Abstract:
PROBLEM TO BE SOLVED: To provide an improved method for producing an alkylaromatic compound that results in lower levels of a residual unreacted aromatic compound and an alkylating agent in the final product.SOLUTION: This method of production includes: (1) a process of alkylating the aromatic compound by using the alkylating agent and a catalyst to produce an effluent stream containing the alkylaromatic compound and unreacted materials; (2) a process of heating the effluent stream; (3) a process of stripping the effluent stream in a stripping device in the presence of steam; (4) a process of separating a stripping stream from the stripping device (the stripping stream is rich in the unreacted materials); and (5) a process of separating a product stream from the stripping device (the product stream is rich in the alkylaromatic compound).
Abstract:
Disclosed are a process and an apparatus for synthesizing nitroalkanes by reaction of a hydrocarbon feedstock with aqueous nitric acid. Energy and capital costs may be reduced by recycling a majority of the aqueous phase back to the reactor.
Abstract:
A process is proposed for distillatively removing dinitrotoluene from process wastewater from the preparation of dinitrotoluene by nitrating toluene with nitrating acid, which comprises basifying the process wastewater to a pH of >8.5, feeding it to a stripping column in the upper region thereof and stripping it with steam in countercurrent to obtain a vapor stream laden with dinitrotoluene and a bottom stream depleted in dinitrotoluene compared to the process wastewater used.
Abstract:
Alkaline waste waters containing 100-3000 ppm benzene and 1000-10000 ppm nitrobenzene is treated by separating undissolved benzene and/or nitrobenzene from the alkaline waste water; optionally, stripping residual benzene and/or nitrobenzene from the alkaline waste water; and heating the alkaline waste water from 150-500[deg]C under pressure in the absence of oxygen.
Abstract:
A method for stabilizing nitro compounds against discoloration. The method comprises reacting nitro compounds containing color-forming impurities with nitric acid, neutralizing and washing the product, and distilling therefrom purified nitro compounds.
Abstract:
PROBLEM TO BE SOLVED: To provide a method for excluding and regenerating nitric acid, particularly sulfuric acid, nitric acid and nitrogen oxide from a nitration process and to provide a plant for practicing the method. SOLUTION: In the method for excluding and regenerating a mixed acid mixture, particularly nitric acid, sulfuric acid and nitrogen oxide from a nitrated raw material product produced in nitration of an aromatic nitro compound after a mixed acid was excluded by a plurality of extraction processes, these extraction processes are each composed of at least two steps and either one step is practiced by an alternating current method and the other step is practices by a countercurrent extraction method. The production plant uses the above method. COPYRIGHT: (C)2007,JPO&INPIT