Methods for producing mesoporous zeolite multifunctional catalysts for upgrading pyrolysis oil
A method of making a multifunctional catalyst for upgrading pyrolysis oil includes contacting a hierarchical mesoporous zeolite support with a solution including at least a first metal catalyst precursor and a second metal catalyst precursor, each or both of which may include a heteropolyacid. The hierarchical mesoporous zeolite support may have an average pore size of from 2 nm to 40 nm. Contacting the hierarchical mesoporous zeolite support with the solution deposits or adsorbs the first metal catalyst precursor and the second catalyst precursor onto outer surfaces and pore surfaces of the hierarchical mesoporous zeolite support to produce a multifunctional catalyst precursor. The method further includes removing excess solution and calcining the multifunctional catalyst precursor to produce the multifunctional catalyst comprising at least a first metal catalyst and a second metal catalyst deposited on the outer surfaces and pore surfaces of the hierarchical mesoporous zeolite support.
1. A method for upgrading pyrolysis oil, the method comprising:
contacting the pyrolysis oil with a multifunctional catalyst at mild reaction conditions comprising reaction temperatures of less than 500 degrees Celsius (° C.) and pressures less than 6 megapascals (MPa);
where the pyrolysis oil comprises multi-ring aromatic compounds and the multifunctional catalyst is produced by a process comprising:
contacting a hierarchical mesoporous zeolite support with a solution comprising at least a first metal catalyst precursor and a second metal catalyst precursor, where:
the hierarchical mesoporous zeolite support has an average pore size of from 2 nanometers to 40 nanometers as determined by Barrett-Joyner-Halenda (BJH) analysis;
the first metal catalyst precursor, the second metal catalyst precursor, or both, comprises a heteropolyacid; and
the contacting deposits the first metal catalyst precursor and the second metal catalyst precursor onto outer surfaces and pore surfaces of the hierarchical mesoporous zeolite support to produce a multifunctional catalyst precursor;
removing excess solution from the multifunctional catalyst precursor; and
calcining the multifunctional catalyst precursor to produce the multifunctional catalyst, where the multifunctional catalyst comprises at least a first metal catalyst and a second metal catalyst supported on the zeolite support; and
where contact of the pyrolysis oil with the multifunctional catalyst at the reaction conditions converts at least a portion of the multi-ring aromatic compounds in the pyrolysis oil to one or more C 6 -C 8 aromatic compounds.
2. The method of claim 1 , in which the C 6 -C 8 aromatic compounds include one or more of benzene, toluene, ethylbenzene, xylene, or combinations of these.
3. The method of claim 1 , in which contacting the pyrolysis oil with the multifunctional catalyst at the reaction conditions converts the portion of the multi-ring aromatic compounds in the pyrolysis oil to C 6 -C 8 aromatic compounds in a single step, without conducting a subsequent chemical reaction step.
4. The method of claim 1 , in which the pyrolysis oil is contacted with the multifunctional catalyst at a temperature of from 380° C. to 400° C.
5. The method of claim 1 , in which the pyrolysis oil is contacted with the multifunctional catalyst at a pressure less than or equal to 5 megapascals.