High temperature heat integration method of making carbon black
A high temperature heat integration method of making carbon black. A method of making carbon black is described, including reacting a carbon black forming feedstock with hydrogen gas in a plasma reactor to produce effluent gas containing carbon black and unused hydrogen, cooling the effluent gas for further processing, and recycling the unused hydrogen back into the carbon black forming process, where the unused hydrogen gas is pre-heated in a heat exchanger to a temperature up to the reaction temperature in the reactor before being recycled into the carbon black forming process. The heat exchanger for use in such process is also described.
1 . A heat exchanger system comprising:
a heat exchanger comprising a first inlet configured to receive an effluent gas stream produced from a hydrocarbon feedstock in a plasma reactor, the effluent gas stream comprising carbon particles and hydrogen; and
a separator configured to separate at least a portion of the hydrogen from the effluent gas stream, thereby obtaining a separated hydrogen gas stream;
wherein the heat exchanger comprises a second inlet configured to receive the separated hydrogen gas stream;
wherein the heat exchanger is configured to preheat the separated hydrogen gas stream to a temperature of at least 1200° C., thereby obtaining preheated hydrogen, and comprises a high temperature stable material capable of withstanding the temperature of at least 1200° C. and incapable of withstanding an oxidant containing stream at sustained temperatures of at least 1200° C.; and
wherein the heat exchanger comprises an outlet configured to provide the preheated hydrogen to the plasma reactor.
2 . The heat exchanger system of claim 1 , wherein the heat exchanger is configured to preheat the separated hydrogen gas stream to a temperature of up to about 2500° C.
3 . The heat exchanger system of claim 1 , wherein the heat exchanger system is configured to additionally cool the effluent gas stream down to a temperature of 1000° C. or less.
4 . The heat exchanger system of claim 1 , wherein the heat exchanger system is configured to hold the separated hydrogen gas stream at a higher pressure than the effluent gas stream.
5 . The heat exchanger system of claim 1 , wherein the heat exchanger is configured such that the effluent gas stream can flow in a direction counter-current to that of the separated hydrogen gas stream.
6 . The heat exchanger system of claim 1 , wherein the heat exchanger is configured such that the effluent gas stream can flow in a direction cross-flow to that of the separated hydrogen gas stream.
7 . The heat exchanger system of claim 1 , wherein:
(i) the heat exchanger comprises a block of material capable of withstanding a temperature of at least 1200° C.,
(ii) the block of material comprises at least one first and at least one second independent fluid flow passageways therethrough, and
(iii) the at least one first passageway has a diameter larger than that of the at least one second passageway.
8 . The heat exchanger system of claim 7 , wherein the at least one first passageway has a diameter of at least 3 inches.
9 . The heat exchanger system of claim 1 , wherein the heat exchanger comprises at least one of graphite, silicon carbide, refractory metal or high temperature ceramic material.
10 . The heat exchanger system of claim 9 , wherein the heat exchanger is configured to maintain a temperature differential of no more than 300° C. between a wall comprising the at least one of graphite, silicon carbide, refractory metal or high temperature ceramic material and the effluent stream.
11 . The heat exchanger system of claim 1 , wherein an amount of the separated hydrogen gas stream introduced into the heat exchanger is in excess of that required for heating and/or cracking the hydrocarbon feedstock in the plasma reactor.
12 . The heat exchanger system of claim 1 , wherein the carbon particles of the effluent gas are produced by reacting the hydrocarbon feedstock with the preheated hydrogen in the plasma reactor.
13 . The heat exchanger system of claim 1 , wherein the separator comprises a filter.
14 . The heat exchanger system of claim 1 , wherein:
(i) the heat exchanger comprises multiple blocks,
(ii) each block of the multiple blocks comprises at least one first and at least one second independent fluid flow passageways therethrough,
(iii) at least one block of the multiple blocks is capable of withstanding a sustained temperature generated in the plasma carbon black generating process; and
(iv) the multiple blocks are configured to be integrally connected with one another such that during use:
the at least one first independent fluid flow passageway in each block is in fluid flow communication with the at least one first independent fluid flow passageway in the other blocks,
the at least one second independent fluid flow passageway in each block is in fluid flow communication with the at least one second independent fluid flow passageway in the other blocks, and
connected blocks are sealed therebetween so as to prevent any substantial loss of fluid between the individual blocks.
15 . The heat exchanger system of claim 14 , wherein the at least one first independent fluid flow passageway has a diameter larger than that of the at least one second independent fluid flow passageway.
16 . The heat exchanger system of claim 14 , wherein the sustained temperature is at least 1200° C.
17 . The heat exchanger system of claim 14 , wherein the at least one block of the multiple blocks comprises at least one of graphite, silicon carbide, refractory metal or high temperature ceramic material.
18 . The heat exchanger system of claim 14 , wherein the at least one first independent fluid flow passageway has a diameter of at least 3 inches.
19 . The heat exchanger system of claim 14 , wherein the heat exchanger is contained in an insulated shell comprising insulation material that is capable of withstanding a temperature of at least 1200° C.
20 . The heat exchanger system of claim 14 , wherein the multiple blocks are configured to be compressed together by one or more vessel expansion joints during use.