Abstract: Mixtures of m- and p-dichlorobenzene can be separated by treating such mixtures in the liquid phase with a pentasil zeolite at from 20.degree. to 250.degree. C., a filtrate enriched in m-dichlorobenzene being removed and the p-dichlorobenzene being obtained by desorption of the pentasil zeolite. The pentasil zeolites may contain, as exchangeable cations, protons, cations of the first or second main group of the Mendeleev Periodic System, cations of the rare earth metals or a mixture of a plurality thereof. In order to prepare the liquid phase a solvent is used that belongs to the group of cyclic saturated hydrocarbons having 5 to 15 carbon atoms, alkyl-substituted aromatic hydrocarbons having 8 to 12 carbon atoms, and halogen-substituted aromatic hydrocarbons having 6 to 10 carbon atoms and 1 to 3 halogen atoms. The solvents ethylbenzene, chlorobenzene, p-xylene, p-chlorotoluene and dichlorobenzene are excepted. A mixture of a plurality of these solvents may also be used.

Abstract: Dialkyl carbonates can be prepared by the reaction of carbon monoxide with alkyl nitrites in a continuous gas phase reaction, using a platinum group metal catalyst on an alumosilicate zeolite having acidic centers, preferably in the H.sup.+ form, as a support, which catalyst may optionally comprise additional material of a compound of antimony, bismuth, aluminum, copper, vanadium, niobium, tantalum, tin, iron, cobalt, nickel or a mixture of a plurality of these, and hydrogen halide being added in the course of the reaction intermittently or continuously. In this reaction, the dialkyl carbonates are formed with almost quantitative selectivity; the corresponding dialkyl oxalates cannot be detected in most cases.

Abstract: Substituted lactams of the formula ##STR1## can be prepared from lactam N-carboxylates or lactim O-carboxylates of the formulae ##STR2## by thermal or mixed thermal and catalysed CO.sub.2 elimination at 80.degree.-450.degree. C. Lactams substituted on the N atom by aliphatic groups such as those produced herein are useful as industrial aprotic solvents.

Abstract: Dialkyl carbonates can be prepared by the reaction of carbon monoxide with alkyl nitrites in a continuous gas phase reaction, using a platinum metal catalyst on an amorphous alumosilicate having a content of 30-80 atom% Al, based on the sum of Al and Si, as a support, which catalyst may optionally comprise additional material of a compound of antimony, bismuth, aluminium, copper, vanadium, niobium, tantalum, tin, iron, cobalt, nickel or a mixture of a plurality of these, and hydrogen halide being added in the course of the reaction intermittently or continuously. In this reaction, the dialkyl carbonates are formed with almost quantitative selectivity; the corresponding dialkyl oxalates cannot be detected in most cases.

Abstract: A process for the production of silica-bound zeolite granulates is disclosed, wherein zeolite to be formed into a granulate is mixed with silica sol. The process is carried out by adding aqueous alkali metal silicate to the silica sol immediately before the silica sol is mixed with the solid zeolite to be granulated. By the described process, granulates of various grain sizes can be obtained, and the resultant granulates can have a narrow grain size distribution.

Abstract: N,N-dialkylanilines can be prepared by reacting the anilines on which they are based with lower alcohols or with the corresponding ethers, at an increased temperature in the gas phase in the presence of a proton-containing zeolite catalyst of the pentasil type having an SiO.sub.2 /Al.sub.2 O.sub.3 ratio of >60, it being advantageous to carry out the alkylation process under a pressure of 2-30 bar.

Abstract: A process for the reduction of nitrogen oxides in flue gases and engine exhaust gases is improved by contacting the gases with a zeolite catalyst containing oxides of the transition elements from Periods 4, 5 and 6 of the Periodic Table of Elements or oxides of the rare earths. In particular, faujasite zeolites, mordenites and SiO.sub.2 -rich zeolites are preferred.

Abstract: A process for the rapid and effective removal of iodine, organic iodine compounds with a small number of carbon atoms or mixture thereof from gases and/or vapors, comprising passing said gas or vapor through an adsorbent bed containing a silver-lead-exchanged zeolite X.

