| Summary: | 碩士 === 崑山科技大學 === 環境工程研究所 === 100 === The purposes of this study was to understand the characteristics of VOCs emission from printing industry (including the emission approaches, emission sources and feasible reduce methods of VOCs. Besides, the reduction efficiencies of VOCs from delivery and storage of raw materials and the process by the economic and technical feasibility methods were evaluated.
According to the form of plate lithography, the printing industry can be divided letterpress printing, gravure, screen printing and so on. VOCs pollution release from the solvent of ink, cleaning reagent , and maintenance reagent during the storage of raw materials, coloring, addition of materials. The VOCs of process release from printing, drying machine, the equipments of ink adjustment and machinery of cleaning operations.
In this study, possible VOCs reduction methods or techniques were valuated from raw materials, processes, operation management and control at the end of three printers selected. Case one the VOCs generated from the printing ink, and cleaning agents without pollution control equipment. The exhaust devices of plant''s workplace were used to extracted powder and heat not for the VOCs of printing machine directly, so VOCs directly emitted in the workplace. It is recommended to increase the exhaust port placed in the top of the ink tank, and to improve the exhaust efficiency. 20% release of VOCs of ink and 70% extraction efficiency were estimated; therefore 2.01 ton / yr VOCs can be collected. Another VOCs release source was cleaning reagent, which was used with 8.880 ton / yr. To reach the collection efficiency of VOCs from detergent and the appropriate enclosure equipment was used during cleaning process before starting pumping device. The 4.44 ton/yr release VOCs can be collected under 50% collect efficiency. The total collected amount of VOCs was 6.45 ton / yr( 2.01 ton / yr +4.44 ton / yr). But the total amount of VOCs cannot decrease without treatment facilities, an activated carbon adsorption tower was recommended, and its operating costs and interest of equipment depreciation was 500,613 per year. The annual savings in air pollution fee was 58,080 dollars.
Case two has been allowed to use the emission factor from the factory, and the VOCs air pollution fee was paid up to 618,912 dollars per year. Our collection is currently not set the exhaust gas processing equipment, and therefore out of the oven emission factor to estimate the amount that its annual emissions of VOCs. The emission factors were used to estimate the release amount of VOCs, which equals the emission amount without equipments of collection and treatment.If the curtain is set along the both sides of printing machine to the top of the device, an exhaust hood can collect 80% of release VOCs. Biological filtration or regenerative incinerator can be selected to degradation VOCs under consideration of inlet VOCs concentration. The removal efficiency of VOCs is 80% by bio-filter bed to save VOCs emission fees at 426,720 dollars per year. Case three has operated for 70 years in printing industry. In accordance with the current operating condition, the amount of VOCs escaping is 0.182 tons / month (= 0.55 tons/season) with the calculation of mass balance. The amount is less than one ton of standard amount quarterly.
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