Production of Natural Gas from Algae Plant Design

Abstract

The goal of the project is to design a plant that is capable of converting an algae feedstock into compressed natural gas (CNG). This product is intended to be sold as a green replacement for CNG produced using traditional methods. In addition to CNG, hydrogen gas is produced; this product will be sold as a biofuel as well. The CNG produced in this process is created by gasifying algae in supercritical water and then reacting the algal matter over an Ru/C catalyst. The resulting gas is then purified and compressed to produce CNG and hydrogen. A process hazard analysis was conducted to identify and help reduce safety and environmental hazards. An economic analysis showed that the plant's net present value is ($37.5 million); therefore, it was not recommended that the plant be built at this time. Future work includes developing a cheap Ru/zirconia catalyst to replace the expensive Ru/C catalyst currently used in the process. Designs for vessels containing supercritical fluids should also be evaluated to find ways to minimize purchase and installation cost. In addition, pilot scale testing of specific pieces of equipment is required to ensure innovations included in the design function as expected.