The invention discloses a process and system for the flow gasification of solid fuel for energy production, in particular bituminous coal, brown coal or biomass, which comply with the requirements in the field of power industry in terms of energy efficiency above 90%, and thus result in a lower production cost of power and heat.

The traditional processes for thermal coal gasification have efficiency of the coal gasification process which is insufficient for energy industry, and the efficiency when oxygen (O2) is used as the gasification medium is between 70% and 80%, and it is about 50% when air is used as the gasification medium.

The flow gasification process of fine coal has a higher gasification efficiency level of above 50%, and it is performed in a high-temperature jet reactor in which the gasification reaction occurs between solid coal particles and surrounding gases in a gasification mixture, such as air or oxygen (O2) , in conditions of multiple vortexing which ensures intensive mixing of gases in the gasification mixture and coal particles. As the gasification mixture which comprises oxygen (O2) or air is fed directly to the jet reactor simultaneously with the coal fuel in the form of dust, the released volatile parts of the fuel are oxidised first, while the solid particles formed when the fuel is not gasified are oxidised subsequently only; therefore, the heat energy necessary to conduct the endothermic gasification reaction is formed not in the combustion process of coke residues but in the coal dust combustion process, which generates losses and reduces the energy efficiency of the gasification process.

In addition, the known flow gasification processes of solid fuels for energy production occur in high temperature conditions above 1200°C and under high pressure above 1 MPa, which requires materials with high mechanical and thermal strength and a special design of the gasification reactor, for example with a side wall cooling system. For example a system developed by Mitsubishi Heavy

Industries (MHI) from Japan is known in which two processes are conducted in separate zones in a high- temperature jet reactor for coal dust gasification: a coal dust combustion process in a high-temperature zone at a temperature of 1800°C and a coal dust gasification process in a lower temperature zone at 1100°C using air as the gasification medium under pressure of about 1 MPa. Although the gasification and combustion zones are separated, combustion gases for energy production as the heat carrier for the endothermic gasification reaction form as a result of combustion of coal dust rather than coke residues; in consequence, losses occur in the coal dust fed to the gasification reaction, which ultimately leads in gasification efficiency at a level of 65%. In addition, the jet reactor for coal dust gasification produced by EAGLE from Japan, whose application is known, has two separate zones with temperatures differing by about 500°C: a bottom zone with a temperature of 1700°C in which coal combustion in oxygen atmosphere occurs and a top zone with a lower temperature of 1200°C in which the gasification reaction using combustion gases as an energy source formed in the bottom zone occurs with a small contribution of oxygen (O2) of 20%. The gasification process occurs at a pressure of 2.5 MPa. The use of combustion gases for energy production as a component of the gasification mixture together with oxygen (O2) , reduces the previous consumption of oxygen as the gasification mixture; however, the production process of combustion gases as an energy source occurs at the expense of consumption of the coal dust which feeds the jet reactor in the gasification process and, therefore, energy efficiency of up to 76% may be obtained, which is lower than the energy efficiency needed in energy industry of 95% to 98%.

The objective of this invention is to eliminate the energy losses found in the process of flow gasification of solid fuel for energy production, in particular coal fuel, because they reduce process efficiency, and to develop a process and system for the flow gasification of solid fuel for energy production, in particular coal, as they ensure the energy efficiency level of the gasification process required in energy industry of 95% to 98%.

The essence of the process for the flow gasification of solid fuel for energy production, in particular bituminous coal, brown coal or biomass, based on the flow gasification of fine solid fuel in a jet reactor, which uses steam as the gasification medium, combustion gases for energy production, of the invention is in that combustion gases for energy production, the main component of the gasification mixture, are produced by combustion of the residue from low-temperature flow gasification of solid fuel for energy production, preferably coke residue, in a cyclone burner located outside the low-temperature jet reactor; subsequently, the combustion gases for energy production formed in the cyclone burner with a temperature of 1500°C-1700°C are transported via the main duct for combustion gases for energy production after continuous temperature measurement using the first thermocouple, transmitted to the first analogue input of the computer control system to the bottom inlet into the low-temperature jet reactor.

