阅读说明：本技术 硫化型加氢催化剂及制备方法和硫磺装置绿色开工方法 (Vulcanization type hydrogenation catalyst, preparation method thereof and green start-up method of sulfur device ) 是由 刘爱华 刘增让 宫超 刘剑利 陶卫东 徐翠翠 常文之 张艳松 吕才山 郝国杨 于 2018-07-27 设计创作，主要内容包括：硫化型加氢催化剂及制备方法和硫磺装置绿色开工方法,属于硫磺回收技术领域。其特征在于,质量百分比组成为：氧化铝54.2%~84.5%,二氧化硅5%~45%,扩孔剂0.2%~2%,粘结剂0.2%~1%,三氧化钼5%~15%,氧化钴1%~3%。步骤：将氢氧化铝干胶和白炭黑混合均匀,加入扩孔剂、粘结剂,再将钴盐溶于稀酸加入,经挤条、干燥、焙烧后制成复合载体；采用络合剂将活性组份钼浸渍于复合载体上,干燥焙烧即得硫化型加氢催化剂。在惰性气体存在下装填于硫磺装置加氢反应器使用。本发明开工过程不用硫化,易操作、缩短开工时间,实现硫磺装置的绿色开工。(A vulcanization type hydrogenation catalyst, a preparation method thereof and a green start-up method of a sulfur device, belonging to the technical field of sulfur recovery. The composite material is characterized by comprising the following components in percentage by mass: 54.2-84.5% of aluminum oxide, 5-45% of silicon dioxide, 0.2-2% of a pore-expanding agent, 0.2-1% of a binder, 5-15% of molybdenum trioxide and 1-3% of cobalt oxide. The method comprises the following steps: uniformly mixing the aluminum hydroxide dry glue and the white carbon black, adding a pore-expanding agent and a binder, dissolving cobalt salt in dilute acid, adding, extruding, drying and roasting to prepare a composite carrier; and (3) impregnating the active component molybdenum on the composite carrier by using a complexing agent, drying and roasting to obtain the sulfide hydrogenation catalyst. Loading the mixture into a hydrogenation reactor of a sulfur plant in the presence of inert gas for use. The invention has the advantages of no need of vulcanization in the start-up process, easy operation, shortened start-up time and realization of green start-up of the sulfur device.)

1. A vulcanization type hydrogenation catalyst is characterized by comprising the following components in percentage by mass: 54.2-84.5% of aluminum oxide, 5-45% of silicon dioxide, 0.2-2% of a pore-expanding agent, 0.2-1% of a binder, 5-15% of molybdenum trioxide and 1-3% of cobalt oxide.

2. The sulfided hydrogenation catalyst of claim 1, wherein: the hole expanding agent is sesbania powder and accounts for 1% by mass.

3. The sulfided hydrogenation catalyst of claim 1, wherein: the binder is water glass and accounts for 0.5 percent by mass.

4. A process for preparing a sulfided hydrogenation catalyst as claimed in claim 1, wherein: the method comprises the following steps:

A) uniformly mixing 54.2-84.5 parts of aluminum hydroxide dry glue and 5-45 parts of fumed silica according to parts by weight, adding 0.2-2 parts of pore-expanding agent and 0.2-1 part of binder, dissolving 1-3 parts of cobalt salt in dilute acid, adding, extruding, drying, and roasting at 400-700 ℃ for 2-6 hours to prepare a composite carrier;

B) and (2) soaking 5-15 parts of active component molybdenum on the composite carrier by using a complexing agent, drying, and roasting at 120-250 ℃ for 2-6 hours to obtain the vulcanization type hydrogenation catalyst.

5. The process for preparing a sulfided hydrogenation catalyst as claimed in claim 4, wherein: the pore volume of the aluminum hydroxide dry glue is more than or equal to 0.8 ml/g; the specific surface area is more than or equal to 400m²(ii)/g; the specific surface area of the fumed silica is more than or equal to 300m²/g。

6. The process for preparing a sulfided hydrogenation catalyst as claimed in claim 4, wherein: the roasting temperature in the step A) is 520-570 ℃, and the roasting time is 3.5-4.5 h.

7. The process for preparing a sulfided hydrogenation catalyst as claimed in claim 4, wherein: the cobalt salt is one or any compound of more than two of basic cobalt carbonate, cobalt carbonate or cobalt acetate, and the dilute acid is citric acid and phosphoric acid in a mass ratio of 1: 0.8 to 1.3 of a combined dilute acid.

8. The process for preparing a sulfided hydrogenation catalyst as claimed in claim 4, wherein: the active component molybdenum is ammonium tetrathiomolybdate, and the complexing agent is one or more of organic amine, alcohols or ethanolamine.

9. A green start-up method of a sulfur device is characterized by comprising the following steps:

1) loading the sulfided hydrogenation catalyst of any of claims 1-3 into a sulfur plant hydrogenation reactor in the presence of an inert gas;

2) purging the hydrogenation reactor with inert gas at an airspeed of 200h^-1~800 h^-1Controlling;

3) establishing inert gas circulation after purging is finished, sequentially passing through a tail gas heater, a hydrogenation reactor, a quench tower and an absorption tower, and putting into use after the inlet temperature of the hydrogenation reactor is raised to 200-230 ℃; simultaneously raising the temperature of the sulfur production part to the condition of introducing acid gas;

4) 2% -5% of hydrogen is introduced into the tail gas treatment system, and acid gas is introduced into the sulfur production part for starting operation.

10. The green startup method of a sulfur plant according to claim 9, characterized in that: and (3) filling the vulcanization type hydrogenation catalyst in the step 1) into a hydrogenation reactor of a sulfur device by adopting anaerobic operation.

Technical Field

A vulcanization type hydrogenation catalyst, a preparation method thereof and a green start-up method of a sulfur device, belonging to the technical field of sulfur recovery.

Background

According to the requirements of national emission standards for pollutants for the oil refining industry (GB 31570-2015), sulfur dioxide emission concentration limit for atmospheric pollutants for sulfur devices is performed at 7, 1/h in 2017, less than 400mg/Nm in dry ethanol, in particular less than 100mg/Nm in dry ethanol. The standards do not give specific requirements on the concentration of sulphur dioxide emissions during the start-up of a sulphur plant, and therefore the latest emission standards are also met during the start-up, which is a great challenge for sulphur plants, in particular for sulphur plants in start-up.

The sulfur device is divided into a sulfur production unit and a tail gas treatment unit, and the conventional start-up method comprises two methods: firstly, a sulfur production unit is started, after the sulfur production unit is stabilized, the Claus tail gas is led to a tail gas treatment unit, and H is controlled₂S/SO₂= 4-6, pre-vulcanizing the hydrogenation reactor of the tail gas unit, and pressing H after the pre-vulcanization is finished₂S-2SO₂If the control is switched to normal production, the method is long in start-up time and easy to cause incomplete vulcanization or temperature runaway of the catalyst, and the range of the control is-0.1 to-0.5. The other method adopts clean acid gas to pre-vulcanize directly, the hydrogenation catalyst is pre-vulcanized while the temperature of the sulfur production unit is raised, and the acid gas is introduced after vulcanization. Both methodsThe tail gas hydrogenation catalyst in an oxidation state is filled.

CN201610146533.X discloses a zero discharge shutdown process for sulfur recovery device, which comprises feeding flue gas into alkali solution absorption tower during start-up and baking at ①, feeding high-temperature flue gas into incinerator from tail gas separating tank for incineration during heating at ②, feeding the high-temperature flue gas into alkali solution absorption tower after recovering waste heat from tail gas waste heat boiler, pre-sulfurizing hydrogenation reactor catalyst with hydrogen sulfide in sulfur production process gas during pre-sulfurization at ③, controlling the concentration with ratio analyzer, introducing hydrogenated tail gas into incinerator from quenching tower for incineration, and absorbing SO with alkali solution absorption tower₂. The method uses an oxidation state tail gas hydrogenation catalyst which is used after being vulcanized on a device, and the start-up process is only to use SO in a gas phase₂Transfer to the liquid phase does not achieve a truly zero emission.

CN202829575U discloses a sulfur device, which introduces raw material acid gas into a hydrogenation reactor to carry out prevulcanization of hydrogenation catalyst while raising the temperature of the whole sulfur device at the start-up point of the furnace, thereby realizing synchronous start-up of a Claus unit and a tail gas purification unit. The device still fills oxidation state catalyst, still exists and starts a worker complicatedly, and phenomenons such as temperature runaway easily appear in the catalyst vulcanization process.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: overcomes the defects of the prior art, and provides a method for greatly reducing the flue gas SO in the process of start-up₂A sulfuration type hydrogenation catalyst with discharge, easy operation and short start-up time, a preparation method and a green start-up method of a sulfur device.

