CN110862844B - Method for preparing natural gas and co-producing hydrogen from rich gas by using low-rank coal according to quality - Google Patents
Method for preparing natural gas and co-producing hydrogen from rich gas by using low-rank coal according to quality Download PDFInfo
- Publication number
- CN110862844B CN110862844B CN201911221881.9A CN201911221881A CN110862844B CN 110862844 B CN110862844 B CN 110862844B CN 201911221881 A CN201911221881 A CN 201911221881A CN 110862844 B CN110862844 B CN 110862844B
- Authority
- CN
- China
- Prior art keywords
- gas
- rich gas
- desulfurization
- coal
- rich
- 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.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
- C10J3/46—Gasification of granular or pulverulent flues in suspension
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
- C01B3/50—Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification
- C01B3/506—Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification at low temperatures
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10K—PURIFYING OR MODIFYING THE CHEMICAL COMPOSITION OF COMBUSTIBLE GASES CONTAINING CARBON MONOXIDE
- C10K1/00—Purifying combustible gases containing carbon monoxide
- C10K1/002—Removal of contaminants
- C10K1/003—Removal of contaminants of acid contaminants, e.g. acid gas removal
- C10K1/004—Sulfur containing contaminants, e.g. hydrogen sulfide
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10K—PURIFYING OR MODIFYING THE CHEMICAL COMPOSITION OF COMBUSTIBLE GASES CONTAINING CARBON MONOXIDE
- C10K1/00—Purifying combustible gases containing carbon monoxide
- C10K1/34—Purifying combustible gases containing carbon monoxide by catalytic conversion of impurities to more readily removable materials
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
- C10L3/00—Gaseous fuels; Natural gas; Synthetic natural gas obtained by processes not covered by subclass C10G, C10K; Liquefied petroleum gas
- C10L3/06—Natural gas; Synthetic natural gas obtained by processes not covered by C10G, C10K3/02 or C10K3/04
- C10L3/08—Production of synthetic natural gas
Abstract
The invention discloses a method for preparing natural gas and CO-producing hydrogen from rich gas by utilizing low-rank coal according to quality, which is characterized in that the rich gas obtained by gasifying and reducing the low-rank coal is processed into natural gas with higher economic value, and CO and H required by the natural gas in the rich gas as raw materials are synthesized into CO and H 2 The natural gas is prepared, the obtained natural gas has less impurities and high quality, so that the volatile components in the low-rank coal are fully and effectively utilized, the raw materials for preparing the natural gas are rich, the cost is lower, the production cost is greatly saved, high-value upgraded coal and coal tar are rich, and the method conforms to the national comprehensive utilization direction of coal.
Description
Technical Field
The invention relates to the technical field of low-rank coal quality-based utilization, in particular to a method for preparing natural gas and co-producing hydrogen from rich gas by using low-rank coal quality-based utilization.
Background
China is a country rich in coal, poor in oil and less in gas, and the coal consumption accounts for more than 60% of primary energy consumption, so that the energy structure mainly based on coal is difficult to change in a long period of time. From the ascertained quality of coal mines, the proportion of low-rank coal in China is very large, so that the reasonable and efficient utilization of the low-and-medium-rank coal to produce high-quality chemical products is particularly important. In recent years, the development of coal gasification, coal pyrolysis, coal gas purification, coal gas separation and other technologies has led to more and more attention being paid to the clean and efficient utilization of middle-low-grade coal.
Natural gas is a highly efficient clean energy source. In recent years, with the successive construction and use of national-level fuel gas transportation projects such as Shanxi gas inlet Jing and Xiqi east transportation, the demand of natural gas is increased explosively. It is predicted that the demand of natural gas in China will reach 1700 billion Nm 3-2100 billion Nm3 in 2015, while the yield of natural gas in the same period can only reach 1400 billion Nm3, and the supply and demand gap is about 300 billion Nm 3-700 billion Nm3. In order to solve the problem of contradiction between supply and demand of natural gas in China, other alternative ways are required to be found besides the domestic resources are established and natural gas resources in other countries in the world are actively utilized.
Natural gas is produced from high-quality coal such as anthracite, and although the yield of natural gas is high, the production cost is high. And many middle and low rank coals in China have poor quality, high ash content and high water content, and the production cost of natural gas can be reduced by preparing the natural gas from the low rank coals. The raw coal gas is obtained by pyrolyzing low-rank coal, which is generally carried out in the presence of a large amount of oxygen (or air), wherein a part of low-rank coal is reacted with oxygen to supply heat and produce a large amount of CO 2 . Due to CO 2 Can not be combusted, belongs to ineffective gas, and has over high nitrogen content due to aerobic combustion, thereby reducing H in the crude gas 2 And CO energy density, so that the calorific value of the crude gas is reduced, and the crude gas produced by pyrolysis has other economic values except for return combustion. The biggest problem of the coal gasification process is that chemical components contained in coal are not fully utilized, and the molecules of the chemical components cannot be completely broken into CO and H 2 And then chemically synthesizing the natural gas. The low-rank coal gasification reduction, reforming technology and natural gas synthesis technology can reserve chemical components in coal to the maximum extent in the form of natural gas.
Disclosure of Invention
In view of this, the present invention aims to provide a method for producing natural gas and co-producing hydrogen from rich gas by using low-rank coal according to quality, wherein the natural gas is synthesized from the rich gas by using the low-rank coal according to quality, and then a liquefaction process is combined to obtain a natural gas product, so that the process has the advantages of low raw material cost, substantial production cost saving, less impurities in the prepared natural gas, high quality, full and effective utilization of volatile components in the low-rank coal, coupling of a methane synthesis process and a liquefaction process, coupling of specific steps of the methane synthesis process, coupling of the methane synthesis process and other coal processing processes, and providing energy for the corresponding processes.
In order to solve the technical problems, the invention provides the following technical scheme:
a method for preparing natural gas and co-producing hydrogen from rich gas by using low-rank coal according to quality comprises the following steps:
(1) Preparing upgraded coal, coal tar and rich gas from low-rank coal sent by a coal preparation system through a gasification reduction process, wherein the rich gas comprises CH (carbon-oxygen) according to the volume ratio 4 28-40% of content, 5-20% of CO content and H 2 25-40% of CO 2 Content of 5-20%, C 2 H 6 Content 2-8%, C 2 H 4 Content 1-4%, C 3 H 6 0.5-3% of C 3 H 8 Content of 0.4-2.5%, C 4 H 8 0.2-2% of H 2 S content 2000-6000ppm and NH 3 The content is less than 100ppm;
(2) Removing sulfur in the rich gas through a pre-desulfurization process to obtain pre-desulfurized rich gas;
(3) Converting all unsaturated hydrocarbons of the pre-desulfurized rich gas into corresponding saturated hydrocarbons by a hydrogenation process, and simultaneously converting organic sulfur into H 2 S, obtaining hydrogenated rich gas;
(4) Removing sulfur in the hydrogenated rich gas through a desulfurization process to obtain a desulfurized rich gas;
(5) And removing carbon dioxide in the desulfurized rich gas through a decarburization process to obtain methane synthesis gas, so that the hydrogen-carbon ratio in the methane synthesis gas is (2.9-3.1): 1;
(6) The methane synthesis gas is prepared by adopting a methane synthesis process in which at least 4 methanation reactors are connected in series, so that carbon monoxide, carbon dioxide and hydrogen in the desulfurized rich gas react in the presence of a methanation catalyst to synthesize methane, and a methane product material flow is obtained;
(7) And introducing the methane product material flow into a liquefaction process, and producing methane with the volume percentage not less than 90% by using a cryogenic liquefaction process to obtain a product natural gas and co-produce hydrogen with the volume percentage not less than 90%.
