Process design for green and selective production of bio-based surfactant with heterogeneous resin catalyst

The aim of this study was to construct an environmentally and eco-friendly production process of a bio-based surfactant, namely a sugar fatty acid ester (SE), using a heterogeneous catalyst. A strongly basic resin was found to show a fairly high catalytic activity in the transesterification of sucrose and a fatty acid methyl ester to produce an SE under mild conditions, i.e., 60 °C and atmospheric pressure, especially when sufficient sucrose was adsorbed on the resin active sites. In a continuous process using a flow reactor packed with the resin, an appropriate combination of sucrose adsorption and sucrose supply during the reaction enabled to maintain the sucrose concentration at high levels. As a result, continuous SE production succeeded in a short residence time of 1.5 h without saponification to form soap for the first time. In this process, the downstream operations to separate the soap and the catalyst from the product were unnecessary. This heterogeneous resin catalyst enables simple, efficient, and environmentally friendly SE production and this process has potential commercial applications.