RU2581360C2 - Primary oil refining plant - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: invention relates to oil refining. Primary oil refining plant comprises crude oil feed pipe connected to first column, upper zone of which is intended for separation of gasoline vapour for further cooling and condensation, and lower zone is designed to guide through a heating device of topped crude oil in second string is used for removal of petroleum from top zone and producing oil in lower part of said column, as well as for production of kerosene and diesel fraction in middle part of column, method is characterised by that installation is equipped with series-arranged heat exchangers, located at inlet of supply of crude oil in first column for heating crude oil due to heat recovery, captured in series with flows of petroleum, kerosene, diesel fraction and fuel oil for crude oil temperature increase to 250-260 °C, electrical dehydrator for purification of crude from salts and water, located before input of heated crude oil in heat exchanger using heat recovery, removed from outlet pipe output in form of ready product of fuel oil, air cooler and oil cooler for cooling and condensation of separated petroleum vapour from top zone of first column to obtain condensate with temperature +40-+60 °C and its direction in reflux tank for separation of hydrocarbon gas and returning at least part of straight-run gasoline in form of cold irrigation in upper zone of first string in-series located air cooler and oil cooler for cooling and condensation of separated petroleum vapour from top zone of second column to obtain condensate and its direction in reflux tank for separation of hydrocarbon gas and returning at least part of petrol in form of cold irrigation in upper zone of second column, wherein said oil coolers are connected with system for cold crude oil to plant.

EFFECT: technical result is increase of level of heat recovery, reduction of capital investments due to reduced power consumption, water, chemicals, fuel.

1 cl, 1 dwg

Description

The invention relates to the field of oil refining and can be used to improve the energy efficiency of process plants in oil and gas chemistry. The invention relates to primary refining at distillation units AT, ABT with the receipt of light petroleum products and residual fuel oil.

The process of primary oil refining is the main one at every oil refinery. Currently, primary oil refining units of various capacities are in operation 1; 1.5; 2; 3; 6 million tons / year. At a number of refineries, the unit capacity of AVT (AT) -type plants reaches 12 million tons / year. Depending on the connection of the electric desalination plants (ELOU) with the primary oil refining units, they are divided into three types: separate ELOUs with the transfer of desalted oil to the tank; ELOU located on the same site with primary processing plants, while desalted oil in front of the evacuation column is heated in preheating heat exchangers; built-in ELOU-installations where desalted oil enters the evacuation column immediately after the electric dehydrators. The first group includes old-type ABT (AT) plants of small capacity (1-2 million tons / year). The second group includes the most common high-performance combined atmospheric and atmospheric vacuum systems ELOU-AT, ELOU-AVT.

For example, the installation for primary distillation of crude oil AT, ABT is known, including two series-connected two- and three (four) section atmospheric columns R-1 and R-2 with upper condensers, a lower heater in the first and a stream of sharp steam in the second, preliminary oil heaters installed in front of each column, and having several selections with light oil products in each column. The AT, ABT installation is composed of five (or more) series-connected atmospheric or nearby columns with upper condensers and lower heaters in the first four columns and a stream of sharp steam in the last fifth (or more) column. The first atmospheric 7-plate column R-1 with a blank plate in the middle is connected by its lower half to a pipe supplying crude oil, the pallet R-1 is connected by a pipe to the heater HI, from which it is returned to the R-1 pan through a pipe into a hot stream, and its heated distillate down the pipe to the bottom of the column R-2. The lower half of R-1 is connected through a K-1 compressor to a pipe with the upper half of R-1, from the upper condenser of which cond1 gases are removed through the pipe, and hydrocarbon condensate is supplied by a pipe to the bottom of the R-2 column from a blank plate. The second atmospheric 9-plate column R-2 is also divided in two by a blank plate, the pipe through the K-2 compressor connects the lower part of R-2 to its upper part, where the NK-85 fraction is removed from the upper condenser cond2 by a pipe, and the other pipe from the blank plate condensate is fed to the upper plates of atmospheric or slightly lower than the plate column R-3. Oil from the R-2 sump is fed through the pipe to the Н2 heater, and then part of it is returned to R-2 through the pipe, and distillation through the pipe is fed to the lower plates of the R-3 gasoline column. Gasoline from the upper condenser cond3 is withdrawn from R-3 through a pipe, and its heated distillation through another pipe is fed into a fourth atmospheric or lower R-4 column, etc. (RU 2264430, C10G 7/00, B01D 3/14, publ. 20.11.2005). Adopted as a prototype.

