CN117683563A - Process for preparing hydrogen by reforming diesel oil - Google Patents
Process for preparing hydrogen by reforming diesel oil Download PDFInfo
- Publication number
- CN117683563A CN117683563A CN202211069774.0A CN202211069774A CN117683563A CN 117683563 A CN117683563 A CN 117683563A CN 202211069774 A CN202211069774 A CN 202211069774A CN 117683563 A CN117683563 A CN 117683563A
- Authority
- CN
- China
- Prior art keywords
- diesel
- reforming
- conversion
- reactor
- hydrogen production
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000001257 hydrogen Substances 0.000 title claims abstract description 60
- 229910052739 hydrogen Inorganic materials 0.000 title claims abstract description 60
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 title claims abstract description 59
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 41
- 238000002407 reforming Methods 0.000 title claims abstract description 40
- 239000002283 diesel fuel Substances 0.000 title claims abstract description 38
- 238000006243 chemical reaction Methods 0.000 claims abstract description 85
- 239000003054 catalyst Substances 0.000 claims abstract description 66
- 238000000034 method Methods 0.000 claims abstract description 41
- 238000000629 steam reforming Methods 0.000 claims abstract description 32
- 238000004821 distillation Methods 0.000 claims abstract description 24
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 19
- 238000000926 separation method Methods 0.000 claims abstract description 19
- 239000007789 gas Substances 0.000 claims description 42
- 238000005984 hydrogenation reaction Methods 0.000 claims description 30
- 239000003795 chemical substances by application Substances 0.000 claims description 22
- 238000006477 desulfuration reaction Methods 0.000 claims description 20
- 230000023556 desulfurization Effects 0.000 claims description 20
- 230000003009 desulfurizing effect Effects 0.000 claims description 17
- 239000007788 liquid Substances 0.000 claims description 14
- 229910052799 carbon Inorganic materials 0.000 claims description 10
- 239000000446 fuel Substances 0.000 claims description 10
- 230000000382 dechlorinating effect Effects 0.000 claims description 8
- 238000000746 purification Methods 0.000 claims description 8
- 229910000480 nickel oxide Inorganic materials 0.000 claims description 5
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 claims description 5
- 230000008569 process Effects 0.000 abstract description 33
- 229930195733 hydrocarbon Natural products 0.000 abstract description 25
- 150000002430 hydrocarbons Chemical class 0.000 abstract description 25
- 239000004215 Carbon black (E152) Substances 0.000 abstract description 20
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 abstract description 18
- 229910052717 sulfur Inorganic materials 0.000 abstract description 17
- 239000011593 sulfur Substances 0.000 abstract description 17
- 231100000572 poisoning Toxicity 0.000 abstract description 9
- 230000000607 poisoning effect Effects 0.000 abstract description 9
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical group [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract description 8
- 229910052759 nickel Inorganic materials 0.000 abstract description 7
- 238000004939 coking Methods 0.000 abstract description 6
- 239000002994 raw material Substances 0.000 abstract description 5
- 238000002360 preparation method Methods 0.000 abstract description 3
- 238000004227 thermal cracking Methods 0.000 abstract description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical group [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 14
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 14
- 150000003464 sulfur compounds Chemical class 0.000 description 12
- 230000000694 effects Effects 0.000 description 10
- 239000000047 product Substances 0.000 description 9
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 8
- 229910002091 carbon monoxide Inorganic materials 0.000 description 8
- 150000001336 alkenes Chemical class 0.000 description 7
- JRZJOMJEPLMPRA-UHFFFAOYSA-N olefin Natural products CCCCCCCC=C JRZJOMJEPLMPRA-UHFFFAOYSA-N 0.000 description 7
- 239000011787 zinc oxide Substances 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 6
- 239000012071 phase Substances 0.000 description 6
- 239000003223 protective agent Substances 0.000 description 6
- QZYDAIMOJUSSFT-UHFFFAOYSA-N [Co].[Ni].[Mo] Chemical compound [Co].[Ni].[Mo] QZYDAIMOJUSSFT-UHFFFAOYSA-N 0.000 description 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- QGKAVFXNTADNHB-UHFFFAOYSA-N [Mg].[K].[Ca] Chemical group [Mg].[K].[Ca] QGKAVFXNTADNHB-UHFFFAOYSA-N 0.000 description 4
- 230000003197 catalytic effect Effects 0.000 description 4
- TVZPLCNGKSPOJA-UHFFFAOYSA-N copper zinc Chemical compound [Cu].[Zn] TVZPLCNGKSPOJA-UHFFFAOYSA-N 0.000 description 4
- 239000012535 impurity Substances 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 238000009833 condensation Methods 0.000 description 3
- 230000005494 condensation Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000007791 liquid phase Substances 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 3
