(225c) Development of An Economically Viable Process for Dehydration of Biobased Glycerol

The purpose of this contribution is to present the results of a joint industry-academia research project to develop an economically viable process for the production of industrially important C3 compounds from biobased glycerol. Additionally, this research will introduce a simple methodology for integrating environmental impact analysis into the standard heuristics of conceptual process design to ensure that the sustainability goals are achieved. This proposed methodology will be illustrated using the conceptual process development as the glycerol dehydration process as a case study example. This case study selected is important from the perspective of sustainability since glycerol is produced as a byproduct of the manufacture of biodiesel.

In terms of energy production, biodiesel has been shown to have an overall positive lifecycle energy balance. Therefore use of biodiesel and its byproducts may have a positive impact on global climate change. Recently published estimates predict that the demand for biodiesel will grow from 6 to 9 million metric tons per year in the United States and from 5 to 14 million metric tons per year in the European Union in the next few years. However, for every 9 kilograms of biodiesel produced, 1 kilogram of crude glycerol is formed as a byproduct. Due to its high viscosity, glycerol must be removed from the biodiesel product, thus reducing the carbon utilization. Therefore, the identification of novel industrial uses for this glycerol is important to the economic viability and overall sustainability of the biodiesel manufacturing process.

By integrating environmental impact analysis into the standard design heuristics used to develop and screen potential conceptual processes, the design engineer can ensure that the resulting process is not only economically optimized, but also is based on minimizing the potential environmental impact. To achieve this goal, the Waste Reduction (WAR) Algorithm, developed by the U.S. Environmental Protection Agency, will be integrated with the standard design and optimization tools of process simulation and thermal pinch analysis. A simple flowchart will be presented that illustrates where the inclusion of environmental impact assessment fits into the conceptual design process. This flowchart will serve as the basis for the proposed methodology. The methodology will be based on using process simulation tools to quickly generate mass and energy balances for potential conceptual processes. Then an environmental impact assessment will be used to select the minimum impact processes from the potential options. The selected processes will be further optimized using thermal pinch analysis. Then, the most economically attractive option for further development will be chosen.

In conclusion, the application of this proposed methodology holds potential for significant contributions to economic and environmental sustainability by the development of novel conceptual processes which are based on cost effective, renewable raw materials. This methodology can be used to ensure that conceptual processes developed using a hierarchical approach based on standard design heuristics will be optimized based on not only economic potential, but also the minimization of the potential environmental impact.