Study On A Novel Technology To Produce Novolac For A Clean Production

Large quantities of waste water are generated in the producing of phenol novolac resins. The waste water contains a lot of free phenols that badly pollute the environment. The concentration of free phenol in the drained water is about 16000～440000ppm. Though there are several methods to deal with the waste water, such as chemical oxidation method, high-pressure steam method, etc., at,the same time they cause other problems such as loss of phenol and increase the cost. Therefore they are still not the ultimate ways to solve this problem.Phenol novolac resin was synthesized in this thesis by using new selective catalyst and new technology (a shortened form as SPN, while phenol novolac which was synthesized by the conventional method was shortened for CPN). The concentration of free phenol in the drained water decreased to below 500ppm when phenol novolac resin was produced by this new technology.The significance of factors (concentration of catalyst, mol ratio of formaldehyde to phenol, reacting time, reacting temperature) influenced the results (yield, soften point, concentration of free phenol in the drained water) and the optimal synthesizing technology were found out through orthogonal experiments. The influence significance to yield and soften point was: reacting time > concentration of catalyst > reacting temperature > mol ratio of formaldehyde to phenol. The influence significance to concentration of phenol in the drained water was: concentration of catalyst > mol ratio of formaldehyde to phenol > reacting temperature > reacting time. The optimal synthesizing technology was: concentration of catalyst was 15%, mol ratio of formaldehyde to phenol was 1.05, reacting time was 12h, reacting temperature was 85℃.The rules of factors influenced the concentration of free phenol in the drained water were revealed through comparative experiments. The concentration of free phenol in the drained water would decrease with the increasing of concentration of solvent (or increasing of concentration of catalyst, or increasing of mol ratio of formaldehyde to phenol, or increasing of reacting time, or decreasing of reacting temperature). The method of using a solvent to extraction novolac was better than...