A comprehensive review of research works carried out at the Industrial Chemistry Research Institute and ordered by the Production Department of PKN ORLEN at Plock for modernization and intensification production processes as wen as for improvement of environmental and corrosion protection was given. In particular results of the research concerning separation of aromatic hydrocarbons and butadiene, manufacturing of phenol and acetone as well as separation of ethylene glycol from wastewater were presented. An importance of new analytical methods used for controlling industrial processes was outlined.