Techno‐economic comparison of different reactor types used in the manufacture of fructooligosaccharides from sucrose

Abstract

AbstractFructooligosaccharides, a low‐calorie alternative sweetener with prebiotic effects, can be synthesized from sucrose via enzymatic reactions. Recently, methods for producing novel fructooligosaccharides using free and immobilized Bacillus licheniformis RN‐01 levansucrase were developed at the laboratory scale. However, there was a need to apply engineering knowledge in production process design and scale‐up to develop and evaluate the feasibility of this technology in the industrial scale. In this paper, three different types of reactors for fructooligosaccharides production using B. licheniformis RN‐01 levansucrase were compared in terms of technical and economic aspects. The previously collected experimental data, including enzyme activities, immobilization yields, product yields, and material balances, were used to estimate the capital and operating costs of fructooligosaccharides production using (a) immobilized enzyme in a stirred‐tank reactor, (b) immobilized enzyme in a packed‐bed reactor, and (c) free enzyme in a stirred‐tank reactor. The technical issues in reactor design and operation were also evaluated. The results showed that, in terms of minimum product selling prices, the process using immobilized enzyme had more economic advantages than the process using free enzyme because the cost savings from enzyme purchasing could compensate the additional equipment and chemical costs in the enzyme immobilization process. The results could be a guideline for selecting suitable reactor types for fructooligosaccharides production and provide directions for further reactor design and development.