摘要:
Lactams, in particular ε-caprolactam, are produced by the hydrolytic cyclization of aminonitriles, in particular 6-aminocapronitrile, in the vapor phase in a plurality of adiabatic fixed bed reaction zones arranged in succession wherein at least a portion of the heat of the exothermic reaction is removed between each of the successive reaction zones. Conducting the reaction in such a manner requires less capital for the reactor itself. It has also been found that the product exiting such a reaction system can be directly fed to a distillation unit without the need of additional cooling or storing.
摘要:
The invention relates to the field of production of lactams from aminonitriles, and in particular to the production of ε-caprolactam by the vapor phase hydrolytic cyclization of 6-aminocapronitrile. A crude liquid caprolactam comprising ε-caprolactam (CL), 6-aminocapronitrile (ACN) and water obtained from a vapor phase cyclization reaction of ACN is contacted with hydrogen in the presence of a hydrogenation catalyst to convert the ACN in the crude liquid caprolactam to a product comprising hexamethylenediamine (HMD) and hexamethyleneimine (HMI). Tetrahydroazepine (THA) in the crude liquid caprolactam is converted to HMI during this hydrogenation. The HMD and HMI have lower boiling points compared to ACN and thus they are more easily separated from CL in the subsequent distillation operations. Thus a process to make CL from ACN with fewer distillation stages, and with lower pressure drop and lower base temperature, is accomplished.
摘要:
Method for making caprolactam from 6-aminocapronitrile that contains greater than 500 ppm tetrahydroazepine and its derivatives (THA) in which the THA is not removed from the method until after the caprolactam is produced.
摘要:
Method for making caprolactam from 6-aminocapronitrile that contains greater than 500 ppm tetrahydroazepine and its derivatives (THA) in which ammonia and water are removed from crude caprolactam in a single separation step and then THA is removed from the resulting caprolactam melt.
摘要:
As described herein, nickel treated with sulfur provides a surprisingly effective source of nickel atoms for generating nickel-phosphorus-containing ligand complexes useful as hydrocyanation catalysts.
摘要:
Nickel(II) compositions for use in manufacturing nickel metal (Ni(0)) compositions, and specifically to methods of making basic nickel carbonates used to produce nickel metal compositions are disclosed. By varying the molar ratios of carbonates and bicarbonates to nickel salts, the methods provide basic nickel carbonates that produce superior nickel metal-containing solids that are well-suited to forming nickel-ligand complexes with phosphorus-containing ligands. The phosphorus-containing ligands can be monodentate or bidentate phosphorus-containing ligands.
摘要:
Nickel(II) compositions for use in manufacturing nickel metal (Ni(0)) compositions, and specifically to methods of making basic nickel carbonates used to produce nickel metal compositions are disclosed. By varying the molar ratios of carbonates and bicarbonates to nickel salts, the methods provide basic nickel carbonates that produce superior nickel metal-containing solids that are well-suited to forming nickel-ligand complexes with phosphorus-containing ligands. The phosphorus-containing ligands can be monodentate or bidentate phosphorus-containing ligands.
摘要:
A process for improving the recovery of solid triphenylboron-pyridine compound (TPBP), while retaining desirable particle characteristics comprises the addition of an acid to neutralize at least a portion of the alkali contained in the aqueous mother liquor. By adjusting the pH of the product slurry to between about 8.5 and about 12, it is possible to increase product recovery by more than 10%, while maintaining desirable particle characteristics.
摘要:
The present invention relates to a method of preparing a nickel complex including nickel and at least one phosphorus-containing ligand by reacting at least a portion of a nickel metal with at least one phosphorus-containing ligand. The nickel metal is prepared from a nickel composition including nickel(II).
摘要:
The present invention relates to a method of preparing a nickel complex including nickel and at least one phosphorus-containing ligand by reacting at least a portion of a nickel metal with at least one phosphorus-containing ligand. The nickel metal is prepared from a nickel composition including nickel(II).