(58a) The Chemistry and Engineering Of C1 Species and The Catalytic Challenges Of Diverse Feedstocks Without C-C Bonds

The recurring cycle of
interest in unconventional carbon sources as precursors to chemicals and
transportation fuels returns our attention (once again) to the conversion of
molecules, such as methane, methanol, and dimethyl ether, lacking C-C bonds.  Such C₁ species, and methane in
particular, present specific thermodynamic and kinetic challenges that lead to significant
complexity and cost in conversion processes. 
 Experience and knowledge,
gathered at significant expense over the last two decades, has brought to us a
clearer view of the inherent bottlenecks. 
This talk gathers such learnings and provides
some guidance about remaining opportunities, 
In doing so, it examines: (i) the kinetic consequences of thermodynamic
constraints and the inherent limitations of catalysis in overcoming them; (ii)
the preeminence of process simplicity and inexpensive oxidants over the allure
of direct conversion processes; (iii) the concepts of kinetic and thermodynamic
protection in indirect methane conversion processes; (iv) the coupling of
separations and reactions and the cascading of multiple reactions within
thermal conduction distances; and (v) the ubiquitous kinetic bottlenecks in
forming the first C-C bond in C₁ species.  This guidance is rooted in the long history
of conversion technologies and brings together fundamental understanding of the
formidable kinetic and thermodynamic constraints with engineering and practical
tools designed to overcome them.  The
conclusions may seem sobering - as the magnitude of the challenge so warrants -
but seek to focus scientific and engineering inquiries within the narrow range
of what is possible and practical and to assess ideas of apparent novelty and
glamour, as they periodically emerge, within a common context of first principles
in kinetics, thermodynamics, and reaction engineering.