Process for converting alkanes to carbon filaments

The present invention includes a process for producing carbon filaments and synthesis gas from a mixture of alkanes, preferably natural gas, comprising converting a first portion of the alkanes, preferably C2 hydrocarbons, directly to carbon filaments and converting a second portion of the alkanes, preferably methane, to syngas. The natural gas may be separated into a first feed stream comprising ethane, propane, and butane and a second feed stream comprising methane. The first feed stream is fed to a carbon filament CF reactor to produce carbon filaments and hydrogen. The second feed stream is fed to a syngas production reactor to produce syngas. Alternatively, the natural gas is fed to at least one carbon filament reactor that is maintained at an effective temperature to convert C2 hydrocarbons in the natural gas to carbon filaments and hydrogen, thereby filtering methane from the natural gas.