Department of Chemical and Biomolecular Engineering Ohio State University
"Chemical Looping Technology"
The concept of chemical looping reactions has been widely applied in chemical industries. Fundamental research on chemical looping reactions has also been applied to energy systems. Fossil fuel chemical looping applications were used with the steam-iron process for coal from the 1900s to the1940s and were demonstrated at a pilot scale with the carbon dioxide acceptor process in the 1960s and 1970s. There are presently no chemical looping processes using carbonaceous fuels in commercial operation. A key factor that hampered the continued use of these earlier processes was the inadequacy of the reactivity and recycleability of the looping particles. This factor led to unsustainable operation of the process. With CO2 emission control now of great concern, interest in chemical looping technology has resurfaced due to their unique ability to generate a sequestration-ready CO2 stream. This presentation will describe the fundamental and applied aspects of modern chemical looping technology that utilizes fossil and other carbonaceous feedstock. The presentation will discuss the reaction chemistry, ionic diffusion mechanisms, metal oxide synthesis and thermodynamics, reactor design, and system engineering along with energy conversion efficiency and economics of the Coal-Direct and Syngas Chemical Looping Processes being developed at the author’s lab. Further, CO2 emission control using the chemical looping technology will be illustrated and compared with other CO2 capture methods. Potential for selective oxidation in the production of fuels and chemicals, as well as solar based chemical looping technology, will also be discussed.
"Chemical Engineering Education in Particles Flows"
Particles are used extensively in industry and represent more than 60% of industrial products or their intermediates. These particles are of sizes varying from nano to cm and with diverse chemical and physical properties and industrial applications in chemical, biochemical, pharmaceutical, agricultural, petrochemical, and metallurgical engineering. The fields covering particles are of interdisciplinary nature. Work related to particles includes such topics as particle synthesis, flows, reactions, and reactors. Education in particle technology is thus important. The traditional curriculum in chemical engineering on flows mainly deals with fluid, gas or liquid. Particles, however are not well represented. The formation of the Particle Technology Forum by AIChE in 1992 has helped promote awareness of the importance of this subject. Much progress has been made since then. However much still remains to be accomplished. This presentation will focus on the flows of particles at sizes ranging from micron to centimeter currently found in much of the industrial systems. There are significant differences in solid transport and fluid transport. Fluid transport can be driven by shear, by pump or by compressor, but solid transport involves complex fluid-solid interaction and solid-solid collision. Their motion is also commonly driven by gravity. This presentation will discuss particle science and technology education in chemical engineering with specific focus on solid flow principles. A survey of particle courses taught in various universities worldwide will be given with the basic learning concepts in particle mechanics highlighted as the foundation for teaching solid flows. Subjects of pertinence to chemical engineers including computational fluid dynamics, measurement techniques and industrial practices will also be discussed.