| The 21st century's theme is "energy saving,low carbon,environmental protection", for solving the problems of volatile compounds polluting atmosphere and workshop hygiene environment during MDF hot-pressing process, the paper applied the method of theory analysis and experimentation, first theoretically analysed the source of VOCs, the influence factors of VOCs emission and research progress on the volatile waste gas treatment technology of domestic and overseas; Hot-pressing process was the important process in the MDF processing, the contents of terpenes, aldehydes ketones and benzenes were quantitatively and qualitatively analyzed through GC-MS and HPLC, the composition and cotent of volatile gases during hot-pressing were determined; Hot-pressing cycle included pressurization, low-pressure pressure-keeping, discharging pressure exhaust three stages, volatiles emission characteristics of three stages were studied; Finally, based on the emission properties analysis of hot-pressing process volatile components, formaldehyde was the main ingredient in hot gases, this paper explored the effect of low temperature plasma technology to reduce formaldehyde, and put forward the control measures and suggestions.The main conclusions could be described as the following:Firstly, the main component of MDF hot-pressing process was formaldehyde, terpenes, aldehydes and ketones, benzene content, saturated hydrocarbons of aldehydes etc, among them the proportion of aldehydes and ketones was 75%, and secondly terpenes, the proportion of benzene content and saturated hydrocarbon was smaller.Secondly, in the multilayer press hot-pressing process of MDF, the volatiles concentration of high pressure, low pressure pressure-keeping and pressing plate open exhausting stage was different, the component was also different, formaldehyde was the main volatiles. The amount of VOCs release quantity was separately 23.45 mg/m3,0.09 mg/m3 and 0.34 mg/m3 in the process of high voltage, low voltage pressure-keeping and discharging pressure exhaust process.Thirdly, this paper studied on different formaldehyde entrance concentration, different processing time, different injection voltage to the influence of formaldehyde removal effect, formaldehyde removal rate could reach 90%, hot-pressing process, it was needed to be further research on the removal of other hot-press volatile gases.Forthly, through enterprises research and experimental analysis, with current domestic waste gas treatment wood processing industry, the weaknesses and prospects of hot-pressing temperature plasma technology, waste gas combustion method, biological method, adsorption method were analyzed in waste gas processing of hot-pressing process. |
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