JPH01172491A - Hydrogenation of solid charge substance containing carbon - Google Patents

Abstract

PURPOSE: To prevent a prepared raw material from drying in a heat exchanger by mixing a gas heated in a hydrogen gas heater with a prepared raw material flow heated in an intermediate heat exchanger.

CONSTITUTION: A prepared raw material flow (3) passed through the heat exchanger (18-20), and a hydrogen gas (5) which, after passing the heat exchanger (21-23), was heated to 300-650°C in the hydrogen gas heater (24), are led to a high-temperature product flow (9) by counter flow. The flow (9) is discharged in a flowing-out direction after heat exchanging. The hydrogen gas and prepare raw material (3) are, after heat exchanging with a gas (5) in the heat exchanger (23), sent to the gaseous hydrogenation reactor (27). The reaction gas flow (10) is passed through the heat exchanger (19) and (22) to heat-exchange with a flow (3) and a gas (5), and is introduced into the intermediate separator (20) to separate a high boiling fraction (11). A remaining flow (12) is passed through the heat exchanger (18) and (21) for heat-exchanging with flow (3) and (5), and successively led into the low-temperature separator (29) through the cooling water heat-exchanger (31) to remove waste water (14) and low boiling fraction (13). The exit gas is recycled through the compressor (30) as a recycled hydrogen gas flow (15).

COPYRIGHT: (C)1989,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention provides for a subsequent gas-phase hydrogenation stage at elevated temperature and pressure, optionally in the presence of a catalyst, in order to A hot separation stage is connected downstream under separate heating of the feedstock stream formed from the substream of the additive gas and the second substream of the hydrogenation gas, with the hot separator head product undergoing indirect heat exchange. carbon-containing solid charge materials, such as coal or lignite, with a hydrogen-containing gas as the hydrogenation gas, under conditions of liquid-phase hydrogenation by releasing its thermal energy into these charge streams. Relating to a method of hydrogenating. In this case, liquid phase reactor temperatures of about 400 to 500°C and gas phase reactor temperatures of about 370 to 450°C are typical, with process pressures of 150 to 1200 ba
You can choose r.

[Conventional technology]

All of the high temperature separator head products are subsequently processed through a connected gas phase hydrogenation stage, and subsequently these oils are processed as intermediate separator liquid phase products where the solvent components are directly used for coal paste production. The pure oil product is recycled to the intermediate separator head product (see DE 35 24 449 and DE 3022.158). Processes are known in which the separation occurs by partial condensation in an intermediate separator.

Furthermore, the heavy oil is fed as charge product to the preheater and heated in a gas heat exchanger through which the hot separator head product flows, or a partial stream of the total required hydrogenation gas quantity is fed to the liquid phase reactor. Methods are known (see German Patent Application No. 3,523,709) in which heavy oil, additives and hydrogenation gas are added to a preheated mixture before inflow. This method, with separate heating of the hydrogenation gas, has already been proposed for coal hydrogenation (see DE 35 05 553 A1).

In order to technically realize the hydrogenation method of liquid phase and gas phase hydrogenation, three characteristics must be taken into account. Firstly, the parameters important for the process (in particular the defined inlet temperatures of the liquid-phase and gas-phase reactors and the defined temperatures in the intermediate dividers) must be adjustable. These temperature controls are made difficult by variable heat transfer capabilities due to fouling of the feedstock heat exchanger. Secondly, the special conditions during heating of the blended raw material and hydrogenation gas in the heat exchanger in the operation method integrating the gas phase hydrogenation stage must be taken into account. This is because it is well known that due to changes in solvent quality, oil stripping with water V:added gas increases the risk of drying out the heat exchanger. Third, the exothermic reaction heat from liquid- and gas-phase hydrogenation is an optimal way for heat recovery to achieve a heat-self-sufficient process or to also reduce the required additional heating equipment. must be used in The mixing raw material heating furnace must be omitted as much as possible. This is because the feed furnace is one of the hazardous components of each liquid phase hydrogenation stage.

In known methods (for example, the above-mentioned German Patent Application No. 3524449 and German Patent Application No. 3022158 IF), the heat transfer capacity of the raw material heat exchanger due to cram recycling and increased fouling is reduced. By means of external cooling, a defined process temperature in the gas phase reactor and intermediate separator is regulated without taking into account changes in the temperature.

Known method (Federal Republic of Germany Patent Appearance Publication No. 3523
Specification No. 709 and Federal Republic of Germany Patent Koyuki Publication No. 3
505553), the risk of drying of the blended raw material in the heat exchanger increases due to the decrease in the amount of hydrogenation gas in the blended raw material heating passage (most of the hydrogenated gas is heated in a separate gas exchanger). ) will be decreased. The above-mentioned regulation of both defined temperatures has not been considered heretofore. In both methods, a heat exchanger for heating the liquid/solid-gas mixture is placed after the gas phase reactor (i.e. at a relatively low temperature level), so that the maximum heating of the liquid/solid-gas mixture is The drawback is that it is not guaranteed. The furnace for heating the liquid/solid-gas mixture, the so-called formulation 1aa5, is therefore reduced in capacity compared to previous hydrogenation processes, but this furnace is not dispensed with.

