Gasification of Algae for the Production of CNG

Abstract

This project involved designing a process that converts algae into compressed natural gas (CNG). The algae enter the process in a water slurry at 2.5% algae by mass. The algae are then converted into methane and other gases at supercritical conditions in a reactor. The gas mixture is then purified by removing the carbon dioxide and hydrogen gases. The sellable products this process produces are CNG and hydrogen. In addition, the carbon dioxide and salts are recycled back to the algae farms. This makes the process environmentally responsible as the carbon dioxide created in the process is not released to the atmosphere. Before the process is built, it is recommended that the reactor and salt separator technologies are tested on a pilot scale to ensure their viability on an industrial scale. A process hazard analysis was completed as a part of this project in order to eliminate any safety issues with the process. Despite the process and equipment optimizations that were performed, the economic analysis suggested that the process is not economically viable. However, it may become viable in the future through the development of the catalyst and equipment technologies.