This work is aimed at developing the first version of a digital twin of a plant prototype for the flexible production of different chemical formulates, to be used in various industrial fields, from the medical health to the tanning sector. The analyzed system is a tubular flow reactor characterized by multiple additions of components and by a series of static mixing elements. Firstly, the 1D dynamic modeling of the reactor is addressed, by defining the geometry, parameters, and operating conditions to reasonably describe the process evolution over time. Then, the corresponding feedback control system is designed to obtain the desired final products, by respecting the required specifications, in terms of mean concentration, degree of mixing, and flow rates. Different types of control architectures are derived and compared. The results show that not only SISO control schemes, but also multivariable solutions are possible, which effectively guarantee set-point tracking and disturbance rejection.