Abstract: A method and cleaning system is disclosed for cleaning the outer surface of a fouled microfiltration (MF) or ultrafiltration (UF) semipermeable hollow fiber membrane after its initial stable transmembrane flux has been decreased to an unacceptably low level. The method is specifically applicable to any fiber used to withdraw purified water from dirty water, particularly water containing organic matter including beneficial bacteria and/or undesirable inorganic salts, where the viability of the bacteria population is to be maintained. The membrane is cleaned by flowing a cleaning fluid, preferably a biocidal oxidative electrolyte having an oxidizing anion and an associated cation through the clean, permeate-side of the membrane, at low pressure no more than the bubble pressure breakthrough, usually <300 kPa (30 psig) for a MF or UF fiber.

Abstract: A process is described for purifying an oil-containing liquid to remove aqueous and solid impurities which comprises passing said liquid through a permeable inorganic membrane previously treated by contacting the membrane with an organic reactant selected from the group consisting of a phosphonic acid, a phosphinic acid, a monocarboxylic acid, a dicarboxylic acid, a boronic acid, a phosphoric acid ester and a precursor which decomposes upon contact with said inorganic membrane to form one of said organic reactants whereby the treated membrane is capable of separating aqueous and solid impurities from hydrocarbons in the oil-containing liquid.

Abstract: A composite HCl adsorbent comprising about 50-95 wt % alumina and about 5-50 wt % Y zeolite wherein the molar ratio of SiO.sub.2 to Al.sub.2 O.sub.3 is about 4.5-6.0. The adsorbent is produced by admixing particles of alumina and acid-treated Y zeolite, agglomerating, aging and activating. The activated composite adsorbent has improved dynamic adsorption behavior for HCl compared with both the alumina and Y zeolite starting materials.

Abstract: An improved Claus catalyst comprising activated alumina in which sodium oxide concentration is controlled to achieve increased sulfur conversion. Sodium oxide is present in an amount greater than 1.0 wt % (1100.degree. C. calcined basis), the remainder being activated alumina. Specific surface area is greater than 100 m.sup.2 /g (BET). The catalyst preferably has a surface area greater than 300 m.sup.2 /g (BET) and an LOI (hydroxyl content as determined by heating from 400.degree. to 1100.degree. C.) between 2.0 and 6.0 wt %.

Abstract: An improved Claus catalyst comprising activated alumina in which sodium oxide concentration is controlled to achieve increased sulfur conversion. Sodium oxide is present in an amount greater than 0.50 wt % (1100.degree. C. calcined basis), the remainder being activated alumina. Specific surface area is greater than 100 m.sup.2 /g (BET). In a preferred embodiment, sodium oxide content is controlled in the range 1.0 to 2.5 wt %. The catalyst preferably has a surface area greater than 300 m.sup.2 /g (BET) and an LOI (hydroxyl content as determined by heating from 400.degree. to 1100.degree. C.) between 2.0 and 6.0 wt %.

Abstract: An improved Claus catalyst is provided in the form of activated alumina in which sodium oxide concentration, LOI and surface area of the catalyst are carefully controlled to achieve increased sulfur conversion. Sulfur recovery is enhanced by choosing an alumina catalyst having properties which minimize chemisorption of sulfur dioxide on the catalyst at reaction conditions. Sodium oxide may be present in an amount of 0.1 to 2.5 wt % of the catalyst (1100.degree. C. calcined basis). The catalyst desirably has a surface area greater than 100 m.sup.2 /g (BET) and an LOI (hydroxyl content as determined by heating from 400.degree. to 1100.degree. C.) between 2.0 and 6.0 wt %. A method of producing the catalyst and a method of using the catalyst are also provided.

Abstract: A low soda pseudoboehmite gel is provided by reacting a NaAlO.sub.2 solution with a NaHCO.sub.3 solution having a concentration of less than 75 grams/liter and preferably less than 50 grams/liter. The soda content of the resulting AlO(OH) gel can be further lowered by repeated washing and/or redispersing (repulping) in water and/or further neutralization with a carboxylic acid having 1 to 6 carbon atoms.