An Exploratory Study of a Photonic Crystal Monolith Reactor for Air Pollution Control

摘要：Kalliat T. Valsaraj和Raghunathan Ravikrishna机构：路易斯安那州立大学提案编号：0520524研究本项目的总体目标是开发一种使用光子带隙（PBG）二氧化钛处理稀废气的整体光催化反应器。假设是，使用溶胶-凝胶化学原位产生并接枝在剥离的光纤管上并以单片配置使用的PBG二氧化钛可以极大地改善UV吸收、量子效率、光催化活性，并减少用于光催化降解气态废物流中的有机物的大规模反应器中的传质限制。与在剥离的光纤上使用粉末状二氧化钛涂层相比，使用在光纤上生长的具有光子带隙的长程有序多孔结构的二氧化钛预期会提高整体光催化效率，这是由于改善的光透射性能和更好的传质。PBG二氧化钛将使用两种用于溶胶凝胶处理的模板在光纤上制造- a）聚苯乙烯微球和B）多泡沫体（乳液）。具有PBG二氧化钛的各个光纤整料将被捆绑在一起以形成复合整料反应器。PBG材料特性将在合成阶段定制，以提高复合材料整料光催化反应器在紫外光下的反应效率。复合材料整体反应器将用于降解测试化合物，1，2-二氯苯，在水溶液中。具体目标是：1.使用溶胶/凝胶（溶液）法在光纤上制备PBG二氧化钛晶体2.光子带隙二氧化钛薄膜的表征及其光子学性能的测定.整体式反应器内部结构的构建.在各种反应条件下对候选化合物测试反应器。获得一个数学模型，以提取动力学速率常数和传质特性有用的可能按比例放大的process.Broad ImpactThe建议是高风险的，因为使用的PBG材料在连续的整料光催化反应器配置是一个概念，尚未进行测试。该技术的发展可能会对光催化工艺在处理废气流中的应用产生重大影响。这是高回报，因为如果成功，反应器设计提供了一个潜在的规模，可以减轻目前的障碍，使用光催化反应器用于工业废气处理。 因此，广泛的影响是在环境可持续性领域。

ABSTRACTPI: Kalliat T. Valsaraj and Raghunathan RavikrishnaInstitution: Louisiana State UniversityProposal Number: 0520524ResearchThe overall objective of this project is the development of a monolith photocatalytic reactor using photonic band gap (PBG) titania for the treatment of dilute waste gases. The hypothesis is that, PBG titania produced in-situ and grafted on stripped fiber optic tubes using sol-gel chemistry and used in a monolithic configuration, can vastly improve UV absorption, quantum efficiency, the photocatalytic activity, and reduce the mass transfer limitations in a large scale reactor for photocatalytic degradation of organics in gaseous waste streams. The use of long range ordered porous structures of photonic band-gap exhibiting titania grown on optical fibers is expected to enhance the overall photocatalytic efficiency as compared to using powdered titania coating on stripped optical fibers due to improved light transmission properties and better mass transfer. The PBG titania will be manufactured on the optical fibers using two templates for solgel processing- a) polystyrene microspheres and b) polyaphrons (emulsions). The individual optical fiber monoliths with the PBG titania will be bundled together to form a composite monolith reactor. PBG material characteristics will be tailored at the synthesis stage in order to enhance the reactive efficiency of the composite monolith photocatalytic reactor in UV light. The composite monolith reactor will be used to degrade a test compound, 1,2-dichlorobenzene, in aqueous solutions. The specific objectives are:1. Preparation of PBG titania crystals on optical fibers using a sol/gel (solution) method2. Characterization of the PBG titania thin films and determination of their photonic properties.3. Construction of the internal configurations for the monolithic reactor.4. Testing the reactor on a candidate compound under various reaction conditions.5. Obtaining a mathematical model to extract kinetic rate constants and mass transfer characteristics useful for possible scale-up of the process.Broad ImpactThe proposal is high risk since the use of PBG materials in a continuous monolith photocatalytic reactor configuration is a concept that is yet to be tested. The development of this technology could have a significant impact on the application of photocatalytic processes to the treatment waste gas streams. It is high return because if successful, the reactor design offers a potential for scale up that can alleviate the current barriers to the use of photocatalytic reactors for industrial waste gas treatment. The broad impact is thus in the area of environmental sustainability.