Small-Scale Fischer-Tropsch

One avenue of research seeks to test the scaling laws applied to the Fischer-Tropsch synthesis, a process by which an array of liquid hydrocarbons is produced from carbonaceous synthesis gas. LCSE researchers are working to develop a model which will demonstrate the viability and cost-saving potential of small scale Fischer-Tropsch reactors for liquid hydrocarbon production.

The Fischer-Tropsch process entails hydrogenation of adsorbed CO to form CH2 “monomers” for stepwise oligomerization. At each stage, adsorbed hydrocarbon can desorb, hydrogenate, or continue chain growth with another monomer. The result is a suite of hydrocarbons of varying chain length and industrial applicability. Historically, research and development of the process assumed singular large-scale structures, embracing and discarding reactor designs under that assumption.

The Fischer-Tropsch synthesis that is the focus of this research explored the advantages of smaller units. Existing reactors separate and recycle the output streams back into their own input stream to maximize conversion, but a network of smaller-scale reactors allows output streams to be customized between reactors. Of particular importance is the study and management of the secondary reactions that occur in a Fischer-Tropsch reactor, as recycled olefins have been demonstrated to be catalytically reabsorbed for further transformation and synthesis. Understanding the conditions under which this occurs and the effect of various operating conditions on selectivity of products informs a networking control strategy; enhanced control of reactants allow more selective control of products.

The model developed and demonstrated had three primary objectives:
• Demonstrate its own viability through simulations that can be correlated with existing Fischer-Tropsch synthesis data
• Identify and quantify cost drivers to existing large-scale optimization strategies and cost savings of smaller scale aggregated networks
• Perform analysis of a simulated aggregate network of small scale modules, identifying and optimizing selectivity and efficiency of liquid hydrocarbon production

Researchers

Klaus Lackner, Ewing-Worzel Professor of Geophysics, klaus.lackner@columbia.edu (PI)
Tom Socci, PhD 2013, Earth and Environmental Engineering