(256c) Pervaporative Purification of 1,3 Propanediol From Binary Solutions and Model Fermentation Broths: Design Optimization On Novel Functionalized Siloxane Membranes

Among biorenewable chemicals, the market for intermediates such as 1,3 propanediol, though nascent, accounts for $575 million worldwide. The bio-fermentation of crude glycerol to 1, 3-propanediol is a profitable  recourse to capitalizing on the current over capacity of glycerol. The purification of 1, 3 PD from the fermentation broth, in which its concentration is ~1.5%,  amounts to almost 50 – 70% of the total production cost. Pervaporative membrane purification is a cheap and energy efficient alternative of upgrading the concentration from a very dilute starting solution. This work presents the design optimization of the pervaporative performance of novel pervaporation membranes based on functionalized Polysiloxanes. The optimal process parameters for the best possible separation factor, balanced by concurrent flux, were determined using a design of experiment by varying paramaters such as feed 1,3 PD concentration, temperature, cross flow velocity and the concentration of co metabolytes in model fermentation broths. Both the enrichment of 1,3 PD concentration and its selectivity over other co-metabolytes was monitored. Response surface methodology (RSM), an important branch of experimental design, was used to find the relationship between experimental parameters and the resultant separation factors and flux of each component in order to find the optimal conditions for the process. Pervaporation can reduce energy consumption in purification by ~80% compared to that required in evaporation / distillation. Additionally, pervaporation proffers a simple process which can be either used stand alone or coupled with other process as well as a continuous fermentation system for achieving high purity at low cost and is easily scalable for large scale operations.