The raw material low-rank coal can be pulverized coal or lump coal, and when the low-rank coal adopts the lump coal, the pulverized coal with smaller granularity can be obtained by crushing and screening the oversize lump coal. The pulverized coal is preferably used as a raw material, on one hand, the pulverized coal does not need to be crushed and screened, so that the process steps are saved, the heating area is large during drying, the drying efficiency is high, and on the other hand, the pulverized coal is low in price compared with lump coal. Pulverized coal having a particle size of less than 20mm is preferably used, and pulverized coal having a particle size of less than 6mm is still more preferably used.
The drying process removes most of moisture in the low-rank coal to obtain the dried low-rank coal and waste gas, and the dried low-rank coal enters a gasification reduction process to react to obtain high-temperature rich gas and upgraded coal with a certain temperature. The oxygen source in the oxygen-free or micro-oxygen environment adopted by the gasification reduction process is mainly divided into the following cases: (1) Air carried in gaps in the raw material low-rank coal and gaps between the materials; (2) A small amount of mixed air is leaked from a feed inlet, a discharge outlet and the like of the gasification reduction process; (3) Below the explosion limit value, O accounting for 5 percent of the coal by mass can be slightly introduced into the gasification reduction process 2 Or (air), and further preferably, O in an amount of 3% by mass of the coal is introduced 2 Or (air), is beneficial to improving the temperature of the gasification reduction reaction, preventing coking and the like, and simultaneously ensures the safety and stability of the whole gasification reduction process reaction; the dried low-rank coal is preferably subjected to gasification reduction reaction in an oxygen-free environment, so that the condition that the dried low-rank coal and oxygen are subjected to combustion reaction in the reaction process of the gasification reduction process to generate a large amount of incombustible CO is avoided 2 Thereby ensuring CO in the obtained high-temperature rich gas 2 The volume percentage of (2) is small, so that the subsequent preparation of rich gas with high energy density is facilitated, the process steps are few, and the method is simple and easy to operate, so that the reaction can be safely carried out.
The high-temperature rich gas contains CO and H 2 、CO 2 Hydrocarbon, dust, coal tar, naphthalene, water vapor, unsaturated hydrocarbon, sulfur-containing compound, etc. and purifying to remove impurities such as solid dust, tar, naphthalene, water vapor, etc. to obtain purified productAnd (4) enriching the gas. Resources such as coal tar, waste water and the like can be recovered in the purification process, and especially the coal tar is an important byproduct of low-rank coal.
Preferably, the pre-desulfurization process comprises using a pre-desulfurization solution, wherein the rich gas enters from the lower part of the first desulfurization device and is in countercurrent contact with the pre-desulfurization solution sprayed from the upper part of the first desulfurization device, so that hydrogen sulfide in the rich gas is removed, and the pre-desulfurization solution comprises at least one of PDS catalyst, methanol and NDH solvent.
So that H 2 S removal to 20mg/Nm 3 The following; further, the pre-desulfurization process comprises a second desulfurization device using at least one of a resistance wire and a pre-desulfurization catalyst, wherein the resistance wire comprises nickel and chromium, the pre-desulfurization catalyst comprises at least one of basic copper carbonate, copper oxide, copper hydroxide, basic zinc carbonate, zinc oxide and zinc hydroxide, the rich gas is introduced into the second desulfurization device, and the resistance wire heats the rich gas to 200-500 ℃ so that H in the rich gas is generated 2 And decomposing S into elemental sulfur, and filtering to remove the elemental sulfur to obtain the pre-desulfurization rich gas. The total sulfur in the purified rich gas is reduced to be below 0.1ppm, so that the catalyst poisoning in the subsequent process caused by sulfur-containing compounds is prevented, and the requirements of the catalyst of the subsequent conversion process and the catalyst of the natural gas synthesis process on the sulfur content are met.
Further, the pre-desulfurization process includes the use of a filtration device loaded with a catalyst comprising an adsorbent material or the pre-desulfurization catalyst.
Preferably, before the rich gas enters the pre-desulfurization process, the particles in the rich gas are removed through a dust removal process.
Then carrying out a desulfurization process on the rich gas, aiming at removing the total sulfur to be below 0.1ppm and preventing the sulfur-containing compound from causing catalyst poisoning in the subsequent process; further, the desulfurization process comprises the step of using a desulfurization solution, wherein the hydrogen-enriched gas enters from the lower part of a third desulfurization device and is in countercurrent contact with the desulfurization solution sprayed from the upper part of the third desulfurization device, so that hydrogen sulfide in the hydrogen-enriched gas is removed, and the desulfurization solution contains an NHD solvent.
Further, in the desulfurization process, pressurized gas is introduced so that the pressure is 0.2 to 1.0MPa, and the temperature is maintained at 20 to 30 ℃.
Preferably, the decarbonization process comprises the use of decarbonization liquid, the hydrogenation rich gas enters from the lower part of a decarbonization device and is in countercurrent contact with decarbonization liquid sprayed from the upper part of the decarbonization device, so that carbon dioxide in the hydrogenation rich gas is removed, and the decarbonization liquid contains NHD solvent.
Preferably, in the decarburization process, a pressurized gas is introduced so that the pressure is 0.3 to 1.0MPa.
The effective component in the methane synthesis gas required by natural gas synthesis is H 2 、CO、CO 2 The requirement for the hydrogen to carbon ratio in methane synthesis gas is expressed as follows: r = (H) 2 -CO 2 )/(CO+CO 2 ) Wherein, the theoretical value of the hydrogen-carbon ratio R value of the methane synthetic gas is 3.0, and the optimal value is 2.95-3.05. The R value of the hydrogen-carbon ratio in the reformed and converted gas prepared by the method can not just meet the R value of 2.9-3.1, so that the R value of the hydrogen-carbon ratio in the methane synthesis gas is adjusted to 2.95-3.05, the low-rank coal is prepared by a gasification reduction process to obtain upgraded coal and rich gas, and the upgraded coal and/or the rich gas are prepared to contain CO and CO 2 And H2, thereby entering a methane synthesis process to synthesize methane.
