CN105000534B - Method for combined preparation of synthetic gas based on slurry gasification and natural gas conversion - Google Patents

Abstract

The invention relates to a method for jointly preparing synthesis gas based on slurry gasification and natural gas conversion. The method includes the steps of slurry gasification, natural gas conversion, synthesis gas distribution and the like. The method has the advantages of wide sources of raw materials, high comprehensive utilization efficiency of raw materials, reasonable energy utilization, less waste discharge, mature unit device technology, easy adjustment of H/C ratio of synthesis gas, high added value of products, and obvious scale benefits. Through gas distribution, the synthesis gas H/C can be adjusted in the range of 1.0 to 2.0. The synthesis gas obtained in step A and step B of the present invention can be directly used as a raw material for methanol synthesis and/or Fischer-Tropsch synthesis without any or a small amount of gas conversion after gas distribution. The synthesis gas produced by gasification per ton of coal is reduced by 40-600Nm ³ /ton of coal, and CO ₂ emission is reduced by 20-300Nm ³ /ton of coal.

Description

A method for joint production of synthesis gas based on slurry gasification and natural gas conversion

【Technical field】

The invention belongs to the technical field of coal chemical industry. More specifically, the present invention relates to a method for jointly producing synthesis gas based on slurry gasification and natural gas conversion.

【Background technique】

As we all know, in the world's mineral energy reserves, natural gas and coal account for a considerable proportion, and realizing the clean and efficient utilization of the above two natural resources has great practical and strategic significance.

Coal resources have the largest reserves among fossil resources, and they are also the resources that are mined the most, used the most, and used the most ways. Among the various methods of coal resource conversion, the gasification method is the best way to realize the clean and efficient utilization of resources, avoiding the disadvantages of low thermal energy utilization rate of direct coal combustion and producing a large amount of greenhouse gases and solid dust, and can reduce the impact on Pollution and destruction of the ecological environment. Due to the inherent properties of coal and the process characteristics of wet gasification, the H/C in the synthesis gas obtained by wet pressurized gasification is relatively low. In order to match the subsequent process, the synthesis gas needs to undergo partial conversion or full conversion. Adjust to proper H/C.

The wet pressurized gasification temperature is relatively high, and the high-temperature syngas is generally cooled by direct cooling, and the sensible heat is not recycled, and the energy utilization is not very reasonable. Due to the high carbon-hydrogen ratio of the generated syngas, the carbon dioxide produced after washing with methanol is often vented, which intensifies the greenhouse effect.

Natural gas is a clean and easy-to-use natural resource. Two-stage reforming of natural gas mainly includes one-stage steam reforming and second-stage pure oxygen reforming. After the natural gas is desulfurized, its sulfur content is reduced to 0.1ppm. The purified raw gas is saturated through the saturation tower, and the process water steam is added according to a certain water-to-carbon ratio. After the heat exchange of the high-temperature synthesis gas in the first stage reformer, the outlet gas of the first stage reformer enters the second stage reformer for reforming reaction with oxygen and steam to generate synthesis gas.

With the large-scale development of natural gas resources and the improvement of infrastructure, some chemical companies use natural gas as chemical raw materials for the production of synthetic ammonia, methanol and other products. When using natural gas as raw material to produce methanol, the H/C ratio in the produced synthesis gas is high, the _H2 content in the synthesis purge gas is high, and the emission is large, resulting in serious waste of resources and power.

The present invention aims at the characteristics of the above two kinds of resources and the corresponding status of the conversion technology, using natural gas and coal as raw materials, through the combination of the natural gas conversion process and the multi-component slurry gasification process, according to the high H/C ratio in the natural gas processing products and the multi-component slurry gasification process Due to the relatively low H/C ratio in the chemical gas composition, rationally utilize the sensible heat of high-temperature syngas to preheat natural gas to produce clean syngas, rationally distribute the gas, adjust the H/C ratio of the syngas, and use it as synthetic raw materials in downstream sections .

The invention adopts the gas distribution of the synthetic gas produced by coal gasification and natural gas conversion, reduces the emission of carbon dioxide, increases the output of the synthetic gas and reduces the greenhouse effect. Through the above process, the full utilization of raw materials in the processing process can be realized. By adjusting the H/C in the synthesis gas, the gas hydrocarbon adjustment range is simplified, energy and catalyst and other consumables are saved, and the production capacity of end products is increased.

【Content of invention】

[Technical problem to be solved]

The purpose of the present invention is to provide a method for joint production of synthesis gas based on slurry gasification and natural gas conversion.

[Technical solutions]

The present invention is achieved through the following technical solutions.

The invention relates to a method for jointly preparing synthesis gas based on slurry gasification and natural gas conversion.

The steps of this method are as follows:

A. Slurry gasification

Firstly, the hydrocarbon-containing raw materials, additives and solvents are made into a slurry with a concentration of 50-70% by weight of dry hydrocarbons; then, the slurry is passed through the slurry pipeline 14 and oxygen is passed through The oxygen pipeline 15 is sprayed into the gasification furnace 1 through the nozzle 8 at the same time; the said slurry and oxygen undergo a partial oxidation-reduction reaction under the conditions of a pressure of 1.0-10.0 MPa and a temperature of 1200-1400 ° C to generate CO, H ₂ , CO ₂ , CH ₄ , H ₂ O main components of crude synthesis gas and molten ash; the molten ash is lowered when passing through the second-stage heating furnace 2 and the first-stage heating furnace 3 successively, and is released from the lock hopper 4 in solid state out of bounds;

The crude synthesis gas passes through the second-stage heating furnace 2 and the first-stage heating furnace 3 to exchange heat with the natural gas from the natural gas pipeline 24; the heat-exchanged crude synthesis gas enters the steam superheater 5 through the solid particle-containing synthesis gas pipeline 16, and the The steam heating from the steam pipeline 22 then enters the solid particle separator 6 through the solid particle separator feed line 17, where the fine ash entrained by the crude synthesis gas is separated and removed; the fine ash is composed of solid particles The bottom pipeline 20 of the separator is discharged outside; the syngas from which the fine ash has been removed is sent to the 1# heat exchanger 7 by the top pipeline 18 of the solid particle separator, and exchanges heat with the steam from the steam input pipeline 21, and the cooled The synthesis gas is combined with the synthesis gas converted from natural gas through the synthesis gas discharge pipeline 19, and then sent to the subsequent processing system after distribution;

