Method for inerting activated carbon in biogas purification equipment
Various embodiments of the present invention are directed to methods of preparing a biogas purification system. Embodiments include flushing an adsorber with a gas stream that is separable by the downstream biogas purification process. Other embodiments include using the separable gas stream to flush a saturated adsorber. Additional embodiments include using a gas stream comprised of CO 2 .
1. A method for purifying a raw biogas, the method comprising:
providing an adsorber unit containing a sorbent material;
contacting the sorbent material contained within the adsorber unit with the raw biogas to adsorb organic impurities and/or H 2 S and thereby form an effluent and a saturated sorbent material, wherein the raw biogas comprises (i) 25-38 vol.% CO 2 , (ii) methane, and (iii) organic impurities and/or H 2 S;
separating CO 2 from the effluent, the separated CO 2 forming a flushing gas;
flushing the saturated sorbent material with the flushing gas to produce a flushed sorbent;
contacting the flushed sorbent with the raw biogas; and
producing a purified biogas from the effluent.
2. The process of claim 1 , wherein the sorbent material is selected from the group consisting of carbonaceous char, activated carbon, reactivated carbon, carbon black, graphite, zeolite, silica, silica gel, alumina clay, metal oxides, and a combination thereof.
3. The process of claim 1 , wherein the sorbent material is selected from the group consisting of catalytic adsorbent material, oxidized catalytic adsorbent material, calcined catalytic adsorbent material, oxidized calcined catalytic adsorbent material, and combinations thereof.
4. The method of claim 1 , wherein the purified biogas is biomethane.