Hydroxypropionic acid, hydroxypropionic acid derivatives, or mixtures thereof are dehydrated using a catalyst and a method to produce bio-acrylic acid, acrylic acid derivatives, or mixtures thereof. A method to produce the dehydration catalyst is also provided.

Hydroxypropionic acid, hydroxypropionic acid derivatives, or mixtures thereof are dehydrated using a catalyst and a method to produce bio-acrylic acid, acrylic acid derivatives, or mixtures thereof. A method to produce the dehydration catalyst is also provided.

Na.sup.+-SAPO-34 sorbents were ion-exchanged with several individual metal cations for CO.sub.2 absorption at different temperatures (273-348 K) and pressures (<1 atm). In general, the overall adsorption performance of the exchanged materials increased as follows: Ce.sup.3+<Ti.sup.3+<Mg.sup.2+<Ca.sup.2+<Ag.sup.+<Na.sup.+<Sr.sup.2+. The strontium exchanged materials excelled at low-pressure ranges, exhibiting very sharp isotherms slopes at all temperatures. The Sr.sup.2+ species were responsible for the surface strong interaction and the cations were occupying exposed sites (SII) in the materials Chabazite cages. All the sorbent materials exhibited higher affinity for CO.sub.2 over the other gases tested (i.e., CH.sub.4, H.sub.2, N.sub.2 and O.sub.2) due to strong ion-quadrupole interactions. Sr.sup.2+-SAPO-34 sorbents are by far the best option for CO.sub.2 removal from CH.sub.4 mixtures, especially at low concentrations.

A method for easily producing a heterogeneous catalyst having excellent catalytic activity at a low cost is provided. The heterogeneous catalyst is used for the purpose of synthesizing a cyclic carbonate by reacting an epoxide and carbon dioxide. A catalyst obtained by this production method and a method for synthesizing a cyclic carbonate with use of this catalyst are also provided.

A method for easily producing a heterogeneous catalyst having excellent catalytic activity at a low cost is provided. The heterogeneous catalyst is used for the purpose of synthesizing a cyclic carbonate by reacting an epoxide and carbon dioxide. A catalyst obtained by this production method and a method for synthesizing a cyclic carbonate with use of this catalyst are also provided.

Disclosed herein is a method for producing silica gel-immobilized phosphonium salt catalysts including the steps of (a) reacting a silane compound with a silica gel in the presence of xylene, to obtain a catalyst precursor having a haloalkyl group or a haloaryl group, wherein the silane compound has a haloalkyl group or a haloaryl group, and a proportion of the silane compound is from 0.001 to 0.06 mol relative to 1 mol of the silica gel, and (b) reacting the catalyst precursor with a tertiary phosphine in xylene, to obtain a catalyst for synthesizing a cyclic carbonate, in which the silane compound is represented by formula (1), and the tertiary phosphine is represented by formula (2):
XR.sup.1Si(OR.sup.2).sub.3(1) ##STR00001##

Disclosed herein is a method for producing silica gel-immobilized phosphonium salt catalysts including the steps of (a) reacting a silane compound with a silica gel in the presence of xylene, to obtain a catalyst precursor having a haloalkyl group or a haloaryl group, wherein the silane compound has a haloalkyl group or a haloaryl group, and a proportion of the silane compound is from 0.001 to 0.06 mol relative to 1 mol of the silica gel, and (b) reacting the catalyst precursor with a tertiary phosphine in xylene, to obtain a catalyst for synthesizing a cyclic carbonate, in which the silane compound is represented by formula (1), and the tertiary phosphine is represented by formula (2):
XR.sup.1Si(OR.sup.2).sub.3(1) ##STR00001##

A transesterification catalyst that is heterogeneous and a method for preparing said transesterification catalyst are provided. The catalyst can be used in a variety of transesterification reactor configurations including CSTR (continuous stirred tank reactors), ebullated (or ebullating) beds or any other fluidized bed reactors, and PFR (plug flow, fixed bed reactors). The catalyst can be used for manufacturing commercial grade biodiesel, biolubricants and glycerin.

A transesterification catalyst that is heterogeneous and a method for preparing said transesterification catalyst are provided. The catalyst can be used in a variety of transesterification reactor configurations including CSTR (continuous stirred tank reactors), ebullated (or ebullating) beds or any other fluidized bed reactors, and PFR (plug flow, fixed bed reactors). The catalyst can be used for manufacturing commercial grade biodiesel, biolubricants and glycerin.

The present invention relates to heterogeneous acid catalysts comprising or consisting of mixed metal salts, of lithium and aluminum phosphates and sulfates, and combinations with metallic cations, such as magnesium, titanium, zinc, zirconium and gallium, to provide adequate Lewis acidity; organic or inorganic porosity promoters, such as polysaccharides; and agglomerates, such as clays, kaolin and metal oxides of the type M.sub.xO.sub.y, where; M=Al, Mg, Sr, Zr or Ti, and other metals of groups IA, IIA and IVB, x=1 or 2 and y=2 or 3, for the formation of particles. A process is disclosed for obtaining from the catalyst by the hydrolysis of aluminum lithium hydride with water and oxygenated solvent, such as an ether. The catalysts are used in batch reactor and continuous flow systems in reactions that require moderate Lewis acidity, such as refining, petrochemical and general chemistry, including the transesterification of glycerides to produce alkyl esters.