B. Natural gas conversion

The natural gas enters the first-stage heating furnace 3 through the natural gas pipeline 24, and indirectly exchanges heat with the crude synthesis gas from the second-stage heating furnace 2, and the preheated natural gas enters the desulfurization tower 9 through the preheated natural gas pipeline 25, and the desulfurization tower 9 in the natural gas is removed. Sulphide; the desulfurized natural gas is sent to the secondary heating furnace 2 through the desulfurized natural gas pipeline 26 together with the steam sent from the superheated steam pipeline 23, where they exchange heat with the crude synthesis gas from the gasifier 1; heating The natural gas and water vapor in the primary reformer are sent to the primary reformer 10 through the feed pipeline 27 of the primary reformer, where the heated natural gas and steam undergo catalytic conversion reaction, and the obtained primary reformed gas passes through the primary reformer discharge pipeline 28, oxygen The oxygen pipeline 29 and water vapor are simultaneously sent to the top of the second-stage reformer 11 through the superheated steam pipeline 34, and the first-stage reforming gas, oxygen and water vapor are carried out in the second-stage reformer 11 for natural gas partial oxidation reaction and steam catalysis Conversion reaction to obtain synthesis gas containing CO, CO ₂ , H ₂ ;

The synthesis gas is returned to the primary reformer 10 through the discharge pipeline 30 at the bottom of the secondary reformer to provide the required heat for the reforming reaction of natural gas and steam; the heat-exchanged synthetic gas passes through the synthetic gas discharge pipeline of the primary reformer 31 is sent to the steam superheater 12, which exchanges heat with the steam sent through the 2# heat exchange steam discharge pipeline 35 to recover the heat of the synthesis gas; the synthesis gas passes through the 2# heat exchange synthesis gas feed pipeline 32 is sent to the 2# heat exchanger 13, which exchanges heat with the steam from the steam input pipeline 36 to realize further cooling, and the cooled syngas is gasified with the above slurry through the 2# heat exchange syngas discharge pipeline 33 The obtained synthesis gas is combined, distributed and sent to the subsequent treatment system for treatment.

According to a preferred embodiment of the present invention, the hydrocarbon-containing material raw material is one or more selected from coal, biomass, oil residue and other raw materials; the solvent is one or more selected from water , organic waste water, carbon monoxide shift condensate and other solvents.

According to a preferred embodiment of the present invention, the additive is one or more selected from sodium lignosulfonate, calcium lignosulfonate, polycondensed sodium naphthalenesulfonate, highly polymerized sodium naphthalenesulfonate or non-colloidal Additive for high phosphorus china clay.

According to another preferred embodiment of the present invention, both the second-stage heating furnace 2 and the first-stage heating furnace 3 are high-temperature radiation boilers.

According to another preferred embodiment of the present invention, the high-temperature radiant boiler is a gas distribution pipe 41 arranged at the bottom, a gas collecting pipe 42 arranged at the top, and the axes of the first-stage heating furnace 3 and the second-stage heating furnace 2 are in the middle. Benchmark, a boiler made of high-temperature-resistant high-grade alloy steel pipes made of tubes or coiled tubes 40.

According to another preferred embodiment of the present invention, the desulfurization agent loaded in the desulfurization tower 9 is cobalt molybdenum hydrodesulfurization agent and/or zinc oxide desulfurization agent.

According to another preferred embodiment of the present invention, the structure of the primary reformer 10 is a tubular reformer, and the primary reforming catalyst sold under the trade name FZ-3 by Xiehua Science and Technology Industry Co., Ltd., Liling City, Hunan Province is filled in the tube.

According to another preferred embodiment of the present invention, the structure of the secondary reformer 11 is a packed reformer, and the furnace is filled with a secondary reforming catalyst sold by Sichuan Tianyi Technology Co., Ltd. under the trade name Z204.

According to another preferred embodiment of the present invention, the H/C of the syngas obtained in the slurry gasification step and the synthesis gas obtained in the natural gas conversion step is 1.0 to 2.0 after gas distribution, and its dry basis composition is It is 30-60% CO, 30-60% H ₂ , 10-25% CO ₂ and the balance of N ₂ , CH ₄ and H ₂ S by volume.

The present invention will be described in more detail below.

The invention relates to a method for jointly preparing synthesis gas based on slurry gasification and natural gas conversion.

The steps of this method are as follows:

A. Slurry gasification

First, the hydrocarbon-containing material raw material, additives and solvents are made into a slurry with a concentration of 50% to 70% by dry hydrocarbon weight; the hydrocarbon-containing material raw material is one or more selected from coal, Biomass, oil residue and other raw materials; the solvent is one or more selected from water, organic waste water, carbon monoxide shift condensate and other solvents; the additive is one or more selected from lignosulfonic acid Additives of sodium, calcium lignosulfonate, polycondensed sodium naphthalenesulfonate, highly polymerized sodium naphthalenesulfonate or non-colloidal high phosphorus china clay. Then, let the slurry pass through the slurry pipeline 14 and allow oxygen to pass through the oxygen pipeline 15 and spray it into the gasifier 1 through the nozzle 8 at the same time; Under the condition of ~1400℃, a partial oxidation-reduction reaction is carried out to generate crude synthesis gas and molten ash containing main components of CO, H ₂ , CO ₂ , CH ₄ , and H ₂ O. The temperature of the crude synthesis gas discharged from the gasifier 1 is 1200-1400° C., the pressure is 1.0-10.0 MPa, and the water vapor content is 10-30% based on the volume of the crude synthesis gas. The molten ash is lowered in temperature when passing through the second-stage heating furnace 2 and the first-stage heating furnace 3 successively, and is discharged out of the boundary from the lock hopper 4 in a solid form.

The crude synthesis gas passes through the second-stage heating furnace 2 and the first-stage heating furnace 3 to exchange heat with the natural gas from the natural gas pipeline 24 to recover the sensible heat of the crude synthesis gas; the heat-exchanged crude synthesis gas passes through the solid particle-containing synthesis gas pipeline 16 enters the steam superheater 5, heats the steam from the steam pipeline 22, and recovers the heat of the crude synthesis gas. The crude synthesis gas then enters the solid particle separator 6 through the solid particle separator feed line 17, where it separates and removes the fine ash entrained by the crude synthesis gas; 20 is discharged outside; the syngas from which the fine ash has been removed is sent to the 1# heat exchanger 7 by the top pipeline 18 of the solid particle separator, and exchanges heat with the water vapor from the steam input pipeline 21, and the cooled syngas passes through the syngas The discharge pipeline 19 is combined with the synthesis gas obtained from the conversion of natural gas, and then sent to the subsequent processing system after gas distribution.