The disadvantage of this installation is the increased energy consumption to ensure heating and cooling of hydrocarbons, the use of inefficient 2-4-section columns operating at atmospheric or slightly higher pressure: it is difficult to organize optimal hydraulics and separation with minimal heat consumption. The location of the oil heaters in front of the columns is not optimal, because leads to useless loss of part of the heat in the upper condenser and side irrigation.

The present invention is aimed at achieving a technical result, which consists in reducing energy consumption for the implementation of the process of primary distillation of oil.

The indicated technical result is achieved in that the primary oil distillation unit, comprising a first column communicated with the crude oil supply pipe, the upper zone of which is intended to separate gasoline vapors for subsequent cooling and condensation, and the lower zone of which is intended for directing topped oil through the heating device to the second the column used to drain gasoline from the upper zone and to obtain fuel oil in the lower part of this column, as well as kerosene and diesel fraction in the middle part It is equipped with sequentially located heat exchangers located at the inlet of crude oil into the first column for heating this crude oil by recovering heat removed from the output pipes in the form of a finished product of kerosene, diesel fraction and fuel oil to increase the temperature of crude oil to 220-260 ° C, an electric dehydrator for the purification of crude oil from salts and water, located in front of the entrance of the heated crude oil into a heat exchanger using heat recovery from the output pipe in the form of a finished product fuel oil, sequentially arranged by an air cooler and an oil cooler for cooling and condensing the separated gas vapors from the upper zone of the first column to obtain condensate with a temperature of + 40- + 60 ° С and directing it to a reflux tank to separate hydrocarbon gas and return at least part straight-run gasoline in the form of cold irrigation in the upper zone of the first column, sequentially arranged air cooler and oil cooler for cooling and condensation of the separated vapors without nzin from the upper zone of the second column to obtain condensate and direct it to a reflux tank to separate hydrocarbon gas and return at least part of the gasoline in the form of cold irrigation to the upper zone of the second column.

These features are significant and are interconnected with the formation of a stable set of essential features sufficient to obtain the desired technical result.

The present invention is illustrated by a specific example of execution, which, however, is not the only possible, but clearly demonstrates the possibility of achieving the desired technical result.

In FIG. 1 is a block diagram of an apparatus for primary distillation of oil.

According to the present invention, a design of a unit for primary distillation of oil, intended to obtain the following petroleum products: straight-run gasoline, kerosene, diesel fraction, fuel oil, is considered.

According to the present invention, an example of a plant (FIG. 1) using cold oil as a working agent for the final cooling of straight-run gasoline is considered. Such a primary oil distillation unit contains a first column in communication with the crude oil supply pipe, the upper zone of which is intended to separate gasoline vapors for subsequent cooling and condensation, and the lower zone of which is intended to direct the stripped oil through a heating device to the second column used to drain gasoline from the upper zone and obtaining fuel oil in the lower part of this column, as well as obtaining kerosene and diesel fraction in the middle part of the column.

The installation also uses:

- sequentially located heat exchangers located at the inlet of the supply of crude oil to the first column for heating this crude oil by recovering heat removed from the output pipes in the form of a finished product of kerosene, diesel fraction and fuel oil to increase the temperature of crude oil to 220-260 ° C ,

- an electric dehydrator for the purification of crude oil from salts and water, located in front of the entrance of the heated crude oil to a heat exchanger using heat recovery from the output pipe in the form of a finished fuel oil product,

- sequentially arranged air cooler and oil cooler for cooling and condensing the separated gas vapors from the upper zone of the first column to obtain condensate with a temperature of + 40- + 60 ° С and directing it to a reflux tank to separate hydrocarbon gas and return at least part of straight-run gasoline in the form of cold irrigation in the upper zone of the first column,

- sequentially arranged air cooler and oil cooler for cooling and condensing the separated gasoline vapors from the upper zone of the second column to obtain condensate and directing it to a reflux tank to separate hydrocarbon gas and return at least part of the gasoline in the form of cold irrigation to the upper zone of the second column.

These oil coolers are in communication with the system for supplying cold crude oil to the installation.

