[PaulHoule]

The Fischer-Trospch process has a stupendously high capital cost because, even though cheap catalysts work, chemical reactions that build up larger molecules (that can proceed explosively under some conditions) compete with chemical reactions that break molecules down and have to be balanced on a knife edge to get hydrocarbons of the right length.

For any normal industrial process people would be really delighted that they could use iron as a catalyst but the economics of FT are so bad they've scoured the periodic table for something better and not had much improvement.

[jmole]

Why cant you just distill them after producing them, instead of worrying about getting exactly the right length?

[PaulHoule]

Main issue is they want to be length 1 methane or length 1000+ polyethylene