Development of a System for Advanced Cleaning of Exhaust Gas from Diesel Engine Utilizing Oxidation and Reduction Reaction Coupled with Heat Recovery

1.催化剂颗粒的制备及性能评价：采用无粘结剂造粒的方法对二氧化钛颗粒进行造粒，制得脱氮催化剂。准确地说，10g的二氧化钛颗粒在锥形床造粒机中以规定的风速进行流态化。结果表明：得到了平均粒径为150~800μm的球形颗粒。通过对饲料粉的筛分，可以控制颗粒的平均大小。颗粒尺寸随流态化气速和操作时间的延长而增大。当气速较高时，颗粒大小呈双峰分布。在这些结果的基础上，认为颗粒在锥形壁上凝聚的颗粒生长过程与颗粒的滚动运动形成颗粒的过程是一致的。在另一种锥形流态化的b…中，颗粒增强实验是通过喷洒聚乙烯醇含水层到颗粒上进行的更多的爱德。利用硬度计对颗粒的抗压强度进行了评价。结果表明：粘结剂喷涂时间越长，抗压强度越高，达到面心立方颗粒抗压强度。颗粒流动特性的研究：以催化裂化和半焦为模型颗粒，考察了颗粒在床层干壁区的流态化特性，包括固含率和淋洗率。得出如下结论：淋洗速率常数与颗粒种类无关，因为它们的终速相同。3.脱氮特性研究：在床内设置紫外光光源的条件下，进行了二氧化钛颗粒的脱氮实验。得到了以下结论。将进气一氧化碳浓度由100ppm降至85ppm左右，并保持几分钟。预计较高的光源功率和/或较高的催化剂颗粒浓度可以很容易地实现90%的脱氮效率。较少

1.Preparation of catalyst particles and evaluation of their properties : To obtain the denitration catalyst, titanium dioxide(TiO_2) particles was granulated by using a binderless granulating method. Precisely, TiO_2 feed particles of 10g were fluidized at prescribed air velocities in a tapered fluidized bed granulator. The findings were as follows ; The spherical granules with the mean size ranging 150 800μm are obtained. The mean granule size can be controlled by sieving feed powder. The granule size increases with fluidizing gas velocity as well as operating time. For higher gas velocity, bimodal granule size distribution is observed. Basing upon these results, it is suggested that the granule growth process whereby the agglomerates of particles coalesces on the tapered wall concurs with the granule shaping process by rolling motions of agglomerates.Granule reinforcement experiment was carried out by spraying polyvinyl alcohol aquifer onto the granules in another tapered fluidized b … More ed. The compressive strength of granules was evaluated by using a hardness testing machine. The following results were obtained ; The compressive strength increases with the binder spraying time and reaches to the value of FCC particles. Specially, the reinforcement of coarser granules is marked.2.Study on flow properties of granules : Fluidizing properties of granules in freeboard region of fluidized bed column including solid holdup and elutriation rate were examined using FCC and char as model particles. The following findings were obtained ; Elutriation rate constant is independent of particle kinds as their terminal velocities are same. The solid holdup depends on the size of duster formed in freeboard.3.Study on denitration characteristics : Denitration experiment using TiO_2 granules were performed in freeboard region of fluidized bed equipped with an ultraviolet light source inside the bed. The following was obtained. ; Inlet nitrogen monoxide concentration of 100ppm was reduced to the off gas concentration of about 85ppm, which was kept for few minutes. It is expected that the higher power of light source and/or the higher concentration of catalyst particles in freeboard would lead to the denitration efficiency of 9O% with ease. Less