Process Scale-up and Design of Novel Supercritical Biodiesel Plant

In the search for sustainable alternatives to petroleum-derived fuels, practicality and cost must be considered. National energy security and current energy prices demand it. By reducing carbon emissions and eliminating the waste of used cooking oil, biodiesel persists as a potential solution. However, currently, through its use of continuous stir reactors, acid and base catalysts, and distillation, the production of biodiesel remains slow, costly, and impractical. We aim to solve this problem through the design of a novel modular biodiesel plant that will produce biodiesel of industry quality and purity standards while reducing the amount of space, time, and energy needed for production.

This plant will be technologically unique by virtue of four characteristics: its modular and transportable design, separation systems, reaction, and reactor design. Firstly, the plant will be made up of eight modular nodes that will be assembled to fit inside a shipping container to transport wherever waste cooking oil is made available and immediately produce biodiesel on site. Its transportable nature will be an advantageous business model and is made possible by the plant’s other novelties. Therefore, secondly, its separation systems will be unique in the utilization of membranes rather than distillation. The membranes will have varying pore sizes so that the differing molecular weights of the components might be exploited for multiple separations. Thirdly, the transesterification reaction of cooking oil with methanol to produce fatty acid methyl ester will not require the presence of a catalyst. This will be accomplished by an experimentally verified optimal supercritical temperature and pressure. Fourthly, the design of the novel spiral-bound tubular plug-flow reactor in which this novel reaction will take place has been properly sized to produce 1000 kg/day.

To formulate this design in a comprehensive manner, I have developed a Piping and Instrumentation Design (P&ID) of our novel process through AutoCAD Plant 3D, and from this P&ID, we have conducted a comprehensive HAZOP study. Additionally, I have developed an Aspen PlusTM simulation in order to analyze the material and energy balances, optimally size the equipment, and model the feasibility of the process. In the future, through sizing equipment and contacting vendors, we aim to complete an accurate bill of materials.