The Effect of Defluidization on Pollutant Emissions in Waste Incineration

Defluidization caused by the agglomeration of bed materials always gives rise to some problems influidized bed incineration of solid waste, even forces the fluidized bed to shut down. The agglomerationaffects the fluidization characteristics, such as minimum fluidization velocity, bubble size and bubblefrequency etc., which are closely related to the operation of fluidized bed incineration. The defluidizationmechanism of fluidized bed consists of sintering and clustering, most researches are focused on the influenceof clustering rather than sintering. On the basis of our previous studies on the hydrodynamic behaviors underhigh temperature, the work in the first year emphasizes the effects of composite materials, such as plastic andheavy metals, on defluidization at high temperature during combustion, and discusses the generation ofpollutants. In solid waste incineration, 2-3% of the solid wastes would transform to hazardous fly ashes,solidification currently is widely applied to treat incinerator fly ash in Taiwan. The leaching rate of heavymetals in fly ash can be lowered if it is re-circulated to the fluidized bed incinerator and co-combusted withwastes. Therefore, fluidized bed incineration has the potential in treating the hazardous fly ash. However, thecompositions of the fly ash will influence the sintering and clustering of bed, this situation is studied in thesecond year. Various artificial wastes and fly ash are combusted to explore their effect on defluidization. Thedetoxification of the fly ash and generation of pollutants will also be studied. In fluidized bed incineration,additives are often applied to control the emission of pollutants such as heavy metals, acid gas and organiccompounds but the effect of additive on defluidization is less evaluated. Therefore, solid additives willdirectly be added to the incinerator to reduce the generation of pollutants and elucidate its relationship withdefluidization in last year. Finally, the valuable information for designing and operating fluidized bed reactorunder high temperature can be provided when the results of three year researches are integrated. Theadequate design and operating will not only reduce the secondary pollution but also decrease the investmentof air pollution control drives.去流體化現象為流體化床焚化爐處理過程上常發生的問題，因為某些因素使得床質聚集成大的塊狀物質，而影響到流體化的性質如最小流體化速度、氣泡的大小、頻率與上升速度等參數，甚至嚴重到可能使爐床產生去流體化的現象，使得整體的操作停頓。流體化床的去流體化機制可分為燒結（sintering）與熔融（clustering）兩種，然而對於去流體化的機制，只有部分研究著重於燒結對去流體化影響。因此，第一年將基於實驗室在高溫流體化床流力行為的研究基礎下，進一步針對廢棄物中含有複合物質，如塑膠、金屬等對流體化床去流體化的影響作探討，以釐清不同廢棄物進料物質所扮演的角色，並對去流體化所產生污染物之間影響作詳細探討。然而廢棄物焚化後會產生2-3 %的有害飛灰，目前大多以固化方式處理，而返送焚化飛灰進入流體化床焚化爐和廢棄物一起進行焚化，可降低飛灰中重金屬的溶出，為一種對於有害的焚化飛灰處理的新技術。由于飛灰含有對高溫流體化床焚化爐燒結、熔融影響的相關成分，基於第一年所探討之廢棄物成分對高溫流體化床焚化爐燒結、熔融影響結果後，第二年之研究進一步將實廠高溫焚化後之有害飛灰返送進入流體化床焚化爐和廢棄物一起進行焚化，預期使飛灰無害化，探討飛灰再處理對去流體化之影響關係，同時針對飛灰添加後處理過程中對污染物排放影響之探討。由於焚化過程中會產生之有害空氣污染物，如酸性氣體、重金屬化合物及有機污染物等，以添加劑控制污染物的產生，為目前普遍應用在流體化床焚化爐中的控制技術，但添加劑對去流體化的影響仍需進一步釐清，所以在第三年的研究中，主要著重於爐內加入添加劑對於流體化床焚化爐產生去流體化與污染物生成的影響作探討，延續與應用前兩年的相關資料與結果，以模擬添加相關添加劑對於流體化品質乃至於不同污染物生成之控制，並探討其生成機制。進一步整合三年的研究成果，藉以得到更完整的高溫流體化床中去流體化機制與污染物生成間的相關資料，提供反應器設計與焚化過程中操作的參考，藉由適當的設計與操作，減少污染物的產生，不僅可以減少污染物控制成本，對大眾健康與生態均有所助益

