Syngas preparation and waste heat recovery process and process system

Abstract

The present invention discloses a synthesis gas preparation and waste heat recovery process and process system. The process system includes a non-catalytic partial oxidation chamber and one or more turbine chambers. The synthesis gas outlet of the non-catalytic partial oxidation chamber is connected to the synthesis gas inlet of the turbine chamber through a pipeline; the turbine chamber includes a casing, a power turbine located in the casing and its support shaft, and a power output shaft fixedly connected to the support shaft; the power output shaft is connected to a turbine generator; the synthesis gas outlet of the turbine chamber is connected to a steam generator, and the steam outlet of the steam generator is connected to a steam turbine generator. The process system can prepare synthesis gas and efficiently utilize the waste heat of synthesis gas, and the process is simple and safe.

Description

Technical Field

[0001] The invention relates to a synthesis gas preparation and waste heat recovery process and a process system. Background Art

[0002] The preparation of synthesis gas by non-catalytic partial oxidation of gaseous hydrocarbons is an important method for preparing synthesis gas in chemical production processes. The gaseous hydrocarbons can be natural gas, coke oven gas, waste gas, refinery gas, etc. The preparation of synthesis gas by non-catalytic partial oxidation of gaseous hydrocarbons mainly involves passing gaseous hydrocarbons, air / oxygen, water vapor and other raw materials into the reformer, and a series of chemical reactions occur in the furnace to generate synthesis gas. In traditional processes, waste heat boilers are usually used to recover the sensible heat of high-temperature synthesis gas, and the steam generated by the waste heat boiler can enter the steam turbine for power generation. However, the process of recovering heat by using waste heat boilers and then using steam turbines for power generation is complicated and has low heat utilization. In addition, a large amount of heat is released during the synthesis gas generation process, making the temperature of the generated synthesis gas as high as about 1300°C, while the heat resistance temperature of the waste heat boiler is usually only 800-900°C. During the heat recovery process, the waste heat boiler is difficult to withstand high temperatures and is easily damaged, with poor safety. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the traditional process for preparing synthesis gas, such as complex heat recovery process of high-temperature synthesis gas, low heat utilization rate, poor safety, etc., and to provide a synthesis gas preparation and waste heat recovery process and process system. The synthesis gas prepared by the process system can effectively recover the heat of high-temperature synthesis gas, and the process is simple and safe.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] The present invention provides a synthesis gas preparation and waste heat recovery process system, which includes a non-catalytic partial oxidation chamber and one or more turbine chambers, the synthesis gas outlet of the non-catalytic partial oxidation chamber is connected to the synthesis gas inlet of the turbine chamber through a pipeline; the turbine chamber includes a casing, a power turbine located in the casing and its supporting shaft, and a power output shaft fixedly connected to the supporting shaft, and the power output shaft is connected to a turbine generator; the synthesis gas outlet of the turbine chamber is connected to a steam generator, and the steam outlet of the steam generator is connected to a steam turbine generator.

[0006] In the present invention, the non-catalytic partial oxidation chamber may be a conventional reformer used in the art for preparing synthesis gas by non-catalytic partial oxidation method, and the reformer may be a top burner furnace or a side wall burner furnace.

[0007] In the present invention, the casing is preferably a volute structure to facilitate the extraction of the synthetic gas.

[0008] In the present invention, the power turbine may be a single-stage or multi-stage power turbine. The power turbine may be an axial flow turbine or a radial turbine, preferably an axial flow turbine. The turbine blades of the power turbine are preferably provided with a film cooling structure. The power turbine is preferably a multi-stage axial flow turbine with film cooling.

[0009] In the present invention, the power output shaft and the turbine generator may be connected in the following manner: the power output shaft is directly connected to the turbine generator; or the power output shaft is connected to the turbine generator via a gear box.

[0010] In the present invention, the steam generator may be a conventional steam generator in the art, which can utilize the heat of the synthesis gas from the outlet of the turbine chamber to heat water to generate steam. The steam generating device is preferably a boiler.

[0011] In the present invention, the turbine generator may be a conventional turbine generator in the art, which generates electricity by driving a turbine. The steam turbine generator may be a conventional steam turbine generator in the art, which generates electricity by driving steam.

[0012] The present invention also provides a synthesis gas preparation and waste heat recovery process, which is carried out in the above-mentioned synthesis gas preparation and waste heat recovery process system, comprising the following steps:

[0013] (1) the feed gas undergoes a non-catalytic partial oxidation reaction in the non-catalytic partial oxidation chamber to generate synthesis gas;

[0014] (2) The synthesis gas enters the turbine chamber, drives the power turbine to do work, and drives the turbine generator to generate electricity through the power output shaft;

[0015] (3) The synthesis gas enters the steam generator through the outlet of the turbine chamber, and the steam generator generates steam to drive the steam turbine generator to generate electricity;

[0016] Wherein, the raw gas includes (a) gaseous hydrocarbon substances, and (b) air and / or oxygen.

[0017] In the present invention, the gaseous hydrocarbon material can be one or more of natural gas, shale gas, coal bed gas, coke oven gas, waste gas and refinery gas. The methane content of the gaseous hydrocarbon material is preferably in the range of 5%-100%.

[0018] In the present invention, the raw gas preferably also includes (c) water vapor.

[0019] In the present invention, when natural gas, oxygen and water vapor are used as raw materials, the volume ratio of the natural gas, the oxygen and the water vapor is preferably 1:(0.65-0.85):(0-0.4).

[0020] In the present invention, when coke oven gas, oxygen and water vapor are used as raw materials, the volume ratio of the coke oven gas, the oxygen and the water vapor is preferably 1:(0.175-0.275):(0-0.1), and more preferably 1:0.23:0.023.

[0021] In the present invention, the temperature of the raw gas at the raw gas inlet of the non-catalytic partial oxidation chamber may be 90-250° C., preferably 220° C. The higher the temperature, the more oxygen consumption can be saved.

[0022] In the present invention, the pressure in the non-catalytic partial oxidation chamber may be 1.0-8.0 MPa, preferably 6.5 MPa.

[0023] In the present invention, the temperature in the non-catalytic partial oxidation chamber may be 1200-1350°C, preferably 1300°C.

[0024] In the present invention, no catalyst exists in the non-catalytic partial oxidation chamber.

[0025] In the present invention, the pressure of the syngas at the syngas inlet of the turbine chamber may be 1.0-8.0 MPa, preferably 6.5 MPa. The pressure of the syngas at the syngas outlet of the turbine chamber may be 0.1-0.5 times the pressure at the syngas inlet of the turbine chamber.

[0026] In the present invention, the temperature of the synthesis gas at the synthesis gas inlet of the turbine chamber may be 1200-1350°C, preferably 1300°C.

[0027] In the present invention, the temperature of the synthesis gas at the synthesis gas outlet of the turbine chamber may be 300-700°C, preferably 500-600°C.

[0028] In the present invention, the temperature of the synthesis gas at the synthesis gas outlet of the steam generator may be 120-180°C, preferably 140-160°C.

[0029] In the present invention, the synthesis gas may include carbon monoxide and hydrogen. When the gaseous hydrocarbon substance is natural gas, the volume ratio of the carbon monoxide to hydrogen is preferably 1: (1.7-2.6).

[0030] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0031] The reagents and raw materials used in the present invention are commercially available.

[0032] The positive progressive effect of the present invention is that the synthesis gas preparation and waste heat recovery process and process system of the present invention integrates a turbine generator and a steam turbine generator, uses a turbine chamber to recover the heat of the high-temperature synthesis gas synthesized in the non-catalytic partial oxidation chamber, and directly uses the high-temperature synthesis gas to drive the turbine blades to work to generate electricity. The synthesis gas coming out of the turbine chamber is further used to produce steam to drive the steam turbine generator to generate electricity. The waste heat utilization rate is high, the process is simple, and the safety is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the synthesis gas preparation and waste heat recovery process system of Example 1 of the present invention.

[0034] Figure 2 For the present invention Figure 1 Schematic diagram of the turbine chamber structure.

[0035] Description of reference numerals:

[0036] Non-catalytic partial oxidation chamber 1;

[0037] Turbine chamber 2, casing 21, power turbine 22, support shaft 23, power output shaft 24;

[0038] Gear box 3;

[0039] Turbine generator 4;

[0040] Steam generator 5;

[0041] Steam turbine generator 6. DETAILED DESCRIPTION

[0042] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0043] Example 1

[0044] A synthesis gas preparation and waste heat recovery process system, the structural schematic diagram of which is as follows Figure 1 and Figure 2As shown. The synthesis gas preparation and waste heat recovery process system includes a non-catalytic partial oxidation chamber 1 and a turbine chamber 2, the synthesis gas outlet of the non-catalytic partial oxidation chamber 1 is connected to the synthesis gas inlet of the turbine chamber 2 through a pipeline; the turbine chamber 2 includes a casing 21, a power turbine 22 located in the casing 21 and its support shaft 23, and a power output shaft 24 fixedly connected to the support shaft 23, and the power output shaft 24 is connected to the turbine generator 4 through a gear box 3; the synthesis gas outlet of the turbine chamber 2 is connected to the steam generator 5, and the steam outlet of the steam generator 5 is connected to the steam turbine generator 6. Among them, the casing 21 is a volute structure, and the power turbine 22 is a multi-stage axial flow turbine with air film cooling.

[0045] Examples of using this process system to prepare synthesis gas and recover waste heat are as follows:

[0046] (1) Coke oven gas (75,000 Nm 3 / h), oxygen (17270Nm 3 / h) and water vapor (1740Nm 3 / h) is introduced into a non-catalytic partial oxidation chamber 1 without a catalyst to carry out a non-catalytic partial oxidation reaction to generate synthesis gas; wherein the temperature of the raw gas at the raw gas inlet of the non-catalytic partial oxidation chamber 1 is 220°C, the pressure in the non-catalytic partial oxidation chamber 1 is 6.5MPa, and the temperature is 1300°C.

[0047] (2) The synthesis gas enters the turbine chamber 2, drives the power turbine 22 to do work, and drives the turbine generator 4 to generate electricity through the power output shaft 24 and the gear box 3; wherein, the pressure of the synthesis gas at the synthesis gas inlet of the turbine chamber 2 is 6.5 MPa and the temperature is 1300°C; the pressure of the synthesis gas at the synthesis gas outlet of the turbine chamber 2 is 0.8 MPa and the temperature is 525°C; the enthalpy difference between the inlet and outlet of the synthesis gas in the turbine chamber 2 is 38.1MW.

[0048] (3) The synthesis gas enters the steam generator 5 through the outlet of the turbine chamber 2. The steam generator 5 generates 20.8 t / h of 8.0 MPaG saturated steam (enthalpy value is 13.2 MW), which drives the steam turbine generator 6 to generate electricity. The temperature of the synthesis gas at the synthesis gas outlet of the steam generator 5 is 140°C.

[0049] The power generation efficiency of the turbine generator is 80%, and the power generation efficiency of the steam turbine generator is 50%. The output power is 38.1×0.8+13.2MW×0.5=37MW.

[0050] The coke oven gas (75,000 Nm 3 / h), oxygen (17270Nm 3 / h) and water vapor (1740Nm 3 / h) of raw gas to prepare synthesis gas, and connect a fire tube boiler after the reformer to produce 86t / h of 8.0MPaG saturated steam (enthalpy value is 55.4MW), which drives the steam turbine generator to generate electricity. The steam turbine power generation efficiency is 50%, and the output power is 55.4MW×0.5=27.7MW. The power generation of the process system of the present invention increases by 34% compared with the conventional method. It can be seen that the process system of the present invention can prepare synthesis gas and efficiently utilize the waste heat of synthesis gas.

Claims

1. A synthesis gas preparation and waste heat recovery process, characterized in that: It is carried out in a synthesis gas preparation and waste heat recovery process system, which includes a non-catalytic partial oxidation chamber and one or more turbine chambers, the synthesis gas outlet of the non-catalytic partial oxidation chamber is connected to the synthesis gas inlet of the turbine chamber through a pipeline; the non-catalytic partial oxidation chamber is a top burner furnace or a side wall burner furnace; the turbine chamber includes a casing, a power turbine located in the casing and its support shaft, and a power output shaft fixedly connected to the support shaft, and the power output shaft is connected to a turbine generator; the synthesis gas outlet of the turbine chamber is connected to a steam generator, and the steam outlet of the steam generator is connected to a steam turbine generator; The synthesis gas preparation and waste heat recovery process comprises the following steps: (1) The feed gas undergoes a non-catalytic partial oxidation reaction in the oxidation chamber to generate synthesis gas; (2) The synthesis gas enters the turbine chamber, drives the power turbine to do work, and drives the turbine generator to generate electricity through the power output shaft; (3) The synthesis gas enters the steam generator through the outlet of the turbine chamber, and the steam generator generates steam to drive the steam turbine generator to generate electricity; The raw gas is coke oven gas, oxygen and water vapor, and the volume ratio of the coke oven gas, the oxygen and the water vapor is 1: (0.175-0.275): (0-0.1), but the content of water vapor does not take a value of 0; the methane content of the coke oven gas ranges from 5% to 100%; The temperature of the raw gas at the raw gas inlet of the non-catalytic partial oxidation chamber is 90-250° C.; the pressure in the non-catalytic partial oxidation chamber is 1.0-8.0 MPa; the temperature in the non-catalytic partial oxidation chamber is 1200-1350° C.; The pressure of the synthesis gas at the synthesis gas inlet of the turbine chamber is 1.0-8.0 MPa; The pressure of the synthesis gas at the synthesis gas outlet of the turbine chamber is 0.1 to 0.5 times the pressure at the synthesis gas inlet of the turbine chamber; The temperature of the synthesis gas at the synthesis gas inlet of the turbine chamber is 1200-1350° C.; The temperature of the synthesis gas at the synthesis gas outlet of the turbine chamber is 300-700° C.; The temperature of the synthesis gas at the synthesis gas outlet of the steam generator is 120-180°C.

2. The synthesis gas preparation and waste heat recovery process according to claim 1, characterized in that: When coke oven gas, oxygen and water vapor are used as raw materials, the volume ratio of the coke oven gas, the oxygen and the water vapor is 1:0.23:0.

023.

3. The synthesis gas preparation and waste heat recovery process according to claim 1, characterized in that: The temperature of the feed gas at the feed gas inlet of the non-catalytic partial oxidation chamber is 220° C. and / or, the pressure in the non-catalytic partial oxidation chamber is 6.5 MPa; And / or, the temperature in the non-catalytic partial oxidation chamber is 1300°C.

4. The synthesis gas preparation and waste heat recovery process according to claim 1, characterized in that: The pressure of the synthesis gas at the synthesis gas inlet of the turbine chamber is 6.5 MPa; and / or, the temperature of the syngas at the syngas inlet of the turbine chamber is 1300° C.; and / or, the temperature of the synthesis gas at the synthesis gas outlet of the turbine chamber is 500-600° C.; And / or, the temperature of the synthesis gas at the synthesis gas outlet of the steam generator is 140-160°C.

5. The synthesis gas preparation and waste heat recovery process according to claim 1, characterized in that: The casing is a volute structure, which is convenient for leading out the synthetic gas.

6. The synthesis gas preparation and waste heat recovery process according to claim 1, characterized in that: The power turbine is a single-stage or multi-stage power turbine; and / or, the power turbine is an axial flow turbine and a radial turbine; And / or, a film cooling structure is provided on the turbine blades of the power turbine.

7. The synthesis gas preparation and waste heat recovery process according to claim 6, characterized in that: The power turbine is an axial flow turbine.

8. The synthesis gas preparation and waste heat recovery process according to claim 6, characterized in that: The power turbine is a multi-stage axial flow turbine with air film cooling.

9. The synthesis gas preparation and waste heat recovery process according to claim 1, characterized in that: The power output shaft is directly connected to the turbine generator; or, the power output shaft is connected to the turbine generator through a gear box.

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