The hydrogenated rich gas mainly comprises CO and CO 2 、H 2 And hydrocarbons, CO and H being well known 2 Can be directly used as a first-grade raw material for chemical synthesis, and hydrocarbons need to be converted to generate CO and H 2 (ii) a Preferably, the desulfurization rich gas is subjected to a shift conversion process to obtain shift conversion gas, so that the molar ratio of hydrogen to CO in the shift conversion gas is (3-10): 1. further, the desulfurized rich gas is passed through an adsorption unit loaded with a composition comprising activated carbon prior to entering the shift process.
Therefore, part of hydrocarbons in the hydrogenated rich gas are reformed and converted by a conversion process to obtain a product containing CO and H 2 Reforming converted gas of (2), CO and H in the reforming converted gas after reforming conversion 2 The total volume percentage is increased, which is beneficial to improving the quantity of the subsequent natural gas synthetic raw materials。
Finally, the methane product stream is liquefied to obtain crude natural gas and natural gas purge gas, and the natural gas purge gas is rich in hydrogen, so that the raw materials can be recycled, and the effective utilization rate of the raw materials is improved.
The natural gas is produced industrially at present, basically, anthracite is gasified into synthesis gas and then the natural gas is produced, the unit cost price of the anthracite is about 1200-1500 yuan/t, about 0.294t of natural gas is produced from 1t of coal, the unit cost price of the low-rank coal as the raw material is 80-100 yuan/t, the volatile component content in the low-rank coal is 20-55 wt%, and the yield of the natural gas produced by utilizing the volatile component in the low-rank coal is 15% by taking 1t of the low-rank coal as the basis. As shown in table 1 below, the unit cost price of the natural gas prepared by using low-rank coal as a raw material is much lower than that of the natural gas prepared by using anthracite coal as a raw material, so that the cost of the raw material is greatly reduced by preparing the natural gas by using the method of the present invention. In addition, in the process of preparing natural gas by using low-rank coal, byproduct upgraded coal and coal tar can be obtained, and the unit price of the upgraded coal is 500-600 yuan/t; the unit price of the coal tar is 2000-2500 yuan/t, and the product value of the upgraded coal and the coal tar is high.
TABLE 1 comparison of the cost per unit of natural gas produced from anthracite and low rank coal
Based on the technical scheme, on one hand, the method processes the rich gas obtained by gasifying and reducing the low-rank coal into the natural gas with higher economic value, and also synthesizes CO and H required by the raw material of the natural gas in the rich gas 2 The natural gas is prepared by the method, the impurities in the natural gas are few, the quality is high, the volatile components in the low-rank coal are fully and effectively utilized, the raw materials for preparing the natural gas are rich, the cost is low, the production cost is greatly saved, high-value upgraded coal and coal tar are rich, and the method accords with the national comprehensive utilization direction of coal.
Detailed Description
The present invention is further illustrated by the following examples, which are not intended to limit the invention to these embodiments. It will be appreciated by those skilled in the art that the present invention encompasses all alternatives, modifications and equivalents as may be included within the scope of the claims.
In the present invention, the raw materials and equipment used are commercially available or commonly used in the art, unless otherwise specified. The methods in the following examples are conventional in the art unless otherwise specified. The terms "first," "second," and the like, in the description herein are used for distinguishing between descriptions and not necessarily for describing or implying relative importance.
Preparation example
The invention discloses a method for preparing natural gas and co-producing hydrogen from rich gas by using low-rank coal according to quality, which comprises the following process steps;
a method for preparing natural gas and co-producing hydrogen from rich gas by using low-rank coal according to quality is characterized by comprising the following steps: the method comprises the following process steps:
(1) The low-rank coal is sequentially treated by a drying process and a gasification reduction process to obtain rich gas, the rich gas is purified by a purification process to obtain purified rich gas, and the purified rich gas contains CO and CO 2 、H 2 And hydrocarbons, wherein the gasification reduction process is a chemical reaction process for heating the dried low-rank coal under the oxygen-free or micro-oxygen condition;
(2) Treating the purified rich gas in the step (1) through a desulfurization process and a first compression process in sequence to obtain hydrogenated rich gas;
(3) The hydrogenated rich gas in the step (2) is treated by a reforming conversion process to obtain a product containing CO and CO 2 And H 2 Reforming the reformed gas of (1);
(4) In the step (3), the reformed conversion gas is subjected to one or more of a decarburization carbon-supplementing process, a conversion process and a hydrogen-supplementing process to obtain methane synthesis gas, wherein the hydrogen-carbon ratio R value of the methane synthesis gas is 2.95-3.05;
(5) And (4) sequentially passing the methane synthesis gas through a second compression process and a natural gas synthesis process to obtain crude natural gas and natural gas purge gas, and then passing the crude natural gas through a natural gas rectification process to obtain a product natural gas.
The raw material low-rank coal can be pulverized coal or lump coal, and when the low-rank coal adopts the lump coal, the pulverized coal with smaller granularity can be obtained by crushing and screening the oversize lump coal. The pulverized coal is preferably used as a raw material, on one hand, the pulverized coal does not need to be crushed and screened, so that the process steps are saved, the heating area is large during drying, the drying efficiency is high, and on the other hand, the pulverized coal is low in price compared with lump coal. Pulverized coal having a particle size of less than 20mm is preferably used, and pulverized coal having a particle size of less than 6mm is still more preferably used.
The low-rank coal generally has 20-55% of volatile components, about 3-15% of tar, 30-60% of fixed carbon, 10-40% of water and the balance of other impurities such as dust. The low-rank coal has low coalification degree, but contains abundant oil and gas resources, and the volatile components in the low-rank coal are very beneficial to extracting the synthesis gas, so that the low-rank coal with the volatile components of 30-55% is preferred.
The drying generally can only remove most of free water in the low-rank coal, but can not remove the bound water in the low-rank coal; the drying process can be a first-stage drying process or a multi-stage drying process, because if the moisture content of the low-rank coal after the first-stage drying process still cannot meet the process requirement, multi-stage drying such as a second-stage drying process and a third-stage drying process can be adopted to continue further drying until the moisture content of the dried low-rank coal meets the process condition. In addition, the multistage drying process can be arranged in series or in parallel, the drying effect can be enhanced when the multistage drying process is connected in series, and the treatment capacity of the drying process can be increased when the multistage drying process is connected in parallel, so that the design that the multistage drying process is connected in series or in parallel or in series and in parallel can be adjusted according to the actual situation according to the requirement of the actual production process as long as the same technical effect can be achieved, and specifically, for example, when the feeding capacity of the drying process is calculated by low-rank coal of 20-30t/h, a one-stage steam drying process can be adopted; when the feeding amount of the drying process is calculated by a low level of 50-70t/h, a secondary steam drying process can be adopted, so that the method is more economical and reasonable.