Simultaneously, a fine mixture, preferably in the form of dust, of fuel with combustion gases at a temperature of 150°-160°C with steam (H2O) from the drying of solid fuel for energy production, preferably coal, is fed to the bottom inlet of the low-temperature jet reactor through a fuel duct from an energy mill, and the energy mill fed with solid fuel, preferably coal, with a humidity of 5% to 20% through a transport feeder, preferably belt feeder, equipped with an automatic feeder controlled by the signal from the first output of the computer control system is fed with combustion gases for energy production with a temperature of 1500°C to 1700°C transported through the main duct and an additional duct for the transport of combustion gases for energy production from the cyclone burner; subsequently, as a result of the low-temperature flow gasification of solid fuel comminuted to the form of dust, preferably coal, in the stream of the gasification mixture which comprises up to 90% of combustion gases for energy production and up to 10% of steam (H2O) , wherein the process occurs under pressure of about 10 kPa and at a temperature of 850°C-950°C measured using a second thermocouple and transmitted to the second analogue input of the computer control system, air gas is obtained at the outlet from the low-temperature jet reactor with chemical composition which preferably comprises 50%-55% of nitrogen (N2) , 25%-28% of carbon monoxide (CO), 10%-12% of hydrogen (H ₂ ) , 3.5%-4.5% of carbon dioxide (CO2) , 4%-6% of steam (H ₂ 0) with the non- gasified residue from the low-temperature flow gasification of solid fuel, preferably with a coke residue, which is fed via the end duct into the inlet to n dust removal cyclones in cascade system, preferably two dust removal cyclones, in which following dust removal from the coke residue, the air gas after dust removal is transported to the external outlet via the main duct at a pressure of 90 kPa to 110 kPa recorded by a pressure transducer transmitted to the third analogue input of the computer control system, and the coke residue after dust removal is fed through the outlet from the cascade of n dust removal cyclones, preferably two dust removal cyclones, to the hopper tank whose filling level with the coke residue is recorded by a filling level sensor which generates signal to the fourth analogue input of the computer control system; subsequently, through a sluice located under the hopper tank controlled by signal from the second outlet of the computer control system, the coke residue is fed to the cyclone burner fed with air at a temperature of 450°C to 550°C at a pressure of 8 kPa to 12 kPa fed through the air transport duct from the heat exchanger fed with air gas after dust removal transported via the main duct, wherein a fan connected to the heat exchanger is controlled by signal from the third outlet of the computer control system. The air supply level to the cyclone burner is in turn recorded by the oxygen level sensor and transmitted to the fifth analogue input of the computer control system, and after combustion of the coke residue in excess air atmosphere in a range of 5% by volume in the cyclone burner the combustion gases for energy production from the cyclone burner are fed to the main duct for the transport of combustion gases for energy production, and the waste product is discharged outside through the end outlet of the cyclone burner.

The essence of the system for the flow gasification of solid fuel for energy production, in particular bituminous coal, brown coal or biomass comprising the jet gasification reactor, ducts which feed the gaseous gasification medium, ducts which feed the solid fuel for energy production in the dust form of the invention is in that the bottom inlet to the low-temperature jet reactor is connected with the main duct for the transport of combustion gases for energy production with the cyclone burner located outside the low-temperature jet reactor, and the main duct for the transport of combustion gases for energy production is equipped with the first thermocouple with the first analogue input of the computer control system. In addition, the bottom inlet to the low-temperature jet reactor is connected with the outlet of the fuel duct for the transport of fuel-combustion gas mixture whose inlet is connected to the outlet of the energy mill which comminutes the solid fuel for energy production, preferably coal, and the inlet of the energy mill is connected with the transport feeder of the solid fuel for energy production equipped with an automatic feeder of the solid fuel for energy production, preferably coal, whose control elements are connected with the first output of the computer control system; in addition, the energy mill is connected to an additional duct for the transport of combustion gases for energy production connected through the main duct for the transport of combustion gases for energy production with the cyclone burner, and the low- temperature jet gasification reactor is fitted at the outlet with the second thermocouple connected to the second analogue input of the computer control system, and the outlet of the low-temperature jet reactor which discharges air gas with chemical composition preferably comprising 50%-55% of nitrogen (N2) , 25%-28% of carbon monoxide (CO), 10%-12% of hydrogen (H ₂ ) , 3.5%-4.5% of carbon dioxide (CO2) , 4%-6% of steam (H2O) with the non- gasified residue from the low-temperature flow gasification of solid fuel, preferably with a coke residue, is connected through the end duct with the inlet of the cascade of n dust removal cyclones, preferably two dust removal cyclones. In addition, the outlet of the dust removal cyclones which discharges solid components of air gas after dust removal preferably in the form of a coke residue is connected with the hopper tank equipped with a filling level sensor for the hopper tank with the coke residue, connected to the fourth analogue input of the computer control system, and the bottom part of the hopper tank is connected through a sluice with the inlet of the cyclone burner, and the sluice opening control element is connected with the second output of the computer control system. The outlet which discharges the air gas after dust removal from the cascade of n dust removal cyclones, preferably two dust removal cyclones, is in turn connected with the main duct which transports air gas after dust removal with chemical composition preferably comprising 50%-55% of nitrogen (N ₂ ) , 25%-28% of carbon monoxide (CO) , 10%-12% of hydrogen (¾) , 3.5%-4.5% of carbon dioxide (CO2) and 4%-6% of steam (H2O) , equipped with an outlet which discharges the air gas outside and with a pressure transducer connected with the third analogue input of the computer control system and also with a heat exchanger connected to a fan which is connected with the third outlet of the computer control system, and the heat exchanger is connected through the air supply duct with the cyclone burner equipped with the oxygen level sensor connected with the fifth analogue input of the computer control system and with the outlet which discharges the waste product outside. The separation of the process for the flow gasification of coal fuel used in the invention, which occurs in the low-temperature jet reactor, from the process for the production of combustion gases for energy production, which occurs in the cyclone burner according to the invention outside the low-temperature jet reactor, and also the fact that the process for the production of combustion gases for energy production is based on the combustion of the coke residue from the gasification process rather than at the expense of the combustion of coal fuel fed to the jet reactor as before provides a considerable increase in the energy efficiency of the coal fuel gasification process to 95%- 98%.

The invention is illustrated by an embodiment in a figure which shows the block conceptual diagram of the system for the flow gasification of bituminous coal.

As shown in the figure, the system for the flow gasification of bituminous coal, for example, has a low- temperature jet reactor RG whose bottom inlet WL is connected with the outlet of the main duct Ks for the transport of combustion gases for energy production connected with the cyclone burner PC, which according to the invention is located outside the low-temperature jet reactor RG. The main channel Ks for the transport of hot combustion gases for energy production at a temperature of 1500°C to 1700°C formed in the cyclone burner PC is equipped with a thermocouple T Pi for the continuous measurement of temperature of combustion gases for energy production connected with the analogue input WE i of the computer control system KUS . In addition, the bottom inlet WL of the low-temperature jet reactor RG is connected via the fuel duct KSP with the outlet of the energy mill M which comminutes bituminous coal into coal dust. The energy mill M is equipped with the coal feeder PTW, for example a belt conveyor, with an automatic feeder D which dispenses the fed volume of bituminous coal whose feeder automation element is connected with the outlet WYi of the computer control system KUS . The energy mill M which comminutes bituminous coal into coal dust with a grain size of 10-100 μπι, for example, is furthermore connected with the additional duct KD for the transport of combustion gases for energy production which is a branch of the main duct Ks for the transport of combustion gases with the cyclone burner PC. The outlet of the reactor RG through which the product of low-temperature flow gasification is discharged in the form of air gas with chemical composition comprising 50%-55%, 52% for example, of nitrogen (N ₂ ) , 25-28%, 27% for example, of carbon oxide (CO) , 10%-12%, 11% for example, of hydrogen (¾) , 3.5%-4.5%, 4% for example, of carbon dioxide ( CO2 ) , 4%-6%, 5% for example, of steam ( H2O ) with the coke residue of the bituminous coal gasification process in the low-temperature jet reactor RG is connected through the end duct Κκ equipped with the thermocouple T P2 with the inlet of the cascade of dust removal cyclones Ci , C2 . The thermocouple T P2 which measures the temperature of the low-temperature flow gasification process in the low-temperature jet reactor RG is connected with the analogue input WE2 of the computer control system KUS . Directly under the outlet of the cyclone cascade Ci , C2 which discharges the coke residue formed in the dust removal process is the hopper tank _ZK equipped with a filling level sensor CW for the hopper tank ZK with the coke residue, connected with the analogue input WE4 of the computer control system KUS . The outlet of the hopper tank ZK is connected according the invention through the sluice S_ whose on/off element is connected with the outlet WY2 of the computer control system KUS with the inlet of the cyclone burner PC. In addition, the outlet of the cyclone cascade Ci , C2 which discharges air gas after dust removal is connected via the main duct KG equipped with a pressure transducer PAC with the analogue input WE3 of the computer control system KUS and external outlet WYZ for the discharge of the air gas and heat exchanger WC with the fan W, wherein the fan W is connected with the outlet WY3 of the computer control system KUS . In addition, according to the invention, the heat exchanger WC is connected through the air supply duct Kp with the cyclone burner PC equipped with the oxygen level sensor CT connected with the analogue input WE5 of the computer control system KUS .

The process for the flow gasification of solid fuel, bituminous coal, for example, of the invention consists in that combustion gases for energy production are produced through the combustion of residue from the gasification process of bituminous coal in the low- temperature jet reactor RG in the cyclone burner PC fitted outside the low-temperature jet reactor RG. The combustion gases at a temperature of 1500°C to 1700°C, 1600°C, for example, formed in the cyclone burner PC are transported through the main duct Ks for the transport of combustion gases after continuous measurement of temperature using the thermocouple TPi, wherein the results of continuous temperature measurement are supplied to the analogue input WEi of the computer control system KUS . The combustion gases for energy production are fed to the bottom inlet WL of the low- temperature jet reactor RG simultaneously with the fuel and combustion gas mixture at a temperature in the range of 150°C to 160°C, 150°C for example, fed via the fuel duct KSP together with steam (H2O) formed by the drying of bituminous coal with a humidity of from 5% to 20%, 10% for example, fed to the energy mill M which is supplied to the energy mill M via the coal feeder PTW, for example a belt feeder equipped with an automatic coal feeder D controlled by signal from the outlet WYi of the computer control system KUS . In addition in the process of coal comminutment into coal dust, the energy mill M is fed by hot combustion gases for energy production at a temperature of 1500°C to 1700°C, 1600°C for example, fed directly through the main duct Ks and the additional duct KD for the transport of combustion gases for energy production from the cyclone burner PC. As a result of the gasification reaction of fine bituminous coal, coal dust for example, in the stream of the gasification mixture which comprises 90% of combustion gases for energy production and 10% of steam (H2O) which occurs at a pressure of 90-110 kPa, 100 kPa for example, and a temperature of 900°C recorded by thermocouple TP2, air gas is obtained with chemical composition comprising 50%-55%, 52% for example, of nitrogen (N2) , 25-28%, 27% for example, of carbon oxide (CO), 10%-12%, 11% for example, of hydrogen (H ₂ ) , 3.5%- 4.5%, 4% for example, of carbon dioxide (CO2) , 4%-6%, 5% for example, of steam (H2O) with the coke residue. According to the invention, the air gas contaminated with the coke residue is fed via the end duct Κκ into the inlet to n dust removal cyclones Ci, C2 in a cascade system in which following dust removal from the coke residue, the air gas after dust removal is transported via the main duct KG at a pressure of 90-110 kPa to the outlet WYZ which discharges of the air gas outside. The pressure values of the air gas in the main duct KG are recorded by the pressure transducer PAC and transmitted to the analogue input WE3 of the computer control system KUS . The coke residue obtained at the outlet of the cascade of for example two dust removal cyclones Ci, C2 is in turn fed to the hopper tank ZK whose filling level is recorded by a filling level sensor CW which generates signal to the analogue input WE4 of the computer control system KUS . Simultaneously, the sluice S _^ located under the hopper tank KZ_ with the coke residue and controlled by signal from the outlet WY2 of the computer control system KUS ensures that the coke residue is fed to the cyclone burner PC fed with air at a temperature of 450°C- 550°C, 500°C for example, at a pressure of 12 kPa, which is fed through the air supply duct Kp from the heat exchanger WC connected into the main duct KG which transports the air gas to the external outlet WYZ . The fan W connected with the heat exchanger WC is controlled by signal from the outlet WY3 of the computer control system KUS . According to the invention, the feeding level of air to the cyclone burner PC is recorded by the oxygen level sensor CT which transmits the signal to the analogue input WE5 of the computer control system KUS . The oxygen level sensor CT_ which monitors the mode of operation of the cyclone burner PC which operates in the combustion mode with a low 5% excess of air prevents the cyclone burner PC from entering the mode of incomplete combustion of the coke residue. After combustion of the coke residue in excess air in a range of 5% by volume, the combustion gases for energy production from the cyclone burner PC are fed to the main duct Ks for the transport of combustion gases for energy production through which, within the further stage of the gasification process of the invention, they are fed to the bottom inlet WL of the low-temperature jet reactor RG. Simultaneously, 100% of slag is discharged outside through the end outlet for waste discharge WO from the cyclone burner PC. When the demand for the air gas transported through the main duct KG increases, pressure in the main duct KG decreases, measured by the pressure transducer PAC which generates signal to the analogue input WE3 of the computer control system KUS ; as a consequence signal is sent from the outlet WYi of the computer control system KUS to the control system for the coal dispenser D at the inlet of the energy mill M which increases the rotational speed and ensures an increased volume of coal being fed. The increased volume of coal fed to the low-temperature jet reactor RG as a result of endothermic reactions results in a decrease in coal gasification temperature below the optimal range of 900°C recorded by the thermocouple TP2. By increasing the signal value at the outlet WY2 which controls the sluice S_, the computer control system KUS increases the output of the coke residue burnt in the cyclone burner PC. Simultaneously, the speed of the fan W connected with the heat exchanger WC is increased by signal from the outlet WY3 of the computer control system KUS to a level which ensures excess of oxygen at a level of 5% by volume in the air fed through the air supply duct Kp to the cyclone burner PC. As a consequence, the temperature of combustion gases for energy production from the cyclone burner PC measured by the thermocouple TPi in the main duct Ks is increased, which restores the temperature of the low-temperature jet reactor RG to the optimal temperature range for coal gasification of 900°C. As a result, the increase in the mass flux of coal fed to the low-temperature jet reactor RG and air to the cyclone burner PC leads to an increase in the air gas output at the external outlet WYZ of the main duct KG for the transport of air gas, which in turn results in the stabilisation of pressure in the main duct KG as measured by the transducer PAC . When the level of the coke residue in the hopper tank _ZK which is monitored by the level sensor CW decreases below a safe value, the computer control system KUS reduces the gasification temperature in the low-temperature jet reactor RG below the optimal temperature range for coal gasification of 900°C. As a result of reduced gasification temperature, the amount of non-gasified coke residue is increased at the expense of the volume of air gas transported via the main duct KG and, in consequence, the hopper tank _ZK is supplemented with the coke residue.

The temperature of combustion gases for energy production measured by the thermocouple TPi in the main duct Ks has both an upper limit which prevents the cyclone burner PC and main duct KG and additional duct KD for the transport of combustion gases for energy production from being damaged and a lower limit which signals that the combustion process in the cyclone burner PC has stopped; as result, the computer control system KUS is programmed to launch a sequence for the emergency gasification reactor RG .

The process and system for the low-temperature flow gasification of coal fuel of the invention provides efficiency measured by the flux level of the air gas of 3.5 to 4 nm ³ /kg. An advantage of the process and system for the flow gasification of coal of the invention is that the temperature of the gasification process in the low- temperature jet reactor RG is reduced to 850°C to 950°C at a pressure of 8 kPa to 10 kPa, which leads to a lower construction cost of the low-temperature reactor because the side wall cooling system is eliminated and less expensive materials can be used; in addition, the invention enables reduction of normal operating costs of the low-temperature coal flow gasification process, simultaneously with a higher level of safety at work ensured .