Patent Application
20160108323
None.
This invention relates to the conversion of bio-sourced materials having alcohol functionalities to other useful compounds and more particularly to the cost efficient conversion of such materials to fuel suitable compounds.
There is considerable interest in the development of alternative sources of fuels and chemicals, other than from petroleum resources. As the public discussion concerning the availability of petroleum resources and the need for alternative sources continues, it is anticipated that government mandates will expand the requirements for transportation fuels to include, at least in part, hydrocarbons derived from sources other than petroleum. As such, there is a need to develop alternative sources for hydrocarbons useful for producing fuels and chemicals.
One possible alternative source of hydrocarbons for producing fuels and chemicals is the natural carbon found in plants and animals. These so-called “natural” carbon resources (or renewable hydrocarbons) are widely available, and remain a target alternative source for the production of hydrocarbons. For example, it is known that carbohydrates and other sugar-based feedstocks can be used to produce ethanol, which has been blended with gasoline to provide an oxygenate to reduce emissions of uncombusted hydrocarbons. However, without government mandates, ethanol blending would diminish as it is not economically or energy efficient.
Carbohydrates, however, also can be used to produce fuel range hydrocarbons. The upgrading of biologically derived materials to materials useful in producing fuels is known in the art. However, many carbohydrates (e.g., starch) are undesirable as feed stocks due to the costs associated with converting them to a usable form. In addition, many carbohydrates are known to be “difficult” to convert due to their chemical structure, or that the hydrocarbon product produced is undesirable or will result in low quantities of desirable product. Among the compounds that are difficult to convert include compounds with low effective hydrogen to carbon ratios, including carbohydrates such as starches and sugars, carboxylic acids and anhydrides, lower glycols, glycerin and other polyols and short chain aldehydes. As such, efforts have been made to increase the effective hydrogen to carbon ratio of the materials including converting oxygenates in the presence of hydrogen, CO, steam, nitrogen, or other reactants, and by employing various catalysts. However, these processes are often complex and are costly, and the reaction products produced as a result of these processes are oftentimes undesirable or produce low weight percentage products, and often result in an increase in undesirable byproducts such as the production of carbon monoxide and carbon dioxide.
As such, development of a process for converting carbohydrates to hydrocarbons which yields significant quantities of desirable hydrocarbon products would be a significant contribution to the art. Furthermore, development of a conversion process for converting biological carbon to a hydrocarbon fuel or chemical product with reduced byproducts such as carbon monoxide and carbon dioxide, and reduced coke production, would be highly desirable.
The invention more particularly relates to a process for converting C1 to C4 bio sourced molecules with one or more oxygen containing functionalities to C5+ hydrocarbons. The process includes providing a C1 to C4 alcohol stream from a biomass conversion process that is contacted with supported metal catalyst at a temperature of at least 500° F. and a pressure of at least 1000 psi. The C1 to C4 alcohol stream is converted to a higher value stream containing hydrocarbons and oxygenates with carbon numbers of between six and 30, and the higher value stream is deoxygenated to remove oxygen from the oxygenate molecules and produce hydrocarbons that may be separated into feedstocks for at least one of gasoline, diesel, jet and gas oil.
A more complete understanding of the present invention and benefits thereof may be acquired by referring to the follow description taken in conjunction with the accompanying drawings in which:
Turning now to the detailed description of the preferred arrangement or arrangements of the present invention, it should be understood that the inventive features and concepts may be manifested in other arrangements and that the scope of the invention is not limited to the embodiments described or illustrated. The scope of the invention is intended only to be limited by the scope of the claims that follow.
In efforts to convert carbohydrates to hydrocarbon fuels, many short carbon chain molecules are formed which include oxygen in single or multiple alcohol function groups such as diols, glycols, triols and polyols. Such efforts to convert biomass to fuels includes hydrolysis, fermentation, gasification, and pyrolysis. Any possibility of economically converting these short carbon chain alcohol function products to gasoline or diesel range hydrocarbons would be very attractive as the gasoline and diesel markets are the largest liquid fuel markets. This present invention seeks to combine such smaller oxygen containing molecules into longer carbon chain alkanes using a catalytic conversion process comprising a fixed bed a catalyst in the presence of hydrogen at elevated temperatures and pressures. The catalyst may be a noble metal/solid acid catalyst, but base metal catalysts have shown interesting performance as well.
Based on initial tests, noble metals with Pt and Pd concentrations between 0.3 and 0.7 wt % seem to work well and base metals with Ni (1-5 wt %) and Mo (20-30 wt %) also perform the chemistry. Preferred supports include silica-alumina and gamma alumina. The catalyst may be reduced under hydrogen and used without sulfiding or may be sulfided.
