DIRECT CONVERSION OF BIOMASS OXYGENATES TO HYDROCARBONS
A single pass direct conversion of biomass derived oxygenates to longer chain hydrocarbons is described. The longer chain hydrocarbons include higher naphthene content which is quite useful in the distillate range fuels or more particularly, the jet and diesel range fuels. Naphthenes help the biomass derived hydrocarbons meet product specifications for jet and diesel while really helping cold flow properties.
1 . A process for producing longer carbon chain hydrocarbon products from shorter carbon chain oxygenate material, wherein the process comprises:
contacting hydrogen and the oxygenate material with a hydrocondensation catalyst which catalyzes the formation of carbon-carbon bonds in the presence of hydrogen to form longer chain hydrocarbon products.
2 . The process according to claim 1 wherein the oxygenate material is derived at least in part from biomass.
3 . The process according to claim 1 wherein the oxygenate material is provided in an aqueous solution and the only feedstocks to the process are aqueous and gas.
4 . The process according to claim 1 wherein the oxygenate material has an oxygen to carbon ratio of at least 0.6 to one.
5 . The process according to claim 1 wherein the oxygenate material includes at least one of: sugar alcohols, sugars, sugar derivatives, hydrogenated sugars, hydrogenated sugar derivatives, glycerol, tetrahydrofurfuryl alcohol, isosorbide, sorbitans, and C3 to C6 polyols and any combination thereof.
6 . The process according to claim 1 wherein the oxygenate material contacts the hydrocondensation catalyst at elevated temperature and elevated pressure and the hydrocarbon products include normal paraffins, iso-paraffins and naphthenes.
7 . The process according to claim 1 wherein the longer chain hydrocarbon products include some oxygenates and wherein the process further includes the step of contacting hydrogen and the longer chain hydrocarbon products with a hydrodeoxygenation catalyst which catalyzes the removal of oxygen from the longer chain hydrocarbon products.
8 . The process according to claim 7 wherein the step of contacting the oxygenate materials with the hydrocondensation catalyst occurs in a first reactor vessel and the step of contacting the longer chain hydrocarbon products with the hydrodeoxygenation catalyst occurs in a second reactor vessel.
9 . The process according to claim 7 wherein the step of contacting the oxygenate materials with the hydrocondensation catalyst occurs in a reactor vessel and the step of contacting the longer chain hydrocarbon products with the hydrodeoxygenation catalyst occurs in the same reactor vessel.
10 . The process according to claim 7 further including the steps of phase separating the organic phase from the aqueous phase and fractionating the organic phase containing most of the deoxygenated longer chain hydrocarbon products into various distillation fractions.
11 . The process according to claim 1 wherein the step of contacting the oxygenate material to the hydrocondensation catalyst produces longer chain hydrocarbon products comprising at least ten weight percent naphthenes.
12 . The process according to claim 1 wherein the step of contacting the oxygenate material to the hydrocondensation catalyst produces longer chain hydrocarbon products comprising at least 15 percent naphthenes.
13 . The process to claim 1 wherein the catalyst comprises metallic and/or acidic catalyst sites.
14 . The process according to claim 1 wherein the catalyst comprises a supported noble metal.
15 . The process according to claim 1 wherein the catalyst comprises a supported base metal selected from the group including Ni, Mo, W, Co and combinations thereof.
16 . The process according to claim 1 wherein the catalyst further comprises Pt and/or Pd on a support comprising silica and/or alumina.
17 . The process according to claim 1 wherein the step of contacting the oxygenate material with a hydrocondensation catalyst comprises contacting the oxygenate material with the hydrocondensation catalyst at a temperature of between 250 to 400° C. at a pressure of between 1000 and 2000 psig where the oxygenate material progresses at a weight hourly space velocity of between 0.4 and 5.0 h −1 .
18 . A system to convert biomass oxygenates to renewable C5-C25 hydrocarbons comprising:
a. an oxygenate feedstock derived at least in part from biomass and comprising one or more polyols, sugars, or carbohydrates in an aqueous solution;
b. a hydrogen feed;
c. a hydrocondensation reactor including a hydrocondensation catalyst for converting the oxygenate feedstock into longer chain hydrocarbons; and
d. a distillation column for separating the renewable hydrocarbons into product streams comprising C5-C25 range hydrocarbons comprising renewable naphtha, renewable gas oil, and at least one distillate range renewable fuel.
19 . The system according to claim 18 further including a phase separator for separating an organic phase including the hydrocarbons from an aqueous phase.
20 . The systems according to claim 18 further including a hydrodeoxygenation reactor including hydrodeoxygenation catalyst for removing residual oxygen from the hydrocarbons from in the hydrocondensation reactor and arranged upstream of the distillation column.