DE2652722A1 - Synthesis gas from carbon and superheated steam - in atmos. free of oxygen and using the superheated steam as sole heat supply - Google Patents

Abstract

Superheated steam is esp. produced by contacting water with a hot heat-transfer medium. The amt. of steam is pref. 2-10 (4-7) times the stoichiometric amt. needed for complete reaction. Pollutant gases are not found in the reaction prod. The ratio of H2:CO in the prod. can be regulated by controlling the temp. and amt. of steam used. No soort or char forms in the reactor. Any S in the C reacts with steam to give H2S, for conversion to H2 and S. Condensn. of excess unreacted steam removese flyash from the prod. gas. Solid waste fuels can supply is no 30% of the energy requirements of the process. The H2 in the prod. is satd. with water vapour and does not cause embrittlement of the steel appts. The synthesis gas can be used as a fuel, for conversion to CH4 (at molar ratio H2:CP = 3:1), to CH3OH (at molar ratio H2:CO = 2:1), or to NH3, N2H4 or liq. fuels, by hydrogenation, (at molar ratio H2:CO of 9:1).

Description

Process for the production of synthesis gas

The invention relates to the production of hydrogen and carbon monoxide by reacting a carbon source with water vapor at high temperature; she in particular enters the production of hydrogen and carbon monoxide through conversion of coal with water vapor, the heat of reaction practically completely from the Water vapor reactants is supplied.

The rise in costs and the shortage of petroleum in the past Years ago, coal gasification has become an interesting alternative for extraction made of fuel. One of the problems with using coal itself Connected as fuel is that much of the mined coal contains a large amount of sulfur.

Sulfur oxide pollution control regulations prohibit the emission of more than 2.17 kg of sulfur dioxide per million keal (1.2 lbs / 106 BTU) by burning produced by coal Warmth. In the case of coal gasification, the sulfur can however, easily removed from the product gas, so that in a plant in which Water gas used as the fuel source is usually not an expensive one and complicated pollution control equipment is required to comply with regulations to suffice.

An economically working coal gasification plant for the production of fuel (fuel) for industrial and energy consumers can be (1) sufficient Produce fuel to power the US, (2) the air pollution control regulations suffice and (3) the coal mining industry in the areas for hard coal with high Revive sulfur levels.

The "water gas reaction" is the conversion of one carbonaceous solid with steam at high temperature for production of hydrogen and carbon monoxide and they have been in practice for many years applied. The water gas reaction is endothermic and essential for carrying out the reaction a considerable amount of heat must be supplied. A method currently in use to provide the heat of reaction consists in fuel and oxygen for to feed the combustion within a gasification reactor. With this method however, a number of difficulties arise. The hot combustion gases, mainly the C02, are in addition to the gases that can accompany the oxygen, like Nitrogen, entrained with the product gas, the product gases are undesirable by this entrained gases are diluted, resulting in considerable difficulties and costs on the production of hydrogen and carbon monoxide sulfur and other impurities can accompany the carbonaceous solid and they become sulfur oxides and other undesirable ones in the combustion reaction gaseous Combustion products oxidized. These oxides must also be from the product gas be separated.

In US Pat. No. 3,787,193 there is a proposal for solving the The problem of the dilution of the water gas by undesired entrained gases is described. As indicated in this patent, molten slag can be in the gasification reactor provided, which the heat required for the water gas reaction supplies, so that it is no longer necessary, a combustion within the gasification reactor perform. In this process, a separate heating section is provided for the production of the molten slag, so that the slag is essentially can be introduced into the gasification reactor free of oxidizing gas. To this In this way, no combustion gases are entrained with the products of the water-gas reaction.

Another method of preventing dilution of the product gas by the products of combustion is the indirect heating of the carbonaceous Solid in a fluidized bed heat exchanger, 8o that the hot combustion gases cannot be mixed with the carbon fluidized bed. One embodiment of this The method is described in US Pat. No. 2,680,065.

It has now been found that the water gas reaction without the addition of a other heat sources can be carried out if one uses excess water used in such an amount and at such a temperature sufficient for the reaction between a carbonaceous solid and water vapor provide required heat.

It is therefore an object of the present invention to provide a new and improved one Process for the production of synthesis gas by reacting carbon with water vapor to develop.

The aim of the invention is also to provide a method for producing Synthesis gas that contains up to 90% hydrogen by converting carbon to be indicated with an excess of superheated steam. The aim of the invention is there is also a process for the production of synthesis gas by converting carbon to develop with superheated steam and the necessary heat of reaction practically completely provided by the heat from the water vapor reactants. Another aim of the invention is to provide a method for producing synthesis gas indicate the predominantly hydrogen and carbon monoxide in the desired ratio contains.

Another object of the invention is to provide a method of manufacture of synthesis gas with the desired ratio of hydrogen to carbon monoxide to develop in which the synthesis gas formed is suitable for further processing is, for example, for conversion to methane, methanol, ammonia or hydrazine liquid fuels by hydrogenation.

The aim of the invention is also a hydrogen and carbon monoxide to produce synthesis gas containing, in which the ratio of hydrogen to Carbon monoxide by regulating the temperature and amount of the fed to the reactor excess water vapor can be regulated. The aim of the invention is also a process for the production of synthesis gas by reacting EohlendD £ f with indicate superheated water vapor, in which the superheated water vapor is either continuous or batchwise.

The aim of the invention is also to provide a method for producing Specify synthesis gas by reacting carbon with water vapor, in which the Amounts of the reactants and the reaction temperature and pressure are chosen can be9 that no unreacted carbon more available and therefore no soot and no activated carbon remain in the reaction vessel Another aim of the invention is to provide a method for producing synthesis gas by reacting a carbon source with superheated water vapor that the carbon source never comes into contact with air or oxygen The invention is also to provide a method for producing clay that is practically pollution-free Specify fuel gas.

