摘要:
The present invention relates to a process for the continuous isothermal preparation of mononitrotoluenes with concentration of the resultant waste sulfuric acid and recycling of the concentrated waste sulfuric acid to the process.
摘要:
The present invention relates to a continuous isothermal process for preparing mononitrotoluenes in the presence of a mixed acid component comprising mixtures of sulfuric acid and phosphoric acid with concentration of the resultant waste acid and recycling of the concentrated waste acid to the process.
摘要:
The present invention relates to a continuous adiabatic process for preparing nitrochlorobenzene in the presence of phosphoric acid. The waste acid produced during the practice of the process is reconcentrated and recycled into the nitration reaction.
摘要:
The present invention relates to a continuous adiabatic process for preparing nitrochlorobenzene, in which the waste sulfuric acid produced during the practice of the process is reconcentrated and recycled into the nitration reaction.
摘要:
1,2-Dichlorobenzene can be reacted very selectively under adiabatic reaction conditions to give 3,4-dichloronitrobenzene by intensively mixing 1,2-dichlorobenzene with nitric acid, sulphuric acid and water, simultaneously or successively, in their total amount, using a mixing energy of 1-50 watts per litre of the total reaction mixture, preferably 3-30 W/l, and maintaining a temperature of from 0 to 60° C. during mixing.
摘要:
Corrosion inhibitor and method of protecting metallic materials in strongly alkaline medium by means of a corrosion inhibitor, characterized in that it contains an amine containing at least one CH group bound to the nitrogen.
摘要:
Process for hydrogenating aromatic polymers in the presence of catalysts, wherein a metal or mixture of metals from group VIII of the Periodic Table together with a support of silicon dioxide, aluminium dioxide or a mixture thereof is used as the catalyst, and the catalyst pore volume defined by pores of diameters between 100 and 1000 Å, measured by mercury porosimetry, is generally from 100 to 15%, in relation to the total pore volume, measured by mercury porosimetry.
摘要:
New hydrated niobium oxide and hydrated tantalum oxide catalysts containing pores having diameters in the range from 0.4 to 10,000 nm are characterized in that the volume of the pores of the catalyst having a diameter of from 100 to 1000 nm is at least 30% of the total pore volume of the catalyst. The catalysts can be prepared by mixing hydrated niobium oxide or hydrated tantalum oxide with an inert solid and converting this mixture into a solid pellet form, with the pressure in the apparatus for preparing catalysts in pellet form being set in such a way that the volume of the pores of the catalyst having a diameter of from 100 to 1000 nm is at least 30% of the total pore volume of the catalyst. Such catalysts are particularly suitable for preparing N-alkylanilines from anilines and alkanols.
摘要:
Dialkyl carbonates can be prepared by reacting carbon monoxide with alkyl nitrites in a continuous gas phase reaction in the presence of a heterogeneous platinum metal catalyst, the activity of this catalyst being maintained by the addition of small amounts of halogen. The dialkyl carbonates are thus formed with almost quantitative selectivity and no deactivation of the catalyst occurs.
摘要:
Hydroxymethyl-cyclopropane (cyclopropyl-methanol) can be obtained in a manner which is both economical and environment-friendly by catalytic hydrogenation of cyclopropanecarboxylic acid alkyl esters under increased pressure at elevated temperature if a chromium-free zinc oxide catalyst is employed as the catalyst.