Chemical synthesis comprising heat treatment by intrmittent dielectric heating combined with a recycling system

Abstract

This invention relates to the design of a process by intermittent dielectric heating combined with a recycling system. This process consists in subjecting reagents to electromagnetic waves selected in the frequencies ranging between 300 GHz and 3 MHz intermittently using a recycling system. This process enables the treatment of oils that are hardly absorbent as well as great investment savings. This process enables operation on different scales, whether in laboratories, on a semi-industrial or industrial scale, without forfeiting the advantages of continuous dielectric heating.

Description

BACKGROUND OF THE INVENTION [0001] Regardless of the complexity of the molecule to be manufactured, chemists always try to find a way to reduce the reaction time and the number of steps required for synthesizing a molecule because of a constant concern regarding costs and profitability. [0002] Many studies have been conducted for the purpose of controlling the various parameters capable of influencing the unfolding and speed of a reaction. Additives, such as solvents, catalysts, have been widely used. Although these compounds stimulate the reaction medium, they are sometimes toxic to man and the environment, and they require expensive post-treatments such as neutralization, washing, drying, filtration. [0003] Today, the trend is toward manufacturing processes that are simple, low in cost, and respectful of man and his environment. [0004] Some physical processes have been tested: the use of ultrasounds, high frequencies, and recently, microwaves. [0005] The various tests conducted us...

AI Technical Summary

Benefits of technology

[0008] This process is original and low in cost. Additionally, this process enables operation on different scales, whether in laboratories, on a semi-industrial or industrial scale, without forfeiting the advantages of continuous dielectric heating. Applications:

[0009] The invention makes it possible to carry out efficient and rapid heat treatments on different scales, whether in laboratories, on a semi-industrial or on industrial scale.

[0039] The Applicant has filed a Patent Application FR No 0108906 concerning an improved apparatus for carrying out dielectric heating. In said patent, the invention relates to a new shape or geometry of a chimney, in particular a chimney with a conical shape or geometry, which permits heating any type of product under microwave frequencies or high frequencies, in statics or dynamics with a sizeable power density without any risk of electric arcs or electrical breakdown.

[0043] The “singlemode” system (localized field) which is formed by singlemode cavities resonating at the transmission frequency according to a radiation in the direction of the guide is preferred to the “multimode” (diffuse field). The singlemode system avoids a non-homogeneous distribution of the electric field and the presence of hot points. Likewise, this type of reactor creates stability in the products exposed.

[0050] This process retains the advantages of continuous dielectric heating while increasing production capacity.

[0052] The intermittent heating process is simple and low-cost. It consists of:

Problems solved by technology

Risks of Electrical Breakdown or Electric Arcs

In the case of hardly absorbent molecules, the choice of applicators is complicated.

The singlemode applicator outfitted with the usual cylindrical chimneys, which is the most suitable one of all common applicators with hardly absorbent molecules, does not permit working with a high density of power without running the risk of electrical breakdown.

Nonetheless, the introducing into the reaction medium of some polar compounds such as water, so as to play the role of intermediary in energy transfer and thus reduce the density of power needed, is still not satisfactory.

The first solution is not attractive due to the complexity of equipment, safety issues, and cost reasons.

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