The simulation results suggest that conventional start-up strategies for DWCs are not generally adaptable or applicable to mDWCs. By simulating the start-up process, potential problems that can occur during the start-up, like the infeasibility of the start-up strategy or excessively long start-up times, can be identified. The discontinuous start-up strategy is found to be infeasible for the mDWC, while the continuous start-up strategy is feasible, but needs to be modified to end up with a reasonable start-up time. Changing the initial reboiler composition to pure heavy boiler is found to have a large influence on the start-up time and can reduce the time significantly. The time of feed introduction can also have a large effect on the start-up process.