Министерство образования и науки Российской Федерации
Филиал Федерального государственного бюджетного образовательного
учреждения высшего образования
«Уфимский государственный нефтяной технический университет» в г. Салавате
(Филиал ФГБОУ ВО УГНТУ в г. Салавате)
Кафедра «Оборудование предприятий нефтехимии и нефтепереработки»
Кафедра общенаучных дисциплин
Технический иностранный язык
Индивидуальное задание
Перевод технических текстов
Исполнитель: студенты гр. МТП21-16-21
|
|
И. П.А. Кузнецов
|
Проверил: доцент, к.п.н. |
|
Ю.А. Жаринов |
Салават 2017
Process of an isomerization of light petrol distillate.
1 Theoretical bases of process
1.1 Characteristic of technological process
The substance of process of an isomerization is a catalytic transfomation of light paraffin of a normal structure in the corresponding isoparaffin. A main objective – receiving a high-octane component of automobile gasoline which provides the required fractional composition and reduces concentration the nagaroobrazuyushchikh of aromatic hydrocarbons in gasolines of catalytic reforming and cracking.
Technological process of the low-temperature isomerization pentane - hexane fraction is developed for catalytic isomerisation of butanes, pentanes, hexanes and their mixes with formation of hydrocarbons with the more branched line-ups having higher octane value.
High performance of process of an isomerization is that as raw materials low-octane components - fraction of N are used to. - 62 °C and raffinates of catalytic reforming. In these raw materials contains in the basic pentanoic and hexane fractions. These raw materials, and also the C5 and C6 fractions received from gas-fractionation installation (GFU) are isomerized in the environment of Hydrogenium in the presence of the catalyst. Receive hydrocarbons with rather high octane value of an isostructure. At an isomerization of pentanoic fraction receive a product with higher octane value. The isomerization of n-pentane is of interest not only for oil processing, but also to the petrochemical industry as isopentane a dehydrogeneration can be turned into an isoprene - raw materials for rubber.
1.2 Process chemistry
At an isomerization pentane - hexane fraction reactions of the following types proceed:
- benzene hydrogenation;
- isomerization;
- disclosure of naphthenic rings;
- hydrocracking.
Benzene hydrogenation. There is an interaction of benzene and Hydrogenium to formation of cyclohexane.
Hydrogenation of benzene is the exothermic reaction (16 800 kcal are allocated for each kmol of the consumed Hydrogenium), however owing to the slight content of benzene in raw materials the generated heat is little significant.
Isomerization. The isomerization represents transformation or structural change of connection with formation of more branched line-ups having higher octane value. Similar structural changes can be represented by means of the formulas given below:
As shown, the given reactions are reversible, and final distribution of isomers depends on the equilibrium composition determined by technical specifications on operation of the reactor and a kinetics of reactions.
Disclosure of naphthenic rings. At isomerization raw materials usually there are three naphthenes – cyclopentane, methylcyclopentane and cyclohexane. Rings of these naphthenes collapse during reaction of hydrogenation with formation of paraffin. At reference conditions conversion of naphthenic rings with formation of paraffin takes place in the isomerization reactor approximately for 20-30%.
Their presence at great manies at raw materials is undesirable as cyclic components are absorbed on the catalyst therefore access to the active sites of its surface necessary for course of reaction of an isomerization of paraffin is limited. Also they consume Hydrogenium and lead to selection of a large amount of heat that is undesirable from the point of view of equilibrium of an isomerization.
Hydrocracking of C7 paraffin is resulted by formation of C3 and C4.
С7H16 +H2 → C3H8+C4H10 .