Abstract: A method is provided for preserving cooking oil in a food fryer which comprises contacting the oil in situ with at least one oil-permeable cement body which is a stand-alone block and which has been hydraulically hardened from a paste comprising (i) white OPC clinker, (ii) white OPC or (iii) a mixture of white OPC clinker and white OPC, wherein the porosity of the cement body, estimable from the difference between its water-saturated and dry weights, is 30-55%, pores in the body being oil receptive by virtue of low un-bound water content.

Abstract: A method is provided for preserving cooking oil in a food fryer which comprises contacting the oil in situ with at least one oil-permeable cement body which is a stand-alone block and which has been hydraulically hardened from a paste comprising (i) white OPC clinker, (ii) white OPC or (iii) a mixture of white OPC clinker and white OPC, wherein the porosity of the cement body, estimable from the difference between its water-saturated and dry weights, is 30-55%, pores in the body being oil receptive by virtue of low un-bound water content.

Abstract: An hydraulically set oil-permeable cement body is provided in the form of a stand-alone block or briquette for preserving cooking oil during deep fat frying, said body. It has substantially no free water or having a low free water content for resisting damage on immersion in cooking oil and initial heating and is enclosed in packaging that resists ingress of water or water vapor The block or briquette consists of >50 wt % of a mixture of milled white OPC clinker and white OPC, optionally silica 1-2 wt % and/or titania (TiO2) 1-2 wt % and optionally further ingredients selected from calcium silicate, magnesium silicate, aluminum silicate, natural feldspars, natural sodium zeolites, natural calcium zeolites, synthetic sodium zeolites, synthetic calcium zeolites, wollastonite, calcium hydroxide, clays, pillared clays, activated clays/earths, talcs/kaolinite, amphiboles, granite porphyry, rhyolite, agalmatolite, porphyry, attapulgite and diatomaceous earth.

Abstract: In the moulding of cementitious articles, a flexible plastics mould e.g. of LDPE may be used to permit de-moulding of the articles e.g. by flexion of the mould. Moulds filled with hydraulically settable material may be supported in frames configured e.g. with plug and socket formations on upper and lower faces for cooperation with moulds to retain them in position and for cooperation with overlying and underlying frames to permit stacking.

Abstract: An hydraulically set oil-permeable cement body is provided in the form of a stand-alone block or briquette for preserving cooking oil during deep fat frying, said body. It has substantially no free water or having a low free water content for resisting damage on immersion in cooking oil and initial heating and is enclosed in packaging that resists ingress of water or water vapour The block or briquette consists of >50 wt % of a mixture of milled white OPC clinker and white OPC, optionally silica 1-2 wt % and/or titania (TiO2) 1-2 wt % and optionally further ingredients selected from calcium silicate, magnesium silicate, aluminium silicate, natural feldspars, natural sodium zeolites, natural calcium zeolites, synthetic sodium zeolites, synthetic calcium zeolites, wollastonite, calcium hydroxide, clays, pillared clays, activated clays/earths, talcs/kaolinite, amphiboles, granite porphyry, rhyolite, agalmatolite, porphyry, attapulgite and diatomaceous earth.

Abstract: A method is provided for preserving cooking oil which may be cold or heated or during frying operations, which comprises in situtreatment of the oil withat least one oil-permeable cement body which has been hydraulically hardened from a paste comprising cement clinker and cement e.g. white OPC clinker and white OPC. The invention further comprises cooking oil having therein at least one oil-permeable cement body which has been hydraulically hardened from a paste comprising cement clinker and cement and an oil-permeable cement body for use in the above method.

Abstract: A method is provided for preserving cooking oil which may be cold or heated or during frying operations, which comprises in situ treatment of the oil withal least one oil-permeable cement body which has been hydraulically hardened from a paste comprising cement clinker and cement e.g. white OPC clinker and white OPC. The invention further comprises cooking oil having therein at least one oil-permeable cement body which has been hydraulically hardened from a paste comprising cement clinker and cement and an oil-permeable cement body for use in the above method.

Abstract: A method is provided for forming zeolite membranes in internal surfaces of a plurality of conduits in a cylindrical porous ceramic monolith, the conduits extending from one end of the monolith to the other and being disposed in a single annulus, said method including a step of: flowing a pre-treatment liquid (50) including a zeolite initiating agent into the conduits; causing at least part of a carrier liquid component of the treatment liquid to flow from the FIG. 4 conduits into and through the body of the monolith to the exterior; and causing zeolite crystals to be deposited in the porous internal surfaces of the conduits as the carrier liquid component flows into the monolith.

Abstract: A method is provided for separating water from an organic solvent which comprises: passing the solvent through at least one conduit within a porous ceramic with a zeolite membrane formed on the internal surface of the conduit; recovering solvent of reduced water content from the conduit; and recovering water which has passed via the membrane through the ceramic to the exterior thereof. The velocity at which the solvent is passed through the conduit induces turbulent flow for scouring solids from the surface of the membrane and reducing or preventing concentration of the organic solvent on the membrane surface e.g.

Abstract: A method is provided for forming zeolite membranes in internal surfaces of a plurality of conduits in a cylindrical porous ceramic monolith, the conduits extending from one end of the monolith to the other, said method including a step of: flowing a pre-treatment liquid including a zeolite initiating agent into the conduits; causing at least part of a carrier liquid component of the treatment liquid to flow from the conduits into and through the body of the monolith to the exterior; and causing zeolite crystals to be deposited in the porous internal surfaces of the conduits as the carrier liquid component flows into the monolith.

Abstract: A method is provided for treating cooking oil during frying operations, which comprises in situ treatment of the oil with a source of calcium or magnesium combined with silicate such that the calcium or magnesium substantially does not leach into the oil. The filter treatment materials may be cement clinker, OPC, calcium silicate and combinations or mixtures thereof e.g. a combination of white OPC clinker and white OPC. The filter treatment materials may be in the form of a free briquette or block immersed in the oil. In other embodiments a decontaminating or filter cartridge is provided for fitting to a deep oil or fat cooker or a frying basket and comprises a foraminous housing containing filtering or decontaminant material. The cartridge may be used in association with a deep oil or fat fryer having a base formed with a depression defining a cool spot, the cartridge fitting in or on said cool spot.

Abstract: An improved porous substrate for zeolite membranes is formed by coating the substrate with a layer of zeolite particles of a narrow particle distribution size of between 20 and 0.01 microns.

Abstract: A process for treating zeolite membranes to improve their performance and to improve their coherence consists of forming a film of zeolite material on a porous support to form a zeolite membrane, contacting the membrane with tetraethylorthosilicate (TEOS), and reacting said TEOS with said zeolite membrane to form a supported membrane with open pores without defective pin holes. The process may further comprise pre-treatment of the porous support with a zeolite initiating agent, or post-treatment of the treated membrane with a silicic or polysilicic acid.

Abstract: A process for treatment of zeolite membranes to improve performance which comprises contacting the membrane with a silicic acid or a mixture of silicic acids.