The technical scheme adopted by the invention for solving the technical problems is as follows: the vulcanization type hydrogenation catalyst is characterized by comprising the following components in percentage by mass: 54.2-84.5% of aluminum oxide, 5-45% of silicon dioxide, 0.2-2% of a pore-expanding agent, 0.2-1% of a binder, 5-15% of molybdenum trioxide and 1-3% of cobalt oxide.

The invention provides a vulcanization type tail gas hydrogenation catalyst which is filled in a hydrogenation reactor by adopting anaerobic operation to realize green start-up of a sulfur device,the method does not need vulcanization in the process of start-up, and can greatly reduce the flue gas SO in the process of start-up₂Discharging to ensure the flue gas SO during the start-up₂The emission always meets the national emission standard. The filled tail gas hydrogenation catalyst is of a vulcanization type, so that the catalyst is not required to be vulcanized after being filled, a series of problems such as catalyst temperature runaway and the like caused in the vulcanization process are avoided, the energy consumption of the device is saved by more than 20% during the start-up period, the operation is easy, the start-up time is shortened, the practical problem of overproof emission in the start-up process of the sulfur device is solved, and the green start-up of the sulfur device is realized.

The pore-expanding agent is one or more of sesbania powder, polyvinyl alcohol and polyethylene glycol. Preferably, the pore-expanding agent is sesbania powder and accounts for 1% by mass.

In the invention, the binder is nitric acid and water glass; preferably, the binder is water glass and accounts for 0.5% by mass.

A preparation method of a vulcanization type hydrogenation catalyst is characterized by comprising the following steps: the method comprises the following steps:

A) uniformly mixing 54.2-84.5 parts of aluminum hydroxide dry glue and 5-45 parts of fumed silica according to parts by weight, adding 0.2-2 parts of pore-expanding agent and 0.2-1 part of binder, dissolving 1-3 parts of cobalt salt in dilute acid, adding, extruding, drying, and roasting at 400-700 ℃ for 2-6 hours to prepare a composite carrier;

B) and (2) soaking 5-15 parts of active component molybdenum on the composite carrier by using a complexing agent, drying, and roasting at 120-250 ℃ for 2-6 hours to obtain the vulcanization type hydrogenation catalyst.

Preferably, the pore volume of the aluminum hydroxide dry glue is more than or equal to 0.8 ml/g; the specific surface area is more than or equal to 400m²(ii)/g; the specific surface area of the fumed silica is more than or equal to 300m²(ii) in terms of/g. The pore volume of the used aluminum hydroxide dry glue is preferably more than or equal to 1.0 ml/g; the specific surface area is preferably more than or equal to 450m²(ii) in terms of/g. Selecting the specific surface area of the white carbon black to be more than or equal to 330m by a gas phase method²/g。

Preferably, the roasting temperature is 520-570 ℃, and the roasting time is 3.5-4.5 h.

Preferably, the cobalt salt is any compound of one or more than two of basic cobalt carbonate, cobalt carbonate or cobalt acetate, the diluted acid in the invention can meet the basic production requirement by using one or more than two of citric acid, phosphoric acid and acetic acid, but the preferable diluted acid is the mixture of citric acid and phosphoric acid according to the mass ratio of 1: 0.8-1.3 of combined diluted acid; better impregnation effect can be ensured.

Preferably, the active component molybdenum is ammonium tetrathiomolybdate, and the complexing agent is one or more of organic amine, alcohols or ethanolamine.

A green start-up method of a sulfur device is characterized by comprising the following steps:

1) loading the sulfided hydrogenation catalyst of any of claims 1-3 into a sulfur plant hydrogenation reactor in the presence of an inert gas;

2) purging the hydrogenation reactor with inert gas at an airspeed of 200h^-1~800 h^-1Controlling;

3) establishing inert gas circulation after purging is finished, sequentially passing through a tail gas heater, a hydrogenation reactor, a quench tower and an absorption tower, and putting into use after the inlet temperature of the hydrogenation reactor is raised to 200-230 ℃; simultaneously raising the temperature of the sulfur production part to the condition of introducing acid gas;

4) 2% -5% of hydrogen is introduced into the tail gas treatment system, and acid gas is introduced into the sulfur production part for starting operation.