Simultaneous Control of NO、SO/sub 2/ and Coal Ash from Flue Gas by a Fluidized Catalyst Bed

為因應日趨嚴格的國內排放標準，以高效率觸媒控制技術處理煙道氣體中之污染物已逐漸受到重視。相關之研究指出將觸媒做適當改良可降低煙道中酸性氣體(如硫氧化物(SO2)、鹽酸(HCl)…等)對觸媒毒化的情形。但大部分煙道氣體是屬於高粉塵之煙道環境，如燃煤火力電廠、廢棄物焚化爐…等。此類型之排放源，部份處理方式是直接將高溫廢氣導入選擇式觸媒反應(SCR)系統，但容易造成觸媒表面物理失活(deactivation)及磨耗(erosion)之現象，降低觸媒催化系統之去除效率及壽命；另一部份是於觸媒反應器前端加設除塵系統(如靜電集塵器)，但是會增加設置及操作成本。本研究擬以實驗室規模之流體化床過濾器去除燃煤火力發電廠的煤灰，並探討同時去除NO 及SO2 的可能性。預計於三年計畫中，第一年將應用流體化介質為觸媒擔體材料，評估流體化床過濾器同時去除飛灰及NO 的可行性；第二年則修正流體化介質的表面物化性質及活性金屬附載方式，增進流體化床過濾器同時去除飛灰及NO 的去除效率；第三年將評估SO2 對流體化介質的毒化行為，改善流體化床過濾器同時去除飛灰、NO 及SO2 之操作程序，以求使流體化觸媒床應用於煙道氣中控制NO、SO2 及煤灰之研究趨於完善。For conforming the strict environmental regulations and criterion, higherefficient catalyst reactor tends to be incorporated into the air pollution control systemof flue gas. The related studies indicated that the modified catalyst can beemployed in combustion flue gas which containing SO2 and HCl. However, theflue gas is higher fly ash condition (such as: coal-fire thermal power plant andincinerator). There are two conventional processes applied in high dust-containingflue gas. One part, the high temperature flue gas is directly treated in a SCR systemfor NO removal. However catalyst tends to be physical deactivation and erosion.Other part, they are removed of particle in filtration control system (such as:Electrostatic Precipitator,ESP ) and subsequently enter the catalyst reactor for NOcontrol. But the system need high installation and operation cost.This study investigates the potential of simultaneous removal of NO, SO2, andcoal ash from flue gas of coal-fire thermal power plant by a fluidized catalyst bed.The research project is schemed for three years. In the first year, the evaluation ofvarious supporting materials suitable for applying in fluidized catalyst bed will beconducted. And the performance of removal of NO in fluidized catalyst bed underhigh dust-containing flue gas will also be investigated. In addition, the filtration ofcoal ash under various operating conditions is comprehensively evaluated todetermine the optimum one. In the next year, the improvements of catalyst for itsdispersion and structure characteristics by mean of catalyst modification includingas support pre-treatment and coating method are conducted to increase theefficiency of NO removal. In the third year, the effects of SO2 on the poisoningand deactivating of catalyst and filtration mechanism of coal ash are studied. Theobtained results could provide important information on the interactions of differentconstituents in the complicated flue gas of coal-fire thermal power plant. Thisrealization is useful from the practical application and operation of a fluidizedcatalyst bed for removing NO, SO2, and coal ash