Known method (Federal Republic of Germany Patent Application No. 2651
No. 253 RoaW) also does not satisfy the above conditions.

This is because this method involves only liquid-phase hydrogenation and the feedstock furnace cannot be omitted.

Process conditions characterized by multiphase flow of gases, vapors, liquids and solids within the tubes introduce considerable uncertainties in the design of furnaces and in the calculation of pressure drops and heat transfer.

Drawbacks in operating technology result from the tendency of deposition on the inner surface of the furnace tubes and from the coking reaction of the products inside the tubes. Attached to this are safety precautions, such as limiting the operating time of the entire hydrogenation plant and the occurrence of so-called hot spots, which can lead to pipe rupture.

[The problem that invention attempts to solve]

The advantages of the present invention are, firstly, that the temperatures critical to the process in the gas phase reactor and intermediate section can be regulated despite the unstable heat exchange capacity of the feedstock heat exchanger; 2
In addition, drying of the blended raw material in the blended raw material heat exchanger is avoided,
Thirdly, the course of the process is designed in such a way that the heat of reaction of the liquid- and gas-phase hydrogenation is utilized for thermal self-sufficiency or for optimization of the thermotechnical process.

According to the invention, this electrification can be achieved by eliminating the raw material heating furnace, by using the hydrogenated gas heater normally in bypass, and only in special operating conditions by indirect heat exchange. It is used when starting up a heat exchanger used for
Heating of the gas to 300 to 650 °C, preferably 450 to 550 °C, is carried out in a hydrogenation gas heater, and subsequent integration with the heated blended feed stream by indirect heat exchange also eliminates the need for a liquid phase heater. This problem can be solved by obtaining a suitable inlet temperature.

The defined temperature regulation is carried out in the gas phase reactor and in the intermediate glaze by means of a gas heat exchanger in bypass operation,
In these gas heat exchangers an indirect heat exchange between the hot separator head product and the separately heated hydrogenation gas takes place and a bypass is on the hydrogenation gas side. Separate gas heating simultaneously eliminates the risk of drying out the raw materials. According to the invention, the defined temperature regulation in the gas-phase reactor is further provided by a high-salt vessel head located in a feedstock heat exchanger arranged between the high-temperature separator and the gas-phase reactor. This is done by means of a different supply of vacuum gas oil in the passage of the high-salt S reactor head product via a bypass on the product side and to the gas-phase reactor.

According to the present invention, optimal 01 feedstock heating utilizes the heat of reaction from liquid and gas phase hydrogenation to allow the high temperature separator head product to transfer its heat to a relatively high temperature level by indirect heat exchange. This is achieved by transmitting to the feedstock-hydrogenation gas mixture and, at a relatively low temperature level, to the hydrogenation gas to be heated separately. As a result, a feedstock heating furnace is dispensed with and, with good thermal insulation, a hydrogenation gas heating furnace is also dispensed with in normal operation. In that case, the hydrogenation gas furnace is usually bypassed during normal operation and is required only for commissioning.

〔Example〕

The invention will be explained below with reference to the drawings.

In an alternative version of the proposed method (see FIG. 1), the feed stream 3 passing through the heat exchanger 18, 19, 20 and the hydrogenation gas stream 5 to be heated separately are fed to the hydrogenation gas furnace 24. Before entering, it is conducted in countercurrent through three heat exchangers 21, 22, 23 to the hot separator head product stream 9.

When dividing the total hydrogenation gas quantity into both substreams, fresh hydrogen is provided as a feed agent for the feedstock stream and recycled hydrogenation gas is provided for the second substream of hydrogenation gas. You can also do it like this.

In this case, the stream 9 successively enters into heat exchange relationship in the direction of exit with the blended feed stream 3 in the heat exchanger 20 and with the partial stream of the hydrogenation gas 5 in the heat exchanger 23 and undergoes gas phase hydrogenation in fixed bed contact. It passes through a reactor 27. The inlet temperature of the gas phase reactor 27 is determined depending on the contamination state of the feedstock heat exchangers 18, 19 and 20, the bypass point of the heat exchangers 20 and 23 and the vacuum gas oil before the heat exchangers 20 and 23 as an alternative. Control is provided by a vacuum gas oil supply and a quench gas supply via a supply device 32 and before the gas phase reactor 27. The purified product stream in reactor 27 is stream 10, stream 3 or stream 5.
The oil passes through the heat exchanger 19 and the heat exchanger 22 while exchanging heat with the oil, and passes through the intermediate separator 28 which separates the high temperature oil swamp fraction 11. Temperature control in the intermediate separator 28 is performed by the heat exchanger 2
This is done by bypass adjustment at 2. The residual stream 12 taken out from the intermediate separator 28 is transferred to the heat exchangers 18 and 2.
1, the remaining heat available for heating the charge product is released into stream 3 and stream 5 and is fed via a water cooler 31 to a cryogenic separator 29, in which it is separated from the wastewater 14. Separation of the waste gas and reflux of the recycled hydrogenated gas component as stream 15 to the process via compressor 30 takes place.