The second-stage heating furnace 2 and the first-stage heating furnace 3 are high-temperature radiation boilers.

The high-temperature radiant boiler is a steel pressure-resistant and temperature-resistant equipment with built-in heat exchange tubes. Usually, the second-stage heating furnace 2, the first-stage heating furnace 3 and the gasifier 1 are integrated equipment. In this kind of equipment, the heat exchange tubes are composed of the gas distribution pipe 41 at the bottom and the gas collecting pipe 42 at the top, based on the axes of the second-stage heating furnace 2 and the first-stage heating furnace 3, the tubes are made of high-temperature resistant high-grade alloy steel pipes Or coiled pipe 40 is formed. The high-grade alloy is, for example, the high-temperature-resistant Incoly600 alloy material currently on the market. The specific structure is shown in FIG. 2 . The surface of the coil in contact with high-temperature gas is coated with high-temperature resistant non-metallic materials, such as high-temperature resistant SiC coating. The heat exchange tube may also be a high-temperature-resistant high-grade alloy steel tube with a straight tube in the middle, such as the high-temperature-resistant Incoly600 alloy steel tube currently on the market. The surface of the heat exchange tube in contact with high temperature gas is coated with high temperature resistant non-metallic materials, such as high temperature resistant SiC coating.

The solid particle separator 6 is a product currently on the market, such as the cyclone separator produced by Fushun Ende Machinery Co., Ltd., and the cyclone separator produced by Nanjing Zhongjian Chemical Machinery Manufacturing Co., Ltd.

Steam superheater 5 and 1# heat exchanger 7 are products currently on the market, such as the shell-and-tube heat exchanger produced by Harbin Boiler Co., Ltd. and the shell-and-tube heat exchanger produced by Dongfang Boiler Co., Ltd. By cold or hot fluid. The thermal fluid used in the present invention is syngas, and in the heat exchanger, the hot syngas exchanges heat with water vapor, the syngas is cooled, and the water vapor is heated/superheated.

According to the present invention, details of the multi-component slurry gasification system such as the nozzle 8, the gasifier 1, and the lock hopper 4 can be found in ZL 200810132975.4.

In this step, the analysis methods for CO, H ₂ , CO ₂ , and CH ₄ in the synthesis gas are all analyzed using GB/T27885-2011 and GB/T10410-2008 standards.

The chemical composition of the synthesis gas obtained in this step is 38-48% CO, 30-40% H ₂ , 15-25% CO ₂ by volume, and the balance of N ₂ , CH ₄ and H ₂ S.

B. Natural gas conversion

Raise the pressure of natural gas to 3.0-3.5MPa, let the natural gas enter the first-stage heating furnace 3 through the natural gas pipeline 24, and exchange heat indirectly with the crude synthesis gas from the second-stage heating furnace 2, and the natural gas is heated from normal temperature to 320-340°C; The hot natural gas enters the desulfurization tower 9 through the preheated natural gas pipeline 25 to remove sulfides in the natural gas and reduce the sulfur content in the raw gas to below 0.1 ppm.

The desulfurized natural gas is sent to the secondary heating furnace 2 together with the steam sent by the superheated steam pipeline 23 through the desulfurized natural gas pipeline 26, where they exchange heat with the crude synthesis gas from the gasifier 1; the heated natural gas and The water vapor is sent to the first-stage reformer 10 through the first-stage reformer feed line 27, and the tube of the first-stage reformer 10 is filled with a first-stage reforming catalyst, in which the heated natural gas and water vapor undergo a catalytic conversion reaction, and the first-stage reformer 10 In the first-stage reforming gas discharged, the methane content is about 30% by volume, and the temperature is about 660-690°C.

The obtained first-stage reforming gas is sent to the top of the second-stage reforming furnace 11 through the first-stage reforming furnace discharge pipeline 28, oxygen through the oxygen pipeline 29, and water vapor through the superheated steam pipeline 34. The first-stage reforming gas, oxygen and water The steam undergoes partial oxidation reaction of natural gas and steam catalytic reforming reaction in the second-stage reformer 11, and the remaining natural gas in the first-stage reforming gas is basically completely converted to obtain synthesis gas containing CO, CO ₂ , and H ₂ ; the second-stage reformer 11 is loaded with a two-stage conversion catalyst, and the temperature of the generated syngas is about 960-1000°C.

The synthesis gas is returned to the primary reformer 10 through the discharge pipeline 30 at the bottom of the secondary reformer to provide the required heat for the reforming reaction of natural gas and steam; the heat-exchanged synthetic gas passes through the synthetic gas discharge pipeline of the primary reformer 31 is sent to the steam superheater 12, and it exchanges heat with the steam sent through the 2# exchange steam discharge pipeline 35 to recover the heat of the synthesis gas. The synthesis gas is sent to the 2# heat exchanger 13 through the 2# heat exchange synthesis gas feed pipeline 32, and it exchanges heat with the steam from the steam input pipeline 36 to realize further cooling, and the cooling synthesis gas passes through the The 2# heat exchange synthesis gas discharge pipeline 33 is combined with the synthesis gas obtained from the above-mentioned slurry gasification, and the gas is distributed and sent to the subsequent treatment system for treatment.

The cobalt-molybdenum hydrodesulfurization agent and/or the zinc oxide desulfurization agent used in the desulfurization tower 9 in the present invention are all currently marketed products. For example, the cobalt-molybdenum hydrodesulfurization agent sold by the Northwest Research Institute of Chemical Industry under the trade name T201; the cobalt-molybdenum hydrodesulfurizer sold by Beijing Sanju Environmental Protection New Materials Co., Ltd. under the trade name T201. Zinc oxide desulfurizer sold under the trade name T305 by Northwest Research Institute of Chemical Industry; zinc oxide desulfurizer sold under the trade name EZ-2 by Hunan Huanda Environmental Protection Co., Ltd.; zinc oxide desulfurizer sold under the trade name Z919 by Shandong Schindler Chemical Co., Ltd. Zinc desulfurizer.

