WO2020082377A1

WO2020082377A1 - Process for using garbage to prepare liquid-state fuel and chemical products, and garbage catalytic pyrolysis system

Info

Publication number: WO2020082377A1
Application number: PCT/CN2018/112224
Authority: WO
Inventors: 宋华
Original assignee: 西安华大骄阳绿色科技有限公司
Priority date: 2018-10-23
Filing date: 2018-10-26
Publication date: 2020-04-30
Also published as: CN109233913A

Abstract

Disclosed in the present invention are a process for using garbage to prepare liquid-state fuel and chemical products, and a garbage catalytic pyrolysis system; the garbage first undergoes a catalytic pyrolysis gasification reaction to generate a gas product, and the separated solid residue is used as environmentally friendly material; the nitrogen, sulphur, and chlorine in the gas are removed, and the removed compounds are used for preparing chemical products; the gas undergoes a water-gas shift reaction to obtain a synthesis gas having a suitable ratio of hydrogen and carbon monoxide; the synthesis gas undergoes a catalytic liquefaction reaction to generate liquid-state fuel; the liquid fuel is collected to be used for processing chemical products, and the gas product is recycled or used as a fuel gas product. The garbage catalytic pyrolysis system comprises a garbage catalytic pyrolysis gasification unit, dechlorination, desulphurisation, and denitration treatment units, a water-gas shift unit, a synthesis gas catalytic liquefaction unit, and a steam unit. The resources are used reasonably, the reaction pressure is greatly reduced, the garbage pyrolysis efficiency is high, the impurity removal is simple and easy to implement, the product quality is greatly increased, and the products are varied.

Description

Process for preparing liquid fuel and chemical products using garbage and garbage catalytic pyrolysis system

Technical field

The invention relates to the technical field of garbage treatment, in particular to a process for preparing liquid fuel and chemical products using garbage and a catalytic pyrolysis system for garbage.

Background technique

The high-speed urbanization process has resulted in a large amount of garbage generation and accumulation, and it is still growing at a rate of 8-10% every year. The main cities in the country produce about 200 million tons of live garbage every year. It is expected to reach 409 million tons by 2030 and 528 million tons by 2050. Over the past years, the total amount of accumulated municipal solid waste has reached 7 billion tons. At present, more than one-third of the cities in China are trapped in the dilemma of garbage siege. The vast majority of these urban domestic wastes that have been greatly increased each year are in the state of being stacked in the open air, which not only seriously affects the city's appearance, but also pollutes the water, atmosphere and soil on which humans depend, and poses a great threat to the health of urban residents.

On the other hand, China's garbage treatment industry as a whole is still in the initial stage of harmless treatment. Simple waste incineration not only wastes a large amount of available carbon sources in the waste, but also produces a large amount of heavy metals such as lead, chromium, arsenic, mercury, etc., causing soil and water pollution, resulting in frequent social group incidents. At the same time, a large amount of nitrogen oxides and sulfur oxides generated during the waste incineration process will directly lead to the destruction of the ozone layer and the generation of acid rain. The simple landfill of garbage not only occupies a large amount of land, but also increases transportation costs and disposal loads, and also causes environmental problems such as leachate pollution and methane release. With the continuous improvement of the domestic urbanization level, more and more urban domestic waste will be generated. Urban domestic waste has become a thorny problem in the development of urban construction. Therefore, it is urgent to find effective technologies and methods for the treatment and disposal of domestic waste.

At present, domestic domestic garbage treatment methods mainly adopt three types of composting, landfilling and incineration:

(1) Composting technology: The process is relatively simple, suitable for the treatment of garbage with high content of perishable organic matter. It utilizes resources of some components in the garbage, and the investment for the treatment of garbage of the same quality is much lower than that of simple incineration. Composting technology started earlier in European and American countries and has now reached the level of industrial application. However, the introduction of foreign technology has a huge investment and is not suitable for China's national conditions. In response to this situation, some research institutes and enterprises in China have begun work in this area and have achieved certain results.

(2) Landfill technology: The landfill technology is characterized by simple operation and can handle all kinds of garbage. However, it covers a large area and there are serious secondary pollution. For example, the waste effluent will pollute the groundwater and soil. The odor generated by the garbage stack seriously affects the air quality around the site. In addition, the methane gas produced by the fermentation of garbage is both a fire and a fire. Hidden danger of explosion, emissions into the atmosphere will produce a greenhouse effect. In recent years, some cities have recognized this problem and established a number of sanitary landfill plants with a high level to solve the secondary pollution problem, but the construction investment is large and the operating cost (including standard landfill, Exudate treatment and methane collection and utilization, etc.) are high. The most important thing is that the treatment capacity of the landfill is limited. After the service period, it still needs to invest in the construction of a new landfill to further occupy land resources.

(3) Incineration technology: Incineration of wastes has a high capacity reduction, volume reduction and harmlessness. The heat generated during the incineration process is used to generate electricity to realize the energyization of wastes, which is a better method of waste disposal. However, improper control of incineration conditions will cause smoke pollution, and equipment investment is huge. At present, foreign countries have solved the problem of exhaust gas pollution by improving the technology of incineration systems and strengthening flue gas treatment, but the investment has also increased accordingly. However, compared with conventional coal-fired power generation, the installed capacity of waste incineration power plants is very small, and due to corrosion problems, the efficiency of current waste incineration power generation is generally much lower than the level of coal-fired power generation, electricity prices can not compete with thermal power, so garbage The operation of power plants often depends on government financial subsidies.

At present, the input of waste treatment in China is still obviously insufficient compared with the demand for waste treatment, and the level of waste treatment is still very low. Generally speaking, the treatment of urban domestic waste is still in the stage of development from rough to disposal. The phenomenon of garbage stacking is widespread. The secondary pollution of waste disposal sites is quite common. There is no complete comprehensive treatment technology. The domestic waste treatment technology and equipment are relatively lack of. It is difficult to meet the processing requirements of harmlessness, reduction, and recycling. Sanitary landfills can achieve a small amount of resource recovery, but the level of resource utilization is still very low; the amount of landfill leachate is large, and the treatment cost is high; the amount of biogas generated, controlling its emissions also increases the treatment cost and takes up space resources. Therefore, it is one of the development trends of landfills to limit the minimum organic content in landfills. Composting produces many toxic and harmful substances, which may cause secondary pollution. The incineration method has the advantages of high reduction degree, short treatment cycle, small area, flexible site selection, and the heat of combustion can be used to generate electricity, but the domestic waste has a high moisture content and low calorific value, requiring more auxiliary fuel and cost High; harmful substances such as dioxins and furans in the exhaust gas cause environmental pollution. Therefore, it is the development trend of the incineration method to focus on the research of emission control and pollution treatment of incineration exhaust gas, and strive to reduce the secondary pollution that may be generated by incineration.

With the development of energy-saving emission reduction and circular economy and the requirements for further improvement of the environment, the search for true comprehensive, harmless and reduced waste comprehensive treatment technology and equipment will gradually become the inevitable development trend of the waste treatment industry.

Summary of the invention

The purpose of the present invention is to provide a process for preparing liquid fuels and chemical products using garbage and a catalytic catalytic pyrolysis system. The process is simple and easy to popularize and can realize catalytic pyrolysis, removal of impurities and final utilization of garbage under mild conditions. Catalytic process for the preparation of liquid fuel and chemical products from the synthesis gas obtained by pyrolysis.

The present invention is achieved through the following technical solutions:

The invention discloses a process for preparing liquid fuel and chemical products by using garbage, which includes the following steps:

1) Catalytic pyrolysis gasification reaction

Under the action of the gasification catalyst, the waste to be treated undergoes pyrolysis and gasification reaction in a pyrolysis atmosphere to generate gas products, and at the same time, solid residues are separated, and the solid residues are used as environmental protection materials;

2) Impurity removal of gas products

After the gas product is cooled and condensed to remove water, it is absorbed with lye or oxide to remove nitrogen, sulfur and chlorine from the gas product to obtain a synthesis gas that does not contain nitrogen, sulfur and chlorine. , Sulfur-containing compounds and nitrogen-containing compounds are used to prepare chemical products;

3) Water gas shift catalytic reaction

Syngas that does not contain nitrogen, sulfur and chlorine undergoes a water gas shift reaction under the action of a catalyst to obtain a syngas mixed with hydrogen and carbon monoxide;

4) Catalytic liquefaction of synthesis gas

After the step 3) the synthesis gas obtained by the water gas shift reaction is condensed to remove water and dried, a liquefaction reaction occurs under the action of the catalyst, and partly converted into liquid fuel;

5) After the liquid fuel and unconverted synthesis gas are condensed to remove water, and then separated by gas-liquid, the liquid fuel is collected for processing chemical products, and the synthesis gas that has not become liquid fuel is used as a fuel gas product or step 1 is repeated again) ~ 4) Recycled.

Preferably, the catalytic pyrolysis gasification reaction is carried out in a gasification furnace provided with a circulating fluidized bed reactor, the pyrolysis atmosphere uses steam or carbon dioxide, the pyrolysis gasification reaction temperature is 600-900 ° C, and the reaction pressure is 0.1 ~ 1.0MPa.

