From DUS airport to Essen main station, you have the following options:

S-Bahn: every 20 minutes, takes about 45 minutes, should not be that expensive, I bet around 5 Euros / OW

regional train: runs about 3 times / hour as well but not in a steady rhythm like the S-Bahn. This one takes about 20-25 minutes. The price should be about the same

ICE (Inter City Express): every once in a while, even an ICE is available. Travel time on that segment is not really shorter compared to the regional train but I bet it's a lot expensive (compared to the other options)

All trains (except the S-Bahn into Düsseldorf that you do not want) leave from the so called "Fernbahnhof" (outside station) You need to take the Skytrain from the Terminal Building (stops at AB and C) to get there.


Let me know if you need more information.