CN104743524B - A kind of acid making system being suitable to hydrogen sulfide gas significantly variable - Google Patents

Abstract

The invention belongs to Chemical Manufacture environmental technology field, relate to a kind of acid making system being suitable to hydrogen sulfide gas significantly variable, adopting containing useless hydrogen sulfide gas is waste sulphuric acid, it is characterized in that this acid making system adopts two set reforming units, often set reforming unit all adopts " 3+2 " double-absorption technological process, i.e. A series and B series；Acid making system is provided with 3 air blower and 3 SO₂Blower fan, two open one standby, according to H in unstripped gas₂The supply situation of S, reforming unit runs in two kinds of situation。The acid making system of the present invention is fully able to reply petrochemical industry and the manufacturing enterprise such as natural gas purification, coal gasification, the production requirement of hydrogen sulfide significantly variable under different condition, the useless hydrogen sulfide waste gas of completely flexible its output of process extracting sulfuric acid。It is 1.34%-125% that the acid making system of the present invention can undertake the variable quantity of hydrogen sulfide。

Description

An acid production system suitable for large-scale variable hydrogen sulfide gas

technical field

The invention belongs to the technical field of chemical production and environmental protection, and relates to a system for preparing sulfuric acid by using waste hydrogen sulfide gas as a raw material.

Background technique

As we all know, the sulfuric acid production plant is generally determined by the sulfur content in the raw material to determine the production scale of the plant. The sulfur content in the raw material and the size of the sulfuric acid plant are causal. Once determined, the two cannot be changed. Of course, a small amount of short-term changes are possible, but they should not exceed 10%-20% of the design capacity of the device.

At present, in the production process of petroleum refining, natural gas purification and coal gasification in China, hydrogen sulfide gas and waste sulfuric acid liquid will appear. Let's take the treatment of waste hydrogen sulfide gas in the state-owned large petrochemical refining system as an example: most of them adopt foreign Claus method technology, Utilize waste hydrogen sulfide to directly produce sulfur, but the investment is relatively large. Small and medium-sized petrochemical refineries currently emit less hydrogen sulfide during the refining process, and generally choose wet technology mastered abroad and domestic dry technology, that is, use waste hydrogen sulfide gas to directly produce sulfuric acid, but for small and medium-sized enterprises, Regardless of wet or dry treatment of hydrogen sulfide gas, it is difficult to achieve in the production process, the reasons are as follows: 1. The current small and medium-sized petrochemical refineries have more than one refinery system, and some refineries have as many as three sets. Moreover, the source of waste hydrogen sulfide gas is not the same device. Due to the influence of crude oil supply or product price constraints, not all refineries of each enterprise are always put into production during the production process, so the output of waste hydrogen sulfide gas varies. It's huge.

2. Due to the unstable source of crude oil in every small and medium refinery in China, the sulfur content in crude oil in each region is not the same, the low sulfur content can reach 0.2%-0.3%, and the high sulfur content can reach more than 25% , which causes the uncertainty of the total amount of waste hydrogen sulfide exhaust gas. The difference between natural gas purification and coal gasification is only the magnitude of the sulfur content.

The above-mentioned reasons are the key to the difficulty of treating small and medium-sized oil refineries, natural gas purification, and coal gasification hydrogen sulfide tail gas.

At present, in order to solve this problem, domestic small and medium-sized oil refining enterprises basically adopt a set of sulfuric acid production equipment first, and burn hydrogen sulfide in the sulfur incinerator at the same time under the premise of mainly producing sulfuric acid to solve the problem. From the point of view of the purpose of treating waste hydrogen sulfide, firstly, the investment in waste hydrogen sulfide treatment has been increased, and secondly, the production of sulfuric acid in China has already been excessive, and this method has increased the burden of sulfuric acid in some areas.

Contents of the invention

The purpose of the present invention is to propose an acid production system suitable for the large variation of hydrogen sulfide gas.