Preferably, the specific operation of step 2) is as follows:

The gas product first passes through condensation and water removal, and then enters the deamination reactor and the desulfurization and dechlorination reactor in turn. After absorption by the lye or oxide, the nitrogen, sulfur and chlorine in the gas product are removed to obtain nitrogen and sulfur free. The synthesis gas of chlorine, and the chlorine-containing compounds, sulfur-containing compounds and nitrogen-containing compounds removed at the same time are used to prepare chemical products of chemical fertilizers.

Preferably, in step 3), the water gas shift reaction temperature is 250-400 ° C., and the reaction pressure is 0.1-1.0 MPa; in the synthesis gas mixed with hydrogen and carbon monoxide, the volume ratio of hydrogen to carbon monoxide is 2: 1.

Preferably, in step 4), the synthesis gas catalytic liquefaction reaction is carried out in a Fischer-Tropsch reactor containing a double-layer fixed bed, the catalytic liquefaction reaction temperature is 300-450 ° C., and the reaction pressure is 0.5-3 MPa.

The invention also discloses a garbage catalytic pyrolysis system for realizing the above process, including a garbage catalytic pyrolysis gasification unit, a dechlorination, desulfurization and denitration treatment unit, a water gas conversion unit, a synthesis gas catalytic liquefaction unit and a steam unit;

The garbage catalytic pyrolysis gasification unit includes a gasification furnace, a cyclone separator No. 1 and a cyclone separator No. 2, a circulating fluidized bed reactor is provided in the gasification furnace, and a catalyst supporting sieve plate is provided in the gasification furnace for gasification The top gas outlet of the furnace is connected to the side air inlet of the No. 1 cyclone separator, and the lower port of the No. 1 cyclone separator is connected to the bottom of the gasifier. It is used to collect the catalyst and the reaction of the No. 1 cyclone separator. Full garbage residue, the top air outlet of No. 1 cyclone is connected with the side air inlet of No. 2 cyclone, the top of the No. 2 cyclone is provided with an air outlet, and the bottom is provided with a lower port for discharging solid residues ;

The dechlorination, desulfurization and denitration treatment unit includes a first condenser, a deamination reactor and a desulfurization and dechlorination reactor connected in sequence. The air inlet of the first condenser is connected to the air outlet of the cyclone separator No. 2;

The water gas conversion unit includes a water gas reactor, a second condenser and a drying tower connected in sequence, and the gas inlet of the water gas reactor is connected to the gas outlet of the desulfurization and dechlorination reactor;

The synthesis gas catalytic liquefaction unit includes a booster pump, a Fischer-Tropsch reactor, a third condenser, a gas-liquid separator and a tail gas treatment device connected in sequence; a double-layer fixed bed is used in the Fischer-Tropsch reactor; the inlet end of the booster pump is connected to The gas outlets of the drying tower are connected;

The steam unit includes a steam generator, and the outlet of the steam generator communicates with the side wall of the water gas reactor and the air inlet of the bottom of the gasification furnace, respectively.

Preferably, the gas outlet of the tail gas treatment device is connected to an external collection device for collecting the discharged gas.

Preferably, a third ball valve is provided at the outlet of the exhaust gas treatment device, a fifth ball valve is provided on the side wall of the pipe where the outlet of the steam generator communicates with the gas inlet at the bottom of the gasifier, and the third ball valve communicates with the fifth ball valve .

Preferably, a drain port is provided at the bottom end of the drying tower, and a drain ball valve is provided at the drain port; a water outlet is provided at the bottom end of the first condenser, the second condenser, and the third condenser, and a drain valve is provided at the water outlet .

Preferably, the drain ball valve and the drain valve communicate with the water inlet of the steam generator.

Compared with the prior art, the present invention has the following beneficial technical effects:

The waste catalytic pyrolysis gasification process disclosed in the present invention, the waste first undergoes catalytic pyrolysis gasification reaction to generate gas products, and the separated solid residue is used as an environmental protection material, and then the nitrogen, sulfur and chlorine in the gas are removed, and the removed compounds It is used to prepare chemical products, and then the gas undergoes a water gas shift reaction to obtain a synthesis gas with an appropriate ratio of hydrogen to carbon monoxide. The synthesis gas then undergoes a catalytic liquefaction reaction to produce liquid fuel. The liquid fuel is collected for processing chemical products, and the gas product is Recycled or used as fuel gas products, resources are reasonably utilized, reaction pressure is greatly reduced, waste pyrolysis efficiency is high, impurity removal is simple and easy, product quality is greatly improved, and product diversification.

The reaction pressure is greatly reduced: the process described in the present invention can achieve the conversion of waste mainly under the reaction conditions of lower temperature and near atmospheric pressure, thereby greatly reducing the equipment investment and production costs and the need for external energy input, while Greatly improve the safety of operation.

