Developing Blending Models for Gasoline and Other Mixtures

Abstract

The construction of gasoline blending models is discussed to illustrate some of the practical problems encountered in mixture experimentation. Attention is focused on the use and modification of the simplex and extreme vertices designs in the development of blending models. The XVERT, WYNN, EXCHANGE, CONSIM, and CADEX algorithms are shown to be useful aids in constructing linear and quadratic model designs when the region of feasible blends is restricted by single-component and multiple-component constraints. The evaluation of competing models and the use of the quadratic blending model in conjunction with linear programming calculations are also discussed. The methodology is general and can be used in all types of mixture experiments and product formulation studies, Examples are included to illustrate the use of the design algorithms and models.

KEY WORDS:

• Blending models
• Computer-aided design
• Constrained experimentation
• Gasoline blending
• Mixture experiments
• Product formulation