In the end of 2014 our company has successfully commissioned the sweetening of butane fraction for LLC «LUKOIL-NNOS» with the use of KSM-X heterogeneous catalyst. The load of butane fraction increased from 16 to 23 tons/h, mercaptan sulfur content was reduced to no more than 5 ppmw, total sulfur content does not exceed 10 ppmw.
Our company has developed new waste-free processes for heterogeneous-catalytic refinement of light hydrocarbon raw materials -DEMER-LUVS and DEMERUS and also for high-boiling hydrocarbon fractions (kerosene — jet fuel and diesel fractions, stable gas condensates) from mercaptan sulphur — DEMER-KSP process, carried out in soft conditions: when temperature is 50-70°С and pressure is 0.3-l.0 MPa using polymeric KS and КSМ catalysts and new extractant DEMERUS.
KS and КSМ catalysts are strongly fixed on the heat-resistant and chemically stable polymeric carrier and made in the form of the convenient nozzle of the special design having an advanced geometric surface and a large free volume. As compared with traditionally used catalysts on coal or coal-fibrous basis (prepared by adsorptive impregnation of porous carbonaceous carriers water-alkaline solutions phthalocyanines of cobalt), polymeric KS and КSМ catalysts have high mechanical durability and stable catalytic activity during long term of operation without additional charging with a catalytically active component for regeneration.
Process DEMER-LUVS is intended for selective refinement of light hydrocarbon raw (the liquefied gases and light petrol fractions) from mercaptans. It is carried out by extraction of mercaptans from hydrocarbons by 10-20 % watered solution of alkali with the subsequent regeneration sated mercaptides of alkaline extractant oxidation of air by oxygen on KS or KSM catalysts. The specified process, since 1990, has been introduced in 8 Petroleum Refineries (PR): Маjeisk, Moscow, Omsk, Lisichansk, Ufa, Yaroslavl, Kstovo and JSC TAIF-NK(Nizhnekamsk) — for sweetening of butane-butylene (BBF) and propane-propelene (PPF) fractions from cat crackabilities. The degree of refinement BBF from mercaptan sulphur in Demer-LUVS process makes not less than 10 ppm wt. by mercaptan sulphur, service life of an alkaline solution in system of refinement is not less than 1 year, and the catalyst is up to 10 years.
Now new updating of the given process — DEMERUS process intended for deep extraction of high-boiling mercaptans from petroleum, and from high mercaptanic light petrols and gas condensates is being developed and patented. Here is used a new highly effective extractant Demerus instead of water-alkaline solution, providing 80-90 % refinement of petrol fractions from mercaptans at the first stage against 40-50 % in known methods. It allows carrying out deep demercaptanization of petroleum fractions in one stage, having excluded the second stage of oxidizing deodorization of heavy mercaptans from the traditional circuit of demercaptanization of petroleum.
Extractant “Demerus” has doubled or tripled sulphur capacity in comparison with water-alkaline solution, it is capable to be separated easily and completely from purified hydrocarbons by simple decantation and it is easy to be regenerated. It also allows excluding from the technological circuit water washing units of demercaptanizied hydrocarbons from alkali and their subsequent dehydration; to reduce the sizes of the devices, the quantity and volumes of sediment capacities and sharply to lower the volume of drains from installation. The designing of commercial units receiving the given absorbent is being conducted now. For deodorization of high-boiling hydrocarbon fractions (heavy gasolines, kerosene and diesel fractions, stable gas condensate and light oils) DEMER-KSP process is developed. It is carried out by direct oxidation of actively corroding and badly smelling mercaptans contained in them into inert disulphides or oxygen-bearing thiosulphonate by oxygen of air on promotor catalyst. As against known domestic and foreign analogues, DEMER-KSP process is carried out in one stage. It does not demand preliminary water-alkaline refinement of hydrocarbon fractions from acid admixtures; the subsequent stages of water washing, salt dehydration and adsorptive additional purifying of demercaptanized hydrocarbon fractions with loams, therefore it is waste-free. The specified process now has successfully passed qualifying tests and is accepted to introduction at 3 largest PRs in Russia (Moscow, Ryazan and Kirishy).
Since 1985 LOCOS process for sulphur-alkaline effluent decontamination (oxidizing Na2S to thiosulphates and sulphates) on KS catalyst has been maintained in Novokuybyshevsk Petroleum Chemical Plant, Moscow Refinery, Pavlodar Refinery, Mažeiksk Refinery and Omsk Refinery.