High efficiency of waste pyrolysis: the solid wastes are mainly pyrolyzed into gas components, and the solid residues are removed. This process realizes the conversion of difficult-to-process wastes into gas-intermediate products that are easy to convert, which is the subsequent treatment , The conversion to high value-added products provides the possibility.

Impurity removal is simple and easy: the garbage is converted from solid to gas, and the contained chlorine, sulfur and nitrogen elements are converted into hydrogen chloride, hydrogen sulfide and ammonia gas, respectively, so that the impurities contained in the removal can pass through the same solid or liquid gas The reaction is realized, and the implementation steps become simple and easy.

Product quality is greatly improved: In the above process, the composition of the gas product can be obtained by strictly controlling the water gas shift, and the highly selective gas catalytic liquefaction synthesis catalyst is selected, so that the carbon chain distribution of the product is very narrow, and the product purity of a specific carbon chain length It is quite high. This can greatly simplify the separation and purification steps at the later stage of the product and further reduce production costs.

Product diversification: By changing the formula of the catalyst, the synthesis gas obtained by pyrolysis of waste can be converted into the final product of the specified carbon chain length according to the specific market demand, to maximize the profit of the product. In the current plan, the target liquid product can not only be liquid fuel, but also can be converted to produce benzene, toluene, xylene and other chemical raw materials according to changes in market conditions, so as to obtain greater market value.

Further, a circulating fluidized bed is added to the gasifier, so that the solids can be better catalytically cracked.

Furthermore, the process of removing impurities can remove nitrogen, sulfur and chlorine in gas products. At the same time, the removed chlorine-containing compounds, sulfur-containing compounds and nitrogen-containing compounds are used for the preparation of chemical fertilizer chemical products, and the intermediate products are used reasonably.

Further, a double-layer fixed bed is provided in the Fischer-Tropsch reactor to facilitate the near-atmospheric liquefaction of synthesis gas.

Further, the water generated by condensation and dewatering in the garbage disposal process is recycled to provide water vapor for the water gas shift reaction and catalytic pyrolysis gasification reaction.

Further, by realizing medium-temperature gasification and near-atmospheric pressure liquefaction, the system's fixed and operating costs can be greatly reduced, thereby facilitating its industrial application.

The garbage catalytic pyrolysis system disclosed in the present invention includes a garbage catalytic pyrolysis gasification unit, a dechlorination, desulfurization and denitration treatment unit, a water gas shift unit, a synthesis gas catalytic liquefaction unit and a steam unit; a garbage catalytic pyrolysis gasification unit uses gas The gasifier is the core, and a circulating fluidized bed is added to the gasifier; the dechlorination, desulfurization and denitration treatment units are mainly deamination reactors and desulfurization and dechlorination reactors, which can remove nitrogen, sulfur and Chlorine; the synthesis gas catalytic liquefaction unit takes the Fischer-Tropsch reactor as the core. The Fischer-Tropsch reactor adopts a double-layer fixed bed, which can make the synthesis gas liquefaction.

Further, the gas outlet of the tail gas treatment device is connected to an external collection device, and the collected gas can be directly sold.

Further, the gas outlet of the tail gas treatment device communicates with the gasification furnace, and the exhausted gas enters the gasification furnace, and is treated together with garbage again.

Further, the bottom of the drying tower is provided with a drain port, a drain ball valve is provided at the drain port, a water outlet is provided at the bottom end of the condenser, and a drain valve is provided at the water outlet, the water discharged from the drain ball valve and the drain valve can enter the steam again The generator is evaporated and used to provide water vapor for water gas shift reaction and catalytic pyrolysis gasification reaction.

BRIEF DESCRIPTION

FIG. 1 is a schematic flow chart of the preparation process of the waste catalytic pyrolysis of the present invention;

2 is a schematic structural diagram of a garbage catalytic pyrolysis device of the present invention;

Figure 3 is the synthesis gas reactant conversion rate and product selectivity index in the process of catalytic liquefaction reaction;

In the picture: 101 is the motor, 102 is the screw rod, 103 is the first heating device, 104 is the star feeder, 105 is the second heating device, 106 is the first gas uniform distribution device, 107 is the gasification furnace, 108 Is the first pressure gauge, 109 is the No. 1 cyclone separator, 110 is the No. 2 cyclone separator, 111 is the first pipe, 112 is the flange; 201 is the first condenser, 202 is the deamination reactor, and 203 is the first Three heating devices, 204 is the desulfurization and dechlorination reactor, 205 is the fourth heating device, 206 is the second pipeline, 207 is the second pressure gauge, 208 is the first gas detection meter, 209 is the water gas reactor, 210 is the second Condenser, 211 is a drying tower, 212 is a drain ball valve; 301 is a booster pump, 302 is a third pressure gauge, 303 is a second gas detection table, 304 is a fifth heating device, 305 is a Fischer-Tropsch reactor, 306 is Second gas uniform distribution device, 307 is a back pressure valve, 308 is a condenser, 309 is a gas-liquid separator, 310 is a first ball valve, 311 is a second ball valve, 312 is an exhaust gas treatment device, 313 is a third ball valve; 401 Is a steam generator, 402 is a steam valve, 403 is a fourth ball valve, 404 is a flow meter, and 405 is a Five ball valve.

detailed description

The present invention will be further described in detail below with reference to specific examples, which are explanations and not limitations of the present invention.

Taking part in the schematic diagram of FIG. 1, the process of preparing liquid fuel and chemical products from garbage of the present invention includes the following steps:

Catalytic pyrolysis and gasification reaction: under the action of a catalyst, garbage undergoes pyrolysis and gasification reaction in a pyrolysis atmosphere to generate gas products, and solid residues are separated at the same time. The solid residues are used as environmentally friendly materials; the pyrolysis atmosphere is water vapor or carbon dioxide , Pyrolysis temperature is 600 ～ 900 ℃, reaction pressure is 0.1 ～ 1.0MPa;

Removal of impurities in gas products: After the gas products are condensed and dehydrated by cooling, and then absorbed by lye or oxides, nitrogen, sulfur and chlorine in the gas products are removed to obtain syngas that does not contain the above impurities, and at the same time The chlorine-containing compounds, sulfur-containing compounds and nitrogen-containing compounds are used for the preparation of chemical fertilizer chemical products including ammonium sulfate and ammonium chloride;

Water gas shift catalytic reaction: Under the action of a catalyst, a water gas shift reaction is performed to obtain a synthesis gas with an appropriate ratio of hydrogen and carbon monoxide. The reaction temperature is 250-400 ° C and the reaction pressure is 0.1-1.0 MPa;

Catalytic liquefaction of syngas: After the syngas obtained by the water gas shift reaction is condensed to remove water and dried, a liquefaction reaction occurs under the action of the catalyst, and a part of liquid fuel is generated. The reaction temperature is 300-450 ° C and the reaction pressure is 0.5-3MPa ;

After liquid fuel and synthesis gas are condensed to remove water, liquid fuel is separated by gas-liquid separation and collected for processing chemical products. Syngas that has not become liquid fuel is used as a fuel gas product, or the steps are repeated again to be recycled. The cooled condensed water can be heated and gasified to pass into the gasification furnace or water-coal converter as a reactant, so as to achieve recycling until the end of garbage treatment.

The garbage catalytic pyrolysis gasification reaction is realized by a circulating fluidized bed, and the synthesis gas catalytic liquefaction reaction is realized by a double-layer fixed bed.

Referring to FIG. 2, a garbage catalytic pyrolysis system of the present invention includes a garbage catalytic pyrolysis gasification unit, a dechlorination, desulfurization, and denitration treatment unit, a water gas shift unit, a synthesis gas catalytic liquefaction unit, and a steam unit. The garbage catalytic pyrolysis gasification unit includes a gasification furnace 107, a cyclone separator 109 and a cyclone separator 110. The gasification furnace 107 is provided with a circulating fluidized bed; the gasification furnace 107 is provided with a supporting catalyst, gas The top gas outlet of the chemical furnace 107 communicates with the side air inlet of the No. 1 cyclone 109, and the lower port of the No. 1 cyclone 109 communicates with the bottom of the gasifier 107 for collection and entry into the No. 1 cyclone separator Catalyst 109 and garbage residues with insufficient reaction, the top air outlet of No. 1 cyclone 109 communicates with the side air inlet of No. 2 cyclone 110, the top of No. 2 cyclone 110 is provided with an air outlet, the bottom A lower port for discharging solid residues is provided; the dechlorination, desulfurization and denitration treatment unit includes a first condenser 201, a deamination reactor 202 and a desulfurization and dechlorination reactor 204 connected in sequence, and an air inlet of the first condenser 201 It is connected to the air outlet of the cyclone separator 110; the water gas conversion unit includes a water gas reactor 209, a second condenser 210 and a drying tower 211 connected in sequence, the gas inlet of the water gas reactor 209 and the desulfurization and dechlorination reaction The gas outlet of 204 is connected; the synthesis gas catalytic liquefaction unit includes a booster pump 301, a Fischer-Tropsch reactor 305, a third condenser 308, a gas-liquid separator 309, and a tail gas treatment device 312 connected in sequence, and the Fischer-Tropsch reactor 305 A double-layer fixed bed is adopted, and the inlet end of the booster pump 301 is connected to the gas outlet of the drying tower 211; the steam unit includes a steam generator 401, and the outlet of the steam generator 401 is respectively connected to the side wall of the water gas reactor 201 and the gasifier The bottom inlet of 107 is connected.

A back pressure valve 307 is provided on the pipe connecting the bottom end of the Fischer-Tropsch reactor 305 and the third condenser 308. A steam valve 402 is provided on a pipe communicating with the outlet of the steam generator 401 and the side wall of the water gas reactor 209, and a flow meter is provided on a pipe communicating with the outlet of the steam generator 401 and the air inlet at the bottom of the gasifier 107 404.

A first heating device 103 is provided in the circumferential direction of the silo, a second heating device 105 is provided in the circumferential direction of the gasification furnace 107, a third heating device 203 is provided in the circumferential direction of the deamination reactor 202, and a desulfurization and dechlorination reactor 204 Is provided with a fourth heating device 205 in the circumferential direction, and a Fischer-Tropsch reactor 305 is provided with a fifth heating device 304 in the circumferential direction.

Pure water is mainly placed in the deamination reactor 202, which is mainly used to absorb NH ₃ in the synthesis gas, and at the same time helps to remove a part of HCl and H ₂ S by forming NH ₄ Cl and NH ₄ S; Dilute lye or oxide can be placed in 204, mainly used for the removal of H ₂ S and a small amount of HCl.

A first gas uniform distribution device 106 is provided at the bottom gas inlet of the gasification furnace 107, and a second gas uniform distribution device 306 is also provided at the bottom end of the Fischer-Tropsch reactor 305.

The top of the gasifier 107 is provided with a first pressure gauge 108, the top of the water gas reactor 209 is provided with a second pressure gauge 207 and a first gas detection table 208, and the top of the Fischer-Tropsch reactor 305 is provided with a third pressure gauge 302 and Second gas detection table 303.

The lower port of the cyclone separator 109 is connected to the bottom of the gasifier 107 through the first pipe 111, and the outlet of the steam generator 401 is connected to the bottom air inlet of the gasifier 107 through the pipe and the flange 112 on the pipe The top of the deamination reactor 202 communicates with the bottom of the desulfurization and dechlorination reactor 204 through a second pipe 206.

The gas outlet of the gas-liquid separator 309 is provided with a first ball valve 310, the liquid outlet is provided with a second ball valve 311, the gas outlet of the exhaust gas treatment device 312 is provided with a third ball valve 313, the outlet of the steam generator 401 and the gasifier A fourth ball valve 403 is provided on the pipe communicating with the bottom inlet of 107. A fifth ball valve 405 is provided on the side wall of the pipe where the outlet of the steam generator 401 communicates with the bottom air inlet of the gasification furnace 107, and the third ball valve 313 communicates with the fifth ball valve 405.

A drain port is provided at the bottom end of the drying tower 211, and a drain ball valve 212 is provided at the drain port. The first condenser 201, the second condenser 210, and the third condenser 308 are all provided with a water outlet at the bottom ends, and a drain valve is provided at the water outlet. The water discharged from the drain ball valve 212 and the drain valve can enter the steam generator 401 again to be evaporated and utilized.

The garbage catalytic pyrolysis gasification unit uses a gasification furnace 107 including a circulating fluidized bed as the core device, and is equipped with a motor 101, a screw 102, a first heating device 103, a star feeder 104, etc. The feeding device sends the pretreated raw materials of suitable size and temperature to the gasification furnace under oxygen-free conditions. The second heating device 105 can keep the gasification furnace at a specified reaction temperature. The water vapor enters the gasification furnace 107 from below through the first gas uniform distribution device 106. The solid residue remaining after the catalytic pyrolysis of the garbage is removed by the first cyclone separator 109 and the second cyclone separator 110 to become the raw materials for making environmentally friendly materials, which are generally used for making construction materials; the gas products generated are subjected to cyclone separation The outlet of the reactor enters the dechlorination, desulfurization and denitration treatment unit.

Before the syngas product enters the dechlorination, desulfurization and denitration treatment unit, it will first pass through the first condenser 201 to remove the moisture in the product, and then enter the deamination reactor 202 and the desulfurization dechlorination reactor 204 in order to remove the gas product The nitrogen, sulfur and chlorine in the mixture are used to obtain synthesis gas without impurities, and the chlorine-containing compounds, sulfur-containing compounds and nitrogen-containing compounds removed at the same time are used for the preparation of chemical fertilizer chemical products. The temperature required by the deamination reactor 202 is controlled by the third heating device 203, and the temperature required by the desulfurization dechlorination reactor 204 is controlled by the fourth heating device 205.

The gas pressure and composition of the gas product after removing impurities through the water gas reactor 209 are monitored by the second pressure gauge 207 and the first gas detection table 208. According to the gas detector data, the reaction in the water gas reactor 209 is adjusted by the opening degree of the steam valve.

In order to make the ratio of hydrogen and carbon monoxide in the gas product reach the optimal value required for catalytic liquefaction, the water gas shift reaction needs to occur in the water gas reactor 209 under the action of the catalyst, and the gas product can be adjusted by controlling the reaction degree or the flow rate of water vapor. The ratio of hydrogen to carbon monoxide. The gas after the reaction passes through the second condenser 210 to remove the water remaining after the reaction, and is dried by the drying tower 211.

The resulting gas product is adjusted to a pressure required for catalytic liquefaction by a booster pump 301, and its pressure and composition are monitored using a third pressure gauge 302 and a second gas detection gauge 303. The synthesis gas that meets the requirements for catalytic liquefaction is sent to the Fischer-Tropsch reactor 305 for liquefaction, and the resulting product passes through the third condenser 308 to achieve temperature drop and liquid product precipitation. Subsequently, the liquid is separated and collected by the gas-liquid separator 309, the liquid fuel is collected for processing other high value-added chemical products, and the gas product is sent to the circulating fluidized bed gasifier 107 through the tail gas treatment device 312 for recycling. Or sold as a flammable product.

The steam required in the process of garbage catalytic pyrolysis and water gas shift reaction is generated by the steam generator 401. The opening and closing of the pipeline for feeding steam to the gasifier 107 is controlled by the fourth ball valve 403 and the flow meter 404, and the opening and closing of the pipeline for feeding steam to the water gas shift reactor 209 is controlled by the steam valve 402.

According to the two patents with patent numbers ZL201620443464.4 and ZL 201621458303.9, we designed and manufactured the waste catalytic pyrolysis pilot and pilot devices of model Huateng 100 and 200. The waste treatment capacity is 30 kg / day and 1 ton / day. After the steps of catalytic pyrolysis, impurity removal, water gas shift, etc., the synthesis gas composition is 43.5% H ₂ , 36.0% CO, 8.7% CO ₂ and 11.8% CH ₄ . The prepared synthesis gas can be continuously produced as a liquid product under the reaction conditions of 450 ° C., 3 atmospheres, and a space velocity of 1,200 h ^-1 . As shown in Fig. 3, the conversion rate of CO and H ₂ has been continuously increasing during the test period, which may mean that the loaded catalyst is continuously activated during the reaction. At the same time, the selectivity of the prepared liquid oily product has been maintained at around 85%, while the selectivity of the gaseous product has remained above 10%. After online gas chromatography detection, it was determined that the gas products obtained were mainly unsaturated hydrocarbons containing C ₂ ～ C ₅ . After mass spectrometry analysis, it was found that the obtained liquid oily product was mainly saturated liquid alkane with a composition of C ₈ to C ₁₀ , and no solid paraffin-like product was collected.

The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the present invention. Within the scope of protection.

Claims

A process for preparing liquid fuels and chemical products using garbage is characterized by the following steps:

1) Catalytic pyrolysis gasification reaction

Under the action of the gasification catalyst, the waste to be treated undergoes pyrolysis and gasification reaction in a pyrolysis atmosphere to generate gas products, and at the same time, solid residues are separated, and the solid residues are used as environmental protection materials;

2) Impurity removal of gas products

After the gas product is cooled and condensed to remove water, it is absorbed with lye or oxide to remove nitrogen, sulfur and chlorine from the gas product to obtain a synthesis gas that does not contain nitrogen, sulfur and chlorine. , Sulfur-containing compounds and nitrogen-containing compounds are used to prepare chemical products;

3) Water gas shift catalytic reaction

Syngas that does not contain nitrogen, sulfur and chlorine undergoes a water gas shift reaction under the action of a catalyst to obtain a syngas mixed with hydrogen and carbon monoxide;

4) Catalytic liquefaction of synthesis gas

After the step 3) the synthesis gas obtained by the water gas shift reaction is condensed to remove water and dried, a liquefaction reaction occurs under the action of the catalyst, and partly converted into liquid fuel;

5) After the liquid fuel and unconverted synthesis gas are condensed to remove water, and then separated by gas-liquid, the liquid fuel is collected for processing chemical products, and the synthesis gas that has not become liquid fuel is used as a fuel gas product or step 1 is repeated again) ~ 4) Recycled.
The process for preparing liquid fuels and chemical products using waste according to claim 1, characterized in that the catalytic pyrolysis gasification reaction is carried out in a gasification furnace provided with a circulating fluidized bed reactor, and the pyrolysis atmosphere uses steam Or carbon dioxide, pyrolysis gasification reaction temperature is 600 ~ 900 ℃, reaction pressure is 0.1 ~ 1.0MPa.
The process for preparing liquid fuel and chemical products using waste according to claim 1, wherein the specific operation of step 2) is as follows:

The gas product first passes through condensation and water removal, and then enters the deamination reactor and the desulfurization and dechlorination reactor in turn. After absorption by the lye or oxide, the nitrogen, sulfur and chlorine in the gas product are removed to obtain nitrogen and sulfur free. The synthesis gas of chlorine, and the chlorine-containing compounds, sulfur-containing compounds and nitrogen-containing compounds removed at the same time are used to prepare chemical products of chemical fertilizers.
The process for preparing liquid fuels and chemical products using waste according to claim 1, characterized in that in step 3), the water gas shift reaction temperature is 250-400 ° C, and the reaction pressure is 0.1-1.0 MPa; hydrogen and carbon monoxide are mixed In the synthesis gas, the volume ratio of hydrogen to carbon monoxide is 2: 1.
The process for preparing liquid fuels and chemical products from waste according to claim 1, wherein in step 4), the synthesis gas catalytic liquefaction reaction is carried out in a Fischer-Tropsch reactor containing a double-layer fixed bed, and the catalytic liquefaction reaction temperature It is 300 ～ 450 ℃, and the reaction pressure is 0.5 ～ 3MPa.
A garbage catalytic pyrolysis system implementing the process according to any one of claims 1 to 5, characterized in that it includes a garbage catalytic pyrolysis gasification unit, a dechlorination, desulfurization and denitration treatment unit, a water gas shift unit, and a synthesis gas catalysis Liquefaction unit and steam unit;

The garbage catalytic pyrolysis gasification unit includes a gasification furnace (107), a cyclone separator (109) and a cyclone separator (110), and a circulating fluidized bed reactor is provided in the gasification furnace (107). A catalyst supporting sieve plate is provided in the gasifier (107), the top gas outlet of the gasifier (107) communicates with the side air inlet of the No. 1 cyclone separator (109), and the lower side of the No. 1 cyclone separator (109) The port communicates with the bottom of the gasification furnace (107) and is used to collect the catalyst and garbage residues that have not fully reacted into the cyclone separator (109). The top gas outlet of the cyclone separator (109) and the second The side air inlets of the cyclone separator (110) are connected, the air outlet is provided at the top of the cyclone separator (110), and the bottom port for discharging solid residues is provided at the bottom;

The dechlorination, desulfurization and denitration treatment unit includes a first condenser (201), a deamination reactor (202) and a desulfurization and dechlorination reactor (204) connected in sequence, the air inlet of the first condenser (201) and the second The air outlet of cyclone separator (110) is connected;

The water gas shift unit includes a water gas reactor (209), a second condenser (210) and a drying tower (211) connected in sequence, an air inlet of the water gas reactor (209) and an air outlet of the desulfurization and dechlorination reactor (204) Connected

The synthesis gas catalytic liquefaction unit includes a booster pump (301), a Fischer-Tropsch reactor (305), a third condenser (308), a gas-liquid separator (309), and a tail gas treatment device (312) connected in sequence; Fischer-Tropsch reaction A double-layer fixed bed is used in the device (305); the inlet end of the booster pump (301) is connected to the gas outlet of the drying tower (211);

The steam unit includes a steam generator (401), and the outlet of the steam generator (401) communicates with the side wall of the water gas reactor (201) and the bottom air inlet of the gasification furnace (107), respectively.
The garbage catalytic pyrolysis system according to claim 6, characterized in that the gas outlet of the exhaust gas treatment device (312) is connected to an external collection device for collecting exhaust gas.
The waste catalytic pyrolysis system according to claim 6, characterized in that the gas outlet of the exhaust gas treatment device (312) is provided with a third ball valve (313), the outlet of the steam generator (401) and the gasifier (107) A fifth ball valve (405) is provided on the side wall of the pipe where the bottom air inlet communicates, and the third ball valve (313) communicates with the fifth ball valve (405).
The garbage catalytic pyrolysis system according to claim 6, characterized in that the bottom end of the drying tower (211) is provided with a drain port, and a drain ball valve (212) is provided at the drain port; the first condenser (201), the first Both the second condenser (210) and the third condenser (308) are provided with a water outlet at the bottom end, and a drain valve is provided at the water outlet.
The garbage catalytic pyrolysis system according to claim 9, characterized in that the drain ball valve (212) and the drain valve communicate with the water inlet of the steam generator (401).