RU2523329C2 - Device for obtaining hydrocarbon propellents - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: device for obtaining hydrocarbon propellents contains connected to pipelines adsorbers for drying and purification of propellent components with placed in them zeolites, heat exchangers, a furnace, a unit of obtaining a hydrocarbon propellent composition. A scheme includes two units of adsorbers with three adsorbers in each unit. A piping layout includes disconnection of any adsorber for performing a regeneration process. The regeneration process of adsorbers in each unit is performed in turns. In order to carry out regeneration a vapour phase of purified propane or butane is used. As a raw material used are: propane and butane.

EFFECT: invention makes it possible to obtain high quality production from propane and n-butane with low content of sulphides, and considerably reduce exploitation and capital costs on realisation of installation and carrying out the process.

2 dwg

Description

Technical field

This invention relates to the chemical industry, specifically to technology and the production of environmentally friendly hydrocarbon gases - propellants used as a propellant for aerosol packaging. A propellant gas is a liquefied hydrocarbon gas in the form of fractions and (or) their mixtures (compositions) and differs in saturated vapor pressure and fractional composition. The quality of the drying and purification of the propellant determines its use in those industries where the gas requirements for the content of mercaptans and moisture are very high (perfumes and cosmetics, medical aerosols, production of car cosmetics, foam, paint and varnish products).

State of the art

A known installation for the production of hydrocarbon propellants, containing connected by pipelines a unit for producing a composition of propellants, adsorbers, filters with type A zeolites for drying and cleaning propellants, a unit for preparing regeneration gas, heat exchangers and furnaces [1], [I. Kuzmenko etc. Propellants for aerosol packaging. - L .: CHEMISTRY, Leningrad Branch, 1970, p.186-196].

The main disadvantages of the installation are:

- insufficiently high degree of purification (mass content of sulfur compounds of 0.0001%);

- only propane-pentane mixture is used as feedstock.

The closest in its technical essence and the achieved technical result is the invention "Installation for the production of hydrocarbon propellants" [2], [patent RU No. 2109030, C1, publication date 04/20/1998]. According to this invention, in a plant for producing hydrocarbon propellants containing a piping assembly for producing a propellant composition, adsorbers for drying and purifying propellants with zeolite layers placed therein, a gas preparation unit for regeneration, heat exchangers and furnaces, zeolites are used such as CaA and NaX, the plant is additionally equipped with a heat exchange apparatus for the preliminary preparation of raw materials connected to the site for receiving the composition of the propellants, and coal adsorbers, and the site for receiving the propellants claimed in a distillation column, the exit from the top of which is connected to the input of the lower portion of the coal adsorbers. A layer of NaA zeolite is placed at the bottom of each adsorber for drying and cleaning propellants, above which are CaA and NaX zeolites.

As raw materials for the production of propellants, a C _{3 + 8} hydrocarbon mixture can be used. Hydrocarbon propellants are released by rectification in the form of a mixture with vapor pressure corresponding to the propellants. Drying and purification of a mixture of hydrocarbon propellants is carried out in adsorbers filled with layers of zeolites NaA, CaA and NaX.

The regeneration gas preparation unit is made in the form of adsorbers filled with synthetic zeolites or in the form of a nitrogen production unit.

The main disadvantage of the prototype are:

- use as a raw material for the production of propellants hydrocarbon mixture C _{3 + 8} ;

- the allocation of the fraction of propellants by rectification method leads to a significant increase in the cost of installation and production costs;

- the use of layer-by-layer filling of zeolites NaA, CaA and NaX in adsorbers leads to mixing of the layers during adsorption drying and purification, which affects the selectivity of the process and, accordingly, the purity of the product propellant;

- the use of coal adsorbers increases the technological complexity and cost of installation;

- the use of pure nitrogen and adsorption blocks as a regeneration gas leads to high production costs.

The objective of the present invention is to provide a plant for the production of hydrocarbon propellants, which allows to obtain high quality products from propane and n-butane with a low sulfur content up to 0.00001%, and significantly reduce operating and capital costs for the installation and the process.

