| CPC C01B 3/52 (2013.01) [B01D 53/047 (2013.01); B01D 53/265 (2013.01); C07C 31/04 (2013.01); B01D 2257/504 (2013.01); C01B 2203/0216 (2013.01); C01B 2203/0283 (2013.01); C01B 2203/0475 (2013.01)] | 26 Claims |
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1. A low-CO2 emission methanol process, comprising the steps of:
a) mixing a hydrocarbon feed stock with water to form a mixed feed stream;
b) reforming the mixed feed stream in a reforming furnace comprising a radiant section and a convection section to form a syngas stream;
c) supplying air and a carbon-lean fuel stream comprising hydrogen to fire the radiant section;
d) passing flue gas from the radiant section to the convection section;
e) cooling the flue gas in the convection section and optionally removing particulates from the flue gas;
f) discharging the cooled flue gas, wherein the flue gas is lean in CO2;
g) cooling the syngas stream;
h) passing the cooled syngas stream directly to an absorber-stripper unit to produce a CO2 rich stream and a CO2-lean syngas stream;
i) compressing and passing the CO2-lean syngas stream to a methanol reactor loop to produce a methanol-rich stream, wherein the methanol reactor loop comprises a methanol synthesis reactor, a methanol recovery section to recover a crude methanol stream and a recycle syngas stream, and a recycle compressor to compress the recycle syngas stream to a pressure of the reactor, wherein the pressure of the reactor is higher than a pressure of the mixed feed stream in step (b);
j) processing the crude methanol stream in a methanol wash unit to recover a methanol product, a condensate stream, and a fusel oil stream;
k) supplying a purge stream from the methanol reactor loop to a pressure swing adsorption unit to obtain a hydrogen-rich stream and a hydrogen-lean tail gas stream;
l) supplying the hydrogen-rich stream to the carbon-lean fuel stream in step (c);
m) supplying at least a portion of the tail gas stream from step (k) to the hydrocarbon feed stock in step (a);
n) purging a remaining portion of the tail gas stream from step (l) to the carbon-lean fuel stream in step (c).
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22. A low-CO2 emission methanol production apparatus, comprising:
a mixing station to mix a hydrocarbon feed stock with water and form a mixed feed stream;
a reformer in a reforming furnace comprising a radiant section and a convection section to reform the mixed feed stream and form a syngas stream;
an air intake and a carbon-lean fuel stream to fire one or more burners in the radiant section;
a flue to pass flue gas from the radiant section and through the convection section;
one or more convection section heat exchangers to cool the flue gas in the convection section;
an optional particulate removal unit in the convection section to remove particulates from the flue gas;
a stack to discharge the cooled flue gas from the convection section, wherein the cooled flue gas is lean in CO2;
one or more process heat exchangers to cool the syngas stream;
an absorber-stripper unit to directly receive the cooled syngas stream and produce a CO2 rich stream and a CO2-lean syngas stream;
a compressor to recirculate the CO2-lean syngas stream in a methanol reactor loop at a higher pressure than the reformer and produce a methanol-rich stream;
a methanol wash unit to recover a methanol product, a condensate stream, and a fusel oil stream from the methanol-rich stream;
a pressure swing adsorption unit to receive a purge stream from the methanol reactor loop to produce a hydrogen-rich stream and a hydrogen-lean tail gas stream;
a line to supply the hydrogen-rich stream from the pressure swing adsorption unit to the one or more burners;
a line to supply at least a portion of the tail gas stream to the hydrocarbon feed stock; and
a line for purging a remaining portion of the tail gas stream to the carbon-lean fuel stream.
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