Adsorbent bed with increased hydrothermal stability

A method of removing methanol and water from a gas feed stream during an adsorption step of an adsorption cycle, wherein the gas feed stream comprises methanol and water, the method comprising:

• directing the gas feed stream having an initial methanol mole fraction and an initial water mole fraction toward an adsorbent bed of an adsorber unit, the adsorbent bed comprising:
• a first adsorbent layer comprising an adsorbent to at least partially adsorb methanol and water from the gas feed stream, wherein the adsorbent comprises one or more of an amorphous silica adsorbent, an amorphous silica-alumina adsorbent, or a high-silica zeolite adsorbent;
• and
• one or more additional adsorbent layers downstream from the first adsorbent layer to adsorb additional methanol and/or water from the gas feed stream, wherein the one or more additional adsorbent layers comprise zeolite 3A, zeolite 5A, or a combination thereof,
• wherein the gas feed stream has a reduced methanol mole fraction when the gas feed stream reaches the one or more additional adsorbent layers that is maintained for at least 90% of the duration of the adsorption step, wherein the reduced methanol mole fraction is less than or equal to about 90% of the initial methanol mole fraction, and wherein a methanol mole fraction of the gas feed stream is from about 500 ppm to about 0.1 ppm when the gas feed stream leaves the adsorber unit.

A thermal swing adsorption system comprising:

• an adsorber unit comprising an adsorbent bed, the adsorbent bed comprising:
• a first adsorbent layer comprising an adsorbent to at least partially adsorb methanol and water from a gas feed stream, wherein the adsorbent comprises one or more of an amorphous silica adsorbent, an amorphous silica-alumina adsorbent, or a high-silica zeolite adsorbent;
• and
• a second adsorbent layer downstream from the first adsorbent layer to adsorb additional methanol and/or water from the gas feed stream, wherein the second adsorbent layer comprises a zeolite, alumina, or a mixture thereof,
• wherein the adsorbent bed is configured such that, during an adsorption step of an adsorption cycle, contact of the gas feed stream with the first adsorbent layer results in a reduced methanol mole fraction that is maintained for at least 90% of the duration of the adsorption step, and wherein the reduced methanol mole fraction is less than or equal to about 90% of an initial methanol mole fraction of the gas feed stream.