Abstract: A process for the production of a bisphenol compound comprising: a step for reacting a phenolic compound (a) with at least one compound (b) selected from the group consisting of dialkenylbenzene compounds, bis(hydroxyalkyl)benzene compounds and (hydroxyalkyl)-alkenylbenzene compounds or at least one compound (c) selected from the group consisting of monoalkenylphenolic compounds and mono(hydroxyalkyl)phenolic compounds in the presence of an acidic catalyst to obtain a reaction mixture containing said bisphenol compound, a step for neutralizing the reaction mixture with an anion exchange resin, a step for removing a remaining phenolic compound from the reaction mixture to concentrate the neutralized reaction mixture, and a step for isolating the bisphenol compound from the resulting concentrated mixture. This process enables to produce a bisphenol compound, which is useful for preparing raw materials of thermoplastic polymers, surface-active agents and stabilizers.

Abstract: A process for the production of lower olefins by dehydrating lower alcohols having 2 to 4 carbon atoms which comprises using a .gamma.-alumina catalyst containing 0.3% by weight or less of impurities in total excluding SiO.sub.2, the impurities including 0.2% by weight or less of sulfur content calculated in terms of SO.sub.4 - and 0.05% by weight or less of sodium content calculated in terms of Na.sub.2 O, and/or a process for the production of lower olefins by dehydrating lower alcohols having 2 to 4 carbon atoms that comprises using a .gamma.-alumina catalyst which contains 0.5 to 5% by weight of SiO.sub.2.According to the process of the present invention, lower olefins can be produced from lower alcohols with high yield and high selectivity for a prolonged period of time without reducing the catalytic activity.

Abstract: Propylene can be prepared in high yield and selectivity by dehydrating isopropanol in the presence of a .gamma.-alumina catalyst having a mean pore diameter of from 30 to 150 .ANG. with a standard deviation (.sigma..sub.n) of from 10 to 40 .ANG. based on statistic calculation from pore diameter and pore volume.