Summary
Henkel-Ecolab bv in Nieuwegein, The Netherlands is a manufacturer of parfums, cosmetics and develops and produces soap-, washing-, detergents and maintenance products.
Formerly the production process of detergents consisted of a number of tanks for mixing and storage with a spray drier to remove water. This water was added to the components for mixing and spraying purposes. Some components such as bleach and enzymes cannot be mixed in a moisture rich environment. Furthermore the hot air (250 °C) in the spray drier is a handicap to the use of low temperature active ingredients in the washing powder. Also the spraydrier requires huge volumes of air which leave the drier, carrying water vapour and odorous components. This requires electric energy to drive the fans and causes possible annoyance in the environment because of the odour. The spray drier has been modified in an earlier TIEB-project (1992) regarding the conversion from oil fired burners to efficient natural gas burners with a new concept. New production technologies are however available.
Other manufacturers use the proces of moisture granulation which comprises a fluid bed drier and the mixing equipment. In this process less water is added to the components compared to the spray drying process, causing the energy consumption to be much lower.
However in this project Henkel Ecolab has implemented a gel granulation process. This process requires even less water and therefore less energy than the moisture granulation process.
A Nauta-mixer mixes the liquid components into a gel, together with the solid components they are mixed in the next mixer. This is the batch process. In order to achieve a continuous process, a third mixer has been added with enough capacity to feed the fluid bed drier during the batch preparation time.
The absence of huge quantities of odorous air from the spray tower benefits the environment and accounts for an substantial reduction of electric energy which was used to drive the fans. Also employee- and maintenance costs have been reduced by eliminating parts of the production process.
After the total change of the process in about four years, total energy consumption wil be reduced by approximately 570,000 kWh and 1,760,000 m³ of natural gas per year. The total subsidised project costs amount to 1,450,000 NLG. Total annual energy savings amount to NLG 270,000 with an additional saving of NLG 30,000 on water purchases. Lower costs for operation and maintenance comprise to NLG 200,000 per annum. The total pay back period is 3 years.
This project has a specific interest for the washing powder manufacturing industry, it is also applicable for the handling and mixing of powdery and liquid components in the food- and beverages industry.