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US 5,401,386 AGranted
Reforming process for producing high-purity benzene
AssigneeChevron Research and Technology Company
InventorsScott G. Morrison, Warren E. Brown
Life of this patent
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Abstract
Provided is a reforming process for producing a high purity benzene product using a non-acidic zeolitic catalyst. The high purity benzene is extracted from a light fraction of reformate that has less than 500 ppm by weight toluene. Generally, a hydrocarbon feed is reformed in a reformer under reforming conditions in the presence of a non-acidic catalyst to produce a reformate. That reformate is separated into a light fraction and a heavy fraction. The extraction unit, preferably an extractive distillation unit, is then used to separate the light fraction into an aromatic extract stream and a nonaromatic raffinate stream.
Claims52
A process for producing a stream that contains aromatics comprising:
- (a) reforming a hydrocarbon feed under reforming conditions in the presence of a non-acidic catalyst to produce a reformate, wherein the non-acidic catalyst comprises at least one Group VIII metal and a non-acidic zeolite support;
- (b) separating the reformate into a light fraction and a heavy fraction, wherein the light fraction has less than 500 ppm by weight toluene;
- (c) introducing the light fraction into an extraction unit;
- and
- (d) separating and removing an aromatic extract stream and a non-aromatic raffinate stream from the extraction unit.
2 more elements
A process for producing a stream that contains aromatics comprising:
- (a) separating a hydrocarbon feed into a light hydrocarbon feed fraction and a heavy hydrocarbon feed fraction;
- (b) reforming the light hydrocarbon feed fraction under reforming conditions in the presence of a non-acidic catalyst to produce a reformate, wherein the non-acidic catalyst comprises at least one Group VIII metal and a non-acidic zeolite support;
- (c) removing C.sub.4- hydrocarbons from the reformate to produce C.sub.5+ hydrocarbon rich reformate that contains less than 0.01 lv % C.sub.4- hydrocarbons;
- (d) separating the C.sub.5+ hydrocarbon rich reformate into a light reformate fraction and a heavy reformate fraction, wherein the light reformate fraction has less than 500 ppm by weight toluene;
- (e) introducing the light reformate fraction into an extraction unit;
- and
- (f) separating and removing an aromatic extract stream and a non-aromatic raffinate stream from the extraction unit.
4 more elements
A process for producing a stream that contains at least 99.9 lv % benzene, said process comprising:
- (a) separating the hydrocarbon feed into a light fraction, a middle hydrocarbon feed fraction, and a heavy hydrocarbon feed fraction, wherein the middle hydrocarbon feed fraction contains less than 5 lv % C.sub.5- hydrocarbons and less than 5 lv % C.sub.7+ hydrocarbons;
- (b) reforming the middle hydrocarbon feed fraction under reforming conditions in the presence of a non-acidic catalyst to produce a reformate, wherein the non-acidic catalyst comprises at least one Group VIII metal and a non-acidic zeolite support;
- (c) removing C.sub.4- hydrocarbons from the reformate to produce C.sub.5+ hydrocarbon rich reformate that contains less than 0.01 lv % C.sub.4- hydrocarbons;
- (d) separating the C.sub.8+ hydrocarbon rich reformate into a light reformate fraction and a heavy reformate fraction, wherein the light reformate fraction has less than 500 ppm by weight toluene;
- (e) introducing the light reformate fraction into an extraction unit;
- and
- (f) separating and removing an aromatic extract stream and a non-aromatic raffinate stream from the extraction unit, wherein the aromatic extract stream contains at least 99.9 lv % benzene.
4 more elements
A process for producing a stream that contains at least 99.9 lv % benzene, said process comprising:
- (a) separating a hydrocarbon feed into a light fraction, a middle hydrocarbon feed fraction, and a heavy hydrocarbon feed fraction, wherein the middle hydrocarbon feed fraction contains:
- (1) less than 5 lv % C.sub.5- hydrocarbons,
- (2) less than 5 lv % C.sub.7+ hydrocarbons, and
- (3) less than 1 lv % C.sub.8+ hydrocarbons;
- (b) reforming the middle hydrocarbon feed fraction under reforming conditions in the presence of a non-acidic catalyst to produce a first reformate, wherein the non-acidic catalyst comprises platinum and a non-acidic zeolite L support;
- (c) separating the first reformate into a light first reformate fraction, a middle first reformate fraction, and a heavy first reformate fraction, wherein the middle first reformate fraction contains:
- (1) less than 0.01 lv % C.sub.4- hydrocarbons and
- (2) less than 50 ppm by weight toluene;
- (d) reforming the heavy hydrocarbon feed fraction under reforming conditions in the presence of an acidic catalyst to produce a second reformate;
- (e) separating the second reformate into a light second reformate fraction, a middle second reformate fraction, and a heavy second reformate fraction, wherein the middle second reformate fraction contains:
- (1) less than 2 lv % C.sub.5- hydrocarbons and
- (2) less than 50 ppm by weight toluene;
- (f) introducing the middle first reformate fraction and the middle second reformate fraction into an extraction unit;
- (g) separating and removing an aromatic extract stream and a non-aromatic raffinate stream from the extraction unit, wherein the aromatic extract stream contains at least 99.9 lv % benzene;
- and
- (h) recycling the non-aromatic raffinate stream to the hydrocarbon feed.
13 more elements
A process for producing a stream that contains at least 99.95 lv % benzene, said process comprising:
- (a) separating a hydrocarbon feed into a light fraction, a middle hydrocarbon feed fraction, and a heavy hydrocarbon feed fraction, wherein the middle hydrocarbon feed fraction contains:
- (1) less than 3 lv % C.sub.5- hydrocarbons,
- (2) less than 3 lv % C.sub.7+ hydrocarbons, and
- (3) less than 0.01 lv % C.sub.8+ hydrocarbons;
- (b) reforming the middle hydrocarbon feed fraction under reforming conditions in the presence of a non-acidic catalyst to produce a first reformate, wherein the non-acidic catalyst comprises platinum and a non-acidic zeolite L support;
- (c) separating the first reformate into a light first reformate fraction, a middle first reformate fraction, and a heavy first reformate fraction, wherein the middle first reformate fraction contains:
- (1) less than 0.01 lv % C.sub.4- hydrocarbons and
- (2) less than 25 ppm by weight toluene;
- (d) reforming the heavy hydrocarbon feed fraction under reforming conditions in the presence of an acidic catalyst to produce a second reformate;
- (e) separating the second reformate into a light second reformate fraction, a middle second reformate fraction, and a heavy second reformate fraction, wherein the middle second reformate fraction contains:
- (1) less than 2 lv % C.sub.5- hydrocarbons and
- (2) less than 25 ppm by weight toluene;
- (f) introducing the middle first reformate fraction and the middle second reformate fraction into an extractive distillation unit that uses a N-formylmorpholine solvent;
- (g) separating and removing an aromatic extract stream and a non-aromatic raffinate stream from the extraction unit, wherein the aromatic extract stream contains at least 99.95 lv % benzene;
- and
- (h) recycling the non-aromatic raffinate stream to the hydrocarbon feed.
13 more elements
Dependencies are inferred from the claim text.