Digester Gas
Scrubbing
Gas Conditioning/
Siloxane Removal
Odor Control Local Representatives Water Environment
Research Article
E-mail
Digester Gas Scrubbing      Inside this Page:   Page 1   Page 2  Page 3  Page 4

REMOVAL AND REGENERATION CHEMICAL REACTIONS


SULFIDE REMOVAL
Hydrated
ferric oxide plus
hydrogen sulfide
will produce
ferric sulfide
and water.



REGENERATION
Ferric sulfide plus oxygen and water will produce
hydrated
ferric oxide and
elemental sulfur.


SULFIDE REMOVAL PROCESS

Time-proven, the "Iron Sponge gas sweetening process" has been "sweetening sour gas" in sulfur-bearing gas fields for over fifty years. This is the most effective method of removing hydrogen sulfide from a gas stream. Digester gas passes through the permeable bed containing hydrated ferric oxide. Hydrogen sulfide reacts with ferric oxide, as demonstrated by the following equation, forming water and black, solid, ferric sulfide.

A Marcab Gas Purifier will remove all hydrogen sulfide present in gas passed through the vessel. Marcab systems are passive; requiring no operator nor any mechanical or electrical power.

 

MARCAB'S REGENERATION METHOD

Marcab's method of regeneration (U.S. Patent # 4,849,191) requires in-vessel flooding of the media, with water, and subsequent introduction of air bubbled through the flooded bed. The bubbled air starts the reaction of oxygen with the ferric sulfide while the heat of the exothermic reaction is harmlessly absorbed by the water.

After 24 hours of aqueous regeneration, the bed is drained. Airflow continues while water vapor dispels any lingering warmth. Within
24 hours the temperature of the escaping vapor reaches ambient, Marcab Regeneration is complete, and the purifier may be returned to service.

Both chemical reactions are exothermic (heat-producing). Negligible heat is generated very gradually during the sulfide removal stage, throughout the life of the media, and dissipates proportionally. Production of excessive heat during unprotected regeneration occurs in only a few hours and cannot be quickly depleted. In fact the insulating quality of the media retains the heat, accelerating the reaction, and without the protection of the Marcab Regeneration Method, may induce spontaneous combustion in the bed.

Site Designed by
Wriwebs.com