High-pressure technology condensation reactions

A Hquid-phase isophorone process is depicted ia Figure 4 (83). A mixture of acetone, water, and potassium hydroxide (0.1%) are fed to a pressure column which operates at head conditions of 205°C and 3.5 MPa (- 500 psi). Acetone condensation reactions occur on the upper trays, high boiling products move down the column, and unreacted acetone is distilled overhead ia a water—acetone a2eotrope which is recycled to the column as reflux. In the lower section of the column, water and alkaH promote hydrolysis of reaction by-products to produce both isophorone and recyclable acetone. Acetone conversion is typically ia the range 6—10% and about 70% yield of isophorone is obtained. Condensation—hydrolysis technology (195—198), and other Hquid-phase production processes have been reported (199—205). 

Rapid progress has been made in the preceding five years in the production and characterization of metal cluster beams. Details of the technology of production and analysis can be found in review articles [1-3]. Pulsed beams of metal clusters are obtained by expanding and condensing in a high-pressure helium stream metal vapors produced by pulsed laser vaporization. Reactant molecules can be introduced into the gas phase along the pathway of metal cluster beams. The nuclearity of the clusters and the products of the reaction between clusters and added molecules can be identified by mass spectroscopy. 

Description The gas feedstock is compressed (if required), desulfurized (1) and process steam is added. Process steam used is a combination of steam from the process condensate stripper and superheated medium pressure steam from the header. The mixture of natural gas and steam is preheated, prereformed (2) and sent to the tubular reformer (3). The prereformer uses waste heat from the flue-gas section of the tubular reformer for the reforming reaction, thus reducing the total load on the tubular reformer. Due to high outlet temperature, exit gas from the tubular reformer has a low concentration of methane, which is an inert in the synthesis. The synthesis gas obtainable with this technology typically contains surplus hydrogen, which will be used as fuel in the reformer furnace. If C02 is available, the synthesis gas composition can be adjusted, hereby minimizing the hydrogen surplus. Carbon dioxide can preferably be added downstream of the prereformer. 

The unprecedented progress in computer technology and in computer science has had a tremendous impact on computational molecular physics and chemistry. Methods, algorithms, and software for performing molecular structure calculations have been developed to predict molecular properties and processes with high accuracy [1-3]. Notably, almost all these methods are applicable only for the isolated molecules thus corresponding to the gas phase at low pressure and temperature. Most chemical processes, in particular biochemical reactions in vivo and in vitro, and industrial processes of great impact take place, however, in condensed (liquid) phase. 

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