Staggered Heat Exchangers For Cracking Hydrocarbons

Abstract

A device for heating molten long-chained hydrocarbons comprises a first heating section having at least one first material flow tube extending from a first heating section inlet to a first heating section outlet, the first material flow tube providing a flow path for the molten long-chained hydrocarbons from the first heating section inlet to the first heating section outlet, and a first heating structure extending along at least a portion of the first material flow tube, the first heating structure being configured to transfer heat to the first material flow tube; and a second heating section having at least one second material flow tube and at least one third material flow tube, the at least one second material flow tube extending from a second heating section inlet to a second heating section outlet, the at least one third material flow tube extending from a third heating section inlet to a third heating section outlet, the second and third material flow tubes providing flow paths for the molten long-chained hydrocarbons from the second and third heating section inlets to the second and third heating section outlets, respectively, wherein the second and third heating section inlets being configured to receive the molten long-chained hydrocarbons from the first heating section outlet, and to split the flow path for the molten long-chained hydrocarbons towards the at least one second material flow tube and the at least one third material flow tube; and wherein the second heating section inlet and the third heating section inlet are arranged on different heights.

1 . A device for heating molten long-chained hydrocarbons comprising:
 a heating section ( 1 ) having at least one material flow tube ( 101 ,  101   a ) extending from a heating section inlet ( 102 ) to a heating section outlet ( 103 ), the material flow tube ( 101 ,  101   a ) providing a flow path for the molten long-chained hydrocarbons from the heating section inlet ( 102 ) to the heating section outlet ( 103 ), and a heating structure ( 111 ,  112 ,  113 ) extending along at least a portion of the material flow tube ( 101 ,  101   a ), the heating structure ( 111 ,  112 ,  113 ) being configured to transfer heat to the material flow tube; and   a disengagement volume ( 120 ,  220 ) downstream of the material flow tube ( 101 ,  101   a ) configured to allow gas bubbles of hydrocarbons in a gas phase to disengage from hydrocarbons in a liquid phase and rise such that the hydrocarbons in the liquid phase assume a lower portion of the disengagement volume ( 120 ,  220 ) and the hydrocarbons in the gas phase assume a higher portion of the disengagement volume ( 120 ,  220 ),   wherein the device is configured to maintain the hydrocarbons in the gas phase separate from the hydrocarbons in the liquid phase.   
     
     
         2 . The device according to  claim 1 , wherein the heating section ( 1 ) is a first heating section ( 1 ), the at least one material flow tube ( 101 ,  101   a ) is a first material flow tube ( 101 ,  101   a ), the heating section inlet ( 102 ) is a first heating section inlet ( 102 ), the heating section outlet ( 103 ) is a first heating section outlet ( 103 ), and the heating structure ( 111 ,  112 ,  113 ) is a first heating structure ( 111 ,  112 ,  113 ); and further comprising:
 a second heating section ( 2 ) having at least one second material flow tube ( 202 ) and at least one third material flow tube ( 203 ), the at least one second material flow tube ( 202 ) extending from a second heating section inlet ( 212 ) to a second heating section outlet ( 213 ), the at least one third material flow tube ( 203 ) extending from a third heating section inlet ( 222 ) to a third heating section outlet ( 223 ), the second and third material flow tubes ( 202 ,  203 ) providing flow paths for the molten long-chained hydrocarbons from the second and third heating section inlets ( 212 ,  222 ) to the second and third heating section outlets ( 213 ,  223 ), respectively,   wherein the second and third heating section inlets ( 212 ,  222 ) are configured to receive the molten long-chained hydrocarbons from the disengagement volume ( 120 ,  220 ), and to split the flow path for the molten long-chained hydrocarbons towards the at least one second material flow tube ( 202 ) and the at least one third material flow tube ( 203 ); and   wherein the second heating section inlet ( 212 ) and the third heating section inlet ( 222 ) are arranged on different heights.   
     
     
         3 . The device according to  claim 1 , wherein the flow paths for the molten long-chained hydrocarbons in the second and third material flow tubes merge adjacent to the second and third heating section outlets. 
     
     
         4 . The device according to  claim 1 , wherein the first heating section has at least two material flow tubes splitting the flow path for the molten long-chained hydrocarbons adjacent to the first heating section inlet and merging the flow path for the molten long-chained hydrocarbons adjacent to the first heating section outlet. 
     
     
         5 . (canceled) 
     
     
         6 . The device according to  claim 1 , wherein a top portion of the first heating section is on a level with a bottom portion of the second heating section. 
     
     
         7 . (canceled) 
     
     
         8 . The device according to  claim 1 , further comprising a connecting portion between the first heating section and the second heating section, wherein the connecting portion forms a flow path for the molten long-chained hydrocarbons from the first heating section to the second heating section, and
 wherein the device is configured to maintain the separation of the hydrocarbons in the gas phase from the long-chained hydrocarbons in the liquid phase while passing through the connecting portion.   
     
     
         9 . The device according to  claim 8 , wherein the connecting portion is configured such that the flow path extends substantially horizontally or extends at an angle of 0° to 45° to a horizontal plane, preferably at an angle of 0° to 10° to a horizontal plane, with the downstream end of the flow path being higher than the upstream end. 
     
     
         10 - 13 . (canceled) 
     
     
         14 . The device according to  claim 8 , wherein the connecting portion is arranged with an upper connecting tube and a lower connecting tube;
 the upper connecting tube being arranged to pass the hydrocarbons in the gas phase, and   the lower connecting tube being arranged to pass the long-chained hydrocarbons in the liquid phase.   
     
     
         15 . The device according to  claim 1 , further comprising at least one third heating section, each of the at least one third heating section having at least two forth material flow tubes each extending from a respective forth heating section inlet to a respective forth heating section outlet, wherein the flow path is split among the at least two forth material flow tubes adjacent to the fourth heating section inlets and merges adjacent to the fourth heating section outlets,
 wherein the first and second heating sections and each of the at least one third heating section being configured such that the material containing long-chained hydrocarbons flows consecutively through each of them,   and wherein at least one of the fourth material flow tubes preferably provides an inner cross section adapted to allow solid material at a predetermined maximum dimension to pass.   
     
     
         16 . The device according to  claim 1 , further comprising a separation structure configured for receiving the hydrocarbons in the liquid phase. 
     
     
         17 . The device according to  claim 16 , further comprising a gas release tube ( 53 ) configured for receiving the hydrocarbons in the gas phase at the disengagement volume ( 120 ,  220 ,  320 ) and for forwarding the hydrocarbons in the gas phase;
 wherein the separation structure is configured for receiving the hydrocarbons in the gas phase at an upper portion of the separation structure and for receiving the hydrocarbons in the liquid phase at a lower portion of the separation structure.   
     
     
         18 . The device according to  claim 1 , wherein at least one of the heating sections is configured such that the flow path from the heating section inlet ( 102 ) to the heating section outlet ( 103 ) extends at an angle of 0° to 45° to a horizontal plane, preferably at an angle of 0° to 10° to a horizontal plane, with the downstream end of the flow path being higher than the upstream end. 
     
     
         19 . The device according to  claim 1 , wherein at least one of the heating sections is configured such that its respective heating section inlet ( 102 ) is lower than the heating section outlet ( 103 ). 
     
     
         20 . A process for heating plastics material to pyrolysis temperature, the process comprising the steps of:
 in a first heating zone, heating a body of molten plastics containing material to provide at least a first liquid phase and at least a first gas phase, the first liquid phase and first gas phase being intermixed in the first heating zone;   allowing the first liquid phase and first gas phase to separate to provide a body of predominantly the first gas phase material and a body of predominantly the first liquid phase material;   passing the first liquid phase material, and optionally the first gas phase material, to a second heating zone having a higher temperature than the first heating zone, and heating to provide at least a second liquid phase and at least a second gas phase, the second liquid phase and second gas phase being intermixed;   allowing the second liquid phase and second gas phase to separate to provide a body of predominantly the second gas phase material and a body of predominantly the second liquid phase material;   optionally repeating the steps of heating, gas phase formation and gas phase separation one or more further times in one or more further heating zones, each subsequent heating zone increasing in temperature; and   passing an output liquid phase of the heating zones, at a pyrolysis temperature, to a pyrolysis reactor and/or distillation apparatus.   
     
     
         21 . A process according to  claim 20  wherein the first, second and subsequent heating zones are heat exchangers, preferably tube and shell heat exchangers. 
     
     
         22 - 25 . (canceled) 
     
     
         26 . A process according to  claim 20  wherein the plastics material is heated to a pyrolysis temperature from about 360 C. to about 550° C., preferably from about 390 C . to about 450 C. prior to injection into the separation vessel. 
     
     
         27 . A process according to  claim 20  wherein the subsequent heating zones are arranged in series with phase separation volumes between at least one or more of the subsequent heating zones. 
     
     
         28 - 29 . (canceled) 
     
     
         30 . A process according to  claim 20  wherein the first heating zone is fed with molten plastics containing material by an extruder. 
     
     
         31 . A process according to  claim 20  wherein the molten plastics containing material comprises polyethylene and/or polypropylene plastics, preferably wherein the sum of polyethylene and polypropylene in the feedstock is at least 50 wt. % by weight of the feedstock, more preferably at least 60 wt. %. 
     
     
         32 - 35 . (canceled) 
     
     
         36 . An apparatus for pyrolyzing waste plastics to one or more hydrocarbon products, preferably at least one or more liquid hydrocarbon products, the apparatus comprising: a device in accordance with claim and downstream thereof at least one pyrolysis zone, and at least one distillation apparatus for distilling pyrolyzed material to give a hydrocarbon product, preferably wherein the hydrocarbon product comprises butane, propane, kerosene, diesel, fuel oil; light distillates, such as LPG, gasoline, naphtha, or mixtures thereof; middle distillates such as kerosene, jet fuel, diesel, or mixtures thereof; heavy distillates and residuum such as fuel oil, lubricating oils, paraffin, wax, asphalt, or mixtures thereof; or any mixtures thereof; hydrocarbons that are saturated, unsaturated, straight, cyclic or aromatic; non-condensable gases comprising methane, ethane, ethene and/or other small molecules; and mixtures thereof.