Disclosure of invention

This object is achieved in that in the installation for producing hydrocarbon propellants from propane and butane, containing adsorbers connected by pipelines for separate drying and purification with zeolites placed in them, filters, heat exchangers, a furnace and a unit for producing propellant compositions, in contrast to the prototype, the drying unit and purification is made in the form of two adsorption blocks for propane and n-butane; for drying, active alumina is used, which is located in the first adsorber along the process and NaA zeolite, is placed th second campaign process adsorber process NaX zeolite for purification disposed in the third downstream of the adsorber. The unit for producing the hydrocarbon propellant composition is presented in the form of tanks, pumps and a mixer, the input of which receives purified propane and butane. A predetermined composition corresponding to saturated vapor pressure of a particular hydrocarbon propellant brand is obtained in a mixer by mixing propane and n-butane or using purified propane or n-butane fractions as propellants.

Drying and purification of hydrocarbons is carried out by passing each component (propane or n-butane) of the hydrocarbon propellant in the liquid phase through sorbents in three sequentially located adsorbers. Active alumina is intended for primary drying of hydrocarbon components of raw materials. Zeolite NaA is designed for deep drying of hydrocarbon components. Zeolite NaX is designed for deep purification of hydrocarbon components from hydrogen sulfide, mercaptans and other impurities. For regeneration, the vapor phase of the component of the propellant passed through the adsorber in cooling mode is used.

The scheme includes two blocks of adsorbers, three adsorbers in each block. Block No. 1 is designed for drying and purifying propane. Block No. 2 is designed for drying and purifying n-butane. The regeneration process of the adsorbers in each block is carried out alternately. For regeneration, the vapor phase of propane in block No. 1 and n-butane in block No. 2 are used. The vapor phase is taken from the storage tank of purified propane or n-butane, compressed to a pressure of 0.6 MPa and fed to a regenerated adsorber for the cooling process. The vapor phase of propane or n-butane, passing through a cooled adsorber, partially heats up and enters a regenerative heat exchanger. The recuperative heat exchanger is designed to recover heat from the regeneration gas. After the recuperative heat exchanger, the vapor phase of propane or n-butane is heated in the furnace to the regulated temperature and enters the upper part of the regenerated adsorber. The regeneration gas after the regenerated adsorber, passing through the pipe part of the regenerative heat exchanger, is partially cooled, giving off heat to the gas entering the regeneration. In winter, a regenerative heat exchanger is used to heat the hydrocarbon mixture supplied to the adsorption to 20 ° C, where the hydrocarbon mixture is heated by cooling the regeneration gas. In the summer, heating the hydrocarbon mixture before adsorption is not required, the heat exchanger is used for the final cooling of the regeneration gas due to the evaporation of the hydrocarbon mixture in the annulus. The heat exchanger is included in the work together with the separator. Cooled, moisture-containing and desorbed impurities regeneration gas enters a special container for collecting regeneration gas. Settled water from the recovery gas recovery tank is periodically drained.

The invention is implemented as follows:

The installation for producing hydrocarbon propellants from propane and butane is shown in the drawings, where Fig. 1 shows a schematic diagram of an adsorption unit No. 1 of a propane drying and purification unit, and in Fig. 2, a unit for producing a hydrocarbon propellant composition from a propane-butane mixture or from purified propane and n-butane.

The drying and cleaning unit is made in the form of two identical adsorption units for propane - unit No. 1 and n-butane - side No. 2.

Each adsorption unit contains a container 1, a drain with which is connected to a pump 2, the discharge pipe of which through a heat exchanger 6 is connected to the entrance to the lower part of the first upstream adsorber 3, with aluminum oxide, the output of which is connected to the entrance to the upper part of the second upstream adsorber 4, with a NaA zeolite, the outlet of which is connected to the bottom of the third adsorber 5 in the upstream direction, with a NaX zeolite, the outlet of which is connected by a filter 14, the outlet of which is connected to a tank 16, the drain of which is connected to the pump 19, the discharge pipe to otorogo connected by a pipeline with the node receiving the composition of the hydrocarbon propellant.

