The calculated distance (air line) between Limburg an der Lahn and Düsseldorf is approximately 80 miles respectively 129 kilometers.
By car or train, the actual journey to Düsseldorf is certainly longer, as only the direct route (as the crow flies) between Limburg an der Lahn and Düsseldorf has been calculated here.
Air line (approximately)
129 kilometers
70 nautical miles