Abstract: Para-substituted o-benzylphenols are prepared by reacting p-substituted phenols with benzylating agents in the presence of zeolites of the faujasite type at elevated temperature.

Abstract: N-alkylated anilines can be prepared by reaction of anilines with lower alcohols or dialkyl ethers at elevated temperature and in the presence of zeolite catalysts of the pentasil type containing protons and having an SiO.sub.2 /Al.sub.2 O.sub.3 ratio of at least 60.

Abstract: Anilines or N-alkyl-anilines are advantageously reacted with alkyl alcohols or the associated dialkyl ethers at elevated temperature in the gas phase, if a .gamma.-Al.sub.2 O.sub.3 is used that is prepared by dehydration of an aluminum oxide/hydroxide hydrate and has a BET surface area from 50 to 400 m.sup.2 /g and a surface acidity of 5 to 600 mmol H.sup.+ /kg.

Abstract: p-Chlorotoluene can be prepared in an improved manner by catalyzed reaction of toluene with a chlorinating agent if a zeolite L containing metal cations is employed as the catalyst and the reaction is carried out in the presence of methylene chloride and/or chloroform.

Abstract: Oligophenyls dihalogenated in the 4,4'-position, of the formula ##STR1## can be prepared by catalyzed halogenation of oligophenyls of the formula ##STR2## wherein, in the formulae, X.sup.1 and X.sup.2 independently of one another represent chlorine or bromine, preferably chlorine,X.sup.3 denotes hydrogen, chlorine or bromine, preferably hydrogen or chlorine and particularly preferably hydrogen,R.sup.1, R.sup.2 and R.sup.3 independently of one another represent hydrogen, C.sub.1 -C.sub.4 -alkyl (preferably methyl or ethyl and particularly preferably methyl), C.sub.1 -C.sub.4 -alkoxy (preferably methoxy or ethoxy and particularly preferably methoxy), fluorine, chlorine or bromine anda assumes the value zero or one,with halogenating agents, the preparation being carried out in the presence of methylene chloride or solvent mixtures essentially containing methylene chloride and in the presence of zeolites of the L structure type which contain metal cations.

Abstract: Thymol can be prepared by reaction of m-cresol with propene at elevated temperature and at atmospheric to superatmospheric pressure by using wide- and medium-pored zeolites which have a pore diameter of at least 5 .ANG. as heterogeneous catalysts.

Abstract: 4-Methyl-2-cyclohexylphenol can be prepared by alkylation of p-cresol with cyclohexanol or cyclohexene by performing the reaction in the liquid phase in the presence of 1-10% by weight, based on the amount of p-cresol, of a large pore, acidic zeolite.

Abstract: Phenylketones etherified in the 4-position can be prepared by reaction of aromatic ethers which have a free 4-position with acylating agents, the acylation being carried out in the presence of zeolite catalysts having pore sizes of at least 5 .ANG..

Abstract: 4,4'-dihalobiphenyls can be prepared by catalyzed halogenation of biphenyls with halogenating agents, the catalysts used being zeolites having pore sizes of at least 5 .ANG..

Abstract: A SiO.sub.2 -bound, substantially carbonate-free, calcium-containing zeolite A granulate in which the calcium content is 0.4 to 1 mole CaO/mole Al.sub.2 O.sub.3 and a process for the production such SiO.sub.2 -bound calcium exchanged zeolite A granulate in a CO.sub.2 -free atmosphere at temperatures of 350.degree. C. to 700.degree. C. The SiO.sub.2 -bound zeolite granulate A being useful as an adsorbent in the recovery of oxygen by the pressure change adsorption process.

Abstract: An improvement in the removal of nitrogen oxides from the exhaust gases of internal combustion engines is achieved by adding urea or a urea-containing reducing agent to the exhaust gases and contacting the gases under oxidizing conditions with a zeolite containing catalyst.

Abstract: N-Alkylanilines can be prepared by reaction of anilines with N,N-dialkylanilines in the gas or liquid phase at elevated temperature by carrying out the reaction in the presence of zeolites.