP layers may result in economical separations to produce green feedstocks for chemicals production (PET from xylene, phenolic resins from phenols, natural products from furans and cyclopentenones).
Some of the observations/characteristics/properties listed above and/or described herein are summarized in Table 7 below:
Miscanthus
Miscanthus
Miscanthus
Miscanthus
Miscanthus
Whether or not a reactant or product described herein is “bioderived” or “biomass derived” may be determined by analytical methods. Using radio carbon and isotope ratio mass spectrometry analysis, the bio-based content of materials can be determined. ASTM International, formally known as the American Society for Testing and Materials, has established a standard method for assessing the biobased content of carbon-containing materials. The ASTM method is designated ASTM-D6866. The application of ASTM-D6866 to derive a “biobased content” is built on the same concepts as radiocarbon dating, but without use of the age equations. The analysis is performed by deriving a ratio of the amount of radiocarbon (14C) in an unknown sample to that of a modern reference standard. The ratio is reported as a percentage with the units “pMC” (percent modern carbon). If the material being analyzed is a mixture of present day radiocarbon and fossil carbon (containing no radiocarbon), then the pNMC value obtained correlates directly to the amount of biomass material present in the sample. Thus, ASTM-D866 may be used to validate that the compositions described herein are and/or are not derived from renewable sources.
The foregoing discussion and examples have been presented for purposes of illustration and description. The foregoing is not intended to limit the aspects, embodiments, or configurations to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the aspects, embodiments, or configurations are grouped together in one or more embodiments, configurations, or aspects for the purpose of streamlining the disclosure. The features of the aspects, embodiments, or configurations, may be combined in alternate aspects, embodiments, or configurations other than those discussed above. This method of disclosure is not to be interpreted as reflecting an intention that the aspects, embodiments, or configurations require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment, configuration, or aspect. While certain aspects of conventional technology have been discussed to facilitate disclosure of some embodiments of the present invention, the Applicants in no way disclaim these technical aspects, and it is contemplated that the claimed invention may encompass one or more of the conventional technical aspects discussed herein. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate aspect, embodiment, or configuration.
This application claims the benefit of U.S. Provisional Patent Application No. 62/484,959 filed Apr. 13, 2017, the contents of which are incorporated herein by reference in their entirety.
The United States Government has rights in this disclosure under Contract No. DE-AC36-08GO28308 between the United States Department of Energy and Alliance for Sustainable Energy, LLC, the Manager and Operator of the National Renewable Energy Laboratory.
| Number | Date | Country | |
|---|---|---|---|
| 62484959 | Apr 2017 | US |