- 239000012495 reaction gas Substances 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- UPHIPHFJVNKLMR-UHFFFAOYSA-N chromium iron Chemical compound [Cr].[Fe] UPHIPHFJVNKLMR-UHFFFAOYSA-N 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 230000009849 deactivation Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000003345 natural gas Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 238000002453 autothermal reforming Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000007809 chemical reaction catalyst Substances 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000013505 freshwater Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000013067 intermediate product Substances 0.000 description 1
- 125000001741 organic sulfur group Chemical group 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 1
- 239000002574 poison Substances 0.000 description 1
- 231100000614 poison Toxicity 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000006057 reforming reaction Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
Landscapes
- Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
Abstract
A diesel reforming hydrogen production process belongs to the technical field of hydrocarbon steam reforming hydrogen production. At present, the diesel steam reforming method for preparing hydrogen is subject to thermodynamic coking caused by long carbon chains of diesel and poisoning, and the diesel steam reforming hydrogen preparation has no breakthrough in the aspect of practicality. The invention comprises the following steps: distilling and separating diesel oil to obtain light components, hydrodesulfurizing, pre-converting, steam reforming and purifying; wherein the light components obtained by distillation separation are components with a distillation range of 300 ℃ and below. The distillation separation of the oil product is combined with the reforming method, the sulfur content in the raw material is reduced to the extent that the nickel-based catalyst can be tolerated through the distillation separation, and the higher hydrocarbon in the raw material is converted into the C1 component through adopting the pre-conversion process, so that the thermal cracking and coking of the diesel oil fraction in the high-temperature area of the reforming reactor are avoided, the heat utilization efficiency of the reforming reactor is improved through the pre-conversion reactor, and the hydrogen production by reforming the diesel oil is realized.
Description
Technical Field
A diesel reforming hydrogen production process belongs to the technical field of hydrocarbon steam reforming hydrogen production.
Background
Hydrogen production technology has been in progress for over a hundred years. In 1905, the water electrolysis hydrogen production process is developed, and the technology is quite mature so far, but the process has high power consumption and high production cost, and is only suitable for small-scale hydrogen users. The natural gas vapor conversion hydrogen production was industrialized in 1928 by standard oil company in the united states. Along with the industrial development of synthetic ammonia, methanol and the like, hydrocarbon steam conversion hydrogen production processes are also rapidly developed. In the application research process of more than half century, experts in various countries have conducted intensive researches on the aspects of converter type, energy utilization, catalyst performance, purification and the like, and have conducted targeted improvement and perfection, so that the process is mature, flexible and convenient to operate, less in investment and continuously reduced in energy consumption, and therefore, the process is widely applied to petrochemical enterprises, and at present, the process has become one of the most common hydrogen production methods applied in the world.
The hydrocarbon steam reforming hydrogen production principle is that raw hydrocarbon is first hydrogenated, desulfurized, etc. to eliminate olefin, sulfur, chlorine, etc. and then reacted with steam in a reformer to produce hydrogen and carbon monoxide, and the intermediate product carbon monoxide is then reacted with steam to produce hydrogen continuously, and the obtained product gas finally enters a purifying part to separate high purity hydrogen. The raw materials of the process are very widely selected, and natural gas, oilfield gas, various refinery gases, liquefied gas, naphtha, topped oil, raffinate oil and the like can be used as raw materials after being treated.
The diesel oil has the characteristics of high energy density, mature and convenient production, transportation, storage and delivery, and the like, and the hydrocarbon steam reforming hydrogen production by adopting the diesel oil as the raw material is a technology with market competitiveness. The technological process of producing hydrogen with diesel oil includes three modes of steam reforming, autothermal reforming and oxidation reforming.
But on the one hand: the benzene ring and organic sulfur content of diesel oil are high, and the substances are easy to combine with catalyst active components to cause poisoning of reforming catalysts, namely, the existing industrial pre-conversion catalysts cannot tolerate sulfur compounds in the diesel oil, the activity of the catalysts is obviously reduced, and the catalysts are usually inactive in 50-100 hours of operation.
On the other hand: the catalyst cannot tolerate long-chain hydrocarbon and olefin of diesel oil, the molecular carbon number of the diesel oil is high, and carbon is easy to be deposited on the surface or in pore channels of the reforming catalyst when reforming reaction occurs, so that the catalyst is deactivated.
