If you inbound from ALC is on time you will have no problem making the connection.
The MCT (Minimum Connection Time) in DUS is 35 min. It is a very small airport.

If the ALC flight is delayed AB needs to rebook you and pay for meals, hotel, extra transportation and EC265.
Best is to have information about alternate ways to get to your final destination. This are the options for a random date this summer after 2 pm:

[KVS Tool 8.0.1 - Timetable/NL]

DUS Dusseldorf Metro / Intl DE = DUS NRN QDF [EDDL]
HKG Hong Kong Chek Lap Kok Intl HK [VHHH]
THU 23 Jun 2016 - 30 Jun 2016

Carrier Flight From Depart To Arrive A/C St Frequency | Dur'n | Dep T | Arr T | Effect | Ending | Exceptions
--------- ------ ---- -------- ---- -------- --- -- ----------------------------------------------------------------
CX 376 DUS 13:25 HKG 06:35 +1 77W 0 12-4-6- 11:10 - 1 02 Jun 30 Jun

LH 2021 DUS 20:30 MUC 21:40 EQV 0 12345-7 12:55 - 2 23 Jun 30 Jun
-> LH 730 MUC 22:20 HKG 15:25 +1 346 0 2 1

LH 87 DUS 19:40 FRA 20:30 319 0 1234567 13:35 - 1 05 Jun 01 Jul
-> LH 796 FRA 22:10 HKG 15:15 +1 388 0 1 1

KL/## 1858 DUS 14:35 AMS 15:30 F70 0 1234567 13:45 - - 18 May 29 Oct
-> KL 887 AMS 17:20 HKG 10:20 +1 74E 0 - 1

AY 708 DUS 18:45 HEL 22:00 EQV 0 1234567 13:45 - 2 23 Jun 30 Jun
-> AY 69 HEL 23:50 HKG 14:30 +1 359 0 2 1

LH 2019 DUS 19:30 MUC 20:40 EQV 0 1234567 13:55 - 2 23 Jun 30 Jun
-> LH 730 MUC 22:20 HKG 15:25 +1 346 0 2 1

4U 9462 DUS 18:25 LHR 18:50 319 0 ------7 14:35 - 2 05 Jun 26 Jun
-> CX 256 LHR 20:10 HKG 15:00 +1 77W 0 3 1

AB 6045 DUS 18:50 MUC 20:05 320 0 12345-7 14:35 - 1 23 Jun 30 Jun
-> LH 730 MUC 22:20 HKG 15:25 +1 346 0 2 1

LX 1027 DUS 19:50 ZRH 21:00 EQV 0 12345-7 14:40 - - 23 Jun 30 Jun
-> LX/## 138 ZRH 22:45 HKG 16:30 +1 77W 0 - 1

G3/A5 8545 DUS 20:35 CDG 21:50 EMJ 0 12345-7 14:50 - 2F 23 Jun 30 Jun
-> AF 188 CDG 23:30 HKG 17:25 +1 EQV 0 2E 1

... and many more longer connections.