Case Study – Zeolite A

Background

Laundry detergents are complex systems that have been optimized for both performance and cost over many years. One of the key components was sodium tripolyphosphate. Beginning in the 1970s, states passed legislation to prohibit the use of sodium tripolyphosphate in order to eliminate its negative environmental effects. As a result, a replacement material was needed.

The Problem

Despite years of research by major consumer products companies, no one was able to replace 100% of the phosphate in laundry detergents without raising costs and/or compromising product performance. The primary role of sodium tripolyphosphate was to sequester calcium and magnesium ions in water that lowered the performance of the soap or synthetic surface–active agents in the detergent. Some progress had been made by using Zeolite A, a naturally occurring aluminosilicate mineral. Although Zeolite A provided sodium tripolyphosphate’s sequestration potential, it did not act as rapidly. Zeolite A also does not provide the surface active role of sodium tripolyphosphate in dispersing and emulsifying that was not appreciated until it was removed.

Method

Dr. Coffey took a complete system–based approach to the replacement of phosphate. In addition to Zeolite A, he added a small amount of a low molecular weight polyacrylate and substituted some of the detergent’s anionic surfactant with non–ionic surfactant. This rebalancing of the detergent formulation compensated for both the kinetic and thermodynamic properties of sodium tripolyphosphate. The nonionic surfactant replaces some of the emulsifying behavior. Polyacrylate provides dispersant power and a “kinetic calcium mop” to quickly sequester the calcium ions present in the water and then deliver them to Zeolite A particles at a more relaxed pace. Once sequestered by Zeolite A, the calcium ions were not free to interfere with the anionic surfactant molecules of the detergent. This was a novel approach, undocumented in the scientific literature and untested in commercial applications, but it proved to be the technical breakthrough that facilitated global conversion.

Results

Dr. Coffey presented his work at an international meeting of the American Oil Chemists’ Society in Honolulu, and his results revolutionized the approach to phosphate replacement. He then changed roles from scientist to marketing executive, successfully driving the adoption of Zeolite A across North America. Detergent formulators rapidly adopted his approach, and that led to a global conversion to non–phosphate formulations. The end result was a dramatic increase in global demand for Zeolite A.

However, at the time, there was little supply of Zeolite A for Pacific Asia, New Zealand and Australia. Dr. Coffey changed roles yet again, this time to business development executive, and in this capacity he led efforts to build the supply of Zeolite A for this region. After extensive travel to research market trends and raw material sources, Dr. Coffey identified Thailand as the optimum center for Zeolite A manufacture and distribution. Dr. Coffey negotiated with the Thai government for the start–up of a joint venture with a Thai industrialist to build a $25 million plant for the manufacture of Zeolite A. This was successfully accomplished by presenting a business proposal to the Thai Board of Investment in spite of political opposition behind the scenes and face–to–face opposition from a competitor during the presentation. Not only did the government approve the plan, they provided $10 million in tax relief. Within 2 months, construction began, and 9 months after start–up the plant was at full capacity with $12 million in annual sales.