The main technical scheme of the present invention: an acid production system suitable for large-scale variable hydrogen sulfide gas, using waste hydrogen sulfide gas as a raw material to produce sulfuric acid, characterized in that the acid production system uses two sets of conversion devices, each conversion device Adopt the "3+2" two-rotation and two-suction process flow, that is, A series and B series; two sets of heat exchangers are arranged, and the process of ⅢⅠ---ⅤⅣⅡ is adopted; the process of the A series or B series: from the drying tower After the furnace gas is boosted by the blower, the temperature is raised to 420--425°C through the third and first heat exchangers, and enters the first stage of the converter for reaction. The reacted gas is cooled by the first heat exchanger and then enters the second converter. The reacted gas enters the third-stage reaction of the converter after heat exchange and cooling in the second heat exchanger, and the reacted gas enters the first absorption tower after heat exchange and cooling in the third heat exchanger and economizer, and passes through The furnace gas after absorbing SO ₃ passes through the heat exchangers V, IV and II to heat up and then enters the fourth stage of the converter for reaction. Stage reaction, the reacted gas enters the second absorption tower to absorb SO ₃ after heat exchange and cooling in the fifth heat exchanger, and the absorbed furnace gas passes through the tail gas treatment device to absorb the residual SO ₂ to meet the national standard emission;

The acid system is equipped with 3 air fans and 3 SO ₂ fans, two open and one standby. According to the supply of H ₂ S in the raw gas, the conversion unit operates in two situations:

The first case: the amount of hydrogen sulfide gas is 30%-50% of the total design amount of the acid making system. After the hydrogen sulfide is burned, the furnace gas is dried, and after being boosted by a SO ₂ blower, it enters the A series according to the above process. For process operation, valves are installed on the B-series pipeline before entering the first absorption tower, on the B-series pipeline from the first absorption tower to the B-series pipeline, and on the B-series pipeline before entering the second absorption tower, so as to To control the gas entering the B series conversion device; or to run the B series, install valves on the relevant pipelines entering the A series;

The second situation: the amount of hydrogen sulfide gas is the total load of the design total amount of the acid making system. After drying, the furnace gas enters two SO ₂ fans to boost the pressure. The furnace gas after the primary conversion from the outlet of the coal burner is collected and enters the first absorption tower. The absorbed furnace gas enters the A and B series respectively in two ways for the second conversion. After coming out of the Ⅴ heat exchanger, they are aggregated into the second absorption tower, and then emptied after tail gas treatment.

The acid production system of the present invention can fully cope with the production requirements of large-scale variable hydrogen sulfide under different conditions in petrochemical, natural gas purification, coal gasification and other production enterprises, completely and flexibly process the waste hydrogen sulfide waste gas produced by it and produce sulfuric acid. The acid production system of the present invention can bear the variation of hydrogen sulfide in the range of 1.34%-125%.

Description of drawings

Figure 1 is a schematic diagram of the process flow of the present invention.

Fig. 2 is a schematic process flow diagram of an embodiment of the present invention.

detailed description

The present invention will be described in detail below in conjunction with the embodiments and the accompanying drawings.

Embodiment: An acid production system suitable for large-scale variation of hydrogen sulfide gas Referring to Figures 1 and 2, sulfuric acid is produced by using waste hydrogen sulfide gas as a raw material.

The acid system adopts two sets of reforming devices, each of which adopts the "3+2" two-transformation and two-absorption process, that is, the A series and the B series; two sets of heat exchangers are arranged, and the IIIⅠ---ⅤⅣⅡ process is adopted; Describe the process of A series or B series: the furnace gas from the drying tower is boosted by the blower, then the temperature is raised to 420--425°C through the third and first heat exchangers, and enters the first stage of the converter for reaction. The gas after the reaction After heat exchange and cooling in the first heat exchanger, it enters the second-stage reaction of the converter, and the reacted gas enters the third-stage reaction of the converter after heat exchange and cooling in the second heat exchanger, and the reacted gas passes through the third heat exchanger and The economizer enters the first absorption tower after heat exchange and cooling, and the furnace gas after absorbing SO ₃ passes through the heat exchange of the fifth, fourth and second heat exchangers and then enters the fourth stage of the converter for reaction. The reacted gas passes through After the heat exchange and cooling of the fourth heat exchanger, it enters the fifth stage of the converter for reaction. After the heat exchange and cooling of the fifth heat exchanger, the reacted gas enters the second absorption tower to absorb SO ₃ , and the absorbed furnace gas is then treated with tail gas. After the device absorbs the residual SO ₂ , it reaches the national standard emission.

