actually a living organism is needed to produce it this way

Wikipedia says "In industry dimethyl sulfide is produced by treating hydrogen sulfide with excess methanol over an aluminium oxide catalyst”.

Which part requires a living organism?

I think they are being a little glib by saying a human is need to make the industrial processes.

Well, someone needs to treat the hydrogen sulphide with excess methanol over an aluminium oxide catalyst. I suppose a robot could do it...

For a non-life explanation, you're really looking for something that could plausibly happen in (abiotic) nature, not an industrial process.

The only thing that could make a nerd happier than detecting alien life would be detecting alien robots.

Wait, what's the difference?

Alien life could just be microbial, while alien robots would require an advanced technological civilization, I guess

Well, there could be nanobots...

Virtually all of them involve non-trivial design by sentient beings.

  Which part requires a living organism?
haha. Do you really need a hint?