High temperature hydropyrolysis of carbonaceous materials

Abstract

Heat from nuclear reactor as a source of thermal energy is applied to the conversion of carbonaceous materials such as heavy petroleum crude oils, coals and biomass to liquid hydrocarbons. The heat is applied to provide at least a portion of the process heat used in the high temperature, short contact time hydropyrolysis of the carbonaceous material which is supplied with hydrogen generated by a high temperature process such as high temperature steam electrolysis, the sulfur-iodine cycle, the hybrid sulfur cycle, the zinc-zinc oxide cycle, a solid oxide fuel cell or by methane steam cracking. The heat from the nuclear reactor may be used to generate electricity to operate high temperature steam electrolysis used in generation of the hydrogen. By the use of nuclear thermal energy, hydrocarbon resource utilization for process heat is eliminated along with carbon dioxide evolution associated with burning of the hydrocarbon resource to generate process heat. The substitution of zero carbon emission sources therefore offers the potential for significant carbon emission reductions in refinery operations where external process heat can be applied and effectively utilized.

1 . A process for the conversion of carbonaceous materials which comprises subjecting the carbonaceous material to hydropyrolysis at a temperature of at least 800° C. in the presence of hydrogen using heat supplied from a nuclear thermal energy source and hydrogen generated by a high temperature process supplied from a nuclear thermal energy source. 
     
     
         2 . A process according to  claim 1  in which the heat from the nuclear thermal energy source is used to generate electricity to operate a high temperature steam electrolysis process used in the generation of the hydrogen. 
     
     
         3 . A process according to  claim 1  in which the heat from the nuclear thermal energy source is used to generate hydrogen by the hybrid sulfur process, the sulfur-iodine cycle, or the zinc-zinc oxide cycle. 
     
     
         4 . A process according to  claim 1  in which the carbonaceous material comprises a solid carbonaceous material selected from lignite, sub-bituminous coal, bituminous coal, anthracite and biomass. 
     
     
         5 . A process according to  claim 1  in which the carbonaceous material comprises a liquid carbonaceous material comprising a heavy petroleum crude oil or a petroleum residual fraction. 
     
     
         6 . A process according to  claim 1  in which the hydropyrolysis is carried out in sequential steps in each of which the carbonaceous material is heated to a temperature of at least 800° C. and is then quenched and the pyrolysis products separated, each step being completed in not more than 2 seconds. 
     
     
         7 . A process according to  claim 1  in which the hydropyrolysis is carried out at a temperature of at least 800° C. with hydrogen heated to a temperature to provide heating at a rate of not less than 500° C. per second. 
     
     
         8 . A process according to  claim 1  in which the hydropyrolysis is carried out using hydrogen as a quenching agent in each step. 
     
     
         9 . A process according to  claim 1  in which the quenching is carried out to a temperature below 400° C. 
     
     
         10 . A process according to  claim 1  in which the heat from the nuclear thermal energy source is passed to a heat transfer medium circulating in a heat transfer loop passing through a core of the nuclear reactor and through a steam generator to generate steam for a high temperature steam electrolysis process used in the generation of the hydrogen. 
     
     
         11 . A hydropyrolysis unit comprising:
 a hydropyrolysis reactor having an (i) inlet for carbonaceous material to be subjected to hydropyrolysis in the reactor, (ii) an inlet for hot hydrogen, (iii) an outlet for products of hydropyrolysis;   a nuclear reactor;   means for transferring heat from the nuclear reactor to the hydropyrolysis reactor at a temperature in the range of 800 to 1500° C.;   means for generating a stream of hot hydrogen and for feeding it to the hot hydrogen inlet of the reactor.   
     
     
         12 . A hydropyrolysis unit according to  claim 11  in which the means for transferring heat from the nuclear reactor to the hydropyrolysis reactor includes a nuclear reactor coolant loop containing a heat transfer medium and comprising a heat exchanger outside the nuclear reactor for transferring heat from the heat transfer medium to the carbonaceous feed. 
     
     
         13 . A hydropyrolysis unit according to  claim 12  which includes a heat transfer loop containing a heat transfer medium for transferring heat from the nuclear reactor to a feed heater through which the carbonaceous feed passes before entering the reactor through the reactor feed inlet. 
     
     
         14 . A hydropyrolysis unit according to  claim 11  which includes a heat transfer loop containing a heat transfer medium for transferring heat from the nuclear reactor to the hydropyrolysis reactor. 
     
     
         15 . A hydropyrolysis unit according to  claim 11  which includes means for generating steam using heat from the nuclear reactor and a steam electrolysis unit for the generation of hot hydrogen using steam from the steam generator. 
     
     
         16 . A hydropyrolysis unit according to  claim 11  which includes means for transferring heat from the nuclear reactor to a hydrogen generator comprising a hybrid sulfur process unit, a sulfur-iodine cycle unit or a zinc-zinc oxide cycle unit. 
     
     
         17 . A hydropyrolysis unit according to  claim 11  which comprises:
 a hydropyrolysis reactor having an (i) inlet for carbonaceous material to be subjected to hydropyrolysis in the reactor, (ii) an inlet for hot hydrogen, (iii) an outlet for products of hydropyrolysis; 
 a nuclear reactor; 
 a heat transfer loop passing through the nuclear reactor and containing a heat exchange medium; 
 a heat exchanger in the heat transfer loop for transferring heat from the heat exchange medium in the loop to the reactor at a temperature in the range of 800 to 1500° C.; 
 a heat exchanger in the heat transfer loop for transferring heat from the heat exchange medium in the loop to a generator of hot hydrogen; 
 a conduit for hot hydrogen from the hydrogen generator to the hot hydrogen inlet of the reactor. 
 
     
     
         18 . A hydropyrolysis unit according to  claim 17  which includes (i) a heat exchanger in the heat transfer loop for transferring heat from the heat exchange medium in the loop to a steam generator to generate high temperature steam, (ii) a high temperature steam electrolysis unit as the hydrogen generator, (iii) means for transferring steam from the steam generator to the electrolysis unit. 
     
     
         19 . A hydropyrolysis unit according to  claim 17  which includes (i) a heat exchanger in the heat transfer loop for transferring heat from the heat exchange medium in the loop to a hybrid sulfur process unit or a sulfur-iodine cycle unit or a zinc-zinc oxide cycle unit as the hydrogen generator and (ii) means for transferring steam from the steam generator to the hydrogen generator. 
     
     
         20 . A hydropyrolysis unit according to  claim 17  which includes (i) a heat exchanger in the heat transfer loop for transferring heat from the heat exchange medium in the loop to a steam generator to generate high temperature steam, (ii) a steam methane reformer as the hydrogen generator, (iii) means for transferring steam from the steam generator to the methane steam reformer. 
     
     
         21 . A hydropyrolysis unit according to  claim 17  which includes (i) a heat exchanger in the heat transfer loop for transferring heat from the heat exchange medium in the loop to (ii) a solid oxide fuel cell as the hydrogen generator and having an anode product outlet connected to the hydropyrolysis reactor to supply hydrogen to the hydropyrolysis reactor. 
     
     
         22 . A hydropyrolysis unit according to  claim 21  which includes a water gas shift reactor connected to the anode product outlet of the fuel cell and which is connected to the hydropyrolysis reactor to supply hydrogen to the hydropyrolysis reactor.