In the present invention, the natural gas conversion is carried out in stages. The structure of the primary reformer 10 is a tubular reformer, and the tube is filled with a primary reforming catalyst through which natural gas and water vapor pass, and the heat required for the conversion is provided by the synthesis gas generated by the secondary reformer 11 . The structure of the secondary reformer 11 is a packing type reformer, and the furnace is filled with a secondary reforming catalyst, and the primary reforming gas, oxygen and water vapor undergo a reforming reaction in the furnace to generate synthesis gas.

The first-stage and second-stage reformers of natural gas are products currently sold on the market, such as the pressure-resistant and high-temperature-resistant natural gas reformer produced by Nanjing Chemical Machinery Manufacturing Co., Ltd., and the natural gas reformer produced by Nuclear Industry Xi'an 524 Plant.

The first-stage reforming catalyst and the second-stage reforming catalyst in the natural gas conversion described above are all currently marketed products. For example, a first-stage reforming catalyst sold under the trade name FZ-3 by Xiehua Science and Technology Industrial Co., Ltd. of Liling City, Hunan Province; a second-stage reforming catalyst sold under the trade name Z204 by Sichuan Tianyi Technology Co., Ltd.

The composition of the synthetic gas after natural gas conversion is 25-35% CO, 55-65% H ₂ , 3-20% CO ₂ , 0.2-1.1% CH ₄ , and N ₂ and H ₂ S in the balance.

In this step, the analysis methods for CO, H ₂ , CO ₂ , and CH ₄ in the synthesis gas are all analyzed using GB/T27885-2011 and GB/T10410-2008 standards.

Described steam superheater 12 and 2# heat exchanger 13 are all a kind of product sold on the market at present, for example the shell-and-tube heat exchanger produced by Harbin Boiler Co., Ltd., the shell-and-tube heat exchanger produced by Dongfang Boiler Co., Ltd. Heat Exchanger.

The H/C of the synthesis gas obtained in step A and step B of the present invention is about 1.0 to 2.0 after reasonable gas distribution, and the dry basis composition of the synthesis gas is by volume: 30 to 60% CO, 30 to 60% H _2. 10-25% CO ₂ , the balance of N ₂ , CH ₄ and H ₂ S.

The synthesis gas obtained in step A and step B of the present invention can be directly used as a raw material for methanol synthesis and/or Fischer-Tropsch synthesis without any or a small amount of gas conversion after gas distribution. The synthesis gas produced by gasification per ton of coal is reduced by 40-600Nm ³ /ton of coal, and CO ₂ emission is reduced by 20-300Nm ³ /ton of coal.

The method of the present invention for jointly preparing synthesis gas based on slurry gasification and natural gas conversion has the following characteristics:

1. The H/C ratio in the slurry gasification synthesis gas is 0.5-0.9, and the H/C ratio in natural gas conversion is 1.8-3.0. The method of the present invention adopts the method of combining slurry gasification and two-stage conversion of natural gas, rationally distributes the synthesis gas obtained by slurry gasification and natural gas conversion, and adjusts the H/C ratio to 0.8-2.0, avoiding the use of a single material The H/C ratio in the slurry gasification synthesis gas is too low, and the H/C ratio of the single natural gas conversion is too high, so as to reduce the waste of carbon, hydrogen resources and power.

2. Reasonable gas distribution of the two kinds of syngas can reduce the conversion degree of the slurry gasification process. The synthesis gas produced by gasification per ton of coal is reduced by 40-600Nm ³ /ton of coal, and CO ₂ emission is reduced by 20-300Nm ³ /ton of coal, which reduces the emission of greenhouse gas CO ₂ in the conversion process, and at the same time supplements enough for natural gas conversion Carbon, increase the output of chemical synthesis products.

3. The syngas produced by slurry gasification has high temperature and high sensible heat, which can be used to preheat natural gas, rationally utilize the high-level heat energy of high-temperature syngas, and reduce the consumption of natural gas as fuel. Combining the two processes, the reduction in energy consumption is the heat exchange between natural gas and syngas from slurry gasification, which is converted into a natural gas volume of about 200-2000Nm ³ /h.

4. Both the slurry gasification process and the natural gas conversion process used in the present invention are mature processes, and the process is easy to realize. The rational combination of the two processes will make the arrangement of the device more compact and improve the utilization rate of the device.

5. The present invention is a combined synthesis gas preparation device for slurry gasification and natural gas conversion. The device requires fewer types of process materials. The present invention can realize the internal circulation of logistics, realize the internal supply of water, steam and some raw materials, and realize resource utilization. purpose of maximizing utilization.

[beneficial effect]

The present invention has following positive effect:

1. The H/C ratio of the synthesis gas obtained by the slurry gasification method is 0.5-0.9, and the H/C ratio of the synthesis gas obtained by the natural gas conversion method is 1.8-3.0. The method of the present invention is a method of combining two stages of slurry gasification and natural gas conversion, and the synthesis gas obtained by them is properly distributed, and the H/C ratio can reach 0.8-2.0, so that single slurry gasification of synthesis gas can be avoided The H/C ratio in the middle is too low, while the single natural gas conversion H/C ratio is too high, reducing the waste of carbon, hydrogen resources and power.

2. Reasonable gas distribution of the two kinds of syngas can reduce the conversion degree of the slurry gasification process. The synthesis gas produced by gasification per ton of coal is reduced by 40-600Nm ³ /ton of coal, and CO ₂ emission is reduced by 20-300Nm ³ /ton of coal, which reduces the emission of greenhouse gas CO ₂ in the conversion process, and at the same time supplements enough for natural gas conversion Carbon, increase the output of chemical synthesis products.

3. The syngas produced by slurry gasification has high temperature and high sensible heat, which can be used to preheat natural gas, rationally utilize the high-level heat energy of high-temperature syngas, and reduce the consumption of natural gas as fuel. Combining these two processes, the reduction in energy consumption is the heat exchange between natural gas and slurry gasification synthesis gas, which is converted into a natural gas volume of about 200-2000Nm ³ /h, which reduces energy consumption very significantly.

4. Both the slurry gasification process and the natural gas conversion process used in the present invention are mature processes, and the process is easy to realize. The rational combination of the two processes will make the arrangement of the device more compact and improve the utilization rate of the device.

5. The present invention is a combined synthesis gas preparation device for slurry gasification and natural gas conversion. The device requires fewer types of process materials. The present invention can realize the internal circulation of logistics, realize the internal supply of water, steam and some raw materials, and realize resource utilization. purpose of maximizing utilization.

The present invention is based on slurry gasification and natural gas conversion as a joint synthesis gas preparation process, using hydrocarbon-containing material raw materials, natural gas, and oxygen as the main raw materials, and simultaneously comprehensively utilizing surrounding wastewater and waste gas, reducing waste treatment costs and The production cost improves the environment, improves resource utilization, saves resources, and expands product categories and production scale, which is in line with the circular economy policy implemented by the state and also meets the requirements of the state to build a resource-saving and environment-friendly society.

In a word, the method of the present invention uses hydrocarbons and natural gas as raw materials to produce synthetic gas with high added value at a low cost and in an environmentally friendly manner through optimized combination, which is a great contribution to the high value-added utilization of non-renewable resources in my country and the chemical industry. Make important contributions to development and environmental protection tasks.

【Description of drawings】

Fig. 1 is a flow chart of the method for jointly producing synthesis gas based on slurry gasification and natural gas conversion in the present invention.

In the picture:

1-gasifier, 2-second-stage heating furnace, 3-first-stage heating furnace, 4-lock bucket, 5-steam superheater, 6-solid particle separator, 7-1# heat exchanger, 8-nozzle, 9 -Desulfurization tower, 10-First stage reformer, 11-Second stage reformer, 12-Steam superheater, 13-2# heat exchanger, 14-Slurry pipeline, 15-Oxygen pipeline, 16-Synthesis of solid particles Gas pipeline, 17-solid particle separator feed pipeline, 18-solid particle separator top pipeline, 19-synthesis gas discharge pipeline, 20-solid particle separator bottom pipeline, 21-water vapor input pipeline, 22-water steam pipeline, 23-superheated steam pipeline, 24-natural gas pipeline, 25-preheating natural gas pipeline, 26-desulfurized natural gas pipeline, 27-first stage reformer feed pipeline, 28-first stage reformer Discharge pipeline, 29-oxygen pipeline, 30-second-stage reformer furnace bottom discharge pipeline, 31-first-stage reformer synthesis gas discharge pipeline, 32-2# heat exchange synthesis gas feed pipeline, 33-2 #Heat exchange synthesis gas discharge pipeline, 34-superheated steam pipeline, 35-2# exchange hot water steam discharge pipeline, 36-water steam input pipeline.

Fig. 2 is a structural schematic diagram of the first-stage heating furnace 3 and the second-stage heating furnace 2 heat exchange tubes;

In the picture:

a- Sectional view of air distribution pipe; b- Side view of heat exchange tube layout; c- Sectional view of air collecting pipe.

40-coil pipe, 41-air distribution pipe, 42-air collecting pipe.

【detailed description】

The present invention will be better understood by the following examples.

Embodiment 1: The present invention is based on slurry gasification and natural gas conversion to jointly prepare synthesis gas

The composition of coal used in this example is listed in Table 1, and the composition of natural gas (by volume on a dry basis) is listed in Table 2.

Table 1: Composition of Raw Coal

Table 2: Dry Basis Composition of Natural Gas, by Total Volume

This embodiment is implemented according to the process flow described in Figure 1 of this specification.

The specific implementation steps are as follows:

Raw coal with a moisture content of 10% is about 25010.66kg/h, and water and a small amount of additives (highly polymerized sodium naphthalene sulfonate) are used to make a slurry with a concentration of 60% by weight of dry coal, and the flow rate of the slurry is about 37515.98kg/h , the slurry is sent to the nozzle 8 through the slurry pipeline 14, and sprayed into the gasifier 1 through the nozzle 8 together with the oxygen from the oxygen pipeline 15 with a flow rate of 15463.54 Nm ³ /h.

The slurry and oxygen undergo a partial oxidation-reduction reaction under the conditions of a pressure of 6.5MPa and a temperature of 1350°C to generate high-temperature crude synthesis gas containing CO, _H2 , _CO2 , _CH4 , and _H2O as main components and melted A mixture of hot slag. The total gas volume of high-temperature syngas is about 52391.91Nm ³ /h, containing about 22% H ₂ O, and its composition on a dry basis is as follows by volume: CO ～ 46%, H ₂ ～ 34%, CO ₂ ～ 19%, other N ₂ , CH ₄ , H ₂ S≤1%, the gas temperature is about 1350°C, and the pressure is 6.4MPa. The flow rate of molten ash produced is 4437.36kg/h. After cooling down in the second-stage heating furnace 2 and the first-stage heating furnace 3, it is discharged from the lock hopper 4 in solid state.

The crude synthesis gas exchanges heat with the natural gas from the natural gas pipeline 24 through the second-stage heating furnace 2 and the first-stage heating furnace 3 to recover the sensible heat of the synthesis gas. The first-stage heating furnace 3 and the second-stage heating furnace 2 are high-temperature radiant boilers, the syngas temperature is reduced from 1350°C to 550°C, and the natural gas is heated from normal temperature to 480°C.

The heat-exchanged crude synthesis gas enters the steam superheater 5 through the synthesis gas pipeline 16, and heats the steam with a flow rate of 118267.62Nm ³ /h sent from the steam pipeline 22, and the crude synthesis gas is lowered from a temperature of 550°C to a temperature of 350°C , the water vapor is heated from a temperature of 310°C to a temperature of 340°C, and the heat of the crude synthesis gas is recovered. The crude synthesis gas is sent to the solid particle separator 6 through the feed line 17 of the solid particle separator, and the fine ash entrained in the synthesis gas is separated and removed, and the fine ash is discharged from the bottom pipeline 20 of the solid particle separator The outside world.

The syngas from which the fine ash has been removed is sent to the 1# heat exchanger 7 through the top pipeline 18 of the solid particle separator, and exchanges heat with the water vapor in the steam input pipeline 21, and the cooled syngas is lowered from a temperature of 350°C to a temperature of 200°C °C, water vapor is heated from a temperature of 160 °C to a temperature of 270 °C. The cooled synthesis gas is combined with the synthesis gas obtained after the conversion of natural gas through the synthesis gas discharge pipeline 19, and a reasonable gas distribution is performed.

The flow rate of natural gas is 20740.39Nm ³ /h, the pressure is increased to 3.2MPa, and it enters the first-stage heating furnace 3 through the natural gas pipeline 24, and exchanges heat indirectly with the synthesis gas from the second-stage heating furnace 2. The temperature of the preheated natural gas is about 340°C. The preheated natural gas pipeline 25 enters the desulfurization tower 9 filled with cobalt-molybdenum hydrodesulfurization agent to remove sulfide in the natural gas and reduce the sulfur content in the raw gas to below 0.1 ppm.

The desulfurized natural gas has a temperature of 320°C, and it is sent to the secondary heating furnace 2 through the desulfurized natural gas pipeline 26 together with the water vapor at a temperature of 340°C sent from the superheated steam pipeline 23, where they are combined with crude synthesis from the gasifier 1 Gas heat exchange, natural gas and water vapor are heated from a temperature of 340°C to a temperature of 480°C. The heat exchange between natural gas and slurry gasification syngas, the energy consumption reduction is equal to the heat exchange between the two, which is converted into a natural gas volume of about 1155.67Nm ³ /h.

The heated natural gas and steam are sent to the primary reformer 10 through the feed pipeline 27 of the primary reformer. The tubes of the primary reformer 10 are filled with a primary reforming catalyst. When natural gas and water vapor pass through the tubes, a primary reforming reaction takes place. The heat required for the reforming reaction is provided by the synthesis gas obtained from the secondary reforming furnace 11 . The methane content in the primary reformed gas discharged from the primary reformer 10 was 30% by volume, and its temperature was 690°C.

The obtained first-stage reforming gas passes through the discharge pipeline 28 of the first-stage reformer, oxygen passes through the oxygen pipeline 29 at a flow rate of 15401.69 Nm ³ /h, and water vapor passes through the superheated steam pipeline 34 at a flow rate of 2000.42 Nm ³ /h and is simultaneously sent to the second-stage reforming Furnace 11 top. The first-stage reforming gas, oxygen and water vapor are subjected to natural gas partial oxidation reaction and steam catalytic reforming reaction in the second-stage reformer 11, and the remaining natural gas in the first-stage reforming gas is basically completely converted to obtain CO, CO ₂ , H ₂ The composition of syngas on a dry basis is as follows: by volume, 31% CO, 64% H ₂ , 3.0% CO ₂ , CH ₄ <0.5%, other O ₂ , H ₂ S < 1.5%, and its temperature is about 980°C, The flow rate is about 69862.13Nm ³ /h.

The synthesis gas is returned to the heat exchange between the tubes of the first reformer 10 through the discharge pipeline 30 at the bottom of the second-stage reformer to provide the required heat for the reforming reaction of natural gas and steam, and the temperature of the synthesis gas drops to 600°C . The heat-exchange synthesis gas enters the steam superheater 12 through the first-stage reformer synthesis gas discharge pipeline 31 to further cool down, heats the steam sent by the 2# heat exchange steam discharge pipeline 35, and recovers the heat of the synthesis gas. The temperature of the steam is determined by 160°C heating/superheating to 270°C. The synthesis gas is sent to the 2# heat exchanger 13 through the 2# heat exchange synthesis gas feed pipeline 32, and exchanges heat with the steam from the steam input pipeline 36 to realize further cooling, and the temperature of the cooling synthesis gas is further improved. When the temperature is lowered to 200°C, the obtained steam can be supplied externally or used by itself; the cooled synthesis gas is combined with the synthesis gas obtained from the above-mentioned slurry gasification through the 2# heat exchange synthesis gas discharge pipeline 33, and the gas distribution is sent to the subsequent processing system deal with.

The gas flow rate of all slurry gasification synthesis gas and all natural gas conversion synthesis gas distribution is 122250.66Nm ³ /h, and its dry basis composition is calculated by volume: 30% CO, 57% H ₂ , 12% CO ₂ , the balance _N2 , _CH4 and _H2S . The H/C ratio is 1.94, gasification can reduce the de-shifted synthesis gas by about 422.16Nm ³ /ton of coal per ton of coal, and reduce CO ₂ emission by 191.66Nm ³ /ton of coal.

Embodiment 2: The present invention is based on slurry gasification and natural gas conversion to jointly prepare synthesis gas

The present invention is carried out with a local coal as the main raw material. The raw coal analysis data is listed in Table 3, and the dry basis composition of natural gas is listed in Table 4.

Table 3: Composition of Raw Coal

Table 4: Dry Basis Composition of Natural Gas, by Total Volume

Element CH ₄ C ₂ H ₆ C ₃ H ₈ N ₂ H ₂ S volumevol% 95.0% 1.0% 0.9% 3.0% trace

The specific implementation steps of this embodiment are the same as those of Example 1, except that the raw coal in a certain place is 13291.9kg/h, and water and a small amount of additive (highly polymerized sodium naphthalenesulfonate) are used to make a material with a concentration of 56% and a flow rate of 20623.8kg/h. Slurry, oxygen flow rate is 12237.2Nm ³ /h, slurry and oxygen are sprayed into gasification furnace 1 through nozzle 8, gasification reaction pressure is 4.5MPa, temperature is 1320°C. After the reaction, the flow rate of ash and slag discharged from the lock hopper 4 is 1460.1kg/h, the flow rate of high-temperature wet syngas is ^15805.3Nm3 /h, and the _H2O content is 30%. H ₂ 35.4%, CO ₂ 24.6%, other N ₂ , CH ₄ and H ₂ S are less than 1%, the temperature of the synthesis gas is 1320°C and the pressure is 4.5MPa.

The synthetic gas exchanges heat with natural gas through the second-stage heating furnace 2 and the first-stage heating furnace 3 . The heat-exchanged synthesis gas enters the steam superheater 5 to heat the steam with a flow rate of 4313.18Nm ³ /h, and the temperature of the crude synthesis gas is lowered to 350°C. The crude synthesis gas enters the solid particle separator 6 to separate the fine ash entrained in the synthesis gas, and the fine ash is discharged out of the boundary. The syngas from which the fine ash has been removed enters the 1# heat exchanger 7 to exchange heat with water vapor, and the temperature of the syngas is lowered to 200°C. The cooled synthesis gas is combined with the synthesis gas obtained after natural gas conversion for gas distribution.

The flow rate of natural gas is about 12823.78Nm ³ /h, the pressure is raised to 3.0MPa, it enters the first-stage heating furnace 3, exchanges heat indirectly with the synthesis gas from the second-stage heating furnace 2, and enters the desulfurization tower 9 to remove sulfides in the natural gas. The desulfurized natural gas is mixed with water vapor and enters the second-stage heating furnace 2 to exchange heat with the synthesis gas obtained from the gasification furnace 1. The heat exchange between natural gas and slurry gasification syngas, the energy consumption reduction is equal to the heat exchange between the two, which is converted into a natural gas volume of about 362.53Nm ³ /h. The heated natural gas and steam enter the primary reformer 10 to undergo a primary reforming reaction to generate primary reforming gas.

The first-stage reforming gas, 7630.18Nm ³ /h oxygen, and 2124.85Nm ³ /h water vapor enter the top of the second-stage reformer 11 at the same time, where partial oxidation of natural gas and steam catalytic reforming occur to generate CO, CO ₂ , H ₂ of synthetic gas. The composition of the syngas on a dry basis is as follows: by volume, 28.0% CO, 57.0% H ₂ , 13.0% CO ₂ , CH ₄ <1%, others <1%, and the flow rate is about 32447.24 Nm ³ /h. The synthesis gas is returned to the tube space of the primary reformer 10 to provide heat required for the primary reforming reaction. The heat-exchanged synthesis gas enters the steam superheater 12 for cooling, and then enters the 2# heat exchanger 13 for further cooling. The cooled synthesis gas is combined with the synthesis gas obtained after slurry gasification for reasonable gas distribution.

The whole slurry gasification synthesis gas is mixed with part of the natural gas conversion synthesis gas, the gas flow rate is about 17427.64Nm ³ /h, and its dry basis composition is calculated by volume: ~37.8% CO, ~38.2% H ₂ , ~23.0% CO ₂ , the balance of N ₂ , CH ₄ and H ₂ S. H/C is about 1.01, gasification per ton of coal can reduce de-shifted synthesis gas by about 92.01Nm ³ /ton of coal, and CO ₂ emission can be reduced by 36.04Nm ³ /ton of coal.

Embodiment 3: The present invention jointly prepares synthesis gas on the basis of slurry gasification and natural gas conversion

The present invention is implemented with coal from a certain place as the main raw material. The raw coal analysis data is listed in Table 5, and the dry basis composition of natural gas is listed in Table 6.

Table 5: Composition of Raw Coal

Table 6: Dry Basis Composition of Natural Gas, by Total Volume

The specific implementation steps of this embodiment are the same as those in Example 1. The raw coal in a certain place is about 14503.07kg/h, and water and a small amount of additive (highly polymerized sodium naphthalene sulfonate) are used to make a concentration of about 57%, and a flow rate of 25443.99kg/h The slurry, the oxygen flow rate is 8628.82Nm ³ /h, the slurry and oxygen are sprayed into the gasification furnace 1 through the nozzle 8, the gasification reaction pressure is 4.2MPa, and the temperature is 1300°C. After the reaction, the flow rate of the ash discharged from the lock hopper 4 is 1663.13kg/h, the flow rate of the high-temperature wet syngas is ^23063.20Nm3 /h, and the _H2O content is 29%. The composition on a dry basis is as follows: by volume, CO 44.2 %, H ₂ 33.6%, CO ₂ 21.5%, other N ₂ , CH ₄ and H ₂ S are less than 1%, the temperature of the crude synthesis gas is 1300°C and the pressure is 4.2MPa.

The crude synthesis gas exchanges heat with natural gas through the second-stage heating furnace 2 and the first-stage heating furnace 3 . The heat-exchanged synthesis gas enters the steam superheater 5 to heat the steam with a flow rate of 7863.50Nm ³ /h, and the temperature of the synthesis gas is lowered to ~350°C. The crude synthesis gas enters the solid particle separator 6 to separate the fine ash entrained in the synthesis gas, and the fine ash is discharged out of the boundary. The synthesis gas from which the fine ash has been removed enters the 1# heat exchanger 7 to exchange heat with water vapor, and the temperature of the synthesis gas drops to 200°C. The cooled synthesis gas is combined with the synthesis gas obtained after the conversion of natural gas for reasonable gas distribution.

The flow rate of natural gas is about 18883.79Nm ³ /h, the pressure is increased to 3.1MPa, it enters the first-stage heating furnace 3, exchanges heat indirectly with the synthesis gas from the second-stage heating furnace 2, and then enters the desulfurization tower 9 to remove sulfides in the natural gas . The desulfurized natural gas is mixed with water vapor and enters the secondary heating furnace 2 to exchange heat with the synthesis gas obtained from the gasification furnace 1 . The desulfurized natural gas exchanges heat with the syngas obtained from slurry gasification, and the reduced energy consumption is the heat exchange, which is converted into a natural gas volume of about 522.06Nm ³ /h. The heated natural gas and steam enter the first-stage reformer 10 to undergo a first-stage reforming reaction to obtain the first-stage reformed gas.

The first-stage reforming gas, 11669.35Nm ³ /h oxygen and 3546.40Nm ³ /h water vapor are sent to the top of the second-stage reformer 11 at the same time, and the natural gas partial oxidation reaction and steam catalytic conversion reaction are carried out to obtain CO, CO ₂ , H ₂ wet synthesis gas, its flow rate is 51310.7Nm ³ /h, the dry basis composition of the synthesis gas is as follows: 28.6% CO, 58.9% H ₂ , 10.7% CO ₂ , CH ₄ <1%, other components <1%. The synthesis gas is returned to the tube space of the primary reformer 10 to provide the required heat for the primary reforming reaction. The heat-exchanged synthesis gas is sent to the steam superheater 12 for cooling, and then enters the 2# heat exchanger 13 for further cooling. The cooled synthesis gas is combined with the synthesis gas obtained after slurry gasification, and the gas distribution is sent to the subsequent treatment system for treatment.

The whole slurry gasification synthesis gas is mixed with part of the natural gas conversion synthesis gas. The gas flow rate is about 38456.41Nm ³ /h. The dry basis composition is: 37.0% CO, 45.2% H ₂ , 16.5% CO ₂ by volume, and the rest amount of N ₂ , CH ₄ and H ₂ S. Its H/C ratio is 1.22. Gasification per ton of coal can reduce the converted synthesis gas by about 182.06Nm ³ /ton of coal, and reduce CO ₂ emissions by 118.9Nm ³ /ton of coal.

