NOx and SOx removals for exhaust gas in glass melting furnace using a plasma and dry chemical hybrid process

Abstract

Laboratory-scale experiments were carried out on simultaneous removal of NOx and SOx from a glass melting furnace using a semi-dry plasma and chemical hybrid process (PCHP). The experimental apparatus is simulated to the aftertreatment system for a full-scale semi-dry glass bottle manufacturing system, and NOx removal processes of plasma-induced ozone gas injection for the oxidation of NO followed by Na2SO3 solution reduction of NO2 and a dry neutralization removal of NO2 by NaHCO3 or Na2CO3. First, NO removal experiments are carried out with water sprayed to form a localized cooling area by heat removal of vaporization in the reactor. As a result, the NO oxidation efficiencies of 76% (Liquid-to-gas ratio, L/G = 0.7 L/m3) and 98% (L/G = 2.0 L/m3) are achieved by the injecting ozone into the localized cooling area. Next, for experiments with a mixed simulated gas of NO and SO2, when the mixed aqueous solution of Na2SO3 and NaOH is sprayed under the conditions of L/G = 0.7 L/m3 and 2.0 L/m3, NOx removal efficiencies of 45% and 48% with NO oxidation efficiencies of 62% and 70% are obtained, respectively. Simultaneously, more than 75% of SO2 is removed. Finally, the neutralization removal of NO2 is investigated for the reaction with NaHCO3 or Na2CO3 onto the filter in the reactor. It is clarified that Na2CO3 is more effective than NaHCO3 for the removal of NO2. The stable NO2 removal is achieved at the dry type reactor. It was confirmed from the experimental results that PCHP combined with dry reduction chemicals method was promising for effective exhaust gas aftertreatment for a glass manufacturing system.

Keywords

• plasma
• ozone
• no oxidation
• chemical reaction
• nox removal
• sox removal
• pollutant
• exhaust gas
• glass melting furnace
• environmental engineering