Chemical and Pharmaceutical Industry

 

Many products need to be protected from contact with moisture and oxygen due to their hygroscopicity or tendency to form explosive mixtures.

Nitrogen, in liquid and/or gaseous form, is the simplest and most economical way to manage all operations in complete safety. Micronization allows to reduce the size of particles of the active ingredient of a drug: the use of liquid nitrogen allows to exploit, in addition to the quality of inert gas, also the frigories obtained in the phase transition from liquid to gas. Liquid nitrogen can also be used for the condensation of solvents contained in gaseous effluents from chemical reactors: SICO proposes itself as a technological partner to advise you on the best solution to adopt.

Liquid nitrogen cryo-condensation

The cryogenic condensation process is based on the possibility of cooling gaseous effluents polluted by volatile organic compounds (VOCs) to very low temperatures, in the order of -100°C, using liquid nitrogen as an energy source.
The separation of pollutants is obtained thanks to the drastic reduction of the vapor pressure to the liquid/vapor or solid/vapor equilibrium values achieved at the minimum temperatures achievable by cryogenic means.
It is therefore possible to recondense and “recover” many organic products present as pollutants in gaseous streams, widely used in many sectors of industrial production.

Legal limits Legislative Decree 3 April 2006, n. 152 for organic compounds in the form of gas, vapour or dust and temperatures required to comply with them.

The operating principle of a cryogenic condenser is really simple and the success of these systems depends a lot on the experience of the manufacturer who is able to achieve an adequate sizing of the exchanger surfaces as well as the use of high quality and reliable instrumentation during use at very low temperatures.

In many sectors of the chemical industry in general, volatile products and solvents are used that generate gaseous emissions rich in VOCs (Volatile Organic Compounds) that become the primary source of pollution of the various gaseous streams in the discharges of these companies. The following table shows the most frequent gaseous pollutants that are suitable for removal treatment by means of Cryocondensation.

 

Gaseous pollutants
Chlorinated solvents Ethyl acetate
Ketones Methanol
Alcohols Toluene
Methylene chloride MEK
Acetone Cyclohexane

Pulmonation and Inertization

Some products must be protected from contact with oxygen and humidity for reasons of increasingly high quality requirements or to avoid the formation of potentially explosive atmospheres.
The blanketing of tanks occurs by injecting nitrogen to saturate the headspace; an automatic analysis system continuously monitors the atmosphere of the plant to be inertized. The transport of flammable products performed using nitrogen instead of compressed air is an effective solution to increase process safety.

Micronization

Micronization is a technique that allows to reduce the size of the particles in the order of microns. Nitrogen is used instead of compressed air in special equipment that uses centrifugal force to break up the granules against the walls of the jet mill.

The use of nitrogen allows:

  • Greater safety.
  • Reduction of energy consumption.
  • Flexibility of operation.

Grinding at controlled temperature

During grinding, the temperature inside the mill increases; this can determine degradation processes of the product, obtaining dimensions and chemical-physical characteristics different from those required.

A valid solution is represented by the use of liquid nitrogen which, introduced into a cryogenic screw, pre-cools the product before entering the mill. The advantages of this technology can be summarized as follows:

  • Obtain smaller and more homogeneous grain sizes.
  • Save energy in grinding.
  • Increase production.

Cryo-grinding

The Cryo-grinding or low-temperature grinding process consists of pre-cooling the product introduced into the grinder:

  • below its embrittlement temperature (classic for plastics, rubber, etc.)
  • or below a temperature that maintains the quality of the ground product

It is used in many industrial sectors such as plastics, elastomers, recycled materials, spices and plant protection products, food products or pharmaceuticals, etc.

Cryo-grinding allows to expand the range of substances that can be ground and to preserve the aromas and active ingredients.

It is important to emphasize that, by means of cryogenic nitrogen control, products containing high levels of water, oil and fat are maintained in a crystalline state during the process and cannot migrate within the mass during grinding.

Biological purification process