Abstract:
PROBLEM TO BE SOLVED: To provide a method in which a solvent can be effectively separated from a hydrogenation carry-out object that is obtained from catalytic hydrogenation and includes a water soluble hydrogenation product material, and that includes the solvent.SOLUTION: A method for separating a solvent from a hydrogenation carry-out object including a solvent is characterized in that the hydrogenation carry-out object is added with water, a phase that includes the solvent is separated and is returned to hydrogenation, in a method for separating the solvent from the hydrogenation carry-out object that includes a water soluble hydrogenation product material that has at least one alcohol, lactone, ether, lactam or an amino group in the solvent that cannot be mixed with water or cannot be mixed with water completely and has a boiling point of lower than 100°C, and that includes the solvent generated from a catalytic hydrogenation method.
Abstract:
PROCESSES FOR DECREASING FUMARIC ACID DEPOSITS IN PREPARING MALEIC ANHYDRIDE BY HETEROGENEOUSLY CATALYZED OXIDATION OF A HYDROCARBON WITH MOLECULAR OXYGEN. MALEIC ANHYDRIDE IS ABSORBED FROM THE CRUDE MIXTURE IN AN ABSORBENT IN AN ABSORPTION COLUMN AND DESORBED IN A DESORPTION COLUMN, THE ENTIRETY OR PORTION OF ABSORBENT DEPLETED IN MALEIC ANHYDRIDE, FOR CONTROLLED PRECIPITATION OF FUMARIC ACID, BEING COOLED AND/OR CONCENTRATED BY EVAPORATING A PORTION OF ABSORBENT SUCH THAT THE DIFFERENCE BETWEEN THE CONCENTRATION OF FUMARIC ACID IN THE RECYCLE STREAM AT THE OUTLET OF THE DESORPTION COLUMN UNDER EXISTING CONDITIONS AND THE EQUILIBRIUM CONCENTRATION OF FUMARIC ACID ACCORDING TO THE SOLUBILITY CURVE AFTER COOLING AND/OR EVAPORATION OF A PORTION OF ABSORBENT IS ?25O PPM BY WEIGHT, AND THE FUMARIC ACID PRECIPITATED AS A SOLID IS REMOVED COMPLETELY OR PARTLY FROM THE ABSORBENT RECYCLING SYSTEM AND THE FUMARIC ACID-DEPLETED ABSORBENT IS RECYCLED COMPLETELY OR PARTLY TO THE ABSORPTION COLUMN. (FIGURE 1)