The low-rank coal dried by the drying process enters the gasification reduction process for reaction, and in order to optimize the process, a gasification feeding process can be added before the dried low-rank coal enters the gasification reduction process, so that the dried low-rank coal can quickly enter the gasification reduction process, the surface area of materials is increased, and the gasification reduction reaction can be accelerated.
Wherein, the gasification reduction process is a chemical reaction process for heating the dried low-rank coal under the condition of no oxygen or micro oxygen. The dried low-rank coal enters a gasification reduction process, under the heating of heating media such as flue gas and the like, additives and other substances are not needed to be added in the reaction process, the temperature is generally 350-800 ℃, and the process of complex chemical reaction is carried out under the pressure of less than or equal to 30Kpa, so as to obtain solid carbon and high-temperature rich gas, wherein the solid carbon is the upgraded coal, and the volatile components in the upgraded coal are 8-15wt%. The high-temperature rich gas comprises CO and H 2 、CO 2 Hydrocarbons, coal tar, naphthalene, halides, dust, and sulfur-containing compounds.
Wherein, the gasification reduction process can be one-stage or multi-stage. When the primary gasification reduction process is adopted, the reaction temperature of the gasification reduction process is 350-800 ℃, the volatile content in the upgraded coal is 8-15wt%, and the reaction temperature of the gasification reduction process is further preferably 400-750 ℃, mainly in order to obtain most of high-temperature rich gas, wherein the temperature directly influences the subsequent gas production rate, the yield of the upgraded coal and the temperature of the primary upgraded coal; still more preferably 450 to 700 ℃. When the multistage gasification reduction process is adopted, the multistage gasification reduction process mainly has the main function of continuously gasifying certain amount of high-boiling-point oily substances (such as similar asphalt and the like) which cannot be gasified in a certain retention time and cannot be separated out or the temperature cannot reach the polycondensation reaction conditions of phenolic compounds, aromatic hydrocarbon compounds and the like in the previous stage gasification reduction process, and continuously reacting and gasifying, so that the gas yield and the quality of upgraded coal are improved. The unit price of the upgraded coal is generally 500-600 yuan/t, and the upgraded coal after gasification and reduction can be sold and the like.
The method preferably adopts a two-stage gasification reduction process, the materials dried by the drying process enter a first-stage gasification reduction process and then enter a second-stage gasification reduction process, the dried low-rank coal enters the first-stage gasification reduction process to obtain first-stage gas and first-stage solid, the first-stage solid enters the second-stage gasification reduction process to be continuously gasified to obtain second-stage gas and second-stage solid, and the second-stage solid is upgraded coal; the feeding temperature of the primary gasification reduction process is 80-120 ℃, the gas outlet temperature is 180-550 ℃, the reaction temperature is 450-650 ℃, and the discharging temperature is 350-600 ℃; the feeding temperature of the secondary gasification reduction process is 350-600 ℃, the discharging temperature is 450-750 ℃, the reaction temperature is 550-800 ℃, and the gas outlet temperature is 450-700 ℃. When the two-stage gasification reduction process is adopted, the aim is to completely gasify most of volatile matters, so that a large amount of gas can be obtained, and upgraded coal with lower volatile matters can be obtained, wherein the volatile matter content in the upgraded coal is 3-8wt%.
The high temperature rich gas discharged from the gasification reduction process contains, in addition to useful components, other harmful impurities such as dust, tar, water vapor, unsaturated hydrocarbons, naphthalene, etc., which are present to seriously affect the normal production of the natural gas synthesis process, and thus, must be purified to a specified standard. The high-temperature rich gas obtained from the gasification reduction process enters a purification process to obtain purified rich gas. The purification process comprises a dust removal process, a tar removal process and the like. The rich gas sequentially passes through a dust removal process and a tar removal process to contain CO and H 2 And a purified rich gas of hydrocarbons. The high-temperature rich gas contains a large amount of dust, coal tar, water vapor, sulfur-containing compounds and the like; firstly, a dust removal device and the like are used for removing dust, so that the temperature of rich gas is prevented from being reduced in the dust removal process, and the coal tar, water vapor and the like are condensed into liquid and adhered with a large amount of dust to cause the blockage of a subsequent process pipeline and the reduction of the dust removal effect; the rich gas should contain a large amount of substances which are easy to solidify or crystallize, such as naphthalene and tar, and if the substances are not removed as much as possible, the substances will cause harm to the subsequent processes and even endanger the safety of the whole device. Therefore, the tar in the rich gas is removed to less than or equal to 1 mg/ml by the tar removing processNm 3 For example, a cooling tower is adopted to cool the gaseous coal tar in the rich gas and simultaneously condense a large amount of substances such as water vapor and naphthalene, and the byproduct coal tar can be obtained by separating oil from water obtained after cooling.
Natural gas synthesis catalysts also have high requirements for the content of impurities in the methane synthesis gas, otherwise the life of the catalyst is reduced and the quality of the natural gas is reduced. Therefore, the methane synthesis gas must be purified, and the purification is to remove the sulfide, oil, water, dust particles, carbonyl iron, chloride, etc. contained therein. Among these, the removal of sulfides is particularly important. Preferably, before the rich gas enters the pre-desulfurization process, the particles in the rich gas are removed through a dust removal process.
The hydrogenated rich gas mainly comprises CO and CO 2 、H 2 And hydrocarbons, CO and H being well known 2 Can be directly used as a primary raw material for chemical synthesis, and hydrocarbons need to be converted to generate CO and H 2 (ii) a Preferably, the desulfurization rich gas is subjected to a shift conversion process to obtain shift conversion gas, so that the molar ratio of hydrogen to CO in the shift conversion gas is (3-10): 1. further, the desulfurized rich gas is passed through an adsorption unit loaded with a composition comprising activated carbon prior to entering the shift process.
Then carrying out a desulfurization process on the rich gas, aiming at removing the total sulfur to be below 0.1ppm and preventing the sulfur-containing compound from causing catalyst poisoning in the subsequent process; further, the desulfurization process comprises the step of using a desulfurization solution, wherein the hydrogen-enriched gas enters from the lower part of a third desulfurization device and is in countercurrent contact with the desulfurization solution sprayed from the upper part of the third desulfurization device, so that hydrogen sulfide in the hydrogen-enriched gas is removed, and the desulfurization solution contains an NHD solvent. Preferably, the pre-desulfurization process comprises using a pre-desulfurization solution, wherein the rich gas enters from the lower part of the first desulfurization device and is in countercurrent contact with the pre-desulfurization solution sprayed from the upper part of the first desulfurization device, so that hydrogen sulfide in the rich gas is removed, and the pre-desulfurization solution comprises at least one of PDS catalyst, methanol and NDH solvent.
