Reaction of Glycerol

Glycerol is obtained from biomass via hydrolysis or methanolysis of triglycerides. The growth in the production of biodiesel by the transesterification of oil is responsible for the increased production of glycerol and its lower cost. This could lead to many applications for glycerol, which can be transformed into valuable chemicals.  

Catalyst BET surface area (m -g ) Acid/base site ratio 

Ceria-supported catalysts are well known in oxidation reactions and gold nanoparticles supported on ceria are excellent general heterogeneous catalysts for the aerobic oxidation of alcohols (see Vivier and Duprez and references therein). Corma and colleagues showed that the efficiency of the catalysts can be improved by using ceria supports with high specific surface areas and attributed this behavior to a cooperative effect between gold and ceria.  

Demirel et al studied the liquid-phase oxidation of polyalcohols with both primary and secondary alcohol groups they compared the reactivity of n-propanol and glycerol at 60°C, pH = 12, / o2 = 1 on ceria-supported gold catalysts. It was difficult to correlate oxidation activity with the specific surface area the most active catalyst was 

1 wt% Au/CeOs with a specific surface area equal to 60 No 

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Animal fats and vegetable oils are triacylglycerols, or triesters, formed from the reaction of glycerol (1,2, 3-propanetriol) with three long-chain fatty acids. One of the methods used to characterize a fat or an oil is a determination of its saponification number. When treated with boiling aqueous KOH, an ester is saponified into the parent alcohol and fatty acids (as carboxylate ions). The saponification number is the number of milligrams of KOH required to saponify 1.000 g of the fat or oil. In a typical analysis, a 2.085-g sample of butter is added to 25.00 ml of 0.5131 M KOH. After saponification is complete, the excess KOH is back titrated with 10.26 ml of0.5000 M HCl. What is the saponification number for this sample of butter ... 

From Glycerol. A procedure for synthesizing alph a-m on ochl orohydrin (3-chloro-l,2-propanediol) in 85—88% yields by the reaction of glycerol [56-81-5] with aqueous hydrochloric acid in the presence of a catalytic amount of acetic acid has been developed (59). An anhydrous procedure that involves the reaction of glycerol and HCl gas in the presence of acetic acid has also been described (60). 

No by-product is formed from this reaction. Toluene diisocyanate (Chapter 10) is a widely used monomer. Diols and triols produced from the reaction of glycerol and ethylene oxide or propylene oxide are suitable for producing polyurethanes. 

Problem 23,1 I One of the steps in fat metabolism is the reaction of glycerol (1,2,3-propanetriol) with ATP to yield glycerol 1-phosphate. Write the reaction, and draw the structure of glycerol 1-phosphate. 

Surfactants are also prepared by the reaction of glycerol derivatives RC02 [CH2CH(0H)CH20] H (R = C6 16 alkyl, n = 1-5) with P4O10 at 60-80°C with subsequent neutralization of the resulting phosphate ester acids with aqueous alkali or alkanolamine solution at 50-70°C [10]. 

Write the structural formula for the product of (a) the reaction of glycerol (1,2,3-trihydroxypropane) with stearic acid, CH5(CH2)16COOH, to produce a saturated fat (b) the oxidation of 4-hydroxybenzyl alcohol by sodium dichromate in an acidic organic solvent. 

The gel point is usually determined experimentally as that point in the reaction at which the reacting mixture loses fluidity as indicated by the failure of bubbles to rise in it. Experimental observations of the gel point in a number of systems have confirmed the general utility of the Carothers and statistical approaches. Thus in the reactions of glycerol (a triol) with equivalent amounts of several diacids, the gel point was observed at an extent of reaction of 0.765 [Kienle and Petke, 1940, 1941], The predicted values of pc, are 0.709 and 0.833 from Eqs. 148 (statistical) and 2-139 (Carothers), respectively. Flory [1941] studied several systems composed of diethylene glycol (/ = 2), 1,2,3-propanetricarboxylic acid (/ = 3), and either succinic or adipic acid (/ = 2) with both stoichiometric and nonstoichiometric amounts of hydroxyl and carboxyl groups. Some of the experimentally observed pc values are shown in Table 2-9 along with the corresponding theoretical values calculated by both the Carothers and statistical equations. 

The use of triols or tricarboxylic acids leads to cross-linked or network polyesters. For example, an alkyd resin is formed by the reaction of glycerol with phthalic anhydride [19]. 

Bigot et al. also used biphasic aqueous conditions for their telomerization reactions of glycerol, focusing mainly on optimization of various parameters for not only mono-, but also di- and tri-telomer production [88]. Unlike Behr, a positive influence of the base sodium hydroxide on activity was observed under their... 

The volatile components identified from the reaction of cystine and DMHF in aqueous medium are shown in Table I. 2,4-Hexanedione, 3,5-dimethyl-l,2,4-trithiolanes and thiophenes are the major compounds. The mechanistic relationship of the three thiophenones produced has been postulated (23). The major groups of volatile components identified from the reaction in the glycerol medium are 1,3-dioxolanes and thiazoles (Table II). 1,3-Dioxolanes are formed by the reaction of glycerol and the degraded carbonyls by ketal or acetal formations. Comparison of the reaction of cystine and DMHF in water and in glycerol is outlined in Table III. 

Figure 6.7. Acrolein in distillate from acid catalyzed reaction of glycerol and FFA in acid oil.

Pouilloux, Y., Abro, S., Vanhove, C., and Barrault, J. 1999. Reaction of glycerol with fatty acids in the presence of ion-exchange resins preparation of monoglycerides. J. Mol. Cata. A Chem.,149,243-254. 

Polyester. A condensation polymer formed by the reaction between a polyhydric alcohol and a polybasic acid, as the polymeric product resulting from the reaction of glycerol and phthallic acid or anhydride. 

CH2(0CH0).CH(0N02).CH2(0N02) mw 210.10, N 13.33%, OB to COa -22.2% It yel oily subst. Can be prepd by the action of nitric acid on the product of the reaction of glycerol and oxalic acid, which is glyceryl monoformin, CH2(OCHO).CHOH.CH2OH. It is an expl compd, more brisant and powerful than Diriitroacetin, described in Vol 1 of Encycl, p A35-L, under ACETINS... 

When glycerol reacts with unsaturated fatty acids, oils are typically formed. The reaction is similar to that with the saturated fatty acids. Oils are, of course, liquids. The fats and oils formed from the reaction of glycerol with the fatty acids are called triglycerides or triacylglycerides. Fats and oils are actually esters of glycerol and... 

Fat—The product formed from the reaction of glycerol and saturated fatty acid. 

The agreement of these equations with experimental results is generally fairly good. Thus, in a study of the reaction of glycerol with dibasic acids, gelation occurred at p = 0.765 [4]. Here one would calculate / =3, = p = 0.50. The experimental value for = p was 0.58. Experimental values for are frequently somewhat higher than the calculated values. 

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