Healthy paints

1998/06/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Ingurumena
• Giza zientziak

Illinois engineers have developed a new system for obtaining ethylene lactate easily and economically. This ester used as a paint solvent is made with ethylene alcohol and lactic acid. Lactic acid is the main acid in milk, and is the
natural substance that occurs in the fermentation of many products.

The annual production of solvents for the manufacture of paints, inks and glues is estimated at 2.5 million tons, allowing ethylene lactate to replace common solvents. It has been shown that one of these solvents, trichloroethylene, is very harmful as it is considered to contaminate groundwater and produce cancer.

Traditionally, for the production of ethylene lactate, corn starch was fermented and lactic acid and ethylene alcohol were produced. Ethylene then mixed more alcohol and heated to 100ºC to combine acid and alcohol and create a new ester. However, in this way, the reaction also generated water, so the reaction was cut reducing the yield to 60%. This required a second expensive phase consisting of water distillation and disposal. Alcohol was also eliminated in this process, but alcohol was recovered, dried and remixed.

In the new system that has now been discovered, the mixture is filtered through a membrane through which the smallest molecule flows, so that hot water evaporates like steam across the membrane. By removing and removing water from the reaction properly, the reaction
performance is much higher.