So that H 2 S taken off to 20mgNm 3 The following; further, the pre-desulfurization process comprises a second desulfurization device using at least one of a resistance wire and a pre-desulfurization catalyst, the resistance wire comprises nickel and chromium, the pre-desulfurization catalyst comprises at least one of basic copper carbonate, copper oxide, copper hydroxide, basic zinc carbonate, zinc oxide and zinc hydroxide, the rich gas is introduced into the second desulfurization device, and the resistance wire heats the rich gas to 200-500 ℃ so that H in the rich gas is generated 2 And decomposing S into elemental sulfur, and filtering to remove the elemental sulfur to obtain the pre-desulfurized rich gas. The total sulfur in the purified rich gas is reduced to be below 0.1ppm, so that the catalyst poisoning in the subsequent process caused by sulfur-containing compounds is prevented, and the requirements of the catalyst of the subsequent conversion process and the catalyst of the natural gas synthesis process on the sulfur content are met.
Further, the pre-desulfurization process includes the use of a filtration device loaded with a catalyst comprising an adsorbent material or the pre-desulfurization catalyst. Further, in the desulfurization process, pressurized gas is introduced so that the pressure is 0.2 to 1.0MPa, and the temperature is maintained at 20 to 30 ℃.
The effective component in the methane synthesis gas required by natural gas synthesis is H 2 、CO、CO 2 The requirement for the hydrogen to carbon ratio in methane synthesis gas is expressed as follows: r = (H) 2 -CO 2 )/(CO+CO 2 ) Wherein, the theoretical value of the hydrogen-carbon ratio R value of the methane synthetic gas is 3.0, and the optimal value is 2.9-3.1. And the R value of the hydrogen-carbon ratio in the prepared reformed gas can not just meet the R value of 2.95-3.05, so that the R value of the hydrogen-carbon ratio in the methane synthesis gas is adjusted to 2.95-3.05, and the upgraded coal and/or the rich gas prepared by the upgraded coal and/or the rich gas are prepared to contain CO and CO through a gasification reduction process, so that the upgraded coal and/or the rich gas are prepared to contain CO and CO 2 And H2, thereby entering a methane synthesis process to synthesize methane. Therefore, part of hydrocarbons in the hydrogenated rich gas are reformed and converted by a conversion process to obtain a product containing CO and H 2 Reforming reformed gas of (1), CO and H in the reforming reformed gas after reforming 2 The total volume percentage is increased, which is beneficial to improving the quantity of the subsequent natural gas synthesis raw materials. Preferably, the decarbonization process comprises the use of decarbonization liquid, and the hydrogenation is carried outAnd (3) the rich gas enters from the lower part of a decarbonizing device and is in countercurrent contact with decarbonizing liquid sprayed from the upper part of the decarbonizing device, so that carbon dioxide in the hydrogenated rich gas is removed, and the decarbonizing liquid contains an NHD solvent. Preferably, in the decarburization process, a pressurized gas is introduced so that the pressure is 0.3 to 1.0MPa.
The main chemical reaction formula of the synthetic natural gas is as follows:
because of the side reactions in the synthesis of natural gas, which generate a large amount of inert gas and accumulate in the process, the natural gas synthesis process must be continuously exhausted, and the exhausted gas is called natural gas purge gas. The main component of the natural gas purge gas is H 2 、CO、H 2 O and CH 4 In the presence of an inert gas, wherein H 2 And CH 4 The volume percentage content is about 90 percent. Recovery of H from natural gas purge gas by pressure swing adsorption 2 And the dual purposes of increasing natural gas yield, saving energy and reducing emission can be achieved. Recovery of H in natural gas purge gas by pressure swing adsorption or the like 2 In supplementing the reformed gas, H recovered from the subsequent natural gas purge gas may also be recovered 2 As recycle gas to supplement the second compression process in the machine with additional recovered H 2 It can also be used as fuel for combustion and heat supply. Or purifying H without pressure swing adsorption 2 And directly introducing the natural gas purge gas serving as circulating gas into a second compression process to be used as a part of raw material for natural gas synthesis. In addition, in the process of synthesizing the natural gas, the pressure of the rich steam is about 2.5MPa generally, the part of steam can be used as a byproduct of the natural gas synthesis tower of the device and can be used as a source of steam for steam reforming conversion in the reforming conversion process, and waste heat wastewater is recycled, so that the process cost is saved.
Crude natural gas obtained from a natural gas synthesis process enters a liquefaction process, methane with the volume percentage not less than 90% is produced through a cryogenic liquefaction process, and the product natural gas is obtained and hydrogen with the volume percentage not less than 90% is co-produced. The recovery rate of the natural gas liquefaction process is about 99.5%, the obtained natural gas is colorless transparent liquid, no peculiar smell is generated, the impurities are few, the quality is high, and the specification of the refined natural gas meets the requirement of the quality index of GB338-2011 high-grade natural gas.
The natural gas is produced industrially at present, basically anthracite is gasified into synthesis gas and then the natural gas is produced, the unit cost of the anthracite is about 1500 yuan/t, about 0.294t of natural gas is produced from 1t of coal, the unit cost of the low-rank coal which is used as the raw material of the invention is 80-100 yuan/t, the content of volatile components in the low-rank coal is 20-55 wt%, and the yield of the natural gas produced by utilizing the volatile components in the low-rank coal is 15% based on 1t of the low-rank coal. As shown in table 1 below, the unit cost price of the natural gas prepared by using low-rank coal as the raw material is much lower than that of the natural gas prepared by using anthracite coal as the raw material, so that the cost expenditure of the raw material is greatly reduced by preparing the natural gas by using the method of the present invention. In addition, in the process of preparing the natural gas by using the low-rank coal, byproduct upgraded coal and coal tar can be obtained, the unit price of the upgraded coal is 500-600 yuan/t, the unit price of the coal tar is 2000-2500 yuan/t, and the value of the product with rich yield is high.
TABLE 1 comparison of cost per unit of natural gas produced from anthracite and low-rank coal
The components of the obtained pre-desulfurized rich gas, the components of the desulfurized rich gas and the energy consumption per kilogram of natural gas are analyzed through a comparative experiment, so that the technical progress of the method for preparing the natural gas and producing the hydrogen is analyzed.
Experimental example 1
A method for preparing natural gas and co-producing hydrogen from rich gas by using low-rank coal according to quality comprises the following steps:
(1) Tong (Chinese character of 'tong')The process comprises the steps of preparing upgraded coal, coal tar and rich gas from low-rank coal sent by a coal preparation system by an over-gasification reduction process, wherein the rich gas comprises CH (carbon-oxygen) according to the volume ratio 4 28-40% of content, 5-20% of CO content and H 2 25-40% of CO 2 Content of 5-20%, C 2 H 6 Content 2-8%, C 2 H 4 Content 1-4%, C 3 H 6 0.5-3% of C 3 H 8 Content of 0.4-2.5%, C 4 H 8 Content of 0.2-2%, H 2 S content 2000-6000ppm and NH 3 The content is less than 100ppm;
(2) Removing sulfur in the rich gas through a pre-desulfurization process to obtain pre-desulfurized rich gas; adopting a conventional wet desulphurization process, wherein the pre-desulphurization process comprises the step of using a pre-desulphurization solution comprising a PDS catalyst, and the rich gas enters from the lower part of a pre-desulphurization device and is in countercurrent contact with the pre-desulphurization solution sprayed from the upper part of the pre-desulphurization device, so that hydrogen sulfide in the rich gas is removed;
(3) Converting all unsaturated hydrocarbons of the pre-desulfurized rich gas into corresponding saturated hydrocarbons by a hydrogenation process, and simultaneously converting organic sulfur into H 2 S, obtaining hydrogenated rich gas; under the action of iron-molybdenum catalyst, unsaturated hydrocarbon, organic sulfur compound (COS, thioether, mercaptan, etc.), oxygen and oxygen in the pyrolysis gas are reacted with hydrogen to convert the unsaturated hydrocarbon in the pyrolysis gas into saturated hydrocarbon and convert the organic sulfur into H easy to be eliminated 2 S；
(4) Removing sulfur in the hydrogenated rich gas through a desulfurization process to obtain a desulfurized rich gas; h is desulfurized by two zinc oxide desulfurizing tanks connected in series and in parallel 2 And (4) S absorption.
(5) And removing carbon dioxide in the desulfurized rich gas through a decarburization process to obtain methane synthesis gas, so that the hydrogen-carbon ratio in the methane synthesis gas is (2.9-3.1): 1;
(6) The methane synthesis gas is prepared by adopting a methane synthesis process with at least 4 methanation reactors connected in series, so that carbon monoxide, carbon dioxide and hydrogen in the desulfurized rich gas react in the presence of a methanation catalyst to synthesize methane, and a methane product material flow is obtained; methanation with low nickel contentThe catalyst comprises methanation catalyst components with NiO content of 12-24% and Al 2 O 3 32-74% of La, 1.2-4.8% of MgO and 2 O 3 1.2-4.8% of CaO, 5-12% of CaO and K 2 0.5-1.2% of O and 1.5-4.5% of graphite; the effective components in the raw material gas are: h 2 CO and CO 2 Methanation reaction is carried out, so that the concentration of the generated methane can reach 75-90%;
(7) And introducing the methane product material flow into a liquefaction process, and producing methane with the volume percentage not less than 90% by using a cryogenic liquefaction process to obtain a product natural gas and co-produce hydrogen with the volume percentage not less than 90%.
Experimental example 2
Experimental example 2 referring to experimental example 1, except that the pre-desulfurization process in experimental example 6 includes a second desulfurization apparatus using a resistance wire including nickel and chromium and a pre-desulfurization catalyst including at least one of basic copper carbonate, copper oxide, copper hydroxide, basic zinc carbonate, zinc oxide, and zinc hydroxide, specifically a mixture of basic zinc carbonate and zinc oxide; the rich gas is introduced into the second desulfurization device, and the resistance wire heats the rich gas to 200-500 ℃ so that H in the rich gas 2 And decomposing S into elemental sulfur, and filtering to remove the elemental sulfur to obtain the pre-desulfurized rich gas.
Experimental example 3
Experimental example 3 referring to experimental example 1, except that in the preliminary desulfurization process and the desulfurization process of experimental example 3, electrodes were provided, and a direct current voltage exceeding 10KV was applied to the electrodes, so that H in the rich gas was 2 And decomposing S into elemental sulfur, and filtering to remove the elemental sulfur to obtain the pre-desulfurized rich gas.
Comparative example 1
The method for preparing natural gas and co-producing hydrogen from rich gas by using low-rank coal according to quality comprises the following steps:
(1) Heating low-rank coal at 400-600 ℃ by isolating air to obtain byproducts of semi-coke, coal tar and rich gas, wherein the component of the rich gas comprises CH 4 28-40% of content and 1% of CO0-15％，H 2 25-40% of CO 2 Content 5-10%, C 2 H 6 Content 2-8%, C 2 H 4 Content 1-4%, C 3 H 6 0.5-3% of C 3 H 8 Content of 0.4-2.5%, C 4 H 8 0.2-2% of H 2 S content 2000-6000ppm and NH 3 The content is 300-800ppm;
(2) Through the spraying water washing purification process adopted by the water washing purification unit 2, the pretreated rich gas is further purified, and ammonia gas and sulfide in the rich gas are removed, so that the load of a subsequent desulfurization procedure is reduced, and the pre-desulfurized rich gas is obtained;
(3) All unsaturated hydrocarbons in the coal gas are converted into corresponding saturated hydrocarbons through the hydrogenation unit 3, and organic sulfur is simultaneously converted into H 2 S, obtaining hydrogenated rich gas;
(4) The fine desulfurization unit 4 adopts a dry desulfurization process to desulfurize by using solid ZnO so as to remove H in the feed gas 2 The S content is reduced to<0.1ppm to obtain the desulfurized rich gas;
(5) Passing the desulfurized gas through a pre-conversion unit 5, and pre-converting the desulfurized gas by using a hydrocarbon steam pre-conversion catalyst with high nickel content, wherein the NiO content in the catalyst is 48-68%, and the Al content in the catalyst is 48-68% 2 O 3 15-36% of La, 1.2-4.8% of MgO and 2 O 3 1.2-4.8% of CaO, 5-12% of CaO and K 2 0.5-1.2% of O and 1.5-4.5% of graphite; the unit leads higher hydrocarbon with more than C2 in the coal gas to generate pre-conversion reaction to generate methane under the conditions of 1.5-3.5MPa of pressure, 400-800 ℃ of temperature and 2-4 of water-carbon ratio; wherein the coal gas after the pre-conversion reaction comprises the following components: CH (CH) 4 30-50% of CO, 13-18% of H 2 30-60% of CO 2 10-15% in content and containing a small amount of water vapor and other impurity gases;
(6) Passing the pre-converted gas through a methanation unit 6, and adopting a methanation catalyst with low nickel content, wherein the methanation catalyst comprises 12-24% of NiO, 32-74% of Al2O3, 1.2-4.8% of MgO, 1.2-4.8% of La2O3, 5-12% of CaO, 0.5-1.2% of K2O and 1.5-4.5% of graphite; the effective components in the raw material gas are: h2, CO and CO2 are subjected to methanation reaction, so that the concentration of the generated methane can reach 75-90%;
(7) And introducing the gas after the methanation reaction into a pressure swing adsorption unit 7, and producing high-concentration methane, namely a product LNG and high-purity hydrogen through a pressure swing adsorption process.
