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US 8,138,371 B2Granted
Production of formic acid
AssigneeBiofine Technologies LLC
InventorStephen W. Fitzpatrick
Life of this patent
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Abstract
Processes for producing formic acid from a carbohydrate-containing material include hydrolyzing a carbohydrate-containing material (e.g., cellulose) in the presence of a mineral acid to form an intermediate hydrolysate comprising one or more sugars, and hydrolyzing the intermediate hydrolysate to form a hydrolysate product including formic acid.
Claims29
A process for producing formic acid from a carbohydrate-containing material, the process comprising:
- introducing a carbohydrate-containing material to a first reactor;
- hydrolyzing the carbohydrate-containing material in the first reactor in the presence of a mineral acid for a first time period at a first temperature and a first pressure effective to form an intermediate hydrolysate comprising one or more sugars, wherein the mineral acid concentration is about 1 to 10% wt of the contents of the first reactor;
- transferring the intermediate hydrolysate from the first reactor to a second reactor;
- hydrolyzing the intermediate hydrolysate in the second reactor for a second time period at a second temperature less than 195 degrees C. and a second pressure effective to form a hydrolysate product comprising formic acid and levulinic acid;
- and
- isolating the formic acid in a vapor from the hydrolysate product, wherein the formic acid is produced in an amount that provides a molar ratio of the levulinic acid to the formic acid of at least 0.9.
3 more elements
A continuous process for producing formic acid from a carbohydrate-containing material using a first reactor and a second reactor, the process comprising
- continuously supplying the carbohydrate-containing material into the first reactor;
- hydrolyzing the carbohydrate-containing material in the first reactor in the presence of a mineral acid in the first reactor for a first time period of 10 to 60 seconds, at a first temperature of 195 to 235 degrees C. and a first pressure effective to hydrolyze at least a portion of the carbohydrate-containing material to form an intermediate hydrolysate comprising one or more sugars, wherein the mineral acid concentration is about 1 to 10% wt of the contents of the first reactor;
- continuously transferring the intermediate hydrolysate from the first reactor to a second reactor;
- hydrolyzing the intermediate hydrolysate in the second reactor for a second time period that is greater than the first time period, at a second temperature of 170 to less than 195 degrees C. and a second pressure to form a hydrolysate product comprising formic acid and levulinic acid in the second reactor, wherein the second temperature and the second pressure are selected to maintain the intermediate hydrolysate as a liquid in the second reactor;
- and
- continuously removing the formic acid in a vapor from the second reactor in an amount that provides a molar ratio of the levulinic acid to the formic acid of at least 0.8.
3 more elements
A process for producing formic acid from a carbohydrate-containing material, the process comprising:
- introducing a carbohydrate-containing material to a first reactor;
- hydrolyzing the carbohydrate-containing material in the first reactor in the presence of a mineral acid in an amount of 3.0 to 4.5% wt of the of the contents of the first reactor in the first reactor for a first time period at a first temperature and a first pressure effective to form an intermediate hydrolysate comprising one or more sugars;
- transferring the intermediate hydrolysate from the first reactor to a second reactor;
- hydrolyzing the intermediate hydrolysate in the second reactor for a second time period at a second temperature of 150 to less than 195 degrees and a second pressure effective to form a hydrolysate product comprising formic acid and levulinic acid;
- and
- isolating the formic acid in a vapor from the hydrolysate product, wherein the formic acid is isolated in an amount that provides a molar ratio of the levulinic acid to the formic acid of at least 0.9.
3 more elements
A continuous process for producing formic acid from a carbohydrate-containing material using a first reactor and a second reactor, the process comprising
- continuously supplying a cellulose-containing material into a first reactor;
- hydrolyzing the material in the first reactor in the presence of a mineral acid in an amount of 2 to 5% wt of the cellulose-containing material in the first reactor for a first time period of 10 to 60 seconds, at a first temperature of 195 to 235 degrees C. and at a first pressure effective to maintain the contents of the first reactor in the liquid phase and to hydrolyze at least a portion of the carbohydrate-containing material to form an intermediate hydrolysate comprising one or more sugars and hydroxymethylfurfural;
- continuously transferring the intermediate hydrolysate from the first reactor to a second reactor;
- hydrolyzing the intermediate hydrolysate in the second reactor for a second time period of 10 to 60 minutes, at a second temperature of 150 to less than 195 degrees C. and a second pressure to form a hydrolysate product comprising formic acid and levulinic acid in the second reactor;
- wherein the second temperature and the second pressure are selected to maintain the intermediate hydrolysate as a liquid at saturated conditions in the second reactor and the second pressure is less than the first pressure;
- and
- continuously removing the formic acid from the second reactor in a vapor;
- and
- condensing the formic acid from the vapor, wherein the formic acid is obtained in an amount that provides a molar ratio of the levulinic acid to the formic acid of at least 0.9.
6 more elements
Dependencies are inferred from the claim text.