Catalytic conversion of cellulose to liquid hydrocarbon fuels by progressive removal of oxygen to facilitate separation processes and achieve high selectivities
Described is a method to make liquid chemicals, such as functional intermediates, solvents, and liquid fuels from biomass-derived cellulose. The method is cascading; the product stream from an upstream reaction can be used as the feedstock in the next downstream reaction. The method includes the steps of deconstructing cellulose to yield a product mixture comprising levulinic acid and formic acid, converting the levulinic acid to γ-valerolactone, and converting the γ-valerolactone to pentanoic acid. Alternatively, the γ-valerolactone can be converted to a mixture of n-butenes. The pentanoic acid so formed can be further reacted to yield a host of valuable products. For example, the pentanoic acid can be decarboxylated yield 1-butene or ketonized to yield 5-nonanone. The 5-nonanone can be hydrodeoxygenated to yield nonane, or 5-nonanone can be reduced to yield 5-nonanol. The 5-nonanol can be dehydrated to yield nonene, which can be dimerized to yield a mixture of C 9 and C 18 olefins, which can be hydrogenated to yield a mixture of alkanes. Alternatively, the nonene may be isomerized to yield a mixture of branched olefins, which can be hydrogenated to yield a mixture of branched alkanes. The mixture of n-butenes formed from γ-valerolactone can also be subjected to isomerization and oligomerization to yield olefins in the gasoline, jet and Diesel fuel ranges.
1. A method for converting glucose to n-butenes the method comprising:
(a) hydrolyzing glucose derived from any source in an aqueous, acid-catalyzed reaction to yield a product mixture comprising levulinic acid and formic acid; then
(b) converting at least a portion of the formic acid present in the product mixture to H 2 and CO 2 without separating the levulinic acid and formic acid present in the product mixture; and
(c) reducing at least a portion of the levulinic acid present in the product mixture to γ-valerolactone using the H 2 produced in step (b); and then
(d) decarboxylating at least a portion of the γ-valerolactone from step (c) by contacting it with a solid acid catalyst, to yield a product mixture comprising n-butenes.
2. The method of claim 1 , wherein step (d) comprises decarboxylating the γ-valerolactone by reacting it with a mineral acid selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, boric acid, hydrofluoric acid, hydrobromic acid, acetic acid, acetic anhydride, oxalic acid, and combinations thereof.
3. The method of claim 1 , wherein step (d) comprises decarboxylating the γ-valerolactone by reacting it with a heterogeneous catalyst comprising a metal selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Ag, Au, Ru and combinations thereof.
4. The method of claim 1 , wherein step (a) comprises hydrolyzing the glucose by reacting it with an acid.
5. The method of claim 4 , wherein step (a) comprises hydrolyzing the glucose by reacting it with a mineral acid selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, boric acid, hydrofluoric acid, hydrobromic acid, oxalic acid, acetic acid, acetic anhydride, and combinations thereof.
6. The method of claim 1 , wherein step (b) comprises converting the converting the formic acid present in the product mixture to H 2 and CO 2 by contacting the product mixture with a heterogeneous catalyst comprising a metal selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Ag, Au, and combinations thereof.
7. The method of claim 6 , wherein step (b) comprises contacting the product mixture with a heterogeneous catalyst comprising Ru.
8. The method of claim 1 , wherein step (c) further comprises extracting the γ-valerolactone so formed into a solvent comprising a polar, aprotic solvent.
9. The method of claim 1 , wherein step (c) further comprises evaporating the γ-valerolactone so formed.