title: Regenerable adsorbent for removing ammonia evolved from anaerobic reaction of animal urine.
abstract: The waste gas evolved from biodegradation of animal urine contains ammonia causing environmental concerns. A new and effective method for removing ammonia from such waste gas using reactive adsorption is presented. In the process, activated carbon impregnated with H2SO4(H2SO4/C) is employed. Ammonia in the waste gas reacts with H2SO4 on the adsorbent instantaneously and completely to form (NH4)2SO4. The H2SO4/C adsorbent is high in NH3 adsorption capacity and regenerable. The NH3 removal capacity of this regenerable adsorbent is more than 30 times that of the adsorbents used normally in the industry. The spent H2SO4/C is regenerated by flowing low-pressure steam through the adsorbent bed to remove the (NH4)2SO4 from the adsorbent. The regeneration by-product is concentrated (NH4)2SO4 solution, which is a perfect liquid fertilizer for local use. Re-soaking the activated carbon with H2SO4 solution rejuvenates the activity of the adsorbent. Thus the H2SO4/C can be reused repeatedly. In the mechanism of this reactive adsorption process, trace of H2O in the waste gas is a required, which lends itself to treating ammonia gas saturated with moisture from biodegradation of animal urine.
authors.affiliation: Department of Civil and Water Resource Engineering, National Chiayi University, Chia-Yi, Taiwan, China.
authors.forename: Liang-hsing
authors.initials: LH
authors.lastname: Chou
authors.forename: Ru-in
authors.initials: RI
authors.lastname: Tsai
authors.forename: Jen-ray
authors.initials: JR
authors.lastname: Chang
authors.forename: Maw-tien
authors.initials: MT
authors.lastname: Lee
mesh_terms: D000327:Adsorption; D000641:Ammonia / Q000737:chemistry / Q000302:isolation & purification*; D000693:Anaerobiosis; D000818:Animals; D001673:Biodegradation, Environmental; D002606:Charcoal / Q000737:chemistry*; D013464:Sulfuric Acids / Q000737:chemistry; D014556:Urine / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*
chemical_list: D013464:Sulfuric Acids; D002606:Charcoal; D000641:Ammonia; C033158:sulfuric acid