Another object of the invention is to provide a method of manufacture to specify synthesis gas by reacting a carbon source with water vapor, where there is enough excess water vapor to react with that in the carbon source contained sulfur for the production of H2S, which is converted into H2 and 5, It is also an object of the invention to provide a method of manufacture of synthesis gas, which is mainly a mixture of hydrogen and carbon monoxide contains, whereby the hydrogen is saturated with water vapor to embrittlement the equipment used to produce and transport the synthesis gas impede. The aim of the invention is also to provide a method for producing Specify synthesis gas by converting carbon with water vapor, at Res by the condensation of the excess unreacted water vapor in the synthesis gas product Fly ash is removed from the product gas. The aim of the invention is also to provide a Specify a process for the production of synthesis gas, in which the gasification reactor formed gas is quickly cooled to the equilibrium with the desired composition to stabilize the reaction product. The invention also aims to provide a Specify process for the production of synthesis gas, in which part of the formed Gas can be used to meet all or part of the energy demand of the proceedings. The aim of the invention is also to provide a method to the Specify the production of synthesis gas using solid waste fuels be able to cover at least about 30% of the energy requirements of the process.

Finally, the aim of the invention is to provide a method of production of synthesis gas by converting the carbon from a carbon source, such as Coal, to be indicated with water vapor, in which the water vapor reactant is practically the represents the only heat source for the reaction and in which the water sump is a temperature below the temperature at which the ash melts (sinters) is supplied to prevent vitrification of the ash, and in which the water vapor is supplied in an amount necessary for the conversion of practically all of the carbon from the carbon source is sufficient.

An essential feature of the present invention is Water vapor in excess in amounts up to 2 to 10 times that for the reaction to supply with the carbon in a gasification reactor required amount. In this way the equilibrium reaction can take the side of the formation of hydrogen be shifted so that the product gas after the removal of carbon dioxide, hydrogen sulfide and excess water vapor can contain up to 90% hydrogen or more. By supplying the water vapor as a heat source, the excess water vapor is supplied enough heat for the reaction, besides being the shift in equilibrium act ion favored in the direction of hydrogen formation. With the known methods, which use a heat source other than the water vapor reactant is used generally no excess steam is used or in this process the excess is kept to a minimum, since the excess water vapor also be heated, making the process uneconomical. According to the invention represents the water vapor reactant is the heat source for the reaction and can therefore with Advantageously used in excess.

Another benefit of adding excess water vapor as a heat source for the reaction consists in the fact that the coal is completely converted can be without soot or activated carbon remaining in the gasification reactor, being a product gas with a high ratio of hydrogen to carbon monoxide receives. Since the hydrogen in the product gas is saturated with water vapor, the the hydrogen also comes from the excess water vapor reactants no embrittlement of the steel equipment and pipes.

Another advantage of using water vapor in excess is in that sufficient excess water vapor can be supplied to provide the heat for converting virtually all of the carbon while at the same time the temperature of the water vapor is kept below the temperature at which the ashes melt (sinter) (about 120400 (22000F)) o This way the glazing the ash never becomes a problem in the gasification reactor.

The ratio of hydrogen to carbon monoxide in the product gas can be done by regulating the amount and temperature of excess water vapor can be easily adjusted in the gasification reactor. By regulating the amount and the temperature of the excess steam becomes the temperature of the product gas at the exit from the gasification reactor (the quenching temperature) is determined. That Gas formed in the gasification reactor can be cooled to remove the excess water vapor to condense, and then it can be further treated, ul carbon dioxide and hydrogen sulfide to remove, taking a product gas of hydrogen and carbon monoxide remains behind.

When a ball heater for the production of superheated steam is used, air can be used as the source of oxygen for combustion to generate the hot gas to heat the balls without overheating Water vapor is diluted by nitrogen or products of combustion0 if the product gas To be converted to methane, it is desirable to have a molar ratio of hydrogen to adjust carbon monoxide of about 3: 1 according to the following equation: 3H2 + CO "CH4 + H200 By adjusting the amount and temperature of the excess Water vapor reactants can easily achieve this ratio. If you can Adjust product gas to a molar ratio of hydrogen to carbon monoxide of about 2: 1 the product gas can be easily converted into methanol according to the following Equation: 2H2 + BO - # OH3OH. By implementing with a considerable excess the product gas is obtained from water vapor in accordance with the method described above a molar ratio of hydrogen to carbon monoxide greater than 9: 1. Such high Hydrogen to carbon monoxide ratios are beneficial in the conversion of the product gas in ammonia, hydrazine and for hydrogenation with the product gas for conversion into liquid fuels.

The well-known water gas reaction of carbon with water vapor is based on the following equations: C + H20 CO + H2 - 14 231 kcal (56 520 BTU) / 0.454 kg-mole (1 lb mole) carbon and c + 2H20 C02 + 2H2 - 9 789 kcal (38 830 BTU) / 0.454 kg-mole (lb. mole) of carbon The above water gas reaction of carbon with water vapor can be taken from the water vapor reactants while at the same time the equilibrium is shifted towards a higher percentage of hydrogen and carbon monoxide in the product gas.

In the known coal gasification process, the water vapor is ßeaktant not supplied at such a temperature or in such an amount that is sufficient to provide all of the heat of reaction for the above water gas reactions.

Instead, another heat source is used, which is the heat of reaction supplies. It is therefore undesirable in these known methods, water vapor in to use a large excess, because the excess water vapor increases Requires heat input, which is due to the fact that the water vapor excess must be heated in the gasification reactor.

