Soluciones de Ingeniería para Plantas Químicas de Sulfonación | Plantas Industriales de Detergentes

El 1,4-Dioxano es un subproducto que se ha asociado a preocupaciones de salud humana, ya que ha sido clasificado como posible carcinógeno humano por la Agencia Internacional para la Investigación del Cáncer (IARC). Es difícil de distinguir de otras sustancias, lo que significa que, si los consumidores se exponen accidentalmente a él, ni siquiera serían conscientes de ello. La forma de entrar en contacto con este compuesto es mediante inhalación, contacto con la piel o ingestión.

Los bajos niveles de 1,4-dioxano observados en algunas materias primas y productos terminados demuestran que, con la tecnología actual, los niveles excesivos de 1,4-dioxano son evitables. Es necesario un monitoreo periódico continuo de los ingredientes y los productos cosméticos terminados para detectar la presencia de 1,4-dioxano.

En los últimos años, MARSINA ENGINEERING ha desarrollado una unidad especial destinada a la eliminación de 1,4-Dioxano del SLES al 70%. Esta unidad ha sido instalada y probada a escala industrial, y puede integrarse en cualquier planta de sulfonación nueva o existente equipada con una sección de producción de SLES, permitiendo así la producción de SLES con bajo contenido de dioxano para uso cosmético, incluso en plantas ya existentes.

Las pruebas químicas más recientes se han llevado a cabo en muestras de SLES desdioxanizado por laboratorios químicos internacionalmente acreditados, como la Universidad Politécnica de Milán (Italia) y la Royal Scientific Society (Jordania).

El funcionamiento de la unidad de Desdioxanización de Doble Etapa (Primera y Segunda Etapa en serie) permite lograr una reducción del contenido de dioxano en el SLES del -96%.

Al instalar y operar la unidad de Desdioxanización de Doble Etapa de MARSINA, se verifica y garantiza la producción de SLES con un contenido residual de dioxano inferior a 3 ppm.

La unidad se gestiona completamente de manera automática mediante un sistema de control que garantiza seguridad, eficiencia y flexibilidad:

El PLC (Controlador Lógico Programable) monitorea continuamente el estado de los dispositivos de entrada y toma decisiones para controlar el estado de los dispositivos de salida, mientras que el SCADA permite monitorear el sistema, registrar eventos, procesar datos en tiempo real e interactuar con los dispositivos y maquinaria de la planta.

Como una mejora adicional a su unidad de Desdioxanización, MARSINA ha perfeccionado tanto el proceso como la unidad de la planta mediante las siguientes innovaciones:

Marsina has developed a proprietary technology for energy recovery from sulphur combustion to produce medium pressure steam.

The heat released by the combustion of sulphur is a valuable source of energy and its most efficient recovery strategy consists in using the heat from sulphur combustion for steam production. 

Being this energy available at high thermic level (temperature between 750°C and 430°C), the production of steam at medium pressure is feasible. 

This technology is based on the installation of a special heat exchanger, shell&tubes type, where hot gaseous stream Air+SO2 from sulphur furnace is cooled down, before conversion, by water (demineralized). 

The hot gaseous stream Air+SO2 crosses the heat exchanger tubes-side while demineralized water is fed shell-side. Hot gaseous stream enters the heat exchanger at temperature of about 750°C and is cooled releasing heat to the demineralized water down to a temperature of about 430°C, as required by the downstream SO2 to SO3 conversion process. 

The heat released by the hot gas stream makes demiwater evaporate so producing medium pressure steam.

Steam is produced at pressure up to 8 barg and rate up to 230 kg of steam/ton of LABSA.

Steam generated is immediately usable for main needs of the sulphonation process, such as sulphur melting (after pressure reduction), combustion air heating, etc.

Furthermore, possible produced steam exceeding the plant requirement is delivered at battery limit at lower pressure to be recovered for other applications, typically hot water production by direct condensation.

The energy recovery unit from sulphur combustion is designed to be easily integrated in any possible existing sulphonation plant. 

The unit is equipped with high reliability full instrumentation, redundant where necessary, in order to allow safe and continuously monitored operation. The unit is fully automatically managed by plant PLC, implementing control logics and safety interlocks both process side and steam production side.

Strong attention is paid by Marsina company in the design and supply of environment-friendly plants. 

Any effluent released by the sulphonation plant is opportunely treated with the most efficient technologies for removal of pollutants or hazardous substances before disposal or discharge.

• Exhaust gas treatment

The main gaseous effluent from sulphonation plant is the exhaust gas coming from the gas/liquid separation after sulphonation reaction. This gas still contains traces of unconverted SO2, unreacted SO3, and organic residues, and it undergoes two purification treatments in series before being discharged to atmosphere in compliance with the strictest environment protection regulations.  

1. The first treatment consists in the SO3 and organic residues removal through two different alternative technologies: through Marsina special exhaust gas filter (EGF), or by the electrostatic precipitator (ESP), a filtration device that removes almost totally the traces of not reacted SO3, organic and traces of dragged H2SO4 contained in the exhaust gas. 
2. The second treatment consists in the removal from the exhaust gas of the residual particles of SO2. They are absorbed by an alkaline solution, typically caustic soda solution, into a scrubbing tower and fixed in form of a mixture of sodium sulphite and sodium sulphate.

The treated gaseous stream leaving the scrubbing unit has SO2 residual content of maximum 5 ppm, so allowing its final discharge to the atmosphere.

• Liquid effluents

The only liquid effluent produced by the sulphonation plant is the sodium sulphite and sodium sulphate solution from the exhaust gas scrubbing unit. It is disposed as inert effluent.

A special use of this effluent is possible in case of presence of a spray drying plant in the same facility of the sulphonation plant.