The additives can be preheated before entry to the system, including a phase change, such as heating EG liquid to the vapor state to provide heat for the reactor. [0396] In the preferred embodiments shown in FIGS. 12a and 12 b, the introducing means comprises a sealable channel, as represented by any of the arrows in FIGS. 12a and 12 b, through the pipe reactor allowing fluid communication between