Science Behind Technology

Desmet Ballestra S.p.A. has adopted an organization, management and control model (the “Model 231”) pursuant to the Legislative Decree n. 231/2001 and a Code of Ethics.

You can download both the Italian and the English version, last updated on 26 July 2019, on this page.

Italian: Desmet Ballestra S.p.A Code of Ethics and Model 231
English: Desmet Ballestra S.p.A Code of Ethics and Model 231

exhaust gasThe exhaust gas exiting the sulphonation reactors is processed to reduce the level of pollutant to values widely accepted by the most stringent international standards on emissions to atmosphere.

The maximum content of the polluting agents guaranteed at plant stack is the following:

  • SO2: 5 ppm (vol.)
  • SO3: 15 ppm (vol.)
  • Organic mist: 25 mg/m3

The exhaust gas undergoes two subsequent steps of treatment before being released to the atmosphere: reduction of organic mist content and final washing with a caustic soda solution to reduce the amount of free SO2 discharged.

This latter step is carried out in a suitable SO2 scrubber, while for the elimination of the organic mist Desmet Ballestra can offer two alternative technological solutions having the same efficiency:

  • Electrostatic precipitator (ESP)
  • Wet brink filter (NEGT)

New Generation Electrostatic Precipitator (ESP)

ESP ELECTROSTATIC PRECIPITATORThe latest generation ESP is characterized by:

  • fixed electrode rods, granting much longer operation and no risk of rupture

  • upper and lower fixation of the electrode rods, completely avoiding the maintenance problems related to the traditional counter-weights and eliminating the risk of swinging

  • round-shaped tubes bundle, designed to ensure the proper gas speed and having higher tube thickness, so ensuring longer life time

  • integrated blowers for upper insulators flushing, directly installed on top of the machine

  • lower insulators flushing by means of dry process air, so preventing any risk of moisture condensation

  • high voltage transformer, able to work up to 60 kV, providing higher efficiency

  • electronic controller, able to select the best operating conditions in terms of voltage according to the detected electric field

Wet brink filter (NEGT)

NEGTThe new unit is based on a special Multicartridge High Efficiency brink filter constantly washed with fresh organic raw material.

This new system, while guaranteeing the same performances of the ESP (in terms of cleanness of the gas at the stack outlet), allows the complete recovery of the sulphonic acid carried over by the exhaust gas.

As additional advantage, the NEGT system enables the recovery, as finished product, of the organic drippings, otherwise normally wasted. For this reason, the system is optimized for processing LABS and MES.


neutrex sm

NEUTREX Loop type double step Neutralization

The NEUTREX unit allows to obtain the surfactant paste at very high concentration, without any risk of degradation during the neutralization step and any need of using solvents or hydrotropes during plant start-up.

It is a compact system, based on a proprietary neutralization reactor of special design, which allows obtaining an extremely homogeneous product with low consumption of energy.

The heat of reaction is removed in a loop, composed of a high efficiency cooler and a recycle pump designed for high viscosity.

The product pH is continuously detected and automatically adjusted by acting on the neutralizing agent proportioning, so to safeguard the chemical properties of the surfactant

A final mixer allows the in-line buffering (controlled by means of an additional pH-meter) and the addition of other ingredients (e.g. preservatives) according to the final application recipe.

The main features of the proposed unit are:

  • High shear mixers of Desmet Ballestra proprietary design, ensuring intimate mixing of reactants even at high concentration conditions

  • Accurate control of the temperature profile in the loop thanks to the high recycling rate and the low pressure drop cooler so to prevent any risk of product degradation

  • Easy in-line transition from low concentration (27-30%) to high concentration (70-75%) paste production

  • Accurate control of free alkalinity

Direct neutralization of sulphonic acids in a wiped film evaporator for the production of top quality, deaerated and “dioxane-free” ethoxysulphate paste as well as the neutralization of all the other anionic surfactants.

The sulphonic acid outcoming from the sulphonation unit is neutralized with caustic soda or an alternative alkaline agent (i.e.: Ammonia). The reaction can be accomplished in a special Double Step Neutralization Unit or, specifically for Ether Sulphates processing, in a Vacuum Neutralization Unit to yield high active neutral paste (70-75% concentration) with low residual dioxane. In both cases, the neutralization process is carried out at high pH values to guarantee the necessary chemical stability to the reaction mass. Final product pH value is adjusted in-line by addition of a buffering agent in a final mixer.

Major advantages of the Desmet Ballestra Vacuum Neutralization Technology:

  • Efficient Dioxane removal from the finished product by evaporation of the azeotropic mixture water/dioxane
  • Possibility to achieve dioxane content in the finished product (SLES) below 10 ppm when coupled with the Desmet Ballestra MTFR
  • Product deaeration to increase density and improve appearance (transparency)
  • Mild operating conditions with accurate control of temperature profile and minimum residence time of the product at high temperature, so as to prevent any risks of hydrolysis
  • High flexibility: the system is capable to process any kind of raw material/product, with the possibility of easily switching from one raw material to a different one with minimum product contamination

In addition to the technology described above, Desmet Ballestra can propose the proprietary

Ultra-Low Dioxane Ethoxysulphates Production Technologylow dx

aimed to produce 70% concentration SLES paste with a residual content < 5 ppm of 1,4-Dioxane on 100% Active Matter basis, responding to the new US environmental restrictions (NY State bill - S4389B) 

Main features of the new system:

  • Contemporaneous neutralization, de-aeration & 1,4-dioxane stripping
  • No risk of quality degradation thanks to the mild operating conditions
  • Direct production of 70% concentration product
  • Dioxane removal up to 90%
  • Lower energy consumption: approx. –50% compared to a conventional stripping system

    grafico dioxane

Please click the video below to see the presentation of Emanuele Caimi, Sales Director Detergents&Surfactants, at the ICIS Digital Surfactant Conference – Sept 16-18, 2020.

Minimizing 1,4 – dioxane content in ethoxysulphates: technology and future trends