A deep processing technology for adjusting oxygen content of coke oven gas

Abstract

The application discloses a deep processing technology for adjusting oxygen content of coke oven gas, which comprises the following steps: coke oven gas oxygen mixing, compression purification, oxygen removal, hydrogenation desulfurization, deep processing and other process units, and the oxygen content of the coke oven gas is adjusted, and system heat and steam are supplemented. The process has the advantages of utilizing hydrogen components in the coke oven gas, hydrogenation without heat supplement, adjusting the oxygen content of the coke oven gas, further adjusting the hydrogen content, adjusting the production load and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high-efficiency deep processing of coke oven gas, and particularly relates to a deep processing process for adjusting the oxygen content of coke oven gas. BACKGROUND

[0002] The existing deep processing technology of coke oven gas is to convert 98% of organic sulfur into inorganic sulfur by pre-hydrogenation and first-stage hydrogenation, and then the coke oven gas enters a first-stage medium-temperature zinc oxide tank to remove hydrogen sulfide in the coke oven gas. The coke oven gas from the first-stage medium-temperature zinc oxide tank enters a second-stage hydrogenation reactor to further convert organic sulfur into inorganic sulfur, and then passes through a second-stage medium-temperature zinc oxide tank to remove residual organic sulfur. The second-stage desulfurization temperature is required to be 350-380 DEG C to remove trace organic sulfur. The oxygen content in the pre-hydrogenation gas fluctuates greatly between 0.1% and 0.8%, and the organic sulfur content fluctuates between 200 and 350 mg / m3, the reaction heat fluctuates greatly, the catalyst bed temperature changes greatly, and the reaction heat decreases at the end of the catalyst, which causes the bed temperature to change greatly. The temperature of the desulfurization system cannot be effectively controlled at 360-390 DEG C, and the design and production operation need to be supplemented by electric heating and heating furnace, which has small operation flexibility. SUMMARY

[0003] The application aims to provide a deep processing process for adjusting the oxygen content of coke oven gas.

[0004] In the present application, % means volume percentage unless otherwise specified.

[0005] The application solves the technical problems by adopting the technical scheme of a deep processing process for adjusting the oxygen content of coke oven gas, which comprises the following steps:

[0006] 1) Oxygen adjustment: according to the pre-hydrogenation hot spot temperature, the temperature is preferably controlled at 360-390 DEG C, and according to the oxygen content of the coke oven gas after the blower, the coke oven gas is automatically mixed with compressed air and nitrogen mixture according to the oxygen content of the coke oven gas before oxygen adjustment to adjust the oxygen content of the coke oven gas, preferably the oxygen content of the coke oven gas is less than 1.5%, and the maximum is less than 2%. According to the temperature change and the steam content, the temperature is automatically adjusted. According to the logic of reaction heat calculation, the oxygen content is adjusted. For every 0.1% increase in oxygen content, the reaction gas increases by 14 DEG C. According to the production load, the hydrogen content is adjusted. For every 1% increase in oxygen content of the coke oven gas, the hydrogen load is reduced by 2%.

[0007] 2) compression purification, after the pretreated coke oven gas, the macromolecular impurities in the coke oven gas are preliminarily removed by gas-liquid separation or adsorption, and then the coke oven gas is buffered and stored in a gas tank, and then is compressed by a compressor, and then is sent to a purification unit, and the coke oven gas is removed from the purification unit by washing, gas-liquid separation, adsorption, tar, naphthalene, ammonia and hydrogen cyanide impurities to the process requirement index, and the purified coke oven gas is sent to an oxygen removal unit;

[0008] 3) oxygen removal unit, the amount of oxygen removal agent catalyst used meets the operating load of the coke oven gas containing 0-2% of oxygen, the oxygen in the coke oven gas is removed by the reaction of oxygen and hydrogen, and the preheating pre-hydrogenation temperature and the first-stage hydrogenation temperature are adjusted according to the pre-hydrogenation and first-stage hydrogenation production load and the catalyst usage;

[0009] 4) hydrogenation desulfurization, by pre-hydrogenation and first-stage hydrogenation, the pre-hydrogenation and first-stage hydrogenation bed temperature is maintained at 360-390 DEG C, 98% of organic sulfur is converted into inorganic sulfur, and then the coke oven gas is sent to a first-stage medium-temperature zinc oxide tank to remove hydrogen sulfide in the coke oven gas, the coke oven gas from the first-stage medium-temperature zinc oxide tank is further sent to a second-stage hydrogenation reactor to further convert organic sulfur into inorganic sulfur, and then the remaining organic sulfur is removed through a second-stage medium-temperature zinc oxide tank, and the second-stage desulfurization temperature is required to be 350-380 DEG C to remove trace organic sulfur;

[0010] 5) deep processing unit: coke oven gas is synthesized into methanol and LNG, and hydrogen is co-produced or hydrogen is deeply processed.