At present, the hydrogen production by the diesel steam reforming method is still in a research stage, the literature reports mainly focus on the form of a 'high-efficiency' catalyst or a reactor, and the diesel steam reforming hydrogen production has no breakthrough in the aspect of practicality due to thermodynamic coking caused by long carbon chains of diesel and poisoning. Therefore, there is a need for development in terms of processes and catalysts, and new solutions are sought.
Disclosure of Invention
The technical problems to be solved by the invention are as follows: overcomes the defects of the prior art and provides a diesel reforming hydrogen production process which can avoid catalyst sulfide poisoning or blockage deactivation in the diesel reforming hydrogen production process.
The technical scheme adopted for solving the technical problems is as follows: a process for preparing hydrogen by reforming diesel oil is characterized in that: the method comprises the following steps: distilling and separating diesel oil to obtain light components, hydrodesulfurizing, pre-converting, steam reforming and purifying; wherein the light components obtained by distillation separation are components with a distillation range of 300 ℃ and below.
The cutting, desulfurizing and pre-converting processes of diesel oil are set. The inventor notices that the main sulfur compounds and olefin components of the diesel oil are mainly present in the fraction after 300 ℃, the invention firstly uses distillation to cut the light and heavy components of the diesel oil, the initial distillation point of the diesel oil is about 180 ℃, the final distillation point is about 370 ℃, the light component fraction within 300 ℃ is selected, more than 70% of the diesel oil components can be reserved for subsequent reforming hydrogen production, and meanwhile, most of sulfur compounds and olefin are cut, so that the content of the sulfur compounds is reduced to about 2ppm, and on the basis, hydrogenation and desulfurization are carried out, thereby realizing the purification again, further reducing the content of olefin and sulfur compounds of the diesel oil, and reducing the content of the sulfur compounds to below 0.5 ppm.
The pre-conversion step can be used for carrying out a conversion reaction of hydrocarbon steam on the light component of the diesel oil to obtain a process gas (the main component is methane and the hydrogen content is less) with the dry-basis composition of mainly methane, carbon monoxide, carbon dioxide and hydrogen. The pre-converted effective components enter a steam reforming step, so that the influence of sulfur compounds and long-chain hydrocarbons on a reforming catalyst can be effectively avoided, and continuous production of hydrogen by diesel steam reforming is realized.
However, the pre-conversion step is usually a high nickel catalyst and is extremely sensitive to sulfur, so that the method is difficult to apply to the reforming hydrogen production process of diesel oil in the prior art, and after the diesel oil is subjected to two-step purification treatment of distillation separation and hydrodesulfurization, the content of sulfur compounds and olefin components entering the pre-conversion step are greatly reduced, so that the pre-conversion step is added in the process method to carry out hydrocarbon steam conversion reaction, and process gas is provided for the steam reforming step for a long time and stably, thereby obtaining hydrogen.
Preferably, in the hydrodesulfurization step, the light component sequentially passes through a hydrogenation reactor and a desulfurization tank, and a dechlorinating agent and a desulfurizing agent are filled in the desulfurization tank for dry desulfurization.
The most sulfur compounds in the light components can be effectively removed through the preferential hydrodesulfurization step.
Further preferably, two desulfurization tanks are arranged in series at the outlet of the hydrogenation reactor.
Two serially connected desulfurization tanks can be switched to replace each other, and when one of the desulfurization tanks is saturated by adsorption, the desulfurization tank can be cut off from the process line and replaced, so that the process line is ensured to continuously run.
Further preferably, the inlet temperature of the hydrogenation reactor is 330-350 ℃, the outlet temperature is less than or equal to 390 ℃, and the hydrogen-oil volume ratio is controlled to be 800-1200.
The bed temperature of the desulfurization tank changes along with the outlet temperature of the hydrogenation reactor, so that the reaction condition in the hydrogenation reactor can be kept stable under the conditions, and the most proper working temperature of the desulfurization tank is ensured at the same time, so that the sulfur capacity of the desulfurizing agent is fully utilized.
The hydrogenation catalyst arranged in the hydrogenation reactor is more preferably a cobalt molybdenum nickel-based hydrogenation catalyst, the cobalt molybdenum nickel-based catalyst has lower sensitivity to sulfur components, and the activity effect of catalyzing olefin and sulfur compounds is better. Meanwhile, a hydrogenation protective agent is preferably arranged in the hydrogenation reactor, the hydrogenation protective agent has high porosity, large pore volume, proper specific surface area and catalytic activity, metal impurities and solid particles in oil products are removed, poisoning and carbon formation of the catalyst are slowed down, and the service life of the main catalyst is prolonged.
