List of recommended hotels, located near the Symposium site:

City Hotel Essen             (2min. walk, homepage not available at the moment)

https://www.motel-one.com/de/hotels/essen/hotel-essen/      (15min. walk)

http://handelshof.select-hotels.eu/            (20min. walk, next to train station)

https://www.intercityhotel.com/hotels/alle-hotels/deutschland/essen/intercityhotel-essen  (20min. walk, next to train station)

https://www.essener-hof.com      (20min. walk, next to train station)

https://www.welcome-hotels.com/hotels/essen/  (10min. walk)

There are several other hotels and accommodations nearby. The university can also be easily reached by public transport ("Rheinischer Platz" or "Universität Essen" stops)