[0011] Specifically, the opening degrees of the regulating valves for automatically adding air and nitrogen in the oxygen supply are consistent.

[0012] The present application has the following beneficial effects:

[0013] 1) The present application adjusts and utilizes hydrogen, an effective gas component originally present in the coke oven gas, to the greatest extent by increasing the oxygen content, utilizes reaction heat to reduce the coke oven gas consumption of electric heaters and heating furnaces, simultaneously utilizes reaction heat to generate steam, and the oxygen content in the coke oven gas fluctuates greatly between 0.1% and 0.8%, and the organic sulfur content fluctuates between 200 mg / m 3 At the end of the catalyst, the reaction heat is less, resulting in a large change in the bed temperature;

[0014] 2) According to the temperature change and the steam content, temperature automatic adjustment is realized, according to the reaction heat calculation, the reaction gas is increased by 14 DEG C for every 0.1% increase in the oxygen content, steam can be generated by utilizing the self-reaction heat, and carbon emission is reduced;

[0015] 3) The present application utilizes the surplus hydrogen to the greatest extent, reduces the coke oven gas consumption, cancels the electric heaters and heating furnaces, according to the organic sulfur content of the coke oven gas and the oxygen content, utilizes the self-reaction heat to reduce the electric heating, heating furnace and other heat supplement processes, and reduces the energy consumption and tail gas emission.

[0016] 4) According to the market situation and environmental weather conditions, and according to the product price of hydrogen, liquid ammonia, steam and the like in the subsequent process, the oxygen content is adjusted to adjust the hydrogen content of the coke oven gas, and the load of the subsequent processes such as hydrogen production and ammonia synthesis is adjusted. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The flow chart of the present application. DETAILED DESCRIPTION

[0018] The present application will now be further described in detail in conjunction with the accompanying drawings.

[0019] As Figure 1 A deep processing process for adjusting the oxygen content of coke oven gas, comprising the following steps: coke oven gas oxygen supply, compression purification, oxygen removal, hydrogenation desulfurization, deep processing and the like process units, by adjusting the oxygen content of the coke oven gas, supplementing the system heat and steam, the process has the advantages of utilizing the hydrogen component in the coke oven gas, hydrogenation without heat supplement, adjusting the oxygen content of the coke oven gas, adjusting the production load and the like.

[0020] 1) Oxygen supply: the coke oven gas is controlled at 200-300°C according to the pre-hydrogenation temperature, the oxygen content of the coke oven gas after the blower is adjusted according to the logical relationship, the mixture of compressed air and nitrogen is automatically supplied according to the online analyzer of the oxygen content of the coke oven gas before oxygen supply, the oxygen content of the coke oven gas is adjusted, the oxygen content of the coke oven gas is preferably <1.5%, and the maximum is <2%; according to the temperature change and the steam content, the temperature is automatically adjusted, the oxygen content is adjusted according to the logic of reaction heat calculation, the reaction gas is increased by 14°C for every 0.1% increase of the oxygen content; according to the production load, the hydrogen content is adjusted, the hydrogen load is reduced by 2% for every 1% increase of the oxygen content of the coke oven gas.

[0021] The detection of the gas purification is taken as the basis for the oxygen content of the coke oven gas, the coke oven gas temperature to be increased and the hydrogen load to be adjusted are calculated, the air and nitrogen automatic adjusting valves are accurately introduced according to the calculation, the air and nitrogen valve openings are consistent, and at the same time, the online analyzer of the oxygen content of the coke oven gas before compression is fed back to the adjusting valve to avoid excessive introduction of air.

