A feasibility study on the use of glycerol as a solution to waste renewable energy storage in the United Kingdom

Abstract

This study has analysed to feasibility of incorporating a biologically derived liquid organic hydrogen carrier (LOHC) into the energy grid as a method of reducing waste renewable energy.

With this goal in mind, a scenario has been devised in using glycerol to transport hydrogen for release at domestic homes for use in PEM fuel cells. Through this, a packed bed reactor can fulfil the average load with a glycerol conversion of 94 %. The peak load can be fulfilled by using 3 of these reactors at each home and reducing the temperature to decrease conversion when the energy is not needed. Through the dehydrogenation, many side products are formed, including methanol and ethanol which can be used to regenerate glycerol in a transesterification reaction. For a target conversion of 98 %, a 7.08 m³ reactor vessel would be required to handle the alcohol output of 100 houses.

After these simulations, an economic analysis and life cycle assessment was performed. The economic showed operating costs to be around 76.5 $/h, and the capital cost per home to be $33,000. 60% of this investment is the cost of the catalyst used in the dehydrogenation of glycerol. An alternative catalyst is required to reduce this total cost. The life cycle assessment showed very high effectiveness in reducing carbon missions, however, the other pollutants severely damper its viability.