Optimum design of an acetylated starch plant from Manihot esculenta Crantz, variety INIVIT-Y-93-4

Abstract

Considering the applicability and added value of acetylated starches, it is necessary to find technological variants to obtain them with favorable technical-economic results and energetic and environmental compatibility. The objective of the work is to optimize economic and dynamic indicators of profitability of acetylated starch production, by considering as optimization criteria the productive capacity, the degree of substitution and the temperature of the drying air, establishing the design of the installation in optimal conditions. Technologies adopted from the mechanized native starch processes were selected, and the design and development of the slurry heating, acetylation, and pneumatic drying stages were proposed. A composite central experimental design was generated for profit (P), net present value (NPV), and internal rate of return (IRR), and the quadratic models obtained through the Response Surface Methodology were optimized. For the evaluation of the indicators, the economic indexes of the process were determined, after technological selection, material and energy balances, and technological design. The optimum operating parameters are achieved at a production capacity of 12.57 tcassava/d, degree of substitution of 0.505 and 124.98 °C in the air supply to the pneumatic dryer. Under these conditions, the production of acetylated starch requires larger volume acetylators  than for acetylated gelatinized starch process, but the technological requirements of gelatinized pulp are eliminated, achieving remarkable energy efficiency with pneumatic drying.