The light component passing through the hydrogenation reactor passes through a dechlorinating agent and a desulfurizing agent in sequence in a desulfurizing tank. The dechlorinating agent is preferably a calcium-magnesium-potassium-based dechlorinating agent. The desulfurizing agent is preferably a zinc oxide desulfurizing agent and a copper-zinc-based desulfurizing agent. The medium firstly flows through the calcium-magnesium-potassium-based dechlorinating agent, then flows through the zinc oxide desulfurizing agent, and finally flows through the copper-zinc-based desulfurizing agent.
Preferably, the pre-conversion uses a high nickel catalyst having a nickel oxide content of 35% by weight or more. It is further preferred to use a high nickel catalyst having a nickel oxide content of 55% by weight or more.
The lower the nickel content is, the easier the catalytic activity is lost under the influence of sulfur and impurities, but the catalyst production cost is low, while the catalyst with high nickel has longer service life and higher catalytic activity, but the higher the nickel content is, the higher the cost is, and the invention benefits from the purification step, can efficiently utilize the high nickel conversion catalyst to obtain the highest hydrocarbon steam conversion reaction efficiency, has lower influence degree on the nickel active center, has small service life reduction degree, and therefore, has low requirement on the high nickel catalyst and stronger suitability.
Preferably, the pre-conversion adopts a pre-conversion reactor, the inlet temperature of the pre-conversion reactor is 360-450 ℃, the water-carbon ratio is controlled to be 2.0-3.2, and the outlet temperature is less than or equal to 520 ℃.
The diesel steam pre-conversion reaction is exothermic reaction, the temperature control condition can avoid high temperature or coking to damage the pre-conversion catalyst, and the outlet temperature can be controlled by adjusting the water-carbon ratio so as to control the temperature in the reactor.
Preferably, the pre-conversion is performed alternately by using two pre-conversion reactors arranged in parallel.
Although diesel oil is purified twice, a certain amount of sulfur still exists, the pre-conversion catalyst is usually extremely sensitive to sulfur, the catalyst activity loss is inevitably generated, and when the activity of one reactor is too low, the two pre-conversion reactors arranged in parallel are replaced by the other reactor, so that the continuous operation of a process line is ensured, and the catalyst is updated in time.
The invention effectively solves the problem that the conversion catalyst cannot endure higher hydrocarbons with the distillation range of more than 220 ℃ for a long time, solves the problem of sulfur poisoning of the conversion catalyst and prolongs the operation period of the whole device by arranging the pre-conversion reactor with one open and one standby and the subsequent desulfurization tank.
It is further preferable to use the difference between the inlet and outlet temperatures of the pre-conversion as the sign of switching the pre-conversion reactor. This parameter is based on: the pre-conversion reaction of the higher hydrocarbons is an exothermic reaction, and the temperature difference directly shows the activity of the catalyst.
At the end of the use of the pre-conversion catalyst, the dry basis composition of the process gas can be analyzed to determine C 2 Hydrocarbons (e.g. ethane, ethylene) and even C may occur 3 Hydrocarbons (such as propane and propylene), when the temperature difference appears, the pre-conversion catalyst has lower activity and C 2 、C 3 The rising of the hydrocarbon content also prompts the operator to pay attention to the operation conditions of the pre-conversion reactor and the catalyst, and makes a preparation in advance for switching the pre-conversion reactor.
Preferably, the gas-liquid separation operation is also carried out between the pre-conversion and the steam reforming.
The pre-converted reaction gas is subjected to heat exchange and condensation until the temperature of the reaction gas is 40-100 ℃, preferably 80-100 ℃. Because the water at 100 ℃ is in a pressurized state and does not boil, the initial boiling point of the unreacted long-chain liquid hydrocarbon is far higher than the temperature, and the temperature of the medium is higher, on the one hand, the size and the operation cost of cooling equipment can be reduced, and on the other hand, the separated gas-phase medium contains more saturated water than at low temperature, and the subsequent steam is saved by the variable phase.
Then separating the gas phase from the liquid phase, wherein the purpose of the gas-liquid separation is as follows: when the pre-conversion catalyst is used in middle and later stages, the C-C bond breaking reaction of hydrocarbon is incomplete, and partial unreacted liquid hydrocarbon enters a subsequent reforming reactor, and the carbon-forming reaction can rapidly occur at high temperature due to the carbon chain length of the liquid hydrocarbon, so that irrecoverable damage can be caused to the steam reforming catalyst. Thus, by providing a gas-liquid separation, these diesel components which have not reacted in the pre-shift reactor are separated from the gas, together with the unreacted water. The separated gas is introduced into a steam reforming reformer.
