Elimination of Odors Emitted from Hot-Melting of Recycle PS by Oxidative-Reductive Scrubbing

Abstract

Hot-melt granulation of waste plastics emits fumes with unpleasant plastic-burning odor during the heating process. This study uses sodium hypochlorite (NaOCl) solution to scrub and oxidize the volatile organic compounds (VOCs) and the associated odors from polystyrene (PS) hot-melting exhaust. An alkaline hydrogen peroxide (H 2 O 2 ) solution was followed to remove Cl 2 emitted from the oxidative solution. Laboratory scrubbing bottles with a liquid volume of 600 mL were used with the hot melt gas injected into the system at a rate of 1 L/min at 25°C.Results indicate that by purging the test gas through a solution with an available chlorine of 300-370 mg/L at an adjusted pH (6.5-7.0) for oxidation of the absorbed odorous compounds, and then through a solution with pH > 12.0 and 0.35% H 2 O 2 for absorption and reduction of Cl 2 (< 11.2 ppm) in the exhaust gas from the oxidation liquid, around 90% of the VOCs in the range of 3.2-55.5 ppm (expressed as methane equivalent) was removed.Estimations indicate that it requires around 1.62, 0.0452, and 0.0827 kg NaOCl solution (12% available Cl 2 ), H 2 O 2 solution (35% H 2 O 2 ), and sodium hydroxide solution (45% NaOH), respectively, for scrubbing 1,000 m 3 of the exhaust gas with 10 ppm NMHC (expressed as methane equivalent). The chemicals cost a total of approximately USD 0.32.The study has developed a new, effective and economic process for reducing odorous compounds in the hot-melted gas. When commercialized the process is hoped to decrease a lot of odorous complaints.

Application of Olfactometry to Assess the Anti-Odor Properties of Filtering Facepiece Respirators Containing Activated Carbon Nonwovens

“…The sources of malodor include both natural and man-made activities. Those found at workplaces are usually anthropogenic and arise mainly from activities of chemical, petrochemical [1,2], pharmaceutical, food, and plastic processing [3][4][5][6] industries, as well as agriculture [7][8][9][10]. In addition, significant quantities of odorous compounds come from waste processing and storage [11][12][13] and wastewater treatment plants [14][15][16].…”

Investigation of Air Quality beside a Municipal Landfill: The Fate of Malodour Compounds as a Model VOC

“…Moreover, many compounds are characterized by unpleasant odour, which is a cause of citizens' complaints about environment quality. The progress in urbanization and municipal infrastructure in many countries contributes to a negative phenomenon connected with the fact that residential areas are too close to such municipal objects as sewage treatment plants or municipal landfills [2][3][4][5]. The volatile organic compounds emitted from these sources and characterized by unpleasant odour include mercaptanes, sulphides (disulphides), amines, carboxylic acids, aldehydes, ketones, aliphatic and aromatic hydrocarbons [6][7][8].…”