The unit for producing the hydrocarbon component composition is presented in the form of a container 20, for collecting purified propane, a drain with which is connected to a pump 21, a discharge pipe of which is connected to a mixer 24 and through valves with a capacity of 25, of a container 22, for collecting purified n-butane, drain with which is connected to a pump 23, the discharge pipe of which is connected to the mixer 24 and through valves with a capacity of 27. The propane-butane mixture after the mixer 24 is piped to a container 26 for collecting commodity propellant. Capacity 25 is used to collect purified propane. Capacity 26 is used to collect purified n-butane.

Adsorbents are regenerated in adsorbers 3, 4, 5 by the vapor phase of purified propane from tank 16 in adsorption unit No. 1 and the vapor phase of purified n-butane from tank 16 in adsorption unit No. 2.

The regeneration scheme of block No. 1 is identical to the scheme of block No. 2.

Description of the regeneration scheme of block No. 1.

The regeneration of adsorbers 3, 4 and 5 is carried out separately.

The vapor phase of propane from the upper part of the tank 16, flows through the pipeline to the compressor 15, is compressed to 0.6 MPa and flows through the pipeline 18 to the lower part of the adsorber 4 and from the upper part of the adsorber to the regenerative heat exchanger 8. The regenerative heat exchanger is connected by a pipeline to the furnace 9, in which the regeneration gas is heated to the operating temperature and through a pipe 17 enters the upper part of the adsorbers 3 or 5. The outlet of the regeneration gas from the lower part of the adsorber 3 or 5 is connected by a pipe to the filter 7. The purified regeneration gas is connected ene conduit with a recuperative heat exchanger 8 for cooling and partially sent to the air cooler 10 for final cooling. The outlet from the air cooler is connected by a pipe to a tank 12 for collecting regeneration gas. In winter, the regeneration gas from the lower part of the adsorbers 3, 4, 5 is sent to a recuperative heat exchanger 6 to recover heat and preheat the hydrocarbon mixture entering the adsorption. The exit from the heat exchanger 6 is connected by a pipe to a tank 12, which is connected by a drain line to the pump 13. The pipe from the pump 13 is designed to pump out liquid hydrocarbon propane butane fraction for the needs of a gas station. The heat exchanger 6 is connected by pipelines to the separator 11.

To carry out the cooling process of the adsorbent that has undergone high-temperature regeneration, the vapor phase of propane is partially heated and cools the hot adsorbent in adsorbers 3 or 5 that have undergone high-temperature regeneration, and enters from the upper part of the adsorbers to a recuperative heat exchanger 8. At this time, adsorber 4 is at the stage of high-temperature regeneration .

Installation works as follows.

The drying and cleaning unit is made in the form of two identical adsorption units for propane - block No. 1 and n-butane - block No. 2.

Description of the operation of the adsorption unit No. 1 for cleaning and drying propane.

Liquid propane is taken into the tank 1 and pump 2 is fed into the lower part of the adsorber 3, which is filled with active alumina for general use, intended for primary drying. From the upper part of the adsorber, propane enters adsorber 4, which is filled with NaA zeolite for deep drying. In the adsorber 5, filled with NaX zeolite, there is a deep purification of propane from hydrogen sulfide, mercaptans and other impurities. Ready propane from the adsorber 5 is cleaned in the fine filter 14 from zeolite dust and enters the tank 16, designed to collect propane.

Adsorbents are regenerated in adsorbers 3, 4, 5 by the vapor phase of purified propane from tank 16 in adsorption unit No. 1 and the vapor phase of purified n-butane from tank 16 in adsorption unit No. 2.

The regeneration scheme of block No. 1 is identical to the scheme of block No. 2.

Description of the regeneration scheme of block No. 1.

The regeneration of adsorbers 3, 4 and 5 is carried out separately.