The separated liquid phase fraction (comprising oil and water) is further preferably subjected to a liquid separation process, the liquid being re-separated by standing, the lower water being introduced into a drum for production of process steam, and the upper oil being introduced into a heavies tank as fuel.
Further preferably, the gas phase after the gas-liquid separation is desulfurized once more. Generally, the primary zinc oxide desulfurizer is used for desulfurization before entering steam reforming, namely, the gas is blown through the zinc oxide desulfurizer with the working temperature below 400 ℃ to serve as primary insurance, so that the sulfur content of the gas entering steam reforming is further ensured to be lower.
The high temperature raw product gas obtained after steam reforming can be subjected to heat recovery and steam is generated: a double air drum is provided, a drum b for generating steam by using fresh water and a drum a for generating steam by using recycled water. Wherein the steam generated by the steam drum a is continuously used in the process device and is not externally transmitted, so that other equipment or devices using the steam are not polluted; the steam generated by the steam drum b can meet the requirement of the process device and can be output.
Preferably, the gas after steam reforming is catalyzed and reacted by a CO high-temperature shift catalyst after the CO shift reactor is further used for purification.
After steam reforming hydrogen production, although the hydrogen content in the dry-based gas can reach about 70vol%, part of carbon monoxide can be further converted into hydrogen, and the CO high-temperature change catalyst is more preferably an iron-chromium-based catalyst, which is a common carbon monoxide shift catalyst, and the hydrogen content in the shifted product gas can reach 73vol% or more.
After the converted product gas is subjected to multiple heat exchange, condensation and separation, the obtained condensed water is introduced into a steam drum a for continuous recycling for generating steam. According to the requirements of hydrogen users, PSA, VPSA or other hydrogen purification equipment with different scales or purification precision can be matched to obtain hydrogen with different purities.
Preferably, the heavy component separated by distillation is used as fuel separated by diesel distillation or steam reforming fuel.
Compared with the prior art, the invention has the following beneficial effects: the distillation separation and reforming method of the oil product are combined together, and complex high dry point compounds and sulfur compounds thereof in the diesel oil fraction are cut off, so that only compounds with lower dry points of diesel oil components and sulfur compounds with simpler sulfur forms are reserved. By means of the pre-conversion process and the catalyst thereof with excellent conversion effect on the higher hydrocarbon, the diesel oil is converted into methane-rich gas at a lower temperature, so that thermal cracking and coking of the diesel oil in a high-temperature area of the reforming reactor are avoided, the heat utilization efficiency of the reforming reactor is improved, and the whole energy consumption is effectively reduced. The hydrocarbon entering the reforming reactor, whether the complexity or the poison content, is greatly weakened compared with the diesel, and can be treated by adopting a conventional conversion catalyst, so that the hydrogen production by reforming the diesel is realized.
Detailed Description
The present invention will be further described with reference to the following examples, with example 1 being the best mode of carrying out the invention.
Example 1
A process for preparing hydrogen by reforming diesel oil comprises the following steps:
1) Distilling and separating the military diesel oil to obtain a fraction with a distillation range less than or equal to 300 ℃ (the material content of the fraction accounts for 78% -80% of the total feeding amount of the military diesel oil), and introducing the fraction into a hydrogenation reactor; the upper part of the hydrogenation reactor is filled with a hydrogenation protecting agent, the lower part is filled with a cobalt molybdenum nickel hydrogenation catalyst, and a gas phase sequentially passes through the hydrogenation protecting agent and the cobalt molybdenum nickel hydrogenation catalyst, wherein the hydrogenation protecting agent accounts for 20%, the cobalt molybdenum nickel hydrogenation catalyst accounts for 80%, and the hydrogenation protecting agent can remove metal impurities and solid particles in oil products, slow down the poisoning and coking of the catalyst and prolong the service life of a main catalyst; the inlet temperature of the hydrogenation reactor is controlled to be 330-350 ℃ (through heat exchange and steam heating), the outlet temperature is about 380 ℃, and the hydrogen-oil volume ratio is 800-1200; the light components passing through the hydrogenation reactor enter the desulfurization tanks, two desulfurization tanks are arranged in series at the outlet of the hydrogenation reactor, and the gas coming out of the hydrogenation reactor can be desulfurized by the alternative access system. The bottom of the desulfurization tank is filled with a copper-zinc-based desulfurizing agent, the middle part is provided with a zinc oxide desulfurizing agent, the upper part is filled with a calcium-magnesium-potassium-based dechlorinating agent, and the filling ratio from top to bottom is 1:3:1, a step of; the gas component to be treated sequentially passes through a calcium-magnesium-potassium-based dechlorinating agent, a zinc oxide desulfurizing agent and a copper-zinc-based desulfurizing agent in a desulfurizing tank.
