Biomass conversion process to hydrocarbons
A process for the production of a higher hydrocarbon useful as gasoline component from solid biomass is provided. The process provides for longer ZSM-5 condensation catalyst life by contacting the stable oxygenated hydrocarbon intermediate containing diols produced from digestion and hydrodoxygenation of the solid biomass to an amorphous silica alumina catalyst to reduce the diols content, and optionally removing water, prior to contacting with the ZSM-5 condensation catalyst.
1. A process for the production of a higher hydrocarbon from solid biomass, said process comprising:
a. providing a biomass solid containing cellulose, hemicellulose, and lignin;
b. digesting and hydrodeoxygenating the biomass solid in a liquid digestive solvent in the presence of a hydrothermal hydrocatalytic catalyst and hydrogen at a temperature in a range of 110° C. to less than 300° C. and at a pressure in a range of from 20 bar to 200 bar, said liquid digestive solvent containing a solvent mixture having a boiling point of at least 40° C., to form a stable oxygenated hydrocarbon intermediate product having a viscosity of less than 100 centipoise (at 50° C.), a diol content of at least 2 wt %, less than 2 wt % of sugar, and less than 2 wt % acid (acetic acid equivalent), based on the stable oxygenated hydrocarbon intermediate product, and at least 60% of carbon exists in molecules having 9 carbon atoms or less;
c. reacting at least a portion of the stable oxygenated hydrocarbon intermediate product with an acidic amorphous silica alumina catalyst at a temperature in a range from 300° C. to 400° C. to convert diol in the stable oxygenated hydrocarbon intermediate product into monooxygenates compounds thereby producing a monooxygenated stream containing water and organic monooxygenates having a boiling point of at least 40° C.;
d. optionally condensing the monooxygenated stream to an aqueous phase and an organic liquid phase; and
e. contacting the organic monooxygenates having boiling point of at least 40° C. in the monooxygenated stream obtained from the step c or the step d with an acidic ZSM-5 catalyst at a temperature in a range from 325° C. to about 425° C. thereby producing water and an aromatics-rich higher hydrocarbons stream having at least 50 wt % of aromatics containing hydrocarbon based on the aromatics-rich hydrocarbons stream.
2. The process of claim 1 wherein water is removed from the monooxygenated stream to produce an organic liquid phase.
3. The process of claim 2 wherein at least a portion of the organic liquid phase is provided to the step b as a portion of the liquid digestive solvent.
4. The process of claim 1 wherein the step b is carried out at a temperature in a range of from 150° C. to 300° C.
5. The process of claim 1 wherein the acidic amorphous silica alumina catalyst has a BET surface area of greater than 200 m 2 /g.
6. The process of claim 1 wherein the hydrothermal hydrocatalytic catalyst is a heterogeneous catalyst.
7. The process of claim 1 wherein the solid biomass is a lignocellulosic biomass.
8. The process of claim 1 wherein a yield of aromatics-rich hydrocarbons stream in the step e is greater than 40% of carbons based on the biomass solid carbons.
9. The process of claim 1 wherein a fraction of diol converted in the step c is at least 25%.
10. The process of claim 9 wherein the fraction of diol converted in the step c is at least 50%.
11. The process of claim 10 wherein the fraction of diol converted in the step c is at least 75%.
12. The process of claim 1 wherein a reaction pressure in the step c is within a range of from atmospheric pressure to about 200 psi.