SU1255055A3 - Method of hydrofining heavy petroleum fractions - Google Patents

Abstract

The raw hydrocarbon material (1) is separated into a plurality e.g. four component streams identical in number with the number of strands in a multi-strand furnace (F) preceding a catalytic reactor (G), and they are mixed with gases (2) containing hydrogen likewise previously separated into an equal number of streams at temperatures below 520 DEG K. After preheating the mixed raw materials and gases in counter- current with the reaction products leaving the reactor (G), and subsequently heating further in the furnace (F) to reaction temperature, the streams are fed into the reactor (G). After reaction and cooling by heat exchange (in B, C, D, E) with the materials being preheated, the temperature of the reaction mixture is adjusted to enable separation favourable from the energy point of view by heat exchange (in A) with the infeed of raw material before separation of the latter into the component streams. <IMAGE>

Description

The invention relates to methods for hydrotreatment of heavy petroleum fractions in the presence of hydrogen-containing gas and a catalyst, and can be used in the petrochemical industry.

one

The goal of the invention is to reduce the energy consumption for the process by controlling the costs of raw materials and iodine-containing gas.

Baseline has the following characteristics:

Density at 50 ° С

, 895

Fractional composition

(ASTM 2887), vol.%:

10 boils away at C,. 35

3040-

50442

70472

90509

Coking ability (according to Kond-Radson),% 0,35

3.5% by weight of nickel and 9% by weight of molybdenum are used as a catalyst for hot-watering.

N. 1 and 2 are schematic diagrams of the implementation of the known and proposed methods, respectively.

Example 1.f the well-known method, figure 1,

The yellow oil fraction with a temperature of 463 K, fed through line 1, and a hydrogen-containing gas with a temperature of 433 K and pressure of 6.84 MPa, fed through line 2 are mixed and heated in successively connected Tx heat exchangers 3-7 to 633 K is then divided into four streams without regulation and fed to furnace 8. In the IDC furnace, it is generally heated to temperature K

As a consequence of the non-uniform separation of 45 with the mixture of reaction products to the darkness of the gas-cold mixture, separate streams of different temperatures (703; 650 and 683 K) are obtained at the exit of the furnace. The streams are then mixed and fed to the reactor 9, where a hydrocatalytic conversion is carried out at a pressure of 6.0 MPa.

The pressure loss due to the deposition on the catalyst increases by 0.4 MPa in the first two meters of the upper catalyst bed for 100 days. The mixture of reaction products at the outlet of the reactor has a temperature of 683 K.

255055 2

The reaction products are cooled in heat exchangers 7, 6, 5, 4, 3 to a very favorable temperature section.

neither to a temperature of 513 K. The separation is carried out in a hot separator.

10. Received gas is withdrawn through the line.

11, liquid — through line 12. Controlling and maintaining the desired temperature (513 K in the hot separator is provided by partially circulating heat exchangers, i.e., a part of the initial heavy oil fraction is mixed into the gas-liquid mixture immediately before entering the furnace 8.

For the compression of hydrogen-containing gases passing through a closed circuit, the ratio of the pressure of the gas supplied through line 2 before its mixing point with the feedstock and the gas leaving the hot separator is of decisive importance. In this case, this ratio is

tavl em

6.84 MPa

-J.

5.62 NPa

 1, 21708.

The differential pressure has a value of 1, 22 Sha. This value corresponds to 180 days of the installation when

200. heavy distillate oil and 80,000 hydrogen-containing gas. Such a pelvic flow rate is set at 124 days of plant operation, while at the initial gas flow rate of 60000

after I18 days, the installation would have to be disconnected due to the displacement of the furnace thread ...

PRI me R 2 (proposed

the method of FIG. The heavy oil fraction supplied to the cycle via line 1 with a temperature of 463 K is heated in the tube space of the heat exchanger 2 due to heat exchange

503 K, then, when regulating the flow, are divided into four equal partial flows and mixed with a hydrogen-containing gas,

supplied by line 3, divided into four identical partial flows, also adjustable by flow, at a pressure of 6.36 MPa and a temperature of 433 K. After that, the mixed

These flows are directed along lines 4, 7 respectively, to tag exchangers.

8-11 and heated to a temperature of 633 K and then heated in a four-sectional furnace to the inlet temperature of the reactor, i.e. up to 668 K. The close temperatures of the individual streams at the exit of the furnace (668.8; 667.7i 668.1 and 667.5 k) indicate a uniform distribution of the gas-liquid mixture over the individual sections of the furnace. Thus, localized overheating is avoided. At a pressure of 6.0 MPa, the hydrocatalytic transformation in the reactor 13

The pressure drop in the reactor is 0.02 MPa and remains constant throughout the operation time.

The mixture of reaction products is withdrawn from the reactor with a temperature of 683 K and cooled in heat exchangers 8-11 to a temperature of 538 K. The energetically favorable separation conditions for the separation of gas and liquid in the hot separator 14 are controlled by heat exchange with the feedstock in apparatus 2, and possibility of partial circumference of the feedstock. The hot separator 14 operates at a temperature of 513 K and a pressure of the Research Institute of 5.84 MPa.

Pressure ratio of hydrogen-containing gas supplied to lines 2 before the point of mixing with the initial heavy fraction and gas.

,

line 15 is

6.36 MPa, G.OPP / “5 L08904. The differential pressure has a value of 0.52 MPa. These values correspond to the 180 days of operation of the plant at a flow rate of 200 tons of heavy oil fraction and 60,000 hydrogen-containing gases flowing in a closed loop.

At this gas flow rate, the unit operates continuously.

Thus, the reduction in energy consumption for compression is achieved by reducing the amount of circulating gas, as well as by the small difference in pressure in the direction of the circulating gas. The energy consumption for gas compression in Example 2 is 32% of the energy consumption in Example 2. In terms of equal amounts of gas, the energy consumption in Example 2 is 43% of the consumption in Example 1.

In addition, the proposed method eliminates local overheating in the furnace tubes due to uneven loading and preventing the displacements of the Kli threads from a strong increase in pressure loss in the furnace and reactor, reducing the tendency to coking the reactants and prolonging the service life of the catalyst, as well as reducing the amount of circulating gas.

FIG.

V

u is

I ъ

v

J

e

Claims (1)

METHOD FOR HYDRAULICATION OF HEAVY OIL FRACTIONS partially or completely in the liquid phase in the presence of a hydrogen-containing gas and catalyst by heating the feedstock using countercurrent heat exchange with the target product, then in the furnace to the process temperature, followed by feeding to the reactor, cooling the mixture of the target product and hydrogen-containing gas at help heat transfer with the feedstock and hydrogen-containing gas and the establishment of energy-favorable conditions for the separation of the target product from the hydrogen-containing about gas at a temperature of 513 K, with the fact that, in order to reduce energy consumption, the feedstock after heat exchange with the target product when regulating its consumption is divided into four streams identical to the number of sections of the furnace, mixed with pre flow rate-controlled hydrogen-containing gas, separated at a partial hydrogen pressure of 6.36 MPa and a temperature of 433 K, into the same number of streams, followed by mixing them before being fed to the reactor, and energy-efficient conditions for separating the target product from the hydrogen-containing gas set by heat exchange with the feedstock. СО № ςπ cl, f cl cl sl * 1255055