2) The desulfurized gas enters a pre-conversion reactor. The inlet temperature of the pre-conversion reactor is 420 ℃, and the outlet temperature is about 495 ℃; carbon space velocity 2000h -1 The water-carbon ratio is controlled at 3.0; inlet pressure 3.05MPa and outlet pressure 3.0MPa; the catalyst adopted in the pre-conversion is a Z505 high-nickel pre-conversion catalyst developed and sold by Mitsubishi Qilu company, and the nickel oxide content is 55%; the composition of the process gas obtained by the pre-conversion is as follows: 59.85% of methane, 0.79% of carbon monoxide, 23.57% of carbon dioxide and the balance of hydrogen.
3) The pre-converted gas is subjected to heat exchange condensation to the temperature of the reaction gas of about 90 ℃, then the gas-liquid separation is carried out, the separated liquid phase part enters a liquid separation process, the liquid is separated again by standing, the water at the lower part is introduced into a steam drum a for producing process steam, and the oil at the upper part can be introduced into a heavy component tank as fuel.
4) The gas phase part obtained by gas-liquid separation is mixed with steam after being subjected to desulfurization insurance by a zinc oxide desulfurizing agent and then enters a steam reforming reactor to carry out hydrocarbon steam conversion reaction, so as to obtain hydrogen-rich gas. The conversion catalyst filled in the steam reforming reactor is medium petrochemicalA Z417/Z418 alkali promoted hydrocarbon steam reforming catalyst developed and sold by Lutzfeld corporation, the steam reforming reactor operating at a carbon space velocity of 1000 hours -1 The water-carbon ratio is 3.2, the inlet pressure is 2.7MPa, the outlet pressure is 2.6MPa, and the methane content of the process gas at the outlet of the steam reforming reactor is lower than 7% at the outlet temperature of 810 ℃.
5) The process gas obtained after steam reforming enters a CO shift reactor, carbon monoxide in the process gas is further converted into hydrogen through an internal iron-chromium-based catalyst to obtain product gas, and the carbon monoxide content at the outlet of the CO shift reactor is less than or equal to 2 percent.
6) The obtained product gas is used for a fuel cell, 2-grade PSA is arranged, the first-grade PSA produces hydrogen with the purity of 99.9 percent, then the hydrogen is introduced into the second-grade PSA to produce hydrogen with the purity of 99.999 percent, and the tail gas of the 2-grade PSA is fed into a gas pipe network to be used as fuel.
The process adopts a double steam system, namely two steam drums, wherein one steam drum b provides fresh steam for supplying heat and gas to each link, and the other steam drum a collects condensed process water, wherein the condensed process water comprises process steam condensed water generated by heat exchange after a pre-conversion link and condensed water obtained by heat recovery after a CO conversion reactor; the steam in the drum b of fresh steam can be used for any other link, while the drum a for collecting condensed process water only supplies air for the two links (pre-conversion and conversion), and avoids pollution while recovering heat.
In the preparation process, two parallel pre-conversion reactors are alternately used for pre-conversion, and the temperature difference between the inlet temperature and the outlet temperature of the pre-conversion is less than or equal to 10 ℃ and is used as a mark for switching the pre-conversion reactors. The operation time of the pre-conversion reactor is more than 500 hours, the operation of changing the catalyst is needed, and the operation time of the reforming reactor is more than 35000 hours.
The fuel in the process is PSA stripping gas and diesel oil fraction with the distillation range of more than 300 ℃ in the step 1), and the shortage of the fuel is supplemented by military diesel oil. The operating temperature and the composition of the outlet gas components at each part in the pre-conversion reactor are related with the operating time of the pre-conversion reactor as shown in the table 1 below.
Table 1 example pre-conversion reactor monitoring
。
According to the data, the pre-conversion catalyst has high catalyst activity and activity stability in the operation process, and can stably operate for more than 500 hours.