A green start-up method of a sulfur device is widely applied to the start-up process of the sulfur device in industries such as petroleum refining, natural gas purification, coal chemical industry and the like, and is particularly suitable for the sulfur device which cannot introduce acid gas in the initial start-up stage caused by some reasons. The sulfuration type hydrogenation tail gas hydrogenation catalyst is filled in a hydrogenation reactor by adopting anaerobic operation, SO that green start-up of a sulfur device is realized, vulcanization is not needed in the start-up process of the method, and the flue gas SO in the start-up process can be greatly reduced₂Discharging to ensure the flue gas SO during the start-up₂The emission always meets the national emission standard, the operation is easy, the temperature runaway phenomenon of a catalyst bed layer during the vulcanization period can be effectively avoided, the start-up time is shortened, and the method is widely applied to the start-up process of sulfur devices in the industries of petroleum refining, natural gas purification, coal chemical industry and the like.

Preferably, in step 1), the vulcanization type addition is performedThe hydrogen catalyst is filled in a hydrogenation reactor of the sulfur device by adopting anaerobic operation. The anaerobic operation method comprises the steps of searching a proper nitrogen supplementing point, establishing nitrogen circulation or replacing a hydrogenation reactor in an anaerobic state, performing micro-positive pressure on the hydrogenation reactor, and performing O treatment on the operation environment₂And combustible gas and toxic and harmful gas are detected, and anaerobic operation conditions are ensured.

The appearance of the vulcanization type hydrogenation catalyst is phi 3 clover or clover bar catalyst.

Operating each device of the sulfur production part in the step 3) according to normal working conditions, controlling the temperature of a hearth of a reaction furnace to be between 900 ℃ and 1400 ℃, preferably between 1000 ℃ and 1300 ℃, the temperature of a primary reactor bed to be between 300 ℃ and 400 ℃, preferably between 320 ℃ and 330 ℃, the temperature of a secondary reactor bed to be between 220 ℃ and 240 ℃, preferably between 220 ℃ and 230 ℃, the temperature of a hydrogenation reactor bed to be not more than 250 ℃ and 350 ℃, preferably between 300 ℃ and 330 ℃, the temperature of an absorption tower top to be between 20 ℃ and 42 ℃, preferably between 25 ℃ and 35 ℃, and H in the regenerated lean solution₂The S concentration is 0.5g/L or less, preferably 0.2g/L or less. The outlet temperature of the process gas of the primary sulfur condenser, the secondary sulfur condenser and the tertiary sulfur condenser is controlled to be 140-150 ℃. The method avoids a series of problems of catalyst temperature runaway and the like caused by a vulcanization process, saves the energy consumption of the device by more than 20 percent during the start-up period, is easy to operate, shortens the start-up time, solves the problem of excessive emission in the start-up process of the sulfur device, and realizes the green start-up of the sulfur device.

The start-up process of the invention is not only limited to a sulfur device adopting a gas-gas heat exchange mode, but also applicable to sulfur devices of processes such as high-temperature blending, electric heating, heating furnaces and the like.

The nitrogen start-up cycle process is not limited to nitrogen, and other inert gases relative to a sulfur device are also suitable.

In the nitrogen start-up circulation process, the adding position of the nitrogen is not limited to be in front of the three-stage heat exchanger, and the nitrogen start-up circulation process is also suitable for other positions.

The inlet temperature of the tail gas introduced into the hydrogenation reactor in the step 3) is 180-250 ℃, and preferably 200-230 ℃.

The catalyst is a vulcanization type Claus tail gas hydrogenation catalyst, avoids the vulcanization process of the start-up catalyst, further simplifies the start-up, and avoids a series of problems of catalyst temperature runaway and the like caused by the start-up process.

The invention adopts the special vulcanized Jiaqing catalyst to start work, adopts nitrogen to establish a new circulating system, can reduce the start time of a sulfur device by more than 30 hours, and reduces the flue gas SO in the start process₂The discharge is less than 100mg/m³And the standard discharge in the start-up process is realized.

In the start-up process, the hydrogen at the outlet of the hydrogenation reactor is required to be controlled to be 1-5%, and preferably 2-5%.

