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US 2022/0089515 A1Published application
Continuous processes for the selective conversion of aldohexose-yielding carbohydrate to ethylene glycol using low concentrations of retro-aldol catalyst
AssigneeIowa Corn Promotion Board
InventorsDavid James Schreck, Mark Nunley, Donald Bunning, Brooke Albin, Louis A. Kapicak, Michael Bradford
Life of this patent
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Abstract
Retro-aldol processes are disclosed that use very low concentrations of retro-aldol catalyst in combination with hydrogenation catalyst of certain activities, sizes and spatial dispersions to obtain the high selectivities to ethylene glycol.
Claims27
A continuous, catalytic process for producing ethylene glycol from an aldose-yielding carbohydrate-containing feed, comprising:
- (a) continuously or intermittently supplying the feed to a reaction zone containing a liquid medium having therein heterogeneous, nickel-containing hydrogenation catalyst, wherein the feed is supplied at a rate of at least about 50 grams per hour of carbohydrate per liter of liquid medium, and wherein said liquid medium is at catalytic conversion conditions including the presence of dissolved hydrogen, a temperature of at least about 235° C., a pH greater than 3 and a residence time sufficient to react at least 99 mass percent of the aldose-yielding carbohydrate, wherein:
- (i) the heterogeneous hydrogenation catalyst has a maximum particle dimension of less than about 100 microns, and
- (ii) the hydrogenation catalyst is dispersed in the liquid medium in an amount of less than about 100 grams per liter thereby providing a spatial relationship among catalytically active hydrogenation sites in the liquid medium;
- (b) continuously or intermittently supplying to the reaction zone homogeneous, tungsten-containing retro-aldol catalyst the concentration of solubilized tungsten compounds, calculated as tungsten atoms, in the liquid medium in the reactor is between about 200 and 1500 milligrams per liter, wherein the relative amounts of hydrogenation catalyst and retro-aldol catalyst are sufficient to provide, under the catalytic conversion conditions, a cumulative conversion efficiency of the aldose-containing carbohydrate to ethylene glycol of at least 75 percent for a duration of 100 hours;
- and
- (c) continuously or intermittently withdrawing from the reaction zone a raw product stream containing ethylene glycol
- wherein the feed comprises carbohydrate and a portion of the liquid medium from the reaction zone that has an absence of hydrogenation catalyst.
4 more elements
A continuous, catalytic process for producing ethylene glycol from an aldose-yielding carbohydrate-containing feed, comprising:
- (a) continuously or intermittently supplying the feed to a premixing zone in the presence of tungsten-containing retro-aldol catalyst and thereafter to a reaction zone containing a liquid medium having therein heterogeneous, nickel-containing hydrogenation catalyst, wherein the feed is supplied at a rate of at least about 50 grams per hour of carbohydrate per liter of liquid medium, and wherein said liquid medium is at catalytic conversion conditions including the presence of dissolved hydrogen, a temperature of at least about 235° C., a pH between 3.8 and 8 and a residence time sufficient to react at least 99 mass percent of the aldose-yielding carbohydrate, wherein:
- (i) the heterogeneous hydrogenation catalyst has a maximum particle dimension of less than about 100 microns, and
- (ii) the hydrogenation catalyst is dispersed in the liquid medium in an amount of less than about 100 grams per liter thereby providing a spatial relationship among catalytically active hydrogenation sites in the liquid medium;
- (b) continuously or intermittently supplying to the reaction zone homogeneous, tungsten-containing retro-aldol catalyst the concentration of solubilized tungsten compounds, calculated as tungsten atoms, in the liquid medium in the reactor is between about 200 and 1500 milligrams per liter, wherein the relative amounts of hydrogenation catalyst and retro-aldol catalyst are sufficient to provide, under the catalytic conversion conditions, a cumulative conversion efficiency of the aldose-containing carbohydrate to ethylene glycol of at least 75 percent for a duration of 100 hours;
- and
- (c) continuously or intermittently withdrawing from the reaction zone a raw product stream containing ethylene glycol.
3 more elements
A continuous, catalytic process for producing ethylene glycol from an aldose-yielding carbohydrate-containing feed, comprising:
- (a) continuously or intermittently supplying the feed to a reaction zone containing a liquid medium having therein heterogeneous, nickel-containing hydrogenation catalyst, wherein the feed is supplied at a rate of at least about 50 grams per hour of carbohydrate per liter of liquid medium, and wherein said liquid medium is at catalytic conversion conditions including the presence of dissolved hydrogen, a temperature of at least about 235° C., a pH greater than 3 and a residence time sufficient to react at least 99 mass percent of the aldose-yielding carbohydrate, wherein:
- (i) the heterogeneous hydrogenation catalyst has a maximum particle dimension of less than about 100 microns, and
- (ii) the hydrogenation catalyst is dispersed in the liquid medium in an amount of less than about 100 grams per liter thereby providing a spatial relationship among catalytically active hydrogenation sites in the liquid medium;
- (b) continuously or intermittently supplying to the reaction zone homogeneous, tungsten-containing retro-aldol catalyst the concentration of solubilized tungsten compounds, calculated as tungsten atoms, in the liquid medium in the reactor is between about 200 and 1500 milligrams per liter, wherein the relative amounts of hydrogenation catalyst and retro-aldol catalyst are sufficient to provide, under the catalytic conversion conditions, a cumulative conversion efficiency of the aldose-containing carbohydrate to ethylene glycol of at least 75 percent for a duration of 100 hours;
- and
- (c) continuously or intermittently withdrawing from the reaction zone a raw product stream containing ethylene glycol
- wherein the temperature is adjusted to balance the retro-aldol conversion and hydrogenation conversion.
4 more elements
Dependencies are inferred from the claim text.