The acid making system of the embodiment is provided with 3 air fans and 3 SO2 fans, _two are on and one is on standby, and according to the supply of H2S in the raw gas, the conversion device operates in _two situations:

The first case: the amount of hydrogen sulfide gas is 30%-50% of the total design amount of the acid making system. After the hydrogen sulfide is burned, the furnace gas is dried, and after being boosted by a SO ₂ blower, it enters the A series according to the above process. For process operation, valves are installed on the B-series pipeline before entering the first absorption tower, on the B-series pipeline from the first absorption tower to the B-series pipeline, and on the B-series pipeline before entering the second absorption tower, so as to To control the gas entering the B series conversion device; or to run the B series, install valves on the relevant pipelines entering the A series;

The second situation: the amount of hydrogen sulfide gas is the total load of the design total amount of the acid making system. After drying, the furnace gas enters two SO ₂ fans to boost the pressure. The furnace gas after the primary conversion from the outlet of the coal burner is collected and enters the first absorption tower. The absorbed furnace gas enters the A and B series respectively in two ways for the second conversion. After coming out of the Ⅴ heat exchanger, they are aggregated into the second absorption tower, and then emptied after tail gas treatment.

It can be seen from the above examples that the acid production system of the present invention can cope with the production requirements of large-scale variable hydrogen sulfide under different conditions in petrochemical, natural gas purification, coal gasification and other production enterprises, and completely and flexibly process the waste hydrogen sulfide produced by it waste gas and produce sulfuric acid.

Claims (1)

1. An acid-making system suitable for large-scale variation of hydrogen sulfide gas, which uses waste hydrogen sulfide gas as a raw material to produce sulfuric acid, and is characterized in that the acid-making system adopts two sets of conversion devices, and each conversion device adopts "3 +2" two-rotation and two-suction process flow, that is, A series and B series; two sets of heat exchangers are arranged, using ⅢⅠ---ⅤⅣⅡ process; the process of the A series or B series: the furnace gas from the drying tower After being boosted by the blower, the temperature is raised to 420--425°C through the third and first heat exchangers, and enters the first-stage reaction of the converter, and the reacted gas enters the second-stage reaction of the converter after heat exchange and cooling by the first heat exchanger. The reacted gas enters the third stage of the converter after heat exchange and cooling by the second heat exchanger, and then enters the first absorption tower after heat exchange and cooling by the third heat exchanger and economizer, and absorbs SO ₃ The final furnace gas enters the fourth stage of the reformer for reaction after heat exchange by the fifth, fourth and second heat exchangers, and the reacted gas enters the fifth stage of the reformer for reaction after heat exchange and cooling by the fourth heat exchanger. The reacted gas enters the second absorption tower to absorb SO ₃ after being heat-exchanged and cooled by the fifth heat exchanger, and the absorbed furnace gas then passes through the tail gas treatment device to absorb the residual SO ₂ to meet the national standard for emission; The acid system is equipped with 3 air fans and 3 SO ₂ fans, two open and one standby. According to the supply of H ₂ S in the raw gas, the conversion unit operates in two situations: The first case: the amount of hydrogen sulfide gas is 30%-50% of the total design amount of the acid making system. After the hydrogen sulfide is burned, the furnace gas is dried, and after being boosted by a SO ₂ blower, it enters the A series according to the above process. For process operation, valves are installed on the B-series pipeline before entering the first absorption tower, on the B-series pipeline from the first absorption tower to the B-series pipeline, and on the B-series pipeline before entering the second absorption tower, so as to To control the gas entering the B series conversion device; or to run the B series, install valves on the relevant pipelines entering the A series; The second situation: the amount of hydrogen sulfide gas is the total load of the design total amount of the acid making system. After drying, the furnace gas enters two SO ₂ fans to boost the pressure. The furnace gas after the primary conversion from the outlet of the coal burner is collected and enters the first absorption tower. The absorbed furnace gas enters the A and B series respectively in two ways for the second conversion. After coming out of the Ⅴ heat exchanger, they are aggregated into the second absorption tower, and then emptied after tail gas treatment.