The purpose of this study is to examine the characteristics of odorant materials caused in unregulated charbroiling restaurants, which often receive complaints, and propose an effective removal of such odor.
According to a report published in 2013, there are around 28,390 under-fired charbroiling restaurants in Korea, which accounted for 16.17% of unregulated facilities excluding septic tanks, and 31% complaints relating to odor were attributed to restaurants, among unregulated facilities.
More odor removal technologies are using a hybrid device combining physical, chemical, and biological methods instead of using one method for more effective removal.
In industrial fields as well, combination of methods such as 『Ozone Oxidation+Chemical absorption+ adsorption hybrid system, 『AEROSEP System』 and 『RTO + 3-Stages Chemical Absorption System』is applied and new hybrid technologies like 『Water scrubbing + Electrolysis』, 『Electrostatic precipitator + Catalyst + adsorption』, 『Pre-filter + Grease filter + plasma + A/carbon』are being developed for unregulated facilities .
The study of characteristics of odor emission according to the type of meat and use of spices, the odors were strongest in the order of raw pork > raw chicken > chicken with spice > raw beef > beef with spice > and pork with spice. And, ammonia was found to be the highest concentration of odor from raw pork and spiced meat, while methyl mercaptan & acetaldehyde, n-valeraldehyde and i-valeraldehyde were the highest contributors to odor.
In terms of removal efficiency for dilution value, hybrid method showed the highest average efficiency of 83.44%, followed by absorption, 52.03%, filtration 51.51%, and dilution 36.4%. The partial removal efficiency of hybrid methods was 81.2% for absorption, 74.2% for adsorption, 67.4% for electrostatic precipitator, and 85.7% for assembled hybrid system.
Comparison between vertical hybrid system and cylindrical hybrid system showed that, for dilution value, vertical & cylindrical system had 82.79% of removal efficiency and horizontal & plate system had 68.80%.
In the vertical and cylindrical type, over 90% of aldehydes, 61.03% of ammonia, and 64.14% of toluene, and 85.28% of butyl acetate was removed. In horizontal and plate type, 70.77 ~ 93.32% of aldehydes and 47.62% of ammonia was removed.
Prior to internal cleaning, the removal efficiency of dilution value was 51.93% and the figure increased by 33.12% after the internal cleaning, to 85.05%. Also, removal efficiency of ammonia increased by 46%, and toluene by 59.62%, which implies that removing particulate matters like oil mist, black carbon and replacing active carbon, is an important factor for removal efficiency of odor.
Comparison of efficiency according to change of applied voltage showed that increase of applied voltage leads to increase of theoretical dust collection efficiency of 2.5 ㎛ particle from 41.27 % to 99.88 %, and the efficiency of dilution value from 51.92 % to 85.05 %. Longer retention time in collecting electrode and active carbon also led the efficiency of dilution value by 21.25%, from 30.67 % to 51.92 %.
Therefore, Electrostatic Precipitator & Adsorption Hybrid system removes both smoke and odor at the same time. Particulate matters such as oil mist and black carbon by using electrostatic precipitation was removed. Gaseous odorant was not removed by the electrostatic precipitator, was removed by using adsorption,
As the experimental result of this study, applying hybrid system removed odors caused in under-fired charbroiling restaurant which are unregulated, is more effective device that settle civil complaints and preserve environment.