Below is a specific example of the installation (Fig. 1). The installation includes:

- T-1 - heat exchanger 1 oil / kerosene;

- T-2 - heat exchanger 2 oil / diz. fuel;

- T-3 - heat exchanger 3 oil / fuel oil;

- ABO-1 - air cooler 4 vapor of gasoline from the topping (first) column 5 (K-1);

- ABO-2 - air cooler 6 vapor of gasoline from the main (second) column 7 (K-2);

- ABO-3 - air cooler 8 TC-1;

- ABO-4 - air cooler 9 diesel fraction;

- ABO-5 - air cooler 10 fuel oil;

- E - electric dehydrator 11;

- K-1 - topping column 5;

- K-2 - the main distillation column 7;

- E-1, E-2 - reflux capacities, respectively pos. 12 and 13;

- P - furnace 14;

- X-1, X-2 - oil refrigerators, respectively pos. 15 and 16.

Crude oil is preheated in refrigerators X-1 and X-2, and then in heat exchangers T-1 and T-2 to a temperature of + 120- + 130 ° C due to the recovery of heat from straight-run gasoline, kerosene and diesel fraction.

In the electric dehydrator E, oil is purified from salts and water.

Further, the oil is heated to a temperature of + 250- + 260 ° C in the T3 heat exchanger due to the recovery of heat of fuel oil.

In the K-1 column, the bulk of gasoline vapors are separated, which are removed from the top of the column, cooled and condensed sequentially in the ABO-1 air cooler, and then in the X-1 oil cooler. As a rule, in ABO-1 hydrocarbons are cooled to a temperature of + 60- + 80 ° C; post-cooling to a temperature of + 40- + 60 ° С (especially in the hot summer period) is carried out in oil coolers with oil with a temperature of + 15- + 27 ° С.

The cooled stream from X-1 is sent to the reflux capacity E1. Separated hydrocarbon gas is discharged from the top of the E-1; straight-run gasoline is discharged from the bottom of E-1, part of which is supplied in the form of cold irrigation to the upper section of K-1, and the balance amount is removed from the unit.

Topped oil from the bottom of K-1 is heated in furnace P and fed to a temperature of K-2 with a temperature of up to + 360 ° С.

From the top of K-2, the remainder of the gasoline is discharged. The cooling process in ABO-2, X-2 and separation in E-2 is similar to the process in the technological chain of devices ABO-1, X-1 and E-1.

Kerosene is removed from K-2, releases part of the heat in T-1 of crude oil and is further cooled in ABO-3 to + 60 ° С.

The diesel fraction is removed from K-2, releases part of the heat in T-2 of crude oil and is further cooled in ABO-4 to + 60 ° С.

Fuel oil is removed from the bottom of K-2, releases part of the heat in T-3 oil and, if necessary, is cooled down to + 90- + 100 ° С in ABO-5.

The proposed version of the heat transfer system of the ELOU-AT installation has a number of advantages compared to the traditional one:

1. excludes the use of recycled water for the final cooling of gasoline fractions;

2. excludes investments in the construction of a water cooling tower;

3. significantly reduced the cost of electricity, water, chemicals required for the operation of the cooling tower;

4. Reduces the burden on plant-wide wastewater treatment plants from the cooling tower;

5. by increasing the level of heat recovery in the technological process of oil distillation, the furnace load and, consequently, fuel consumption are reduced, which in turn reduces the amount of fuel combustion products.

Claims (1)

The primary oil distillation unit, containing the first column in communication with the crude oil supply pipe, the upper zone of which is designed to separate gasoline vapors for subsequent cooling and condensation, and the lower zone of which is used to direct the stripped oil through a heating device to the second column used to drain gasoline from the upper zone and obtaining fuel oil in the lower part of this column, as well as receiving kerosene and diesel fraction in the middle part of the column, characterized in that it is equipped with well-located heat exchangers located at the inlet of the supply of crude oil to the first column for heating this crude oil by recovering heat removed sequentially from the flows of gasoline, kerosene, diesel fraction and fuel oil to raise the temperature of crude oil to 250-260 ° C, an electric dehydrator for cleaning crude oil from salts and water located in front of the entrance of heated crude oil to a heat exchanger using heat recovery from the output pipe in the form of a finished fuel oil product, sequentially with an air cooler and an oil cooler for cooling and condensing the separated gas vapors from the upper zone of the first column to obtain condensate with a temperature of + 40- + 60 ° С and directing it to a reflux tank to separate hydrocarbon gas and return at least part of straight-run gasoline in the form cold irrigation to the upper zone of the first column, sequentially arranged air cooler and oil cooler for cooling and condensation of the separated gasoline vapors from the upper zone of the second Lonna for condensation and direct it in a reflux tank for separating a hydrocarbon gas and returning at least a portion of gasoline as a cold reflux to the second column top zone, said oil coolers communicated with a system for supplying cold crude oil to be installed.

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