The Development of Composite Membrane for Carbon Dioxide Separation

為了控制溫室效應所造成的全球暖化問題，如何對溫室氣體進行捕獲與封存是非常重要的，特別是二氧化碳。因為二氧化碳是所有溫室氣體中含量最多，且排放問題嚴重，是影響暖化溫度急遽上升的主因。近年來各國皆關心的課題在於如何減少環境中二氧化碳的含量及發展新技術將二氧化碳進行捕獲、封存與再利用以降低二氧化碳的排放量。目前對於二氧化碳的分離方法可分為吸收法、吸附法與生物處理法，但這些方法皆有價格昂貴或是有條件限制的問題。薄膜分離法被認為可以大幅降低生產成本並廣泛應用在各種場所，是種極具潛力的分離方法。而目前應用在二氧化碳的分離以高分子薄膜較多，但其熱穩定性不佳及滲透率較低，故為了實際應用的考量，薄膜需加以改質，才能使薄膜分離二氧化碳技術趨於完善的效果。在本計劃中，本實驗室利用高分子、奈米無機材料及碳分子篩薄膜結合，以應用於二氧化碳的純化與分離，三年計畫過程中，將評估適用在二氧化碳分離的高分子與奈米無機材料合成複合式高分子薄膜，再將其與碳分子篩結合成多層複合式薄膜，繼而應用在氣體分離上希望對於二氧化碳有良好的分離效率。因此本研究主要著重（1）開發純高分子薄膜與碳分子篩薄膜結合為多層複合式薄膜及將其應用在CO2 氣體分離（2）尋找具有氣體吸附特性之奈米無機材料，將其合成為無缺陷且分散均勻的多層奈米複合薄膜並評估其在CO2 的分離效果（3）評估應用多層奈米複合薄膜在不同壓力、溫度的混和氣體之純化分離。此外，本研究所製備出之多層奈米複合薄膜將以FESEM、AFM、FTIR、XRD、BET 等方法分析，並討論其薄膜物化特性與氣體純化分離之間的關係。To control the greenhouse effect caused by global warming, the capture and storage of the greenhouse gas(GHG), particularly carbon dioxide, is an important concern. Of all the GHGs, carbon dioxide accounts forthe most serious problems. Its emissions contribute to the increase of global temperature, or global warmingas it is generally known.In order to reduce the emission of carbon dioxide, in recent years, countries have become concernedabout how to reduce the content of carbon dioxide in the environment, and in developing new technologywhich can capture, storage and reuse carbon dioxide. Additionally, it should be reusable. Current carbondioxide separation methods can be classified into absorption, adsorption, and biological treatment. However,these methods are either expensive or conditional. Membrane separation has been shown to significantlylower production costs and has been widely used in various places. Thus, membrane separation is extremelyvaluable. Nevertheless, the present application of isolation in CO2 is limited to the polymer membrane whichdoes not possess good thermal stability and high permeability. Therefore, in consideration of the practicalapplication, the need to modify pure polymer membrane is imperative in order to make the membraneseparating carbon dioxide capable of complete results.In this research, we present and discuss the results of a study on the polymer membrane and multilayercomposite membrane fabricated from nano-materials and carbon molecule sieve (CMS) for carbon dioxideseparation and purification. The three-year endeavor consists of finding the appropriate polymer precursorsand inorganic nano-materials for the preparation of polymer membrane and further incorporating it withCMS to form a multi-layer composite membrane to provide the expected carbon dioxide gas separation. Forthese reasons, we focus on (1) developing combination of pure polymer selectivity layer and CMS membraneto generate multi-layer composite membranes for the separation of carbon dioxide, (2) finding the gasadsorption inorganic nano-materials which can contribute to the fabrication defect-free nano-compositemembrane with excellent dispersion capability and high CO2 selectivity and purification level and evaluatethe separation effect, and (3) evaluating the gas separation and purification of multilayer compositemembrane at different test pressures, temperatures, and mixtures of gases. Furthermore, the multilayercomposite membrane is characterized by FESEM, AFM, FTIR, XRD, and BET to discover the correlationwith membrane properties and gas separation