The Halliburton Oil Well Cementing Company, a subsidiary of Halliburton, Inc., developed a commercial process using sorbates instead of the prior practice of using cement or resins. This process is directed to a reduction in the amount of water produced during cementing. The reduction in water is accomplished by bringing a solvent, such as butyl acetate, into contact with the C-S-H gel prior to the addition of cement, drying the C-S-H gel while it is wet by adding sorbate adsorbent, and drying the wet C-S-H gel with air to remove the remaining solvent. Because the C-S-H gel is already dry, no solvent is wasted.
As shown in figure 18, these zeolites have a negative zeolite crystallinity number, which is due to the presence of C + H groups. The known natural zeolites have a negative crystallinity number in the range of -30 to -66; the Cs, -29 to -22; the P, -5 to -3. The Figure also shows that the resultant zeolite product textural characteristics are a balance of the properties of the hydrothermally reacted precursor gel-like material and the subsequent acid leaching. The textural properties are directly related to the hydrothermal treatment, which is based on the diffusion of water, cationic species, and anions into and out of the reactant gel network, and the subsequent leaching of cationic species in an acid medium. The amount of acid used and the reaction time vary with the desired product characteristics, such as the average pore diameter.
Heteropoly acids are cyclic, complex, multinuclear oxoanions that have strong Lewis acid functionality, shown in figure 19. These functionalities are not adequately bound in the case of the traditional ligands, such as the typical carboxylates or sulfonates. A few ligands, specifically those having heteroatoms such as nitrogen and oxygen, allow H to be coordinated while still significantly weakening the neighboring oxygen-oxygen double bonds. The resulting acid complexes are useful initiators when a conventional ligand is difficult to obtain. d2c66b5586