Zinc titanate sorbents
Gupta, R., Gangwal, S., & Jain, S. C. (1998). IPC No. U.S.Zinc titanate sorbents (Patent No. 5714431.)
The present invention provides a zinc titanate sorbent materialuseful in desulfurization applications. The zinc titanate materialis in the form of generally spherical particles of substantiallyuniform chemical distribution. The sorbent material is capable ofabsorbing sulfur compounds from a gaseous feed in an amount of atleast about 15 weight percent based on the weight of the sorbent.The sorbent material is prepared by a process including: (a)forming a zinc oxide/titanium dioxide dry blend, (b) preparing asubstantially uniform aqueous slurry comprising the zincoxide/titanium dioxide dry blend, organic binder, and at leastabout 1 weight percent inorganic binder based on the solids weightof the slurry, (c) spray drying the slurry to produce substantiallyspherical particles, and (d) calcining the particles at atemperature of between about 750.degree. C. to about 950.degree. C.The dry blend is formed by mixing between about 0.5 to about 2parts zinc oxide having a median particle size of less than about0.5 .mu., and about 1 part titanium dioxide having a medianparticle size of less than about 1 .mu.. The slurry containssubstantially no free silica and may be prepared by the processincluding (1) preparing an aqueous solution of organic binder, (2)adding the dry blend to the aqueous solution of organic binder, and(3) adding the inorganic binder to the solution of organic binder,and blend. Additional reagents, such as a surfactant, may also beincorporated into the sorbent material. The present invention alsoprovides a process for desulfurizing a gaseous stream. The processincludes passing a gaseous stream through a reactor containing anattrition resistant zinc titanate sorbent material of the presentinvention.