MIXED OXIDES FOR THE OXIDATIVE CLEAVAGE OF LIPIDS USING OXYGEN TO AFFORD MONO- AND DI-CARBOXYLIC ACIDS

Abstract

This invention relates to the synthesis of new catalysts based on earth crust abundant mixed oxides that can produce cleavage of fatty acids (FA), FA methyl esters, or even lipids in a single step using oxygen as oxidant in solventless conditions.

Claims

1. Mixed oxides of formula x(CeO.sub.2) y(Nb.sub.2O.sub.5), wherein x varies from 0.2 to 10, y from 1 to 10, further comprising oxides of one or more metal selected from the group consisting of Cu, La, K, Bi.

2. Mixed oxides according to claim 1 of formula x(CeO.sub.2) y(Nb.sub.2O.sub.5)z(La.sub.2O.sub.3) s(K.sub.2O) t(Bi.sub.2O.sub.3) wherein z ranges from 0.1 to 5, s from 0.1 to 2, t ranges from 0.1 to 5.

3. Mixed oxides according to claim 1 which are quaternary oxides of formula x(CeO.sub.2) y(Nb.sub.2O.sub.5)m(CuO), in which x, y, and m range from 1 to 2.

4. A process for the preparation of the mixed oxides of claim 1 by subjecting precursor salts, oxides or carbonates of the active metal elements to High Energy Milling (HME) followed by calcination.

5. Process for the preparation of saturated monocarboxylic and dicarboxylic acids or derivatives thereof comprising the oxidation of unsaturated carboxylic acids and/or derivatives thereof with oxygen, or a gas containing oxygen, in the presence of catalysts comprising mixed oxides according to claim 1.

6. Process according to claim 5, wherein the catalyst comprises mixed oxides of general formula x(CeO.sub.2) y(Nb.sub.2O.sub.5) z(La.sub.2O.sub.3) s(K.sub.2O) t(Bi.sub.2O.sub.3), wherein z ranges from 0 to 5, s from 0 to 2 and t from 0 to 5.

7. Process according to claim 6, wherein x varies from 1 to 10, y varies from 1 to 10, z varies from 1 to 5, s varies from 1 to 2, t varies from 1 to 5.

8. Process according to claim 5, wherein the catalyst comprises mixed oxides of general formula x(CeO.sub.2)y(Nb.sub.2O.sub.5)m(CuO) where x, y and m vary between 1 and 2.

9. Process according to claim 5 wherein the cleavage takes place at temperatures ranging from 80 to 180° C. in absence of solvents.

10. Process according to claim 5, wherein the unsaturated carboxylic acids are fatty acids, either vegetal or animal, of general formula R.sup.1—CH.sub.2—[HC═CH]—R.sup.2 where R.sup.1 is a linear alkyl chain with 1 to 12 carbon atoms and R.sup.2 is —(CH.sub.2).sub.n—COX moiety, where n is an integer number from 2 to 12 and X is selected from the group consisting of —OH, —OCH.sub.3 or glyceryl group.

11. Process for the preparation of saturated monocarboxylic and dicarboxylic acids or derivatives thereof comprising the oxidation of unsaturated carboxylic acids and/or derivatives thereof with oxygen, or a gas containing oxygen, in the presence of catalysts comprising mixed oxides of formula x(CeO.sub.2)y(Nb.sub.2O.sub.5), wherein x varies from 0.2 to 10 and y from 1 to 10.

12. The use of mixed oxides according to claim 1 in a process for the preparation of saturated monocarboxylic and dicarboxylic acids or derivatives thereof comprising the oxidation of unsaturated carboxylic acids and/or derivatives thereof with oxygen, or a gas containing oxygen.

13. The use of mixed oxides according to claim 1 in a process for the preparation of carboxylic acids by aerobic oxidative cleavage of monounsaturated fatty acids, either vegetal or animal, of general formula R.sup.1—CH.sub.2—[HC═CH]—R.sup.2 where R.sup.1 is a linear alkyl chain with 1 to 12 carbon atoms and R.sup.2 is —(CH.sub.2).sub.n—COX moiety, where n is an integer number from 2 to 12 and X is selected from the group consisting of —OH, —OCH.sub.3 or glyceryl group.

14. The use of mixed oxides of formula x(CeO.sub.2) y(Nb.sub.2O.sub.5), wherein x varies from 0.2 to 10 and y from 1 to 10, in a process for the preparation of saturated monocarboxylic and dicarboxylic acids or derivatives thereof comprising the oxidation of unsaturated carboxylic acids and/or derivatives thereof with oxygen, or a gas containