阅读说明：本技术 一种使用燃料气掺烧的硫回收工艺 (Sulfur recovery process by using fuel gas for blending combustion ) 是由 张虎存 温彦博 徐庆 王兴盛 吕洋 刘健童 史玉军 吕东荣 石磊 李水龙 张青 于 2021-07-07 设计创作，主要内容包括：本发明公开了一种使用燃料气掺烧的硫回收工艺,所述硫回收工艺通过硫回收装置实施,所述硫回收装置包括氧气流量调节阀、燃料气流量调节阀、氮气流量调节阀、主燃烧室、酸性气流量调节阀、主燃烧室炉膛、一级反应预热器、二级反应预热器、三级反应预热器,其回收工艺包括以下步骤,点火预处理、点火预热、催化预热和催化反应。本发明提出的硫回收工艺可以在酸性气浓度较低的情形下,仍然保证超级克劳斯硫回收主燃烧室不熄火,装置不停车,硫回收装置的硫回收率不受影响,依旧可对酸性气中99.1％的硫元素进行回收,硫回收尾气中SO2含量可以确保达标排放。(The invention discloses a sulfur recovery process by using fuel gas for co-combustion, which is implemented by a sulfur recovery device, wherein the sulfur recovery device comprises an oxygen flow regulating valve, a fuel gas flow regulating valve, a nitrogen flow regulating valve, a main combustion chamber, an acid gas flow regulating valve, a main combustion chamber hearth, a primary reaction preheater, a secondary reaction preheater and a tertiary reaction preheater. The sulfur recovery process provided by the invention can still ensure that the main combustion chamber of the super Claus sulfur recovery does not flameout, the device does not stop, the sulfur recovery rate of the sulfur recovery device is not affected under the condition of low concentration of the acid gas, 99.1% of sulfur element in the acid gas can be recovered, and the content of SO2 in the sulfur recovery tail gas can be ensured to be discharged after reaching the standard.)

1. A sulfur recovery process using fuel gas to mix combustion is characterized in that the sulfur recovery process is implemented by a sulfur recovery device, the sulfur recovery device comprises an oxygen flow regulating valve (1), a fuel gas flow regulating valve (2), a nitrogen flow regulating valve (3), a main combustion chamber (4), an acid gas flow regulating valve (5), a main combustion chamber hearth (6), a primary reaction preheater (7), a secondary reaction preheater (8), a tertiary reaction preheater (9), a quaternary reaction preheater (10), a sulfur cooler (11), four Claus catalytic reactors (12), an incinerator (13) and a tail gas chimney (14), the air inlet end of the main combustion chamber (4) is sequentially connected with the oxygen flow regulating valve (1), the fuel gas flow regulating valve (2), the nitrogen flow regulating valve (3) and the acid gas flow regulating valve (5), the first-stage reaction preheater (7), the second-stage reaction preheater (8), the third-stage reaction preheater (9) and the fourth-stage reaction preheater (10) are respectively connected with air inlets at the upper parts of four Claus catalytic reactors (12), the four Claus catalytic reactors (12) are sequentially communicated, the air outlet ends of the first three Claus catalytic reactors (12) are connected with the air inlet end of a sulfur cooler (11), the fourth Claus catalytic reactor (12) is connected with an incinerator (13), and the incinerator (13) is connected with a tail gas chimney (14);

the sulfur recovery process using fuel gas blending combustion comprises the following steps:

s1: performing ignition pretreatment, connecting and debugging each device, introducing nitrogen to purge each device before use, and ensuring that no residual impurities exist in the device before ignition;

s2: igniting and preheating, namely opening an oxygen flow regulating valve (1) and a fuel gas flow regulating valve (2) to ensure that the fuel gas flow and the oxygen flow are minimum flows capable of maintaining combustion, and igniting in a main combustion chamber hearth (6) of a main combustion chamber (4);

s3: the method comprises the following steps of (1) catalytic preheating, wherein medium-pressure steam is introduced to preheat a first-stage reaction preheater (7), a second-stage reaction preheater (8), a third-stage reaction preheater (9), a fourth-stage reaction preheater (10) and four Claus catalytic reactors (12), and after the catalytic reactors are heated to the design temperature, the flow of an oxygen flow regulating valve (1) and a fuel gas flow regulating valve (2) is adjusted to ensure that the fuel gas is fully combusted by 95%;

s4: and (3) carrying out catalytic reaction, opening the acid gas flow regulating valve (5), introducing acid gas, gradually increasing the acid gas to the maximum value, and controlling the proportion of oxygen and the acid gas to be 0.13 all the time by regulating the opening degree of the oxygen gas flow regulating valve (1): 1, gradually reducing the flow of the fuel gas after the combustion is stable but not completely withdrawing, and adjusting the flow of the fuel gas to control the temperature of the combustion chamber to be 950-1050 ℃.

2. The process of claim 1, wherein the fuel gas comprises mainly H2 and CO, and the content of organic alcohol ethers such as methanol, ethanol, dimethyl ether, etc. in the fuel gas is not higher than 1%.

Technical Field

The invention relates to the technical field of sulfur recovery, in particular to a sulfur recovery process using fuel gas co-combustion.

Background

Nowadays, the country and the society pay high attention to environmental protection, the country greatly improves the emission index requirements of the tail gas of chemical enterprises, and under the background, SO2 and H2S in the tail gas react to recover S elements, and the generated H2O and CO2 reach the emission standards, SO that the economic benefit is created in sulfur production, the sulfur content in the tail gas is reduced, and the two purposes are achieved. At present, the sulfur recovery method mainly comprises wet method and dry method desulfurization, wherein the super Claus process is the improvement of the traditional Claus process, and is widely applied due to the characteristics of less influence of excessive oxygen on reaction selectivity, continuous process, high sulfur recovery rate, low investment cost and the like. The main reaction mechanism of the current super Claus process is H2S + O2 → SO2+ H2O; H2S + SO2 → S + H2O. The specific operation mode is that fuel gas and air are firstly used for combustion in a main combustion chamber, after the temperature of the combustion chamber is raised to 1000 ℃, acid gas containing H2S is introduced and mixed with oxygen (air) in a certain proportion for combustion. And (3) feeding the unreacted H2S and the generated SO2 into a subsequent four-stage Claus catalytic reactor to generate sulfur and water, SO that the tail gas reaches the emission standard.

However, after the temperature of the main combustion chamber of the sulfur recovery device rises to 1000 ℃, the process device leads the acid gas containing H2S to be burnt with O2, and the concentration of the acid gas is required to be more than or equal to 40 percent so as to maintain the temperature of a hearth by using reaction heat generated by the reaction and ensure the continuous reaction. For production enterprises, production devices using natural gas and petroleum as raw materials have extremely low sulfur content of raw materials, while production devices using coal as raw materials have low sulfur content of high-quality coal in partial production places, and the concentration of generated acid gas cannot reach 40%, so that the gas amount participating in the reaction is reduced, and the generated reaction heat is not enough to maintain the combustion reaction to be carried out at the designed temperature, thereby causing flameout of a main combustion chamber.

Disclosure of Invention

Based on the technical problems in the background art, the invention provides a sulfur recovery process using fuel gas co-combustion.

The invention provides a sulfur recovery process by blending combustion of fuel gas, which is implemented by a sulfur recovery device, wherein the sulfur recovery device comprises an oxygen flow regulating valve, a fuel gas flow regulating valve, a nitrogen flow regulating valve, a main combustion chamber, an acid gas flow regulating valve, a main combustion chamber hearth, a primary reaction preheater, a secondary reaction preheater, a tertiary reaction preheater, a quaternary reaction preheater, a sulfur cooler, four Claus catalytic reactors, an incinerator and a tail gas chimney, the air inlet end of the main combustion chamber is sequentially connected with the oxygen flow regulating valve, the fuel gas flow regulating valve, the nitrogen flow regulating valve and the acid gas flow regulating valve, the primary reaction preheater, the secondary reaction preheater, the tertiary reaction preheater and the quaternary reaction preheater are respectively connected with the upper air inlets of the four Claus catalytic reactors, and the four Claus catalytic reactors are sequentially communicated, the air outlet ends of the first three Claus catalytic reactors are connected with the air inlet end of the sulfur cooler, the fourth Claus catalytic reactor is connected with the incinerator, and the incinerator is connected with the tail gas chimney;

the sulfur recovery process using fuel gas blending combustion comprises the following steps:

s1: performing ignition pretreatment, connecting and debugging each device, introducing nitrogen to purge each device before use, and ensuring that no residual impurities exist in the device before ignition;

s2: igniting and preheating, namely opening an oxygen flow regulating valve and a fuel gas flow regulating valve to ensure that the fuel gas flow and the oxygen flow are minimum flows capable of maintaining combustion, and igniting in a hearth of a main combustion chamber of the main combustion chamber;

s3: catalytic preheating, namely introducing medium-pressure steam to preheat and heat a primary reaction preheater, a secondary reaction preheater, a tertiary reaction preheater, a quaternary reaction preheater and four Claus catalytic reactors, and after the catalytic reactors are heated to the design temperature, ensuring that the fuel gas is fully combusted by adjusting the flow of an oxygen flow regulating valve and a fuel gas flow regulating valve;

s4: and (3) carrying out catalytic reaction, opening an acid gas flow regulating valve to introduce acid gas and gradually increasing the acid gas to a maximum value, and controlling the proportion of oxygen and the acid gas to be 0.13 all the time by regulating the opening degree of an oxygen gas flow regulating valve: 1, gradually reducing the flow of the fuel gas after the combustion is stable but not completely withdrawing, and adjusting the flow of the fuel gas to control the temperature of the combustion chamber to be 950-1050 ℃.

Preferably, the fuel gas components mainly comprise H2 and CO, and the content of organic alcohol ethers such as methanol, ethanol, dimethyl ether and dimethyl ether in the fuel gas is not higher than 1%.

The invention has the beneficial effects that:

the sulfur recovery process provided by the invention can still ensure that the main combustion chamber of the super Claus sulfur recovery does not flameout, the device does not stop, the sulfur recovery rate of the sulfur recovery device is not affected under the condition of low concentration of the acid gas, 99.1% of sulfur element in the acid gas can be recovered, and the content of SO2 in the sulfur recovery tail gas can be ensured to be discharged after reaching the standard.

Drawings

FIG. 1 is a schematic structural diagram of a sulfur recovery process using fuel gas blending according to the present invention.

In the figure: 1 oxygen flow control valve, 2 fuel gas flow control valve, 3 nitrogen flow control valve, 4 main combustion chamber, 5 acid gas flow control valve, 6 main combustion chamber furnace, 7 first-order reaction preheater, 8 second-order reaction preheater, 9 third-order reaction preheater, 10 fourth-order reaction preheater, 11 sulphur cooler, 12 claus catalytic reactor, 13 incinerator, 14 tail gas chimney.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

Example 1, referring to fig. 1, a sulfur recovery process using co-combustion of fuel gas, the sulfur recovery process being implemented by a sulfur recovery device, the sulfur recovery device including an oxygen flow regulating valve 1, a fuel gas flow regulating valve 2, a nitrogen flow regulating valve 3, a main combustion chamber 4, an acid gas flow regulating valve 5, a main combustion chamber furnace 6, a primary reaction preheater 7, a secondary reaction preheater 8, a tertiary reaction preheater 9, a quaternary reaction preheater 10, a sulfur cooler 11, four claus catalytic reactors 12, an incinerator 13, and a tail gas chimney 14, an air inlet end of the main combustion chamber 4 being connected to the oxygen flow regulating valve 1, the fuel gas flow regulating valve 2, the nitrogen flow regulating valve 3, and the acid gas flow regulating valve 5 in sequence, the primary reaction preheater 7, the secondary reaction preheater 8, the tertiary reaction preheater 9, and the quaternary reaction preheater 10 being connected to upper air inlets of the four claus catalytic reactors 12 respectively, the four Claus catalytic reactors 12 are sequentially communicated, the gas outlet ends of the first three Claus catalytic reactors 12 are connected with the gas inlet end of the sulfur cooler 11, the fourth Claus catalytic reactor 12 is connected with the incinerator 13, and the incinerator 13 is connected with the tail gas chimney 14;

the sulfur recovery process using fuel gas blending combustion comprises the following steps:

s1: performing ignition pretreatment, connecting and debugging each device, introducing nitrogen to purge each device before use, and ensuring that no residual impurities exist in the device before ignition;

s2: igniting and preheating, namely opening an oxygen flow regulating valve 1 and a fuel gas flow regulating valve 2 to ensure that the fuel gas flow and the oxygen flow are minimum flows capable of maintaining combustion, and igniting in a main combustion chamber hearth 6 of a main combustion chamber 4;

s3: catalytic preheating, namely introducing medium-pressure steam to preheat and heat a primary reaction preheater 7, a secondary reaction preheater 8, a tertiary reaction preheater 9, a quaternary reaction preheater 10 and four Claus catalytic reactors 12, and after the catalytic reactors are heated to the design temperature, ensuring that the fuel gas is fully combusted by adjusting the flow of an oxygen flow regulating valve 1 and a fuel gas flow regulating valve 2;

s4: and (3) carrying out catalytic reaction, opening the acid gas flow regulating valve 5 to introduce acid gas and gradually increasing the acid gas to the maximum value, and controlling the proportion of oxygen and the acid gas to be 0.13 all the time by regulating the opening degree of the oxygen gas flow regulating valve 1: 1, gradually reducing the flow of the fuel gas after the combustion is stable but not completely withdrawing, and adjusting the flow of the fuel gas to control the temperature of the combustion chamber to be 950-1050 ℃.

In the invention, the fuel gas components mainly comprise H2 and CO, and the content of alcohol ether organic matters such as methanol, ethanol, dimethyl ether and the like in the fuel gas is not higher than 1%.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.