Flow through Packed and Fluidized Beds
Chemical engineering operations commonly involve the use of packed and fluidized beds. These are devices in which a large surface area for contact between a liquid and a gas (absorption, distillation) or a solid and a gas or liquid (adsorption, catalysis) is obtained for achieving rapid mass and heat transfer, and particularly in the case of fluidized beds, catalytic chemical reactions. You will find a good deal of information about flow through packed and fluidized beds in the book by McCabe, Smith, and Harriott (1) and Perry’s Handbook (2). Here, only a brief summary is given. First, let us consider flow through a packed bed.
Packed Column With Wet Scrubber For Boiler Exhaust Purification
Diesel and Heavy Fuel Oil (HFO) emit Sulphur and Nitrogen Oxides when combusted in boilers. Industrial boilers burn large amounts of fuel for steam generation. It has become essential to control these gas emissions from boilers due to sensitivity to the environment. Packed column is a technology used for Gas absorption process and distillation process in industrial applications. This research mainly targets on utilizing packed column gas absorption for purification of Exhaust gas in HFO Boiler exhaust. Industrially available economical packing materials cannot withstand high temperature flue gas exiting a boiler. The discussed solution used a combination of a packed column and a wet scrubber to achieve the optimum performance and cost of packed column absorber. Cooling effect created by the scrubber made it possible to use an economical packing material where the packed bed operated at $90^{\circ}\mathrm{C}$ temperature.
Synthesis of 2,4-dideoxy-.beta.-D-erythro-hexopyranosyl nucleosides
The synthesis of 1-(2,4-dideoxy-β-D-erythro-hexopyranosyl)thymine (12) 1 was accomplished using two different synthetic routes. It was obtained starting either from 1,2:5,6-di-O-isopropylidene-α-D-glucofuranose or from tri-O-acetyl-D-glucal. The other modified nucleosides, with either a cytosine, guanine, or adenine moiety, were synthesized using the second reaction scheme. Deoxygenation reactions were accomplished with the (2,4-dichlorophenoxy)thiocarbonyl derivatives generated in situ