The vapor phase of propane from the upper part of the tank 16 enters the compressor 15, is compressed to 0.6 MPa and enters the lower part of the adsorber 4 and from the upper part of the adsorber to the regenerative heat exchanger 8 and then to the furnace 9, in which the regeneration gas is heated to the operating temperature and enters in the upper part of the adsorbers 3 or 5. Next, the regeneration gas enters the filter 7 for cleaning from zeolite dust. The purified regeneration gas enters the recuperative heat exchanger 8 for partial cooling and is sent to the air cooler 10 for final cooling and enters the tank 12 for collecting the regeneration gas. In winter, the regeneration gas from the lower part of the adsorbers 3, 4, 5 is sent to a recuperative heat exchanger 6 to recover heat and preheat the hydrocarbon mixture entering the adsorption. The outlet from the heat exchanger 6 is connected to a tank 12, which is connected by a drain line to a pump 13, designed to pump out the liquid hydrocarbon fraction of propane for the needs of a gas station. The heat exchanger 6 is connected to the separator 11.

To carry out the cooling process of the adsorbent that has undergone high-temperature regeneration, the vapor phase of propane is partially heated and cools the hot adsorbent in the adsorbers 3 or 5 that have passed the high-temperature regeneration, and enters from the upper part of the adsorbers to the recuperative heat exchanger 8. At that time, the adsorber 4 is at the stage of high-temperature regeneration.

Dried and purified propane from the adsorption unit No. 1 and n-butane from the adsorption unit No. 2 are fed to the unit for producing the composition of hydrocarbon propellants and propane-butane mixture. Purified propane enters the tank 20 and is fed to the mixer 24 by the pump 21. The purified n-butane enters the tank 22 and is fed to the mixer 24 by the pump 24. The propane-butane mixture after the mixer 24 is piped to the tank 26 for collecting commercial propellant. Capacity 25 is used to collect purified propane. Capacity 26 is used to collect purified n-butane.

During mixing in the mixer 24 propane and n-butane, changing the ratio of their costs, get in the tank 26 two compositions of hydrocarbon components:

The composition of the brand No. 1, with a saturated vapor pressure of 0.30-0.40 MPa;

The composition of the brand No. 2, with a saturated vapor pressure of 0.43-0.47 MPa.

Purified propane, which is a commercial hydrocarbon propellant of grade No. 3, with a saturated vapor pressure of 0.72-0.83 MPa, enters the vessel 25.

Purified n-butane, which is a commercial hydrocarbon propellant of brand No. 4, with a saturated vapor pressure of 0.11-0.16 MPa, enters the tank 27.

Achievable technical result

The advantage of the claimed installation over the prototype are:

- production of high quality hydrocarbon propellants with a low sulfur content up to 0.00001%;

- the use of propane and n-butane as a raw material;

- implementation of the principle of comprehensive deep drying and purification of raw materials;

- a new loading scheme has been proposed in the adsorber unit: the first adsorber along the way is filled with active alumina intended for primary drying; the second adsorber downstream is filled with NaA zeolite intended for deep drying; the third adsorber is filled with NaX zeolite, designed for deep purification from hydrogen sulfide, mercaptans and other impurities;

- obtaining compositions of hydrocarbon propellants by mixing propane and n-butane in a mixer;

- obtaining propellants from purified propane or n-butane.

- the use of recuperative heat exchangers for the recovery of heat from regeneration gas;

- preheating the regeneration gas due to the heat obtained during the cooling stage of the adsorber after high-temperature regeneration.

Claims (1)

Installation for producing hydrocarbon propellants from propane and butane, containing adsorbers connected by pipelines for drying and purification, with zeolites placed in them, filters, heat exchangers and furnaces, a unit for producing propellant compositions, characterized in that the unit for drying and purification is made in the form of two adsorption units for propane and butane, each adsorption unit contains a container, the drain of which is connected to the pump, the discharge pipe of which through the heat exchanger is connected to the entrance to the lower part of the first adsorber downstream active alumina, the outlet of which is connected to the entrance to the upper part of the second upstream adsorber filled with NaA zeolite, the outlet of which is connected to the entrance to the lower part of the third upstream adsorber filled with NaX zeolite, the outlet of which is connected by a pipeline to the tank, the drain to which is connected with a pump, the discharge pipe of which is connected by a pipeline to the unit for producing the hydrocarbon propellant composition, which is presented in the form of a container, the drain of which is connected to the pump, the discharge pipe of which connected to a mixer to obtain a propane-butane mixture, which flows through a pipeline into a container for collecting commercial propellant.

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