The sulfuration type sulfur tail gas hydrogenation catalyst is filled in a hydrogenation reactor, so that green start-up of a sulfur device is realized, the sulfuration type sulfur tail gas hydrogenation catalyst is mainly suitable for the start-up process of the sulfur device in industries such as petroleum refining, natural gas purification and coal chemical industry, and is particularly suitable for the sulfur device in which acid gas cannot be introduced at the start-up initial stage caused by some reasons. Because the vulcanization type hydrogenation catalyst is filled, the vulcanization process is avoided in the start-up process, and the start-up time and a series of problems brought by the vulcanization process are greatly shortened.

The invention can lead the flue gas SO in the start-up process₂The discharge is less than 100mg/m³And the standard discharge of the device in the process of starting is realized.

Compared with the prior art, the invention has the beneficial effects that: the invention develops an environment-friendly startup method of a sulfur device, which is mainly suitable for the startup process of the sulfur device in the industries of petroleum refining, natural gas purification, coal chemical industry and the like, and is particularly suitable for the sulfur device in which acid gas cannot be introduced at the initial startup stage caused by some reasons. Compared with the prior art, the method has the following positive effects: (1) provides a vulcanization type Claus tail gas hydrogenation catalyst which has high activity and meets the hydrogenation requirement of the latest environmental protection standard. (2) Provides a green start-up method of a sulfur device, which comprises the steps of filling a vulcanization type Claus tail gas hydrogenation catalyst into a hydrogenation reactor by adopting anaerobic operation, and carrying out hydrogenation on the hydrogenation reactor under the micro-positive pressure condition of nitrogen after fillingNitrogen purging with nitrogen purging amount of 200h at space velocity^-1~800 h^-1Controlling, establishing nitrogen circulation after purging is finished, sequentially passing through tail gas heating, a hydrogenation reactor, a quench tower and an absorption tower, and putting into use after the inlet temperature of the hydrogenation reactor is raised to 200-220 ℃, SO that green start-up of a sulfur device is realized₂The discharge is less than 100mg/m³(ii) a (3) Provides a new technology for avoiding direct vulcanization on a sulfur device, can avoid on-line vulcanization of a sulfur tail gas hydrogenation catalyst, and shortens the start-up time.

Drawings

FIG. 1 is a schematic diagram of the nitrogen circulation steps during sulfur start-up of the present invention.

Wherein, the system comprises 1, 2 nitrogen, 3 three-stage heat exchangers, 4 hydrogenation reactors, 5 start-up circulation lines, 6 steam generators, 7 quench towers, 8 absorption towers, 9 regeneration towers, 10 incinerators and chimneys.

Detailed Description

The invention is further illustrated by the following specific examples, of which example 1 is the best mode of practice.

Referring to figure 1: the normal operation of sulfur production unit intensifies, and tail gas hydrogenation unit establishes nitrogen gas circulation, and nitrogen gas 1 gets into tail gas circulation system after passing through tertiary heat exchanger 2 heating, passes through hydrogenation ware 3, steam generator 5, quench tower 6 in proper order, along start-up circulation line 4 return to tertiary heat exchanger 2 anterior. The nitrogen circulation volume is 200h at the airspeed^-1~800h^-1Controlling the temperature rise rate to be 20-30 ℃/h; when the inlet temperature of the hydrogenation reactor reaches 220-230 ℃, the temperature is kept constant, and the condition of receiving acid gas is achieved. When the parameters of the sulfur production and tail gas hydrogenation units are normally operated, the acid gas is directly introduced into the sulfur, and the sulfur production tail gas enters a hydrogenation reactor so as to be converted into normal production.

The hydrogenation reactor 3 is filled with a vulcanization type hydrogenation catalyst, and SO in the sulfur production tail gas is generated under the action of the catalyst₂、COS、CS₂Hydro-hydrolysis of iso-sulfur compounds to H₂S，H₂S enters into regeneration after being absorbed by a quench tower 6 and an absorption tower 7And in the tower 8, the purified gas from the top of the absorption tower is incinerated by an incinerator 9 and then discharged to a chimney 10. The invention can lead the flue gas SO in the start-up process₂The discharge is less than 100mg/m³The device realizes the standard discharge in the process of starting the device, reduces the operation steps of starting the device and shortens the time of starting the device by about 30 hours.