HYDROGENATION OF MULTI-BROMINATED ALKANES
Methods and systems for the hydrogenation of multi-brominated alkanes are provided herein. An embodiment of the present invention comprises a method, the method comprising: reacting at least hydrogen and multi-brominated alkanes in the presence of a catalyst to form a hydrogenated stream comprising brominated alkanes having fewer bromine substituents than the multi-brominated alkanes reacted with the hydrogen. Embodiments of the method further may comprise forming brominated alkanes. Embodiments of the method further may comprising forming product hydrocarbons from brominated alkanes.
1 . A method comprising:
reacting at least hydrogen and multi-brominated alkanes in the presence of a catalyst to form a hydrogenated stream comprising brominated alkanes having fewer bromine substituents than the multi-brominated alkanes reacted with the hydrogen.
2 . The method of claim 1 , wherein the multi-brominated alkanes comprise di-brominated methane, and wherein the brominated alkanes having fewer bromine substituents comprise mono-brominated methane.
3 . The method of claim 1 , wherein the catalyst comprises a catalyst capable of forming multiple thermally reversible complexes with bromine.
4 . The method of claim 1 , wherein the catalyst comprises a catalyst selected from the group consisting of iron oxide deposited on a support and platinum dispersed on a support.
5 . A method comprising:
forming bromination products comprising brominated alkanes from bromination reactants comprising alkanes and bromine, wherein the brominated alkanes comprise mono-brominated alkanes and multi-brominated alkanes;
forming hydrogenation products comprising additional mono-brominated alkanes from hydrogenation reactants comprising hydrogen and at least a portion of the multi-brominated alkanes formed from the bromination reactants; and
forming synthesis products comprising hydrocarbons from synthesis reactants comprising reactant mono-brominated bromines, wherein the reactant mono-brominated bromines comprise at least a portion of the mono-brominated alkanes formed from the bromination reactants and at least a portion of the additional mono-brominated alkanes formed from the hydrogenation reactants.
6 . The method of claim 5 , wherein the multi-brominated alkanes present in the brominated alkanes comprise di-brominated methane.
7 . The method of claim 5 , wherein forming the bromination products comprises reacting at least the alkanes and the bromine in the presence of a catalyst.
8 . The method of claim 5 , wherein forming the hydrogenation products comprises reacting at least the hydrogen and the portion of the multi-brominated alkanes in the presence of a catalyst.
9 . The method of claim 8 , wherein the catalyst comprises a catalyst capable of forming multiple thermally reversible complexes with bromine.
10 . The method of claim 8 , wherein the catalyst comprises a catalyst selected from the group consisting of iron oxide deposited on a support and platinum dispersed on a support.
11 . The method of claim 5 , comprising reacting at least alkanes and steam to form produced hydrogen, wherein the hydrogen present in the hydrogenation reactants comprises the produced hydrogen.
12 . The method of claim 5 , comprising electrolyzing hydrogen bromide to form produced hydrogen, wherein the hydrogen present in the hydrogenation reactants comprises the produced hydrogen.
13 . The method of claim 5 , comprising electrolyzing a metal bromide salt to form produced hydrogen, wherein the hydrogen present in the hydrogenation reactants comprises the produced hydrogen.
14 . The method of claim 5 , wherein forming the synthesis products comprises reacting at least the reactant mono-brominated alkanes in the presence of a catalyst.
15 . The method of claim 14 , wherein the catalyst comprises a synthetic crystalline aluminosilicate oxide framework.
16 . The method of claim 5 , comprising recovering a liquid product stream comprising C5+ hydrocarbons, wherein the C5+ hydrocarbons are present in the hydrocarbons formed in the step of forming synthesis products.
17 . The method of claim 5 , comprising recovering a liquid product stream comprising olefins, wherein the olefins are present in the hydrocarbons formed in the step of forming synthesis products.
18 . The method of claim 5 , comprising:
separating hydrogen bromide from at least a portion of the hydrocarbons present in the synthesis products by dissolving the hydrogen bromide in water;
neutralizing at least a portion of the hydrogen bromide to form a metal bromide salt; and
oxidizing at least a portion of the metal bromide salt to form oxidation products comprising recovered bromine; and
recycling the recovered bromine formed in the oxidizing step, wherein the recovered bromide is used in forming additional brominated alkanes.
19 . The method of claim 18 , comprising:
electrolyzing another portion of the hydrogen bromide to form electrolysis products comprising produced hydrogen and additional recovered bromine,
recycling the produced hydrogen, and
recycling the additional recovered bromine.
20 . The method of claim 18 , comprising:
electrolyzing another portion of the metal bromide salt to form electrolysis products comprising produced hydrogen and additional recovered bromine,
recycling the produced hydrogen, and
recycling the additional recovered bromine.
21 . The method of claim 5 , comprising separating hydrogen bromide from at least a portion of the hydrocarbons present in the synthesis products, the separating comprising reacting the hydrogen bromide with a metal oxide to form a metal bromide;
oxidizing the metal bromide to form oxidation products comprising the metal oxide and recovered bromine; and
recycling the recovered bromine formed in the oxidizing step, wherein the recovered bromine is used in forming additional brominated alkanes.
22 . The method of claim 21 , comprising:
prior to the step of separating the hydrogen bromide, separating the synthesis products into a first synthesis product stream and a second synthesis product stream, wherein the first synthesis product stream comprises the portion of the hydrocarbons reacted with the metal oxide;
separating additional hydrogen bromide from the hydrocarbons present in the second synthesis product stream; and
electrolyzing at least a portion of the additional hydrogen bromide to form electrolysis products comprising produced hydrogen and additional recovered bromine;
recycling the produced hydrogen; and
recycling the recovered bromine.
23 . The method of claim 21 , comprising:
prior to the step of separating the hydrogen bromide, separating the synthesis products into a first synthesis product stream and a second synthesis product stream, wherein the first synthesis product stream comprises the portion of the hydrocarbons reacted with the metal oxide;
separating additional hydrogen bromide from the hydrocarbons present in the second synthesis product stream;
neutralizing the additional hydrogen bromide to form neutralization products comprising a metal bromide salt;
electrolyzing at least a portion of the additional metal bromide salt to form electrolysis products comprising produced hydrogen and additional recovered bromine;
recycling the produced hydrogen; and
recycling the additional recovered bromine.
24 . The method of claim 5 , comprising:
introducing the synthesis products into a product recovery unit, wherein the synthesis products further comprise hydrogen bromide and unreacted methane;
removing a liquid product stream comprising product hydrocarbons from the product recovery unit;
removing a stream comprising the hydrogen bromide and the unreacted methane from the product recovery unit;
electrolyzing at least a portion of the hydrogen bromide to form electrolysis products comprising recovered bromine and produced hydrogen;
recycling the recovered bromine; and
recycling at least a portion of the produced hydrogen.
25 . The method of claim 5 , comprising: operating at least one electrolysis cell used in the electrolyzing step in an air-depolarized mode, such that the electrolysis products further comprise water.
26 . The method of claim 5 , comprising separating the bromination products into a bypass stream and a hydrogenation feed stream comprising the hydrogenation reactants.
27 . The method of claim 26 , wherein the separating step comprises cooling the bromination products.
28 . The method of claim 27 , comprising:
heating the bypass stream; and
heating the hydrogenation feed stream.
29 . A system comprising:
a bromination reactor configured to form bromination products comprising brominated alkanes from bromination reactants comprising alkanes and bromine, wherein the brominated alkanes comprise mono-brominated alkanes and multi-brominated alkanes;
a hydrogenation reactor in fluid communication with the bromination reactor and configured to form hydrogenation products comprising additional mono-brominated alkanes from hydrogenation reactants comprising hydrogen and at least a portion of the multi-brominated alkanes from the bromination reactor; and
a synthesis reactor in fluid communication with the hydrogenation reactor and configured to form synthesis products comprising hydrocarbons from synthesis reactants comprising reactant mono-brominated bromines, wherein the reactant mono-brominated bromines comprise at least a portion of the mono-brominated alkanes from the bromination reactor and at least a portion of the additional mono-brominated alkanes from the hydrogenation reactor.
30 . The method of claim 5 , wherein the alkanes are sourced from natural gas, coal-bed methane, regasified liquefied natural gas, gas derived from gas hydrates and/or chlathrates, gas derived from anerobic decomposition of organic matter or biomass, gas derived in the processing of tar sands, synthetically produced natural gas or alkanes, or mixtures of these sources.
31 . The method of claim 5 , wherein the alkanes are sourced from synthetically produced alkanes.
32 . The method of claim 5 , wherein the alkanes are sourced from synthetically produced natural gas.
33 . The method of claim 5 , wherein the alkanes are sourced from gas derived in the processing of tar sands.