| dc.description.abstract | High-tech industries apply various volatile organic ccompounds (VOCs) in the processes and the emission of VOCs causes serious impact to the environment. Several methods are available to remove VOCs from processes, for example, incineration is a method to convert VOCs to harmless gases including CO2 & H2O(g), which have much less impact to the environment. Nowadays, more and more high-tech companies apply RTO to destory VOCs from waste gas streams. This research is focus on comparison of removal efficiency of NMHC and formation of NOX & SOX with four different operating conditions, condition I: high flowrate with high temperature; condition II: high flowrate with low temperature; condition III: low flowrate with low temperature; condition IV: low flowrate with high temperature, in a Copper Clad Laminate (CCL) plant which has three sets of RTO.
The result shows that temperature has great effect on the removal efficiency of NMHC, the higher temperature, the better removal efficiency. The flowrate has less effect on removal efficiency. However, the smaller flowrate (the longer HRT), the higher removal efficiency. The order of the NMHC removal efficiencies achieved with are condition I & IV > condition III > condition II. On the formation of NOX, the thermal NOX and prompt NOX are the major formation mechanisms. Large amounts of NOX were measured in flue gas of RTO#2, because the waste gas stream contains high concentration of DMF. The results also indicate that higher temperature and longer HRT result in greater formation of NOX. The order of NOx formation are condition IV > condition III > condition I > condition II. As for the formation of SO2, the main source of SOX in flue gas comes from fuel oil which contains sulfur. It is necessary to control temperature in RTO by using fuel oil when the combustion heat of VOCs is not enough to maintain pre-set temperature in system. Therefore, SO2 emission increases with increasing of fuel consumption. The condition II has the largest emission, follows by condition III and IV, the condition I has less emission of SO2.
The fuel consumption of RTO is related to combustion heat of VOCs. The order of fuel consumptions in RTO are condition II > condition III > condition I & IV. The fuel consumption will affect emission of SO2 in flue gas and SO2 emission is proportional to fuel consumption. The annual operating & maintenance cost of RTOs in plant A is estimated as NT$ 9,752,000. On the other hand, the annual operating & maintenance cost of RTOs in Plant A will be NT$18,652,000 if depreciation and amortization is included.
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