Solvay Sa

Solvay (Societe Anonyme)

Maurizio Paganin

Oliviero Diana

Philippe Morelle

Peter M Predikant

Dominique Balthasart

Patrick Gilbeau

Philippe Krafft

Christoph Sommer

Alain Fobelets

A hydrogen fluoride supply unit which comprises a plurality of transportable hydrogen fluoride storage containers connected to a hydrogen fluoride supply line and a chemical plant comprising the hydrogen fluoride supply unit. Such chemical plant may be for the manufacture of fluorine, wherein the hydrogen fluoride supply line is connected to an electrolysis cell for producing fluorine by HF electrolysis of a molten salt electrolyte. A process for the manufacture of a chemical comprising using such chemical plant. Also a method for supply of hydrogen fluoride to a chemical plant, which comprises: (a) filling at least one transportable hydrogen fluoride storage container with hydrogen fluoride, (b) transporting the hydrogen fluoride storage container to the hydrogen fluoride supply unit, (c) connecting the hydrogen fluoride storage container to the hydrogen fluoride supply line, and (d) supplying hydrogen fluoride from the hydrogen fluoride storage container to the hydrogen fluoride supply line.

Hydrogen fluoride supply unit

Elemental fluorine is used as etching agent for the manufacture of electronic devices, especially semiconductor devices, micro-electromechanical devices, thin film transistors, flat panel displays and solar panels, and as chamber cleaning agent mainly for plasma-enhanced vapor deposition (PECVD) apparatus. For this purpose, fluorine often is produced on-site. The invention provides a process wherein the contamination of the elemental fluorine with gaseous impurities, such as air or moisture, is prevented by producing it on site and delivering it to the point of use under a pressure higher than ambient pressure.

Method for the supply of fluorine

Elemental fluorine is often manufactured electrochemically from a solution of KF in hydrogen fluoride and contains varying amounts of entrained electrolyte salt in solid form as impurity. The invention concerns a process for the purification of such impure elemental fluorine by contact with liquid hydrogen fluoride, e.g., in a jet gas scrubber or by bubbling the raw fluorine through liquid hydrogen fluoride. After this purification step, any entrained hydrogen fluoride is removed by adsorption, condensing it out or both. After passing through a filter with very small pores, the purified fluorine is especially suited for the semiconductor industry as etching gas or as chamber cleaning gas in the manufacture of semiconductors, TFTs and solar cells, or for the manufacture of micro-electromechanical systems ('MEMS').

Method for the purification of fluorine

Process for manufacturing dichloropropanol according to which, a) in a liquid reaction medium containing water, which is in contact with a gaseous phase, glycerol is reacted with hydrogen chloride under a partial pressure of hydrogen chloride in the gaseous phase greater than 0.2 bar absolute, and b) at least part of the liquid reaction medium and optionally part of the gaseous phase from step a) is (are) subjected to at least one separation operation and, prior to said separation operation, the part of the liquid reaction medium and the part of the gaseous phase from step a) is (are) subjected to bi) at least one treatment for reducing the weight ratio between the hydrogen chloride and the water in the part of the liquid reaction medium so as to attain a ratio less than or equal to the weight ratio between the hydrogen chloride and the water in the binary azeotropic hydrogen chloride/water composition at total pressure of the separation operation, and/or bii) at least one treatment for reducing the weight ratio between the water and the dichloropropanol in the part of the liquid reaction medium so as to attain a ratio less than or equal to the weight ratio between the water and the dichloropropanol in the ternary water/dichloropropanol/hydrogen chloride azeotrope at total pressure of the separation operation.

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Brussels, Belgium

Maurizio Paganin