Chemistry and thermodynamics of process. Reforming catalysts. Raw materials. Process parameters. Reforming industrial devices. Criteria of an assessment of catalysts. Catalyst promoters. Temperature influence The volumetric feed rate. Rigidity of process.
Аннотация к работе
Its size generally is defined by the content of naphthenic hydrocarbons in raw materials and makes 250 ТАФ 630 KJ/kg.Reforming catalysts 2 basic functions: dehydrogenating-hydrogenating and acidic 1) Metals VIII of group of the Periodic system of elements of D. I. The catalysts combining both functions (dehydrogenating, acid), are called bifunctional .Main criteria of an assessment of catalysts rate of volume flow of giving of raw materials, exit of a stable reformate (catalyzate), octane value of a product or exit of aromatic hydrocarbons, the maintenance of light distillates in a reformate, exit and composition of gas, endurance of the catalyst.Catalyst promoters 1) metals VIII of group: rhenium and iridium known as catalysts of a hydrogenation and hydrogenolysis ; 2) metals, almost inactive in reforming reactions, such as germanium, tin and lead (IV group), gallium, indium and rare earths (III group) and cadmium (from the II group). Increasing of pressure interferes with fast poisoning of catalyst; partially it occurs because coking up of the catalyst and sensitivity to poisoning with harmful impurity with buildup (increase) of pressure considerably decrease, However thus the possible exit of aromatic hydrocarbons decreases thermodynamic and the speed of reactions of hydrocracking and dealkylation increases. With increase in rate of volume flow in process the reactions proceeding quicker start playing the prevailing role: dehydrogenerations of naphthenic hydrocarbons, hydrocracking of heavy paraffin hydrocarbons and isomerization of C4 and C5 hydrocarbons.Ratio of the circulating hydrogenous gal and raw materials Increase of fractional pressure of hydrogen suppresses reactions a dehydrogeneration, reduces falling in it temperatures in the reactor; as a result the average temperature of the catalyst and speed of course of reactions increase. It consists of four blocks: the block of hydrotreating of gasoline to the content of sulfur no more than 1 mg/kg; the reactor block intended for heating and conversion of raw materials; heating is carried out before each of three reactors because of endothermic (on average) reactions; reactors are loaded by the catalyst in the ratio 1:2:4; to support approximately equal conversion on reactors; the block of separation of a steam-gaseous phase from fluid, consisting of the regenerative heat exchanger, the refrigerator and a separator of high pressure where hydrogenous gas (VSG) separates, and a liquid phase is choked and comes to a separator of low pressure for office of hydrocarbonic gas; the gasoline stabilization block where in a column of stabilization receive stable gasoline and byproducts of hydrocracking - condensed gas and hydrocarbonic gas.The raw materials according to the routine scheme pass hydrotreating, are stabilized in a column of RK-1 and arrive on the reforming block.