Claims (9)

1. it is a kind of that the method that based Joint prepares synthesis gas is converted into natural gas with slip gasification, it is characterised in that the method Step is as follows：

A, slip gasification

It is containing in terms of hydrocarbon raw material of substance weight 50 by dry that hydrocarbon raw material of substance, additive and solvent will be contained first to make a kind of concentration ~ 70% slip；Then, described slip is allowed to pass through slip pipeline（14）And allow oxygen to pass through the first oxygen pipeline（15）Together When Jing nozzles（8）It is sprayed onto gasification furnace（1）In；Described slip is with oxygen in 1200 ~ 1400 DEG C of 1.0 ~ 10.0MPa of pressure and temperature Under conditions of carry out Some redox reaction, generate and contain CO, H₂、CO₂、CH₄、H₂The crude synthesis gas of O main components and melting Lime-ash；Described molten ash successively passes through two-stage nitration heating furnace（2）With one section of heating furnace（3）When lowered the temperature, in solid form from Lock hopper（4）Discharge out-of-bounds；

Described crude synthesis gas successively pass through two-stage nitration heating furnace（2）With one section of heating furnace（3）With from gas pipeline（24）'s Heat exchange gas；The crude synthesis gas of heat exchange are by the pipeline of synthesis gas containing solid particle（16）Into the first steam superheater（5）, will From water vapour pipeline（22）Steam heating, then pass through solid particle separator feeding pipe（17）Into solid particle Separator（6）, the fine ash of the crude synthesis gas entrainment is separated off wherein；Described fine ash is by solid particle separator lower tube Road（20）Discharge out-of-bounds；The synthesis gas of fine ash is removed by solid particle separator top pipeline（18）It is sent to 1# heat exchangers（7）, with From the first water vapour intake line（21）Water vapour heat exchange, cooled synthesis gas passes through synthesis gas discharge line（19）With The synthesis gas obtained by natural gas conversion merges, and follow-up processing system is sent to Jing after distribution；

B, natural gas conversion

Natural gas passes through gas pipeline（24）Into one section of heating furnace（3）, and from two-stage nitration heating furnace（2）Crude synthesis gas between Heat exchange is connect, the natural gas of preheating is by preheating gas pipeline（25）Into desulfurizing tower（9）, remove the sulfuration in the natural gas Thing；The natural gas of desulfurization passes through desulphurised natural gas pipeline（26）With by the first superheated steam pipeline（23）The water vapour sent is together It is sent to two-stage nitration heating furnace（2）, they here with from gasification furnace（1）Crude synthesis gas heat exchange；The natural gas of heating steams with water Vapour passes through one-stage converter feeding pipe（27）It is sent to one-stage converter（10）, the natural gas for heating wherein carries out with water vapour Catalytic conversion reaction, for obtaining section is converted gas and is discharged pipeline by one-stage converter（28）, oxygen pass through the second oxygen pipeline （29）And water vapour passes through the second superheated steam pipeline（34）It is sent to secondary reformer simultaneously（11）Top, described one section turns Activating QI, oxygen and water vapour are in secondary reformer（11）In carry out gas by partial oxidation of natural reaction and vapor catalyzed conversion reaction, Obtain containing CO, CO₂、H₂Synthesis gas；

Described synthesis gas passes through secondary reformer furnace bottom discharge line（30）Return to one-stage converter（10）In be natural gas The heat needed for providing is reacted with Steam Reforming；The synthesis gas of heat exchange passes through one-stage converter synthesis gas discharge line（31）Send To the second steam superheater（12）, it with pass through 2# heat-exchanging water vapour-discharge tubes road（35）Synthesis is reclaimed in the water vapour heat exchange sent The heat of gas；Described synthesis gas is by 2# heat exchange synthesis gas feeding pipes（32）It is sent to 2# heat exchangers（13）, it with from the Two water vapour intake lines（36）Water vapour heat exchange, realize further cooling, the synthesis gas of cooling is exchanged heat synthesis gas by 2# Discharge line（33）The synthesis gas obtained with the gasification of above-mentioned slip merges, and aftertreatment systems process is sent to after distribution.

2. method according to claim 1, it is characterised in that described is to be selected from for one or more containing hydrocarbon raw material of substance Coal, biomass, the dregs of fat and other raw materials；Described solvent is one or more cold selected from water, organic wastewater, carbon monodixe conversion Lime set and other solvents.

3. method according to claim 1, it is characterised in that described additive is one or more selected from sulfomethylated lignin The additive of sour sodium, calcium lignosulfonate, polycondensation sodium naphthalene sulfonate, high polymerization sodium naphthalene sulfonate or non-gluey high phosphorus china clay.

4. method according to claim 1, it is characterised in that two-stage nitration heating furnace（2）With one section of heating furnace（3）All it is high temperature Radiant boiler.

5. method according to claim 4, it is characterised in that described hyperthermia radiation boiler is a kind of in its bottom configuration Gas distribution pipe（41）, top configuration discharge（42）, in the middle of it with one section of heating furnace（3）With two-stage nitration heating furnace（2）Axis be base Standard, by high temperature resistant high-grade alloy steel pipe tubulation or coiling coil pipe are made（40）The boiler of composition.

6. method according to claim 1, it is characterised in that desulfurizing tower（9）The desulfurizing agent of middle filling is cobalt molybdenum hydrodesulfurization Agent and/or Zinc oxide desulfurizer.

7. method according to claim 1, it is characterised in that one-stage converter（10）Structure be tubular type reburner, pipe It is interior to load a section of conversion catalyst sold with trade name FZ-3 by Li- ling city Xie Hua Scientific and Technical Industry Co., Ltd of Hunan Province.

8. method according to claim 1, it is characterised in that secondary reformer（11）Structure be material filling type reburner, stove It is interior to load the secondary reforming catalyst sold with trade name Z204 by Sichuan Tianyi Science ＆ Technology Co., Ltd.

9. method according to claim 1, it is characterised in that（A）Synthesis gas that slip gasification step is obtained with（B）It is natural The H/C of the synthesis gas that the synthesis gas that gas step of converting is obtained is obtained after distribution is 1.0 ~ 2.0, and its butt composition is with volume 30 ~ 60%CO of meter, 30 ~ 60%H₂、10~25%CO₂And the N of surplus₂、CH₄And H₂S。