Abstract: In the process for reforming a biomass in accordance with the present invention, a mixture of a biomass and water as a raw material is compressed by a compressing pump 2 to be deposited into the inlet side of a circulating pump 43 in a primary reactor 41. The mixture is discharged from the circulating pump 43, conveyed to a heater 45, and then heated at a temperature ranging from 200 to 260° C., and sent to a reacting bath 47. In the reacting bath 47, hemicellulose contained in the biomass dissolves in hot water and subjected to a carbonizing reaction. The mixture derived from the primary reactor 41 is deposited in the inlet side of a circulating pump 44 of a secondary reactor 42, and sent to a heater 46, heated here at a temperature ranging from 270 to 330° C., and sent to the reacting bath 47. In the reacting bath 47, cellulose contained in the biomass dissolves in hot water, and is subjected to a carbonizing reaction.

Abstract: A hydrodemetallizing catalyst for a hydrocarbon oil comprising a support and a catalytic component carried on the support, this catalyst having a surface, part of which has a coating layer composed of an inert substance having substantially no demetallizing activity, this coating layer allowing substantially no reaction fluid to permeate therethrough. This catalyst preferably has a reaction flow path through which a reaction fluid flows thereinside and is preferred to be, for example, in the form of a honeycomb structure or cylinder having one or a plurality of through holes.In the hydrodemetallization of heavy oils using the above hydrodemetallizing catalyst for a hydrocarbon oil, the sticking of the catalyst can be prevented and the spacing between catalyst particles can be maintained to thereby prevent a rapid increase of differential pressure, so that a continuous operation can be performed for a prolonged period of time.

Abstract: Terephthalic acid produced by oxidizing paraxylene can be obtained in the form of dried powder from the slurry containing terephthalic acid and acetic acid and/or water by using combination of a tubular type heater having at least one heating tube and a separation chamber in which the heating tube(s) open(s) at one end(s) thereof.Critical slurry concentrations for smooth operation are given.

Abstract: Reaction mother liquor of terephthalic acid production is treated to separate volatile component mainly composed of acetic acid and solid components composed of used catalyst or heavy metal salt(s), residual terephthalic acid and reaction by-products by using combination of a tubular type heater having at least one heating tube of a relatively small diameter and a separation chamber in which the heating tube(s) open(s) at one end thereof.