Example 2
Based on the embodiment 1, the pre-conversion catalyst in the step 2) is changed into a Z503 high nickel catalyst developed and sold by Mitsui Jiulou, the nickel oxide content is 50%, and other conditions are the same as those in the embodiment 1.
The operation time of the pre-conversion reactor is more than 500 hours, the operation of changing the catalyst is needed, and the operation time of the reforming reactor is more than 35000 hours.
Example 3
The inlet temperature of the pre-conversion reactor is set to 360 ℃ and less than 520 ℃ on the basis of the embodiment 1, and other conditions are the same as the embodiment 1.
The operation time of the pre-conversion reactor is more than 500 hours, the operation of changing the catalyst is needed, and the operation time of the reforming reactor is more than 35000 hours.
Comparative example 1
The hydrogen production process by reforming diesel oil is based on the embodiment 1, wherein the hydrogenation reactor is not arranged in the step 1), and the other conditions are the same as the embodiment 1.
After the pre-conversion reactor is operated for 100 hours, C in the exhaust gas 2 The component exceeds 10vol%, and the total sulfur is 1.7mg/L. The pre-conversion catalyst was discharged and the sulfur content was detected to be 0.46% (mass ratio), and it was apparent that sulfur poisoning occurred in the pre-conversion catalyst.
Comparative example 2
In the diesel reforming hydrogen production process, step 1) was not provided with a desulfurization tank on the basis of example 1, and the other conditions were the same as in example 1.
After the pre-conversion reactor is operated for 100 hours, C in the exhaust gas 2 The component exceeds 10.5vol% and the total sulfur is 1.8mg/L. Discharging the pre-conversion catalyst, and detecting that the sulfur content of the catalyst reaches 0.44In mass%, it is evident that sulfur poisoning of the pre-conversion catalyst occurred.
Comparative example 3
The diesel reforming hydrogen production process is based on the embodiment 1, wherein the distillation separation is not arranged in the step 1), and the subsequent steps are carried out by adopting full distillate oil, and the other conditions are the same as the embodiment 1.
The operating temperature and the composition of the outlet gas components at each part in the pre-conversion reactor are related with the operating time of the pre-conversion reactor as shown in the following table 2.
Table 2 comparative example 3 pre-conversion reactor monitoring
。
From the above evaluation data, it can be seen that the pre-conversion catalyst has a faster slip rate at 1/3 of the bed temperature when treating full fraction military diesel, indicating that the catalyst has a more pronounced deactivation.
Comparative example 4
Based on the embodiment 1, the distillation separation of the step 1) is performed to obtain a fraction with a distillation range less than or equal to 310 ℃ (the material content of the fraction accounts for 80-85% of the total feeding amount of military diesel oil), the inlet temperature of a pre-conversion reactor is increased to 450 ℃, and other conditions are the same as those of the embodiment 1. The temperature of the pre-inversion reactor was increased because: after the cutting temperature is increased, the amount of impurity components such as sulfur entering the pre-conversion reactor is increased, and the inlet temperature must be increased to improve the catalytic activity of the pre-conversion reaction catalyst and ensure the normal operation of the reaction.
The operating temperature and the composition of the outlet gas components at each part in the pre-conversion reactor are related with the operating time of the pre-conversion reactor as shown in the table 3 below.
Table 3 comparative example 4 pre-conversion reactor monitoring
。
As can be seen from the above evaluation data, when the pre-conversion catalyst is used for treating the fraction with the military diesel oil distillation range less than or equal to 310 ℃, the temperature at the 1/3 position of the bed layer still slowly drops, and the catalyst is slowly deactivated.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the invention in any way, and any person skilled in the art may make modifications or alterations to the disclosed technical content to the equivalent embodiments. However, any simple modification, equivalent variation and variation of the above embodiments according to the technical substance of the present invention still fall within the protection scope of the technical solution of the present invention.
Claims (10)
1. A process for preparing hydrogen by reforming diesel oil is characterized in that: the method comprises the following steps: distilling and separating diesel oil to obtain light components, hydrodesulfurizing, pre-converting, steam reforming and purifying; wherein the light components obtained by distillation separation are components with a distillation range of 300 ℃ and below.
2. The diesel reforming hydrogen production process according to claim 1, characterized in that: in the hydrodesulfurization step, the light components sequentially pass through a hydrogenation reactor and a desulfurization tank, and the desulfurization tank is filled with a dechlorinating agent and a desulfurizing agent.
3. The diesel reforming hydrogen production process according to claim 2, characterized in that: the two desulfurization tanks are connected in series and arranged at the outlet of the hydrogenation reactor.
4. The diesel reforming hydrogen production process according to claim 2, characterized in that: the inlet temperature of the hydrogenation reactor is 330-350 ℃, the outlet temperature is less than or equal to 390 ℃, and the hydrogen-oil ratio is controlled to 800-1200.
5. The diesel reforming hydrogen production process according to claim 1, characterized in that: the pre-conversion adopts a high nickel catalyst with the nickel oxide weight content of 35% or more.
6. The diesel reforming hydrogen production process according to claim 1, characterized in that: the pre-conversion adopts a pre-conversion reactor, the inlet temperature of the pre-conversion reactor is 360-450 ℃, the water-carbon ratio is controlled to be 2.0-3.2, and the outlet temperature is less than or equal to 520 ℃.
7. The diesel reforming hydrogen production process according to claim 1, characterized in that: the pre-conversion is carried out alternately by using two pre-conversion reactors which are arranged in parallel.
8. The diesel reforming hydrogen production process according to claim 1, characterized in that: and the gas-liquid separation operation is also carried out between the pre-conversion and the steam reforming.
9. The diesel reforming hydrogen production process according to claim 1, characterized in that: the gas after steam reforming is catalyzed and reacted by a CO high-temperature shift catalyst after the CO shift reactor is also used before the purification.
10. The diesel reforming hydrogen production process according to claim 1, characterized in that: the heavy component separated by distillation is used as fuel separated by diesel distillation or fuel reformed by steam.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211069774.0A CN117683563A (en) | 2022-09-02 | 2022-09-02 | Process for preparing hydrogen by reforming diesel oil |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211069774.0A CN117683563A (en) | 2022-09-02 | 2022-09-02 | Process for preparing hydrogen by reforming diesel oil |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117683563A true CN117683563A (en) | 2024-03-12 |
Family
ID=90137735
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211069774.0A Pending CN117683563A (en) | 2022-09-02 | 2022-09-02 | Process for preparing hydrogen by reforming diesel oil |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117683563A (en) |
-
2022
- 2022-09-02 CN CN202211069774.0A patent/CN117683563A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7879919B2 (en) | Production of hydrocarbons from natural gas | |
| CN101113126B (en) | Olefin-containing lighter hydrocarbons catalytic hydrogenation method | |
| CN100534581C (en) | Control of hydrogen in hydrogen-containing streams from hydrogen sources | |
| US20180215682A1 (en) | Efficient oxidative coupling of methane processes and systems | |
| JP5288840B2 (en) | Hydrogen production system | |
| EP2167617A1 (en) | Process to produce a methane rich gas mixture from gasification derived sulphur containing synthesis gases | |
| US20080237090A1 (en) | Process and system for redcuing the olefin content of a hydrocarbon feed gas and production of a hydrogen-enriched gas therefrom | |
| US11572517B2 (en) | Processing facility to produce hydrogen and petrochemicals | |
| KR20220108806A (en) | Processing facilities to form hydrogen and petrochemicals | |
| KR20230090311A (en) | Process for synthesizing hydrocarbons | |
| CN101343566B (en) | Method for improving running period of hydrogenation plant for poor petroleum naphtha | |
| CN103552984A (en) | Method for producing hydrogen with high yield and high purity by reforming and transforming dry refinery gas | |
| KR102325304B1 (en) | Method and system for reforming methane and light hydrocarbons into liquid hydrocarbon fuels | |
| WO2006087971A1 (en) | Process for production of aromatic compound and process for production of hydrogenated aromatic compound | |
| JP5138586B2 (en) | Liquid fuel synthesis system | |
| AU2010287744B2 (en) | Hydrocarbon synthesis reaction apparatus, hydrocarbon synthesis reaction system, and liquid hydrocarbon recovery method | |
| CN105722953B (en) | The method for converting coal into chemicals | |
| CN104105658A (en) | Process for preparing a paraffin product | |
| CN101113127B (en) | Method for preparing menthol by using refinery gas as raw material | |
| CN117683563A (en) | Process for preparing hydrogen by reforming diesel oil | |
| AU2013369328B2 (en) | Process for preparing a paraffin product | |
| JP2009084257A (en) | Method for producing aromatic compound | |
| CN115151625A (en) | System and process for direct upgrading of crude oil to hydrogen and chemicals | |
| US20150322358A1 (en) | Purification of a raw gas by hydrogenation | |
| RU2776173C1 (en) | Method for producing liquid hydrocarbons using the fischer-tropsch process integrated in petroleum refining plants |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |