Analysis and Steps to Mitigate Heat Exchanger Fouling in an Aromatics Plant

A heat exchanger, upstream a distillation tower for the separation of BTX (benzene, toluene, xylene) from crude benzene in an aromatics plant, experiences heavy fouling. The fouling mechanism and countermeasures to mitigate or eliminate it, were investigated. An Alcor Hot Liquid Process Simulator (HLPS)was used for the fouling rate measurement. The main mechanism is a combination of precipitation fouling and chemical reaction fouling. Effects, such as temperature, vapor ratio (vapor mole fraction of the fluid), heater materials, surface roughness and the addition of some different types of chemicals were studied. From the experiments, some countermeasures for this fouling were proposed. A decrease in the vapor liquid ratio and a continuous supply of the more effective antifoulant chemical (dispersant) successfully reduced fouling in the plant

STUDY OF AN ORGANIC CRYSTALLIZATION FOULING PROBLEM

One of the aromatic compound plants in Mitsubishi Chemical Corporation has a heavy crystallization fouling problem. We have been studying the crystallization process using the shell and tube heat-exchanger. In order to solve our fouling problem of the heat exchanger, we developed the specified evaluation equipment (crystallization fouling simulator : CFS) which consists of a single tube heatexchanger (Tube size: ID=10.3mm Length=500mm). The result of the modeling for describing the crystallization fouling rate and the countermeasure of the fouling problem are discussed in this work. It can be possible to describe the fouling rate as one equation which has two parameters, and the fouling rate of the industrial plant and the evaluation equipment agree with each other

Measurement and Modeling for the Mitigation of Organic Crystallization Fouling

One of the aromatic compound plants in Mitsubishi Chemical Corporation has a heavy crystallization fouling problem. In order to solve this problem, using a low power gamma ray sensor, we found the location of heaviest fouling and measured the fouling growth rate. We also made a crystallization fouling laboratory test unit (simulator) to study the effects of some factors, such as temperature, liquid velocity, surface roughness and liquid composition. Fouling rates of the industrial plant cooler and the laboratory fouling test unit were modeled using a combination of Kern-Seaton and Reitzer models. However, the parameters of the plant and test unit did not agree with each other, perhaps because of scale up problems. We also measured the melting process (removal) of the fouling with the test unit. The heat flux necessary to melt the foulant was measured and used for the actual plant melting system. In the industrial plant, a steam trace melting system was installed at the position of heaviest fouling, and the plant now runs better than before

Seeking Collaborative Instruction Models beyond the Pandemic: Lessons Learned from the JapanKnowledge Workshop Series hosted by the Plains to Pacific Alliance

As the Pandemic disrupted normal communication patterns and networking opportunities, videoconferencing, usually using the Zoom platform, became the preferred method for academic institutions to continue providing instruction to students and supporting researchers. In 2021, the Plains to Pacific Alliance (PPA) developed plans to use this technology to present a workshop series on the JapanKnowledge database that would be open to Japanese studies researchers and students in North America and beyond. This entailed deciding on content, developing instructional materials, promoting the workshops in collaboration with the North American Coordinating Council on Japanese Library Resources, creating a registration system, presenting the workshops through Zoom and analyzing the post-workshop survey results