A Chemical Reactor that Builds Itself
Modern chemical processing plants are extremely complex and large designs that cost millions of dollars to develop an operate. This project concerns developing a new, cheap and simple platform for promoting chemical reaction of organic gases within a vapor film of microscale thickness formed during the so-called "film boiling" process. Film boiling is a mode of heat transfer in which the surface is so hot that bubbles that form on it coalesce and form a vapor blanket. This is a very different process than boiling water in a teapot where a continuous stream of bubbles can be seen at discrete sites on the surface. Figure 1 shows the configuration of film boiling on a horizontal tube, as well as a photograph of film boiling.
Figure 1: Schematic of film boiling on a horizontal tube. The vapor film thickness () is on the order of 10 to 100 mPhotograph of film boiling showing bubble dynamics.
Within the vapor film of film boiling, temperatures can be very high to drive chemical reaction of the confined gases. The film of thickness in the above figure is the actual reactor volume. The self-assembly of the reactor is implied by development of film boiling as being a natural consequence of transitioning from nucleate boiling (e.g,. boiling water in a teapot) at low heat inputs to film boiling at high heat inputs. One only has to adjust the power input to the surface to create the "reactor" – film boiling – as an entirely passive process
The high temperatures developed in the vapor film as a result of the insulating effect of the gas surrounding the surface creates the potential to convert chemical wastes in a simple manner with this process. Biodiesel production is accompanied by large amounts of glycerine, and film boiling can be used to convert the glycerine formed to a more useful substance - synthesis gas (a mixture of carbon monoxide and hydrogen).
The project will involve designing a new containment for the reactant liquid that resembles a distillation column as shown in the adjacent figure.
Figure 2: Schematic of proposed distillation apparatus for a film boiling reactor
Hands-on experience and interest with the physical design of an experimental apparatus is preferred for this project. Undergraduate students would be expected to sign up for about 3 credits with a weekly commitment of about 9 hours. M.Eng students would be expected to sign up for 3 credits.
Recent related publication:
W.C. Kuo, K.H. Choi, C.T. Avedisian, W. Tsang "On Using Film Boiling to Thermally Decompose Liquid Organic Chemicals: application to Ethyl Acetate as a Model Compound,", Int. J. Heat Mass Transf., 68, 456-465 (2014).
For more information please contact Prof. C.T. Avedisian
cta2@cornell.edu mailto:cta2@cornell.edu
607-155-5105Office: 193 Grumman Hall