A technology for the demercaptanization of light hydrocarbon fractions and liquefied petroleum gas with 25% aqueous ammonia is proposed. One advantage of this method for the demercaptanization of oil fractions over conventional processes such as Merox is the absence of a stage of oxidative catalytic recovery of spent caustic and highly toxic sulfur caustic wastewater. Spent (saturated with sulfur compounds) aqueous ammonia is recovered at the same plant for the distillation of sulfur ammonia wastewater in which aqueous ammonia is produced.

Results of laboratory studies of the extraction of light mercaptans (methyl, ethyl, and propyl mercaptans) from hydrocarbons mixtures with a 25% aqueous solution of ammonia (caustic ammonia) are presented and discussed. It is shown that aqueous ammonia can in principle be used for controlled demercaptanization of light hydrocarbon fractions and liquefied hydrocarbon gases containing hydrogen sulfide and lower mercaptans. The advantage of this demercaptanization method over the conventional processes of alkali treatment is that there is no stage of oxidative catalytic regeneration of a spent alkali and there are no its highly toxic wastes, sulfurousalkaline waste waters. The regeneration of a spent (saturated with sulfurous compounds) aqueous ammonia can be comparatively easily performed by its heating (boiling), which leads to a hydrolytic decomposition of ammonium sulfides and mercaptides to release their constituent gases: hydrogen sulfide, mercaptans, and ammonia. Ammonia is recycled into the process as freshly prepared (regenerated) caustic ammonia.

Structure groups and individual compositions of the oilstock and catcracking products from section S-200 of KT-1/1 reactor were analyzed. The data obtained were used to suppose about possible reactions of the catalytic cracking. Quantum chemical methods were applied for thermodynamic calculations of probability of the reactions under the process conditions. The formalized scheme of hydrocarbon transformations comprising the feedstock components, light and heavy gasoil was suggested using the calculation results with allowance for the reaction reversibility; it was used for developing the kinetic model of the catalytic cracking process. Kinetic parameters of the reactions were determined by solving the inverse kinetic problem using experimental data (from the industrial facilities of Gaspromneft-Omsk Refinery Co.) and laboratory analytic data. The error of the calculations based on the kinetic model is no more than 5 % that argues for the model adequacy to the real process of catalytic cracking. The developed kinetic model makes it possible to calculate variations in the concentration of the reactants, quantity and composition of the products, as well as to optimize technological modes of the process depending on the process target (an increase in the yield of gasoline of light gasoil), composition and properties of the feedstock under processing.

The results from industrial tests of technology developed earlier for the reactivation of CoMo/Al 2 O 3 catalyst for the deep hydrotreating of diesel fuel, including the oxidative regeneration of the catalyst with subsequent treatment using organic complexing agents, are presented. Samples of the catalyst, fresh and at different stages of its reactivation, are investigated using a set of analytical and physicochemical methods. The chemical composition, textural characteristics, mechanical strength, structure of the active sulfide component (TEM, XPS) are determined. Catalytic tests are performed that include lifetime tests (360 h) in the hydrotreatment of a straight-run diesel fraction. The restoration of the physicochemical and catalytic properties is observed for a sample subjected to oxidative regeneration with subsequent treatment using organic complexing agents. An industrial batch of deep hydrotreatment catalyst reactivated by this technology is loaded into an L-24-6 industrial plant facility and ensures stable purification of straight-run diesel fuel containing up to 10% of light catalytic cracking gas oil to a residual sulfur content of less than 10 ppm. Comparison of the obtained results and data on the industrial operation of fresh catalysts shows that the technology developed by the Institute of Catalysis and PAO Gazprom Neft ensures almost complete restoration of the properties of the deactivated catalysts.

Industrial testing of the developed technology for reactivation of the CoMo/Al 2 O 3 catalysts for deep hydrotreatment of diesel fuel was the oxidative regeneration of the catalyst followed by the treatment with organic complexing agents. A series of analytic and physicochemical techniques were used for studying samples of the catalyst, both fresh and at different stages of the reactivation. The chemical composition, textural parameters, mechanical strength and the structure of the active sulfide component were determined (TEM, XPS). Catalytic and life (360 h) tests were conducted using hydrotreatment of the straight-run diesel fraction. The physicochemical and catalytic properties of the sample were demonstrated to restore after the said treatments. The reactivated industrial catalyst for the deep hydrotreatment was loaded to an industrial reactor L-24-6 and demonstrated the stable operation in purifying the straight-run diesel fuel (containing up to 10 % of light catcracking gasoil) to provide no more than 10 ppm of the residual sulfur. The results obtained were compared to the performance of fresh industrial catalysts to show that the developed technology ensures practically complete restoration of properties of the deactivation catalysts.