Semicontinuous distillation of impurities for the production of butyl acrylate from bio-butanol and bio-acrylic acid

Chemical production processes which use biosynthetic pathways typically experience variations in the concentration and composition of impurities contained in the products, due to the natural variability of biological behaviour. As a result, downstream processes which use these biosynthetic chemical products need to be quite flexible with respect to the impurity concentrations. In this study, a ternary semicontinuous distillation process is investigated, separating a mixture into three fractions, as a potential candidate for the purification of three different bio-based chemicals (bio-acrylic acid, bio-n-butanol, and bio-n-butyl acrylate) which are generated at various steps in the process to produce bio-n-butyl acrylate from bio-based feedstocks. In this model-based investigation, the performance of this approach is discussed in terms of the energy demand, product loss, and the cycle time. It is shown, that a single ternary semicontinuous system can be applied to purify several bio-based chemicals, allowing a simple increase or decrease of the desired final purity, while being able to handle natural variations of the initial compositions of the feed.