PROCESS AND APPARATUS FOR PRODUCING ETHYLENE VIA PREPARATION OF SYNGAS
A process for producing ethylene from a carbonaceous containing feedstock the process comprising the steps of a) reforming the carbonaceous containing feedstock into a first product stream comprising carbon dioxide, carbon monoxide and hydrogen; b) fermenting the first product stream with an acetogenic anaerobic bacteria to produce a second product stream comprising ethanol; c) concentrating ethanol from the second product stream into a third product stream and; d) dehydrating ethanol in the third product stream to produce ethylene.
1 - 18 . (canceled)
19 . A process for producing ethylene from a carbonaceous containing feedstock the process comprising the steps of
a) reforming the carbonaceous containing feedstock into a first product stream comprising carbon dioxide, carbon monoxide and hydrogen;
b) fermenting the first product stream with an acetogenic anaerobic bacteria to produce a second product stream comprising ethanol;
c) concentrating ethanol from the second product stream into a third product stream; and
d) dehydrating ethanol in the third product stream to produce a first, ethylene enriched, carbonaceous fraction, a second, ethylene depleted, carbonaceous fraction and water and
d1) recycling at least a part of the water, optionally after treatment, to step b) and/or to step a) and/or recycling at least a part of the second, ethylene depleted carbonaceous fraction as a feedstock to step a).
20 . A process for producing an olefin derivative the process comprising
a) reforming the carbonaceous containing feedstock into a first product stream comprising carbon dioxide, carbon monoxide and hydrogen;
b) fermenting the first product stream with an acetogenic anaerobic bacteria to produce a second product stream comprising ethanol;
c) concentrating ethanol from the second product stream into a third product stream;
d) dehydrating ethanol in the third product stream to produce a first, ethylene enriched, carbonaceous fraction, a second, ethylene depleted, carbonaceous fraction and water and
d1) recycling at least a part of the water, optionally after treatment, to step b) and/or to step a) and/or recycling at least a part of the second, ethylene depleted carbonaceous fraction as a feedstock to step a); and
e) converting the ethylene into an olefin derivative.
21 . A process as claimed in claim 19 wherein the steps a) to c) are performed within 5 km of each other.
22 . A process as claimed in claim 19 wherein steps a) to d) are performed within 5 km of each other.
23 . A process as claimed in claim 19 wherein the process produces at least 80 te/d ethylene.
24 . A process as claimed in claim 19 wherein the process produces at least 200 te/d ethylene.
25 . A process as claimed in claim 19 wherein less than 2 te methane equivalent feed stock is used per te of ethylene produced.
26 . A process as claimed in claim 20 wherein step e) comprises polymerizing ethylene to form polyethylene and/or converting ethylene to ethylene oxide and/or converting ethylene into ethylene dichloride, and/or converting ethylene into ethylbenzene.
27 . A process as claimed in claim 26 wherein the ethylene oxide is converted into ethylene glycol.
28 . A process as claimed in claim 19 wherein step d) is performed at a pressure in the range of 0.1 to 3 MN/m 2 .
29 . A process as claimed in claim 19 wherein the dehydration to ethylene step d) is performed in a plurality of reactors.
30 . A process as claimed in claim 19 wherein step d) uses a propylene refrigeration system in the recovery of the ethylene enriched carbonaceous fraction.
31 . A process as claimed in claim 19 wherein the carbonaceous feedstock is at least partially obtained by anaerobic digestion of biomass.
32 . A process as claimed in claim 19 wherein step c) comprises the step of distillation in a plurality of distillation stages arranged in parallel operating at different pressures such that distillate passing from a first distillation stage heats bottoms of a second distillation stage.
33 . A process as claimed in claim 19 wherein surplus energy in the form of steam generated in the dehydration step d) is utilized in the ethanol recovery step c).
34 . A process according to claim 20 , wherein unreacted portions of the ethylene used in the derivative process are recovered, optionally treated, and used as a co-feed to the ethylene recovery cryogenic distillation stage of the ethanol dehydration step c).
35 . A process for the production of ethanol according to claim 19 wherein the ethanol producing step b) is performed in a plurality of biochemical reactors.
36 . A process for the production of ethanol according to claim 19 wherein the carbonaceous feedstock reforming step a) comprises one or more, similar or different reforming reactors.
37 . Apparatus for producing ethylene comprising
i) a reformer for reforming a carbonaceous feedstock into a first product stream comprising carbon dioxide, carbon monoxide and hydrogen;
ii) a fermenter for fermenting the first product stream into a second product stream comprising ethanol;
iii) means for concentrating ethanol from the second product stream;
iv) a dehydrator for dehydrating the ethanol to a first, ethylene enriched, carbonaceous fraction, a second, ethylene depleted, carbonaceous fraction and water;
and either or both
v) means for recycling at least a portion of the second, ethylene depleted, carbonaceous fraction to the reformer and
vi) means for recycling at least a portion of the water to the fermenter and/or reformer.
38 . Apparatus as claimed in claim 37 further comprising vii) means for treating water recycled to the fermenter and/or reformer.