(291e) Past, Present, and Future of Gas to Liquids Technology

The development of technology for the economical conversion of natural gas to easily transportable liquid products (Gas-to-Liquids, GTL technology) has a rich history and yet remains a challenging and important problem for Chemical Engineering. GTL technology was first developed in the 1920s and made use of the Fischer-Tropsch (FT) process to convert synthesis gas (Syngas) to mix of linear alkanes suitable for diesel fuel. Sasol in South Africa has been at the forefront in the application of the Fischer Tropsch technology, using coal and natural gas as a feedstock for Syngas formation. Modifications to the basic Syngas-FT process have been made by Exxon-Mobil, Shell, and others who have produced low-sulfur diesel fuel. Methanol is also readily synthesized as a liquid product from natural gas derived Syngas and Exxon-Mobil's process to convert natural gas into gasoline made use of the methanol intermediate. At present, methanol is the most widely produced liquid product from natural gas, however, several large commercial projects have been recently completed or are under construction for Syngas-FT based GTL. In recent years, increasing oil prices and the availability of large quantities of relatively low cost and underutilized natural gas have driven an increased interest in improving GTL technology, particularly to deal with natural gas resources that cannot currently be developed economically. New process development methodologies and tools play an important role in developing the new generation of GTL processes. We will discuss several new approaches to this problem. Technology developed by GRT Inc. using bromine activation of natural gas allows small scale production of liquid hydrocarbons such as gasoline and aromatics from stranded gas reserves. This new approach can address the problem of monetizing small gas resources and can reduce or eliminate flaring in small to medium size gas fields.