[0022] 2) Compression purification: the coke oven gas from the coking is pretreated, the macromolecular impurities in the coke oven gas are preliminarily removed by using gas-liquid separation or adsorption, enters the gas tank for buffering and storage, and then enters the compressor for compression, and then is sent to the purification unit; the purification unit mainly removes the impurities such as tar, naphthalene, ammonia, hydrogen cyanide and the like in the coke oven gas to the process requirement index by means of washing, gas-liquid separation, adsorption and the like, and the purified coke oven gas is sent to the oxygen removal unit and the hydrogenation desulfurization unit.

[0023] 3) Oxygen removal unit, the amount of oxygen removal agent catalyst is generally cobalt-molybdenum catalyst, the loading amount is 10t-20t, which meets the operating load of the oxygen content of 0.5%-2% in the coke oven gas; through the reaction of oxygen and hydrogen, the oxygen in the coke oven gas is removed, according to the pre-hydrogenation and primary hydrogenation production load and the use of catalyst, the pre-heating pre-hydrogenation temperature and the primary hydrogenation temperature are adjusted, the boiler bypass and the steam production are adjusted, and the production load is adjusted to adjust the pre-hydrogenation and primary hydrogenation temperature.

[0024] 4) Hydrodesulfurization, through pre-hydrogenation and primary hydrogenation, the pre-hydrogenation and primary hydrogenation bed temperature is maintained at 360-390℃, 98% of organic sulfur is converted into inorganic sulfur, and then enters the primary medium-temperature zinc oxide tank to remove hydrogen sulfide in the coke oven gas; the coke oven gas from the primary medium-temperature zinc oxide tank further enters the secondary hydrogenation reactor to further convert organic sulfur into inorganic sulfur, and then passes through the secondary medium-temperature zinc oxide tank to remove the remaining organic sulfur; the secondary desulfurization temperature is required to be at 350-380℃, and trace organic sulfur is removed.

[0025] 5) Deep processing unit: coke oven gas is synthesized into methanol, LNG, co-produced hydrogen or hydrogen for deep processing.

[0026] Example 1:

[0027] The gas treatment capacity of a certain coking plant is 55000Nm 3 / h, the coke oven gas is used to produce LNG and co-produce synthetic ammonia, the oxygen content of the raw gas fluctuates between 0.1%-0.5%, the organic sulfur fluctuates between 150-250mg / m 3 , the pre-hydrogenation temperature before oxygen addition fluctuates between 300-370℃, and the primary hydrogenation inlet temperature fluctuates between 300-360℃.

[0028] (1) Oxygen addition: according to the pre-hydrogenation temperature and the oxygen content of the coke oven gas after the blower, according to the logical relationship, according to the online analyzer of the oxygen content of the coke oven gas before oxygen addition, the compressed air and nitrogen mixture is automatically added to adjust the oxygen content of the coke oven gas, and the oxygen content of the coke oven gas is less than 1.5%; according to the temperature change and the steam content, the temperature is automatically adjusted, the oxygen content is adjusted according to the logic of reaction heat calculation, and the reaction gas rises by 14℃ for every 0.1% increase in oxygen content.

[0029] (2) The detection of gas purification is used as the basis for the oxygen content of the coke oven gas, the required gas temperature and the hydrogen load are adjusted through logical calculation, the air and nitrogen automatic regulating valves are accurately introduced after calculation, the air and nitrogen valve openings are consistent, and at the same time, the online analyzer of the coke oven gas before compression is fed back to the regulating valve to avoid excessive introduction of air.

[0030] (3) compression purification, the coke oven gas from coking is pretreated, and large molecular impurities in the coke oven gas are preliminarily removed by gas-liquid separation or adsorption, enters a gas tank for buffering and storage, and then enters a compressor for compression, and then is sent to a purification unit; the coke oven gas is sent to an oxygen removal unit and a hydrogen desulfurization unit after impurities such as tar, naphthalene, ammonia and hydrogen cyanide in the coke oven gas are removed to process requirement indexes by mainly through washing, gas-liquid separation, adsorption and the like.