In connection with the cold fraction #1 vessel 29, a gas scrubber can be provided for the treatment of the recycled hydrogenation gas component in the usual manner. This type of treatment removes C1 to C4 components that are easily dissolved by the cleaning liquid in the gas scrubber.
Sufficient hydrogen partial pressure in the hydrogenation gas system is ensured.

The separate sub-streams from the total amount of hydrogenation gas to be used can amount to 20 to 95%, preferably 40 to 80%, of the total amount of hydrogenation gas required.

In an alternative embodiment (see FIG. 2), the specified temperature in the intermediate separator 28 is regulated by a bypass operating method of the raw material heat exchanger 19, without the bypass regulated gas heat exchanger 22. Ru. This requires a relatively large exchange surface of the feedstock heat exchanger 19 compared to FIG. 1, but the gas heat exchanger 22 is omitted.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a method according to the invention, and FIG. 2 is a circuit diagram of another embodiment.

Claims (1)

Claims: 1. A hydrogenation process formed from the feed material and a partial stream of the hydrogenation gas, optionally in the presence of a catalyst, and followed by a gas phase hydrogenation stage at elevated temperature and pressure. A hot separation stage is connected afterwards under separate heating of the blended feed stream and a second partial stream of the hydrogenated gas, so that the hot separator head product transfers its thermal energy to these charges by indirect heat exchange. In a method of hydrogenating a carbon-containing solid charge material, such as coal or lignite, with a hydrogen-containing gas as a hydrogenation gas under conditions of liquid-phase hydrogenation by discharging into a stream, heating the blended raw material. If the furnace is omitted and the hydrogenation gas heater is normally used in bypass and only in special operating conditions, during start-up of heat exchangers used for indirect heat exchange or in fouled conditions, the hydrogen Heating of the gas to 300 to 650° C., preferably 450 to 550° C., takes place in an additive gas heater, followed by integration with the heated feedstock stream by indirect heat exchange into the liquid phase reactor. A method for hydrogenating carbon-containing solid charge materials, characterized in that the required inlet temperature is obtained. 2 through heat exchangers (18), (19), (20) and the hydrogenation gas (3) to be heated separately.
A second substream of 5) passes through the heat exchangers (21), (22), (23) in reverse flow to the hot separator head product stream (9) before entering the hydrogenation gas furnace (24). guided by the flow (9
) successively in the outflow direction are the blended feed stream (3) in the heat exchanger (20) and the hydrogenated gas stream (5) in the heat exchanger (23).
), passed through the reactor (27) for gas phase hydrogenation in fixed bed contact, and as stream (10), stream (3)
or through a heat exchanger (19) and a heat exchanger (22) for heat exchange with stream (5) and an intermediate separator (28) for separation of the hot oil fraction (11); By, the flow (
12) for heat exchange with stream (3) or stream (5), a heat exchanger (18) and a heat exchanger (21), a cooling water heat exchanger (31) and a cryogenic separator (29); supplied to
2. Process according to claim 1, characterized in that separation of waste water and waste gas, collection of a cold oil fraction (13) and reflux of the recycled hydrogenated gas component (15) take place. 3. A portion of the circulating hydrogenation gas stream is fed as a quench gas stream (16) to the liquid phase reactor (25), the gas phase reactor (27) and the high temperature separator (26) for temperature regulation. 3. A method according to claim 1 or 2, characterized in that: 4 A heat exchanger (20
) around the gas/steam side bypass or heat exchanger (23
4. Method according to claim 1, characterized in that a bypass on the gas side around ) is also used. 5 The supply of vacuum gas oil as stream (32) to the hot separator head product stream is supplied to the heat exchanger (20) or to the heat exchanger (
5. The process according to claim 1, characterized in that it is carried out before the gas phase reactor (23) or also immediately before the gas phase reactor (27). 6. The gas phase product is bypass-regulated on the gas side to the defined temperature of the intermediate separator (28).
By cooling in 2), the liquid phase component (
6. Process according to claim 1, characterized in that the head component (12) for the pure product is divided into: 11) and a head component (12) for the pure product. 7. A feedstock heat exchanger (19) in which the gas phase product is bypass-regulated to the defined temperature of the intermediate separator (28).
The liquid phase components (11
) and a head component (12) for the pure product. 8. According to one of claims 1 to 7, characterized in that the separately heated substreams (5) represent 20 to 95%, preferably 40 to 80%, of the total amount of hydrogenation gas used. the method of.