Science Behind Technology

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