[0031] (4) oxygen removal unit, according to process requirements, the oxygen content in the coke oven gas is controlled to be 0.7-1%. Oxygen in the coke oven gas is removed by oxygen and hydrogen reaction, the preheating pre-hydrogenation temperature is adjusted to be 250-260 DEG C and the first-stage hydrogenation temperature is controlled to be higher than 330 DEG C according to pre-hydrogenation and first-stage hydrogenation production load and catalyst use, the pre-hydrogenation and first-stage hydrogenation bed temperature is maintained to be 375-380 DEG C, 98% of organic sulfur is converted into inorganic sulfur, and the organic sulfur fluctuates between 200-350 mg / m

[0032] (5) hydrogen desulfurization, through pre-hydrogenation and first-stage hydrogenation, the pre-hydrogenation and first-stage hydrogenation bed temperature is maintained to be 375-380 DEG C, 98% of organic sulfur is converted into inorganic sulfur, and the organic sulfur fluctuates between 200-350 mg / m 3 then enters a first-stage medium-temperature zinc oxide tank to remove hydrogen sulfide in the coke oven gas; the coke oven gas from the first-stage medium-temperature zinc oxide tank further enters a second-stage hydrogenation reactor to further convert organic sulfur into inorganic sulfur, and then passes through a second-stage medium-temperature zinc oxide tank to remove residual organic sulfur, and the second-stage desulfurization temperature is required to be 350-380 DEG C to remove trace organic sulfur.

[0033] (6) deep processing unit: coke oven gas synthesis LNG co-production liquid ammonia process; under the condition that the liquid ammonia price is relatively low, the oxygen content is increased by 0.5%, the hydrogen content is reduced by 1%, the ammonia compressor power consumption is reduced, the hydrogenation temperature is adjusted, and the electric heater is avoided to be started for temperature adjustment.

[0034] The present application is not limited to the above-mentioned embodiments, and any person should know that the structural changes made under the inspiration of the present application, any technical solution with the same or similar to the present application, falls within the protection scope of the present application.

[0035] The technical, shape and structure parts not described in detail in the present application are all known technologies.

Claims

1. A deep processing technology for adjusting the oxygen content of coke oven gas, characterized in that, Includes the following steps: 1) Oxygen Distribution: Based on the pre-hydrogenation temperature and the oxygen content of the coke oven gas after the blower, and according to the online oxygen content analyzer of the coke oven gas before oxygen distribution, the coke oven gas is automatically mixed with a mixture of compressed air and nitrogen to adjust the oxygen content of the coke oven gas, so that the oxygen content of the coke oven gas is <2%. The temperature is automatically adjusted according to temperature changes and steam content. The oxygen content is adjusted according to the logic of reaction heat calculation. For every 0.1% increase in oxygen content, the temperature of the reaction gas increases by 14°C. The hydrogen content is adjusted according to the production load. For every 1% increase in the oxygen content of the coke oven gas, the hydrogen load decreases by 2%. 2) Compression purification: The pretreated coke oven gas is initially removed by gas-liquid separation or adsorption to remove large molecular impurities. After entering the gas holder for buffering and storage, it is then compressed by the compressor and sent to the purification unit. The purification unit removes tar, naphthalene, ammonia, and hydrogen cyanide impurities from the coke oven gas to the required process parameters through washing, gas-liquid separation, and adsorption. The purified coke oven gas is then sent to the deoxygenation unit. 3) Deoxygenation unit: The amount of deoxygenating agent and catalyst used is sufficient to meet the operating load where the oxygen content of coke oven gas is 0-2%. The oxygen in the coke oven gas is removed through the reaction of oxygen and hydrogen. The preheating and pre-hydrogenation temperatures and the first-stage hydrogenation temperatures are adjusted according to the production load of pre-hydrogenation and primary hydrogenation and the catalyst usage. 4) Hydrodesulfurization: Through pre-hydrogenation and primary hydrogenation, the bed temperature of pre-hydrogenation and primary hydrogenation is maintained at 360-390℃, converting 98% of organic sulfur into inorganic sulfur. Then, it enters the primary medium-temperature zinc oxide tank to remove hydrogen sulfide from the coke oven gas. The coke oven gas from the primary medium-temperature zinc oxide tank then enters the secondary hydrogenation reactor to further convert organic sulfur into inorganic sulfur. Then, it passes through the secondary medium-temperature zinc oxide tank to remove the remaining organic sulfur. The secondary fine desulfurization temperature is required to be 350-380℃ to remove trace amounts of organic sulfur. 5) Deep processing unit: synthesize methanol and LNG from coke oven gas, and co-produce hydrogen or perform deep processing of hydrogen.

2. The deep processing technology for adjusting the oxygen content of coke oven gas according to claim 1, characterized in that, The opening degree of the regulating valves for automatically adding air and nitrogen in the oxygen supply is consistent.

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