The process of the present invention may be accomplished in a conventional fixed bed reactor such as shown in
The inventive process for the upgrading alcohols, and polyols to products containing a larger number of carbon atoms per molecule than the respective feedstock comprises passing solutions of alcohols or diols and water over a fixed bed of supported metal catalyst in the presence of hydrogen at elevated temperatures and pressures. A preferred catalyst is noble metal/solid acid catalyst. In the examples below, products were characterized using gas chromatography to quantify individual chemical species and simulated distillation to quantify groups of chemical species boiling above 160° F. Heavy naphtha is defined as organic liquid products boiling between 160° F. and 380° F. Distillate is defined as organic liquid products boiling between 380° F. and 680° F. and fuel oil is defined as organic liquid products boiling above 680° F. Selectivity to a product was defined as the fraction of feed converted to that product divided by the total feed conversion. Yield was defined as the mass of product formed divided by the sum of the mass of liquid feed excluding water
In this invention, a mixture of alcohols, diols, glycols, or polyols are fed to a supported metal catalyst at a temperature of at least 518° F. and a pressure of at least 1200 psi, where the alcohols, diols, glycols, or polyols have a molecular formula of CxHyOz, where x varies between 1 and 4 and z varies between 1 and 4. An oxygenated mixture is produced containing molecules of the formula CxHyOz, where x varies between 1 and 100. This mixture may then be deoxygenated using a hydrotreating catalyst under typical hydrotreating conditions to produce a product that includes gasoline, diesel, and gas oil range components.
The following examples of certain embodiments of the invention are given. Each example is provided by way of explanation of the invention, one of many embodiments of the invention, and the following examples should not be read to limit, or define, the scope of the invention.
A mixture of water and a biomass derived feed consisting of 24.5 wt % methanol, 2.4 wt % ethanol, 2.0 wt % 2-propanol, 0.3 wt % 1-propanol, and 0.6 wt % other alcohols in water was fed to a bed of catalyst containing 0.7 wt % Pd and 0.7 wt % Pt supported on a mixture of silica and alumina at a weight hourly space velocity of 1.0 per hour. Hydrogen was fed at a gas hourly space velocity of 4.2 per h based on volume. The catalyst bed was maintained at a temperature of 518° F. and a pressure of 1200 psig. Under this condition, all of the methanol and ethanol was converted and a mixture of aqueous phase and gas phase species were formed with yields (by weight) of 28.7% 2-butanone, 0.1% acetone, 0.9% methane, 0.2% ethane, 3.7% propane, 2.7% butane, 0.2% pentane, and 0.3% hexane.
A mixture of water and a biomass derived feed consisting of 37.6% 1,2-propylene glycol and 2.4% butanediol in water was fed to a bed of catalyst containing 0.7 wt % Pd and 0.7 wt % Pt supported on a mixture of silica and alumina at a weight hourly space velocity of 1.0 per hour. Hydrogen was fed at a gas hourly space velocity of 4.2 per hour based on volume. The catalyst bed was maintained at a temperature of 518° F. and a pressure of 1200 psig. Under this condition, a mixture of gas phase and organic liquid phase species were produced. An ASTM D2887 simulated distillation curve for the organic liquid product is shown in
A 40 wt % 1,3-propane diol in water solution was fed to a bed of catalyst containing 0.7 wt % Pd and 0.7 wt % Pt supported on silica/alumina at a weight hourly space velocity of 1.0 per hour. Hydrogen was fed to reactor and the catalyst bed was maintained at a temperature of 554° C. and a pressure of 1200 psig. A two phase product with an organic phase on top of a bottom aqueous phase was obtained. An ASTM D2887 simulated distillation curve for the organic phase is shown in
A mixture of 40 wt % glycerol in water was fed to a bed of catalyst containing 0.7 wt % Pd and 0.7 wt % Pt supported on silica/alumina at a weight hourly space velocity of 1.0 per hour. Hydrogen was fed to reactor and the catalyst bed was maintained at a temperature of 590° F. and a pressure of 1200 psig. The product from this operation was directly fed to a reactor containing a sulfided CoMo hydroprocessing catalyst to yield a hydrocarbon with <1 wt % oxygen. An ASTM D2887 simulation distillation boiling point curve for the hydrocarbon product (not shown) indicated that the organic liquid product was made of a mixture of components with carbon numbers ranging approximately from C5 to C29. Nitric oxide ionization spectroscopy evaluation analysis for hydrocarbon types showed that the product consisted of a mixture of different hydrocarbon types with naphthenes making up greater than 50% of the hydrocarbon components.
In closing, it should be noted that the discussion of any reference is not an admission that it is prior art to the present invention, especially any reference that may have a publication date after the priority date of this application. At the same time, each and every claim below is hereby incorporated into this detailed description or specification as additional embodiments of the present invention.
Although the systems and processes described herein have been described in detail, it should be understood that various changes, substitutions, and alterations can be made without departing from the spirit and scope of the invention as defined by the following claims. Those skilled in the art may be able to study the preferred embodiments and identify other ways to practice the invention that are not exactly as described herein. It is the intent of the inventors that variations and equivalents of the invention are within the scope of the claims while the description, abstract and drawings are not to be used to limit the scope of the invention. The invention is specifically intended to be as broad as the claims below and their equivalents.
All of the references cited herein are expressly incorporated by reference. The discussion of any reference is not an admission that it is prior art to the present invention, especially any reference that may have a publication data after the priority date of this application. Incorporated references are listed again here for convenience:
This application is a non-provisional application that claims benefit under 35 USC §119(e) to U.S. Provisional Application Ser. No. 62/064,768 filed Oct. 16, 2014 titled “Upgrading Alcohols, Diols And Glycols to Larger Products”, which is incorporated herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62064768 | Oct 2014 | US |