In the gasification process according to the invention, the water vapor fed at a temperature which is higher than the temperature of the implementation of the Carbon with water vapor, so that the water vapor is both a reactant and as a heat source, which provided the heat of reaction by supplying an excess of water vapor in an amount that corresponds approximately to 2 to 10 times the amount, which is necessary for the complete reaction with the carbon is the Equilibrium reaction towards a higher formation of hydrogen and carbon monoxide shifted in the product gas. The water vapor is preferably supplied in an amount which corresponds to about 4 to 7 times the amount required for the implementation with the Carbon is required.

Including the high temperature product gas from the gasification reactor of Excess water vapor is suitable for heating the supplied water and provides part of the heat requirement for overheating the in the gasification reactor Introduced water vapor already also, the excess water vapor can easily separated from the product gas by condensation. With the condensation of the The excess of water vapor from the product gas is advantageously fine Washed fly ash from the product gas, leaving the ash-free gas behind By quenching (cooling) the product gas to a given temperature the equilibrium reaction at the desired ratio of hydrogen to carbon monoxide be stabilized.

In the process according to the invention, the coal or the carbon come never in direct contact with air or oxygen. In this procedure Air used during combustion to produce superheated steam, however, the air never comes into contact with the coal ',' This avoids that nitrogen and combustion products are contained in the fuel gas formed. The fuel gas can also be used in the proportions suitable for direct methane production nis can be produced from hydrogen to carbon monoxide, producing a gas with high Heat content is generated without never using pure oxygen.

An essential feature of the present invention is that the water vapor is superheated to a temperature which is higher than the temperature the reaction of the carbon with the water vapor without the water vapor passing through Nitrogen or combustion products is diluted.

In this way, dilution gases such as nitrogen and pollution combustion products form such as sulfur oxides and nitrogen oxides, not part of the product gas. One Method of producing superheated steam in this way be stands in that an inert heat transfer material is heated in a container and superheat the water vapor in another container by mixing it with the heated one Bringing inert material into contact while allowing gas separation between the two Maintains vessels0 This is achieved by using a kettle heater as he is known per se in the field of air and steam heating and in "Steam, Its Generation and Use", The Babcock and Wilcox Co., New York (1955), pp 11-19 is described. A description of a kettle heater is also given by W.L. Nelson in "Petroleum Refinery Engineering", McGraw Hill (1949), pp. 528 urrd 529, given. As described in the above cited "Steam, Its Generation and Use "indicated, various suitable materials can be used as the heat transfer medium zoBo uullite balls (72% Al203, 28 ° t SiO2) or magnesium oxide balls are used.

Mullite spheres with a diameter of about 0.635 are preferred to about 1.27 cm (1/4 to 1/2 inch) ¢ Another method of making overheated Water vapor without dilution of the water vapor by nitrogen or combustion products is that nan a ceramic rotary heat recovery device, such as a Ljungstrom heater used as in "Perry's Chemical Engineers' Handbook ", 4th edition, pages 9-63 and 9-64.

As a carbon source, coal with a high sulfur content can advantageously be used (more than 5 wt .-%) can be used when using excess water vapor, such as stated above, is implemented. The sulfur from the coal reacts with the excess Water vapor with the formation of hydrogen sulfide. The hydrogen and the sulfur can each be recovered by known methods. Through the re-coagulation of the hydrogen from the gasification reaction by converting the excess Water vapor formed with high-sulfur coal H i can reduce the amount of educated Product gas can be increased by at least 2% and thereby the molar ratio of hydrogen to carbon monoxide is further increased.

In the following, with reference to FIG. 1, the attached Drawings first a continuous embodiment of the method according to the invention described in more detail.

By means of the pump 12, which is driven by a motor 13 Feed water is introduced into the feed heater section 14 of the product gas cooler 16. In the feed heater (preheater) 14, the feed water is caused by the product gas heated. The water is transferred from the feed heater 14 to a boiler drum 18 a steam boiler 20 is pumped, in which the heated water is converted into water vapor will. The steam is transferred from the steam boiler 20 to the superheater section 22 of the product gas cooler 16 conveyed, in which the water vapor is superheated before it is introduced into the heater 24.

The heater 24 consists of two chambers, a Eugelerhitzerkammer 24A and a steam superheating chamber 24B, the chamber 24A being above the Chamber 24B is disposed; In the kettle heater chamber 24A of the heater 24 is a suitable heat transfer medium, for example a variety of refractory ones Balls, introduced, the balls 26 burning through direct contact with in the air Fuel from the burner 28 can be heated. A preferred heat transfer medium make balls of mullite (72 fo Al203, 28 * sio2) with a diameter of about 0.635 to about 1.27 cm (1/4 to 1/2 inch) thick. The combustion gases flow countercurrently to the entering balls 26 upwards. The hot balls flow in countercurrent to the water vapor entering from the superheater section 22 of the product gas cooler 16 in countercurrent downward into the steam superheat chamber 24B.

Water vapor from the superheater 22 reaches the steam inlet 30 in the steam superheater chamber 24B of the heater 24 and flows upward while it is overheated by the balls 26, and leaves the steam superheater chamber 24B through water vapor outlet 32 after heating to about 16500C (300o0F) has been, by suitable setting of the pressure control device 34 in the kettle heater chamber 24A and the pressure control device 36 in the steam superheating chamber 24B Ensure that the combustion gases in the upper chamber 24A are up flow and not enter the lower chamber 24B. To ensure that no Combustion products get into the steam superheating chamber 24B, one is allowed to weak water vapor bypass flow from superheater chamber 24B into the kettle heater chamber 24A by making the pressure in the superheater chamber 24B slightly higher than the pressure in the kettle heater chamber 24A. By setting the pressure control devices 34 and 36 can be ensured that practically the said superheated water vapor flows through the water vapor outlet 32, with a gas separation between the kettle heater chamber 24A and the steam superheating chamber 24B is maintained.

The mullite balls 26 flow after they give off their heat have been cooled to overheat the water vapor, in a riser 38, in the heated compressed air flowing through the nozzle 40, the balls into one Cyclone 42 lifts by separating the heated air from the balls 26.

The one used to lift the balls out of the outlet 46 of the lower chamber 24B Heated air used in the cyclone 42 is in the compressor 48, which is operated by the Motor 49 is driven, compressed and heated in the heat exchanger 50. It it is advantageous to use some of the hot combustion gases from the Eugelerhitzerkammer 24A as a heat source for heating the air in the heat exchanger 50. The heated, separated air from cyclone 42 is conveyed through line 44 in the Burner 28 steered; and the balls 26 fall into the ball heater section 24A. The heated, separated air from the cyclone 42 enters the burner 28, in which it is combined with the product propellant to burn the propellant and the Raise the temperature of the balls 26 to about 1930 ° C (5500 ° F). It is important, that never have the air and combustion products in the kettle heater chamber 24A come into contact with the carbon source. Solid waste fuel, such as * B0 combustible Garbage can in the burner 21 in an amount up to about 30% of the fuel requirement be used in the burner 21 to achieve a higher efficiency su The Hot gases generated in the burner 28 come with the balls 26 in the ball heater 24A in contact increasing the temperature of the balls to about 1930 ° C (35000F) and the combustion gases are cooled to about 650 ° C (1200 ° F) before being used Leave the ball heater at the combustion gas outlet 52. The cooled combustion gases are passed through the turbine 54 into the heat exchanger 50, in which the combustion gases the compressed air from the compressor 48, which is used to lift the balls into the Zyklon 42 is used, heat.

The superheated steam from the steam superheater chamber 24B is introduced into a gasification reactor 60 through line 56 at inlet 58. In the gasification reactor (gas formation reactor) 60, the superheated water vapor used as both a heat transfer medium and a reactant with carbon 62. A considerable excess of steam is introduced into the gasification reactor 60, so that sufficient heat is supplied to the coal to react with the steam and the equilibrium of the reaction is the formation of hydrogen and carbon monoxide favored.

An important feature of heater 24 is that the ball heating chamber 24A and the steam superheating chamber 24B do not allow substantial gas exchange and that no gas can enter the chamber 243 from the chamber 24A. The Indian Steam superheater chamber 243 formed superheated water vapor can not mix with the combustion gases from the kettle heater chamber 24A and he cannot by nitrogen or any other undesirable constituents in the Combustion gases of the ball heater 24A are contained, can be diluted. It is important that the water vapor is practically the only heat transfer medium in the Gasification reactor 60 illustrates the formation of undesirable gases in the gasification reactor 60 to be kept to a minimum The heater 24 supplies the heat of combustion for heating the balls 26 for efficient and efficient heat transfer to overheat of water vapor in the superheater chamber 24BX without introducing undesired gases into the gasification reactor 60 get carried away.

The coal is fed into the gasification reactor 60 in the manner that they are pumped through the cyclone 64 with air. The air from the cyclone 64 passes into the turbine 65, in which the energy from the air to drive a generator (not shown) or recovered to drive an air blower the additional air through the heat exchanger 67 can be introduced into the steam boiler 20. In the gasification reactor 60, the coal 62 reacts with the superheated water vapor with the formation of reaction products, which predominantly consist of hydrogen and carbon monoxide The ash is collected in the funnel 63 at the bottom of the gasification reactor 60, The product gases flow through outlet 66 of gasification reactor 60 and arrive into a product gas cooler 16 in which the heat is recovered from the product gas and for superheating the water vapor in the superheater section 22 and for heating of the feed water in the feed heater section 14 used will. The product gases are then in the condenser section 68 of the product gas cooler 16 condenses to a substantial proportion of the excess water vapor contained in the product gas to remove.

Together with the excess water vapor in the condensate section 68 condensed impurities are removed in the trap 69. The chilled Product; gases from the product gas cooler 16 are sent to a hydrogen sulfide recovery process, for example in a typical Cirbotol plant, and the product gas is After the removal of the hydrogen sulphide, it goes into a CO2 removal process 719 For example, a typical monoethanolamine absorption system was introduced. That Product gas is then introduced into storage container 72. A part of the so educated Gas is ver @ ends in the burner section 28 of the kettle heater 24A and a part of the product gas is used to meet the fuel requirement in the steam boiler 20. If they are available cheaply, solid waste fuels may have been used, around the burner section 21 and the boiler 20 in addition to using the To supply product gas.

The entire facility is relatively free of pollution.

In the following, with reference to FIGS. 2 and 3, the enclosed Drawings a discontinuous (alternately carried out) embodiment the invention explained in more detail.

In the gasification according to FIG. 2, the feed pump (Feed pump) 12 Water into the feed inhibitor section 14 of the product gas cooler 16 pumped in. In the feed heater 14, the feed water is caused by the product gas from the gasification reactor 60 heated. From the feed heater 14 is the heated Water is pumped into a boiler drum 18 of the boiler 20, in which cias is heated Water converted into water vapor; becomes0 from @@@ Steam boiler 20 the water vapor is introduced into a pressure accumulator 80 in which the water vapor pressure rises to the desired value 0 The water vapor is removed from the pressure accumulator 80 by opening the valve 82 between the superheater section 22 of the product gas cooler 16 and the heater 24 is arranged through the superheater section 22 of the product gas cooler 16 expanded In the superheater section 22, the water vapor is by indirect Contact with the hot product gas from the gasification reactor 60 is overheated from the The superheated water vapor arrives at the superheater section 22 of the product gas cooler 16 in the heater 24, in which the water vapor with the heated balls 26 in contact comes, with the steam being superheated to around 1650 ° C (3oo00F). The heating of the balls 26 is in a separate stage, as with reference to Fig. 3 described, carried out.

During the superheating of the water vapor in the heater 24 the valves SS, 86 and 88 are closed and the valve 90 is open, so that the superheated steam can get into the gasification reactor 60. The valve 92 is closed after the coal 62 from the coal funnel 94 into the gasification area 60 has been introduced. Before any noticeable reaction in the gasification reactor 60 occurs, valve 96 is closed. When the pressure inside the gasification reactor 60 increased to a predetermined value as a result of the formation of propellant gas valve 96 opens so that the hot product gas passes through the product gas cooler, first through superheater section 22, then through the feed water heater 14 and finally through the condenser section 68 can flow.

The ash is collected in the bottom funnel 63 of the gasification reactor 60. The contaminants condensed together with the water vapor in the condenser section 68 are collected in the trap 69 at the bottom of the product gas cooler 16. the end The cooled product gas flows into the product gas cooler 16 through a line 96 a gas storage tank 980 The H2S and C02 in the product gas can be sent to either any point after the product gas has left the product gas cooler 16, removed by any known cleaning method. This can be either before or after storage in the storage container 98, preferably before storage, When the balls are heated according to FIG. 3, the balls 26 in the heater 24, the valve 82 is closed to prevent water vapor from entering The heater 24 is passed since the coal in the gasification reactor 60 from the previous one Gasification is consumed, water vapor fills the heater 24 and the gasification reactor 60. The valve 96 is closed by the increase in pressure in the product gas cooler 16. The valve 100 in the gasification reactor 60 is now opened to allow enough water from the feed pump (feed pump) 12 through the nozzle 102 to inject the pressure in the heater 24 and in the gasification reactor 60 to almost atmospheric pressure to diminish. The valve 90 between the heater 24 and the gasification reactor 60 is then closed and valves 84, 86 and 88 are opened. One lets preheated air from heat exchanger 104 through valve 86 into the heater 24 and one lets product gas from the reservoir 98 through the valve 88 into the Heater 24. Combustion is then initiated in heater 24 to produce the balls 26 to heat. While the balls 26 are heated by combustion in the heater 24 the gasification reactor 60 can be used for the next subsequent gasification run to get prepared. The ash collected in the hopper 63 can be removed and the coal 62 can be opened by opening the valve 92, which is the introduction of the coal 62 from the funnel 94 into the gasification reactor 60 allowed to be reintroduced. Of the The plant can be operated by supplying an auxiliary fuel, such as oil or gas that through fuel inlet 106 into heater 24 and through The auxiliary fuel inlet 108 introduced into the boiler 20 will be started.

The invention is explained below on the basis of preferred embodiments explained in more detail, but without being limited thereto.

Example of a continuous process according to FIG. 1 Preferably the gasification of coal is carried out continuously, as shown in Fig. 1, using a system pressure of about 14.1 kg / cm (200 psi) and using of superheated water vapor of about 16500C (30000F) at the inlet to the coal gasification reactor 60. The following flow rate parameters apply to a Plant with a capacity of approximately 500 tons (540 tons) of coal per day. These flow velocities can be modified for any desired system capacity.

As shown in Fig. 1> is by means of the pump 12 water a rate of 2800 liters (740 gallons) per minute through the charge heater 14 pumped. From the feed heater 14 the water is transferred to a kettle drum 18 of the steam boiler 20 is pumped, in which the entire feed water in steam with 0 from steam boiler 20 is converted to a pressure of 14.1 kg / cm2 (200 psi) the water vapor under a pressure of 14.1 kg / cm2 (200 psi) into the superheater section 22 of the product gas cooler 16 introduced, in which the water vapor under a pressure from 14.1 kg / cm2 (200 psi) to about 650 ° C (1200 ° F). The water vapor 650 ° C (12000F) and 14.1 kg / cm2 (200 psi) is placed in the steam superheater chamber 24B des Heater 24 introduced, being in countercurrent to the downward flowing heated balls 26 flows, and the water vapor is at about 1650 ° C (30000F) before passing through the steam outlet 32 into the line 56 is flowing, The water vapor at 1650 ° C (30,000 F) and 14.1 kg / cm2 (200 psi) is flowing into the inlet 58 of the gasification reactor 60. In the gasification reactor 60 there is coal introduced at a rate of approximately 22,400 kg (49,333 lbs) per hour, so that 0.454 kg-moles of coal for every 5 0.454 kg-moles of water vapor in the gasification reactor are present. The water vapor gives off its heat in the gasification reactor 60, whereby the heat for the conversion between the water vapor and the carbon of the coal provided. The one leaving the gasification reactor 60 through outlet 66 Product gas consists mainly of hydrogen, carbon monoxide, some carbon dioxide and excess water vapor and contains some hydrogen sulfide. The product gas exits reactor 60 at a quench temperature of about 81500 (15000F) a pressure of about 14.1 kg / cm2 (200 psi) and enters the product gas cooler 16. The cooling water is dispensed at a rate of approximately 3.79 x 104 l (104 gallons) introduced per minute into the condenser section 68 of the product gas cooler 16 6, to condense the water vapor out of the product gas. Be in the trap 69 About 2271 liters (600 gallons) per minute of water condensate recovered before the product gas is initiated into the hydrogen sulfide and carbon dioxide removal processes 70 and 71 wird0 The product gas is in the storage container 72 under a pressure of about 13.7 kg / cm2 (195 pei) stored. The product gas thus formed is at a rate of 0.11 x 104 standard = 3 per minute (3.89 x 104 s.c.f.m.). Of this Product gas will be about 666 m3 / minute (23 500 s.c.f.m.) for combustion in the Burner 28 and used in the burner 21 of the steam boiler 20. The total production of hydrogen and carbon monoxide is therefore 436 m3 (15 400 s.c.f.m.).

Batch Process Example As shown in FIG the feed water by means of the pump 12 at a speed of 2801 1 (740 gallons) per minute under a pressure of 42.3 kg / cm2 (600 psi) through the feed heater section 14 of the product gas cooler 16 in which the feed water is heated to 2380C (460 ° F) will. The heated feed water is fed into the boiler drum 18 of the steam boiler 20 pumped, in which water vapor is formed at a pressure of 39.4 kg / cm2 (560 psi) will. From the steam boiler 20, the steam is introduced into a pressure accumulator 80, in which the water vapor is at a pressure of 38.7 kg / cm2 (550 psi) and at 246.5 ° C (4770F) is retained. From the pressure accumulator 80, the water vapor is fed into the superheater section 22 of the product gas cooler 16 introduced, in which the water vapor to 650 ° C (12000F) is overheated, and from there it is introduced into the heater 24 through the valve 82. The heater 24 is a vessel with a diameter of 6 m (20 feet) and a height of 12 m (40 feet), the 45.3 t (50 tons) refractory Bullets set to about 193000 (35000F) (using the method referenced in Fig. 3 described method) have been heated contains.

The coal funnel 94 is driven at a rate of about 20.8 23 tons per hour of coal fed into the gasification reactor 60. In the gasification reactor 60 the water vapor comes out of the heater with a temperature of 1650 ° C (30000F) 24 in contact with the coal and reacts with it to form a product gas, the hydrogen, carbon monoxide, carbon dioxide, unreacted water vapor and contains some hydrogen sulfide. The product gas leaves the gasification reactor 60 at a temperature of about 81500 (15000F) and under a pressure of 36.9 kg / cm2 (525 psi). The ash from the gasification reactor 60 is collected in the hopper 63. The product gas flows through the product gas cooler 16, taking it first the superheater section 22, then the feed heater 14 and finally the Condenser section 68 happens. In the condenser section, the excess becomes Water vapor condenses and the impurities, such as fly ash, serve as Condensation nuclei, so that the fly ash is removed.

The condensation water from the product gas cooler 16 is in the trap 69 collected at a rate of about 2271 l (600 gallons) per minute. This water can be transferred to a water purification system to land the water can thus be reused. The product gas containing about 90% H2 flows at 38 ° C (1000F) and 35.2 kg / cm2 (500 psi) through line 96 into the gas storage canister 98. In the trap 99, the stored gas collects as the cooling continues at ambient temperature in the storage tank 98 more water0 In general this water that collects in the trap 99 becomes at a speed at about 75.7 liters (20 gallons) per minute until the gas is at ambient temperature has cooled down. The product gas from the gas storage vessel 98 is released at a rate of about 0.11 x 104 m3; 89 x 104 s.c.f.m.). About 436 m3 (15 400 ft3) per minute of product gas with a calorific value of 85.7 kcal (340 BTU) / 0.028 m3 (1 s.c.f.) collected as total product gas. The rest of the gas, namely 666 m3 (2.35 x 10 c.f.m.) is used within the system for the generation of water vapor used in the steam boiler 20 (283 m3 (104 c.f.m.)). The total gas production can by using solid waste fuels in the steam boiler 20. As shown in Fig. 3, the balls 26 in the ball heater 24 are placed on the following heated to about 19300C (35000F). The valve 90 is closed, to stop the flow of water vapor into the heater 24. Then the valve 96 closed by the back pressure in the product gas cooler 16. The valve 100 is opened in order to get out of the feed pump (feed pump) 12 water inject into the gasification reactor 6C to reduce the pressure in the heater 24 and in the gasification reactor 60 to reduce to near atmospheric pressure. The valve 90 between the heater 24 and the gasification reactor 6C is then closed and valves 84, 86 and 88 are opened. The combustion in the kettle heater 2 is then introduced by burning 382 m3 (1.35 x i04 c.f.m.) of product gas with 343 ° C (650 ° F) air from heat exchanger 104 to form hot Combustion gases at 2490 ° C (4500 ° F). These hot combustion gases heat 45.3 t (50 tons) of balls in heater 24 to about 1930 ° C (3500 ° F).

The two main factors influencing the efficiency of the above Process affect are the temperature of the heater 24 entering Water vapor and the pressure in the boiler 20. Corresponding to those in the following Data given in Table I, the boiler pressure was selected up to 105 kg / cm2 (1500 psi), the temperature of the refractory heat transfer medium and thus the water vapor temperature at the exit from the heater 24 has been set to a value set between 1930 and 249000 (3500 to 4500 ° F) for different efficiencies with different combinations of the boiler pressure and water vapor temperature @ n to determine. As can be seen from the data in Table I below, the the higher boiler drum pressure and the higher steam temperature are most effective. at Using solid waste in the boiler 20 can achieve this efficiency up to can be increased further to 86% or higher.

Table I Steam boiler pressure in 35 35 105 105 kg / cm2 (psi) (500) (500) (1500) (1500) maximum bulb temp. 1930 2490 1930 2490 in ° C (° F) (35 0) (4500) (3500) (4500) Water vapor flow (water in g / min.) 740 420 740 420 water consumed in g / min. 120 120 120 120 cooling water in g / min. 10000 5700 10000 5500 Temperature rise 23 ° C (40 ° F) Total yield in m3 / min. 436 578 521 620 (scfm) (15400) (20400) (18400) (21900) Efficiency in 6 58 77 69 83 Reaction equilibrium In the process described above, in principle five reaction products are obtained, namely hydrogen, carbon monoxide, carbon dioxide, excess water vapor and unreacted Carbon. The equilibrium equation can be represented as follows: where: a0 = mole of water vapor / mole of carbon originally introduced into the gasification reactor a1 = mole of carbon monoxide / mole of original carbon a2 = mole of carbon dioxide / mole of original carbon a3 = mole of hydrogen / mole of original carbon a1 = mole of excess or unreacted water vapor / Mole original carbon a5 = mole unreacted carbon / mole original carbon.

There are three main equilibrium reactions involved in the water-gas reaction, which can be represented by the three equations given below, where the equilibrium data is for 800 to 12000K.

Gasification: The equilibrium diagrams shown in FIG. 4 were produced using varying amounts of the original water vapor (a0), where a0 = 1, a0 = 2 and aO = 50. The use of no excess water vapor is a typical method according to the prior art. In In the process described here, it is advantageous to use up to 5 moles of water vapor per mole of carbon (a0 = 5).

Except for the equilibrium data for the procedure described here shows the fir. 4 also shows a comparison between the method according to the invention and typical prior art methods where aO = 1. At 10 atmospheres FIG. 4 shows a comparison between the method according to the invention in which aO = 5 and in which no coal remains in the reactor (a5 = 0), and a method according to the state of the art, in which a. = and a5 = 0.1. The point A represents the method according to the invention and point B represents the method according to FIG to the State of the art. At a5 = 0 and at a reactor pressure of 10 atmospheres the reaction temperature of the process according to the invention 604 ° C (11200F), while the reaction temperature of the process according to the prior art (aO = 1) 949 ° C (17400F).

If you move the point A vertically up to the top half of the Extended diagram, the mole percentage of C0 is (a1) for the invention Method 0.2, while the mole percentage of CO (a1) in the method according to Prior art is 0.82. The process according to the invention gives thus about 90% H2 and 10 r ;; CO, while following the procedure according to prior art technology only receives 54.5% H2 and 45.5% CO.

In Table II below are six different examples Specified by design parameter groups to establish the relationships between the product and the energy of the procedure. Each example is based on 0.454 kg-moles (lb moles) of water vapor at the reactor inlet, a temperature of 650 ° C (1200 ° F) at the outlet into the Uberhftzerabschnitt 22 (Fig. 1) and a condenser temperature of 38 ° C (1000F).

Table II Cases 1 2 3 4 5 6 Construction parameters 1.) Carbon supply, C +, 0.454 kg-mole (lb-mole) 0.35 0.35 0.30 0.25 0.30 0.25 2.) maximum temperature, Tr in ° C (° F) 1766 1650 1510 1370 1377 1243 (3240) (3000) (2750) (2500) (2510) (2270) 3.) Quenching temperature, Tein ° C (° F) 816 704 704 704 593 593 (1500) (1300) (1300) (1300) (1100) (1100) 4.) System pressure, P in atm 10 10 10 10 3 6 (permissible 70 12 23 27 3 6) 5.) H2O converted to 0.454 kg-moles (lb-moles) 0.519 0.548 0.487 0.421 0.516 0.444 energy relationships 6.) Heat for the ball heater (effective 6.36 5.54 4.69 3.88 3.92 3.15 health 90%), QH, 103 kcal (BTU) (25.20) (21.97) (18.63) (15.41) (15.53) (12.50) 7.) + Total heat for the steam boiler (efficiency 90%), Qba, 103kcal 3.12 3.77 3.84 3.90 4.49 4.55 (BTU) (12.39) (14.98) (15.23) (15.49) (17.83) (18.01 ) 8.) Heat for the cooling water, QW, 103 kcal (BTU) 1.63 1.49 1.76 2.04 1.64 1.95 (6.46) (5.94) (6.98) (8.10) (6.51) (7.73) Continuation of Table II cases 1 2 3 4 5 6 9.) Pump work, wP, kcal (BTU) 1.76 1.76 1.76 1.76 0.50 1.01 (7) (7) (7) (7) (2) (4) 10.) Fan work, white, kcal (BTU) 7.06 6.81 6.30 5.80 2.02 3.53 (equivalent to 76 cm (30 inches) H2O) (28) (27) (25) (23) (8) (14) Flow rate 11.) Fraction of the gas for the Kugeler 0.332 0.291 0.287 0.289 0.243 0.236 heater 12.) Fraction of the gas for the steam boiler + 0.163 0.198 0.236 0.290 0.279 0.340 13.) moles of air 0.824 0.815 0.750 0.688 0.745 0.685 14.) moles of propellant gas produced 0.354 0.358 0.286 0.211 0.287 0.212 15.) Mol propellant gas (generated by external heat) (0.468) (0.496) (0.428) (0.356) (0.454) (0.382) Product composition 16.) Propellant: CO, % 25.8 21.7 18.8 15.8 11.2 11.2 17.) Propellant gas: H2,% 74.2 78.3 81.2 84.2 88.8 88.8 18.) Mol of CO2 to be absorbed 0.196 0.198 0.187 0.171 0.216 0.194 19.) NH2S / SSO2, 107 0.712 15.9 9.03 4.76 403 202 20.) NH2S / NCOS 91 114 137 169 195 250 continuation of Table II cases 1 2 3 4 5 6 Performance parameters 21.) Higher calorific value (HHV, kcal (BTU) / 86.3 86.3 86.3 86.3 86.3 86.3 m3 (scf)) (342) (342) (342) (342) (342) (342) 22.) ++ Lower calorific value (LHV), kcal 76.5 75.9 75.3 75.0 74.8 74.4 (BTU) / m3 (scf) (303) (301) (299) (298) (297) (295) 23.) Efficiency, HHV (without external Heat),% 73.3 74.1 69.2 61.2 69.4 61.7 24.) + Efficiency, HHV (with external heat), % 80.2 92.7 79.6 75.6 81.3 77.9 25.) Efficiency, LHV (without external heat),% 64.9 65.2 60.5 53.2 60.2 53.2 26.) + Efficiency, LHV (with external heat),% 71.0 81.5 69.6 65.8 70.5 67.2 27.) +% Usable waste heat 17.3 20.2 23.1 26.8 26.0 29.9 For T + tons of coal per day 3020 kcal (12,000 BTU) / 0.454 kg (lb) multiply that excess amounts with 0.0985 T + / C + to gain the moles per minute + it can an external heat source, such as. B. solid waste can be used; (3) external heat not supplied ++ the water is not condensed in the combustion product @ @ @ @ @ @ @ @

Claims (18)

Claims lo method for the production of synthesis gas by Reaction of carbon with water vapor in a reaction vessel in which one introduces solid carbon and water vapor into the reaction vessel and the reaction vessel Adds heat in an amount necessary for the solid carbon to react with the water vapor is sufficient, thereby g e k e n n n e i c h n e t that the reaction vessel supplies superheated steam at such a temperature and in such an amount, which are sufficient to generate the entire heat of reaction for the conversion of the carbon with a part of the superheated water vapor to supply, the superheated water vapor is practically the only heat source that the carbon in the reaction vessel is supplied, and wherein the reaction vessel is substantially free of an oxygen containing gas is. 2. Process for the production of synthesis gas by converting carbon with water vapor, characterized in that the water vapor is brought to a temperature overheated, which is above the reaction temperature of the carbon with the water vapor introduces a source of solid carbon into a reactor that is superheated Introduces water vapor into the reactor in an amount that is at least 2 times, preferably corresponds to 2 to 10 times the amount required for the complete Reaction with the carbon of the carbon source is required, and with a Temperature which is sufficient to absorb the entire heat of reaction for the conversion of the carbon with a part of the superheated steam, and that one can supply the carbon brings into contact with the superheated steam for the production of synthesis gas, the reaction in the reaction vessel essentially free is carried out by an oxidizing gas. 3. The method according to claim 2, characterized in that the overheated Water vapor has a temperature that is above about 10930C (20000F). 4. The method according to claim 2 or 3, characterized in that the Superheated steam is produced by heating an inert heat transfer medium to a temperature which is at least that of the superheated water vapor formed corresponds, and that the heated, inert heat transfer medium with water or brings water vapor into contact with the formation of the superheated water vapor. 5 The method according to any one of claims 2 to 4, characterized in that that the inert heat transfer medium is heated in a heating vessel under Formation of a heated, inert heat transfer medium, the heated inert heat transfer medium introduced into an overheating container to bring it into contact with water, with the formation of superheated water vapor, and that there is a gas separation between maintains the heating tank and the superheating tank to prevent that gas from the heating vessel enters the superheating vessel, and around to prevent gas from entering the heating vessel from the overheating vessel. 6. The method according to any one of claims 2 to 5, characterized in that that one transfers heat from the product gas to water or water vapor in order to thereby to use this transferred heat to produce superheated water vapor. 7. The method according to claim 5, characterized in that the inert heat transfer medium heated by burning fuel (propellant) with oxygen to form hot combustion gases and the heat transfer medium brings into contact with these hot combustion gases. 8. The method according to claim 7, characterized in that one Part of the synthesis gas formed in the reactor is transferred to the heating vessel, to provide at least part of the fuel for combustion. 9. The method according to claim 5, characterized in that the heating container is arranged above the overheating tank and that a connection therebetween exists, on the basis of which the inert heat transfer medium under the influence of Gravity can flow from the heating vessel into the superheating vessel0 10. The method according to claim 9, characterized in that there is water or steam into the superheat container at a point near the bottom of the superheat can introduces to cause the water vapor in countercurrent to the flow of heat transfer medium flows. 11. The method according to any one of claims 2 to 10, characterized in, that about 4 to about 7 moles of superheated steam per mole are fed to the reactor Introduces carbon into the reactor. 12. The method according to any one of claims 1 to 11, characterized in that that one can see the reaction essentially in the absence of nitrogen and / or in the absence of an oxygen-containing gas. 130 Process for the production of synthesis gas by converting Carbon and water vapor in a reaction vessel that produces solid carbon and introduces water vapor into the reaction vessel and heats the reaction vessel in an amount that is necessary for the conversion of the carbon with the water vapor sufficient, characterized in that there is a considerable excess of superheated Introduces water vapor at a temperature and in an amount into the reaction vessel, which are sufficient to generate the entire heat of reaction for the conversion of the carbon with a part of the superheated water vapor to deliver the superheated water vapor practically the only heat source is that of the carbon in the reaction vessel is supplied, and wherein the reaction vessel is substantially free of an oxygen containing gas is. 14. The method according to claim 13, characterized in that the Introduces water vapor in an amount at least about 2 times stoichiometric Corresponds to the amount necessary for the reaction with the carbon in the reactor is required. 15. Process for the production of synthesis gas by converting Carbon with steam, characterized in that one steam up to a temperature which is above the reaction temperature of the carbon with the water vapor is superheated, introduces a source of solid carbon into a reactor, the superheated steam in an amount about 2 to about 10 times stoichiometric Amount equivalent to that for the complete reaction with the solid Carbon of the carbon source is required, introduces into the reactor and that for the production of synthesis gas the carbon with the superheated steam brings in contact. 16. The method according to claim 15, characterized in that the Water vapor is superheated to a temperature above about 1093 C (20000F). 17. The method according to claim 15 or 16, characterized in that the water vapor is introduced into the reactor, which is essentially free of one is oxidizing gas. 18. Process for the production of synthesis gas by converting Carbon with water vapor, characterized in that one water vapor on a Temperature that is above the reaction temperature of the carbon with the water vapor is in one of the reaction vessels that are used for converting the carbon with the water vapor being used, separate container is a source of overheating introduces solid carbon into the reaction vessel, the reaction vessel is substantially free of an oxygen-containing gas, the superheated Introduces water vapor into the reaction vessel at a reaction vessel inlet temperature above 10000C (18320F) and in an amount that is significantly greater than 1 mole Water vapor per mole of carbon of the carbon source, being the superheated water vapor is practically the only heat source that the carbon in the reaction vessel is supplied, and that the carbon is in contact with the superheated steam brings about the formation of synthesis gas, which is carried away in excess water vapor will.