TABLE 2 table for analyzing the composition of the pre-desulfurized rich gas produced in test examples 1 to 3 and comparative example 1 *1
| Composition of | Experimental example 1 | Experimental example 2 | Experimental example 3 | Comparative example 1 |
| CH 4 | 27.67 | 26.17 | 27.86 | 26.38 |
| H 2 | 28.53 | 32.66 | 29.43 | 26.42 |
| CO | 14.70 | 17.20 | 15.58 | 14.60 |
| CO 2 | 18.91 | 17.46 | 18.76 | 16.96 |
| N 2 | 1.08 | 1.12 | 1.06 | 1.52 |
| H 2 O | 1.72 | 1.25 | 1.65 | 6.72 |
| Others | 7.38 | 4.14 | 5.66 | 7.40 |
| Sulfur content | 36.8ppm | 14.6ppm | 16.2ppm | 139.4ppm |
Note: 1. the content is volume percentage content;
2. others include other alkanes and ammonia.
From the results in table 2, the components of the obtained pre-desulfurized rich gas were analyzed, and we could obtain that, firstly, the sulfur content in the rich gas could be significantly reduced by using the PDS catalyst-containing desulfurization solution, and secondly, the sulfur content in the pre-desulfurized gas could be significantly reduced by using the resistance wire and the pre-desulfurization catalyst, which is reduced from 36.8ppm in experimental example 1 to 14.6ppm in experimental example 2; thirdly, the pre-desulfurization process is provided with the electrode, so that the sulfur content in the pre-desulfurized gas can be obviously reduced from 36.8ppm of the experimental example 1 to 16.2ppm of the experimental example 3.
TABLE 3 compositional analysis tables of desulfurized rich gas produced in test examples 1 to 3 and comparative example 1
| Make up of | Experimental example 1 | Experimental example 2 | Experimental example 3 | Comparative example 1 |
| CH 4 | 27.13 | 25.45 | 27.02 | 25.25 |
| H 2 | 30.43 | 33.55 | 31.60 | 28.05 |
| CO | 15.10 | 17.90 | 16.14 | 15.20 |
| CO 2 | 17.14 | 16.55 | 17.23 | 15.82 |
| N 2 | 1.13 | 1.18 | 1.12 | 1.65 |
| H 2 O | 1.75 | 1.32 | 1.58 | 6.96 |
| Others | 7.32 | 4.05 | 5.31 | 7.07 |
| Sulfur content | 0.09ppm | 0.06ppm | 0.01ppm | 2.12ppm |
Note: 1. the content is volume percentage content;
2. others include other alkanes and ammonia.
From the results of table 3, we can obtain, by analyzing the components of the obtained pre-desulfurization rich gas, firstly, the desulfurization effect in the desulfurization stage due to the non-ideal desulfurization effect in the pre-desulfurization stage; secondly, the pre-desulfurization process comprises the use of a resistance wire and a pre-desulfurization catalyst, so that the sulfur content in the pre-desulfurized gas can be obviously reduced, and the sulfur content is also reduced from 0.09ppm of experimental example 1 to 0.06ppm of experimental example 2 in the desulfurization stage; thirdly, the electrodes are arranged in the pre-desulfurization process and the desulfurization stage, so that the sulfur content in the pre-desulfurized gas can be obviously reduced from 0.09ppm of the experimental example 1 to 0.01ppm of the experimental example 3.
TABLE 4 analytical analysis table of energy consumption before cut-off methanation reaction in test examples 1 to 3 and comparative example 1
| Composition of | Experimental example 1 | Experimental example 2 | Experimental example 3 | Comparative example 1 |
| Energy consumption/kJ | 1468 | 1404 | 1348 | 1728 |
Note: the energy consumption analysis is the energy consumption of the methane synthesis gas which can produce 1 cubic meter of LNG before the methanation reaction is stopped.
From the results in table 3, we can obtain that by analyzing the energy consumption of the methane synthesis gas capable of producing 1 cubic meter of LNG before the methanation reaction, firstly, the energy consumption can be effectively reduced due to the elimination of the hydrocarbon conversion process; secondly, the pre-desulfurization process comprises using a resistance wire and a pre-desulfurization catalyst, and can obviously reduce the sulfur content in the pre-desulfurized gas, so that the energy consumption of the system is reduced, and the 1468KJ of the experimental example 1 is reduced to 1404KJ of the experimental example 2; thirdly, the electrodes are arranged in the pre-desulfurization process and the desulfurization stage, so that the sulfur content in the pre-desulfurized gas can be obviously reduced, the energy consumption of the system is reduced from 1468KJ of the experimental example 1 to 1348KJ of the experimental example 2, and the energy consumption is obviously saved due to the fact that the basic energy consumption of the electrodes is low.
In conclusion, the method obtains the volatile components by gasifying and reducing the low-rank coal, and then synthesizes the CO and H required by the raw materials from the natural gas in the volatile components 2 The natural gas is prepared by the method, the impurities in the natural gas are few, the quality is high, the volatile components in the low-rank coal are fully and effectively utilized, the raw materials for preparing the natural gas are rich, the cost is low, the production cost is greatly saved, high-value upgraded coal and coal tar are rich, and the method accords with the national comprehensive utilization direction of coal.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (7)
1. A method for preparing natural gas and co-producing hydrogen from rich gas by using low-rank coal according to quality is characterized by comprising the following steps:
(1) Preparing upgraded coal, coal tar and rich gas from low-rank coal sent by a coal preparation system through a gasification reduction process, wherein the rich gas comprises CH according to the volume ratio 4 28-40% of content, 5-20% of CO content and H 2 25-40% of CO 2 Content of 5-20%, C 2 H 6 Content 2-8%, C 2 H 4 Content 1-4%, C 3 H 6 0.5-3% of C 3 H 8 Content of 0.4-2.5%, C 4 H 8 Content of 0.2-2%, H 2 S content 2000-6000ppm and NH 3 The content is less than 100ppm;
(2) Removing sulfur in the rich gas through a pre-desulfurization process to obtain pre-desulfurized rich gas;
(3) Converting all unsaturated hydrocarbons of the pre-desulfurized rich gas into corresponding saturated hydrocarbons by a hydrogenation process, and simultaneously converting organic sulfur into H 2 S, obtaining hydrogenated rich gas;
(4) Removing sulfur in the hydrogenation rich gas through a desulfurization process to obtain desulfurization rich gas;
(5) And removing carbon dioxide in the desulfurized rich gas through a decarburization process to obtain methane synthesis gas, so that the hydrogen-carbon ratio in the methane synthesis gas is (2.9-3.1): 1;
(6) The methane synthesis gas is prepared by adopting a methane synthesis process with at least 4 methanation reactors connected in series, so that carbon monoxide, carbon dioxide and hydrogen in the desulfurized rich gas react in the presence of a methanation catalyst to synthesize methane, and a methane product material flow is obtained;
(7) Introducing the methane product material flow into a liquefaction process, and producing methane with the volume percentage not less than 90% through a cryogenic liquefaction process to obtain a product natural gas and co-produce hydrogen with the volume percentage not less than 90%;
the pre-desulfurization process comprises the steps of using a pre-desulfurization solution, wherein the rich gas enters from the lower part of a first desulfurization device and is in countercurrent contact with the pre-desulfurization solution sprayed from the upper part of the first desulfurization device, so that hydrogen sulfide in the rich gas is removed, and the pre-desulfurization solution comprises at least one of PDS catalyst, methanol and NDH solvent;
the pre-desulfurization process comprises a second desulfurization device using a resistance wire and a pre-desulfurization catalyst, wherein the resistance wire comprises nickel and chromium, the pre-desulfurization catalyst comprises at least one of basic copper carbonate, copper oxide, copper hydroxide, basic zinc carbonate, zinc oxide and zinc hydroxide, the rich gas is introduced into the second desulfurization device, and the resistance wire heats the rich gas to 200-500 ℃ so that H in the rich gas is generated 2 And decomposing S into elemental sulfur, and filtering to remove the elemental sulfur to obtain the pre-desulfurized rich gas.
2. The process according to claim 1, wherein the desulphurized rich gas is passed through a hydrogen-rich or carbon monoxide-rich gas stream, the molar ratio of hydrogen to CO being (3-10): 1.
3. the method of claim 1, wherein the pre-desulfurization process comprises using a filtration device loaded with a catalyst comprising an adsorbent material or the pre-desulfurization catalyst.
4. The method of claim 1, wherein the particulate matter in the rich gas is removed by a dust removal process prior to entering the pre-desulfurization process.
5. The method of claim 1, wherein the desulfurization process comprises using a desulfurization solution, and the hydrogen sulfide in the hydrogen-rich gas is removed by entering the hydrogen-rich gas from the lower part of a third desulfurization device and countercurrently contacting the desulfurization solution sprayed from the upper part of the third desulfurization device, wherein the desulfurization solution contains an NHD solvent.
6. The method according to claim 5, wherein in the desulfurization process, a pressurized gas is introduced so that the pressure is 0.2 to 1.0MPa and the temperature is maintained at 20 to 30 ℃.
7. The method of claim 1, wherein the decarbonization process comprises using a decarbonization solution, and the hydrogenation rich gas enters from the lower part of a decarbonization device and is in countercurrent contact with the decarbonization solution sprayed from the upper part of the decarbonization device so as to remove carbon dioxide from the hydrogenation rich gas, and the decarbonization solution contains an NHD solvent.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911221881.9A CN110862844B (en) | 2019-12-03 | 2019-12-03 | Method for preparing natural gas and co-producing hydrogen from rich gas by using low-rank coal according to quality |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911221881.9A CN110862844B (en) | 2019-12-03 | 2019-12-03 | Method for preparing natural gas and co-producing hydrogen from rich gas by using low-rank coal according to quality |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110862844A CN110862844A (en) | 2020-03-06 |
| CN110862844B true CN110862844B (en) | 2023-03-10 |
Family
ID=69657281
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911221881.9A Active CN110862844B (en) | 2019-12-03 | 2019-12-03 | Method for preparing natural gas and co-producing hydrogen from rich gas by using low-rank coal according to quality |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110862844B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112897464B (en) * | 2021-01-18 | 2022-05-17 | 西南化工研究设计院有限公司 | Process for producing hydrogen and coproducing LNG (liquefied natural gas) by using raw gas with methanation |
| CN116199185B (en) * | 2023-05-06 | 2023-07-18 | 浙江百能科技有限公司 | High-temperature catalytic hydrogen production reaction system and method by utilizing waste water in coal grading manner |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103733405A (en) * | 2011-05-24 | 2014-04-16 | 沙特阿拉伯石油公司 | Electrochemical promotion of catalysis in hydrodesulfurization processes |
| CN105255531A (en) * | 2015-10-19 | 2016-01-20 | 中国华能集团清洁能源技术研究院有限公司 | System and method for natural gas production and hydrogen co-production through low-temperature dry distillation gas |
-
2019
- 2019-12-03 CN CN201911221881.9A patent/CN110862844B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103733405A (en) * | 2011-05-24 | 2014-04-16 | 沙特阿拉伯石油公司 | Electrochemical promotion of catalysis in hydrodesulfurization processes |
| CN105255531A (en) * | 2015-10-19 | 2016-01-20 | 中国华能集团清洁能源技术研究院有限公司 | System and method for natural gas production and hydrogen co-production through low-temperature dry distillation gas |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110862844A (en) | 2020-03-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20120068120A1 (en) | Syngas production method | |
| CN112897464B (en) | Process for producing hydrogen and coproducing LNG (liquefied natural gas) by using raw gas with methanation | |
| CN101845319B (en) | Process for producing wax and clean fuel oil by using biomass as raw material | |
| CN110862844B (en) | Method for preparing natural gas and co-producing hydrogen from rich gas by using low-rank coal according to quality | |
| EP2657215B1 (en) | Method and device for producing methanol | |
| CN104531186A (en) | Method for producing tar and hydrocarbon fuel products with coal | |
| CN101239702B (en) | High temperature coke oven crude gas hydrogen generating system device and technique | |
| CN109880654A (en) | A method of utilizing volatile matter Fischer Tropsch waxes in low-order coal | |
| CN110862841B (en) | Method for preparing natural gas from coal water slurry | |
| CN101870479B (en) | Fischer-Tropsch synthesis cogeneration process for synthesizing ammonia | |
| CN114149837B (en) | Process for preparing liquefied natural gas and co-producing liquid ammonia or hydrogen by coke oven gas with conversion decarburization | |
| CN110055106B (en) | Method for preparing methanol and oil by poly-generation through low-rank coal quality-based utilization | |
| WO2012130258A1 (en) | Method for the purification of raw gas | |
| CN110804468A (en) | Dry desulfurization process for synthesis gas | |
| CN110002933B (en) | Method for preparing methanol and low-carbon olefin by poly-generation through low-rank coal quality-based utilization | |
| CN110903853B (en) | Method for preparing natural gas and co-producing hydrogen | |
| CN210560263U (en) | Device for preparing Fischer-Tropsch wax by utilizing coke oven gas | |
| CN110846094B (en) | Process for preparing LNG (liquefied Natural gas) from purified gas | |
| CN110981677B (en) | Methane synthesis process | |
| CN110669542A (en) | Method and device for preparing Fischer-Tropsch wax by using coke oven gas | |
| CN110885704A (en) | Method for preparing natural gas by upgrading coal | |
| CN113955716A (en) | Process for preparing synthetic gas and CNG (compressed natural gas) from coke-oven gas submerged arc furnace gas | |
| CN111253975A (en) | Method for grading and utilizing low-rank coal | |
| CN110926106A (en) | Liquefaction process for preparing LNG | |
| CN110862842A (en) | Process for preparing LNG (liquefied Natural gas) from synthesis gas |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |