Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
192 words
A process for making C 2 to C 4 -olefins from gas mixtures containing methanol, dimethylether and optionally steam in the presence of catalysts at temperatures of 250° to 500° C. under pressure of 0.1 to 6 bars, unreacted feed material being recycled, which comprises: evaporating a mixture containing methanol and water in a ratio by volume of 1:(0 up to 2) and reacting it in a reaction zone having the catalyst placed therein; partially condensing the reaction gases by cooling them and separating them, in a separating zone, into three phases; removing the oil phase consisting of higher aliphatic and aromatic hydrocarbons and water-scrubbing the remaining aqueous phase and gas phase in a scrubbing zone under pressures of 1 to 40 bars; removing overhead a gaseous hydrocarbon mixture containing predominantly C 2 to C 4 -olefins and separating it into its components; removing, from the base portion of the scrubbing zone, an aqueous phase containing unreacted methanol and intermediarily formed dimethylether; distilling off therefrom in a stripping zone, the methanol and dimethylether and recycling them into the reaction zone; and removing the water from the base portion of the stripping zone.
Claim 2
Dependent Claim
192 words
A process for making C 2 to C 4 -olefins from gas mixtures containing methanol, dimethylether and optionally steam in the presence of catalysts at temperatures of 250° to 500° C. under pressure of 0.1 to 6 bars, unreacted feed material being recycled, which comprises: evaporating a mixture containing methanol and water in a ratio by volume of 1:(0 up to 2) and reacting it in a reaction zone having the catalyst placed therein; partially condensing the reaction gases by cooling them and separating them, in a separating zone, into three phases; removing the oil phase consisting of higher aliphatic and aromatic hydrocarbons and water-scrubbing the remaining aqueous phase and gas phase in a scrubbing zone under pressures of 1 to 40 bars; removing overhead a gaseous hydrocarbon mixture containing predominantly C 2 to C 4 -olefins and separating it into its components; removing, from the base portion of the scrubbing zone, an aqueous phase containing unreacted methanol and intermediarily formed dimethylether; distilling off therefrom in a stripping zone, the methanol and dimethylether and recycling them into the reaction zone; and removing the water from the base portion of the stripping zone.
Claim 3
Dependent Claim
49 words
A process as claimed in claim 1, wherein the catalyst contains a H ZSM-5 type zeolite and the reaction is carried out under pressures of 0.1 to 3 bars and at temperatures increasing from 280° to 360° C., the temperature being increased consistently with the gradually decreasing catalyst activity.
Claim 4
Dependent Claim
32 words
A process as claimed in claim 1, wherein the reaction temperature is controlled so as to ensure the conversion of an at most 80% proportion of methanol to hydrocarbons, during each passage.
Claim 5
Dependent Claim
28 words
A process as claimed in claim 1, wherein the scrubbing zone comprises an upper absorption zone, a lower expelling zone and an oil separating zone for condensing hydrocarbons.
Claim 6
Dependent Claim
29 words
A process as claimed in claim 1, wherein 1 liter scrubbing water is used in the scrubbing zone per 3 to 200 normal liters gaseous hydrocarbon mixture removed overhead.
Claim 7
Dependent Claim
35 words
A process as claimed in claim 1, wherein the temperature in the base portion of the scrubbing zone is by 5° to 40° C. higher than the temperature in the head portion of said zone.
Claim 8
Dependent Claim
30 words
A process as claimed in claim 1, wherein a portion of the scrubbing solution removed from the base of the scrubbing zone is evaporated and recycled into the reaction zone.
Claim 9
Dependent Claim
19 words
A process as claimed in claim 1, wherein the stripping zone is operated at the boiling temperature of water.
Claim 10
Dependent Claim
46 words
A process as claimed in claim 1, wherein a quantity of water which corresponds at least to the reaction water formed during each passage is removed from the system, the said quantity being taken from the water removed from the base portion of the stripping zone.
Claim 11
Dependent Claim
32 words
A process as claimed in claim 1, wherein a portion of the water removed from the base of the stripping zone is cooled and recycled to the head of the scrubbing zone.
Claim 12
Dependent Claim
32 words
A process as claimed in claim 1, wherein a portion of the water removed from the base of the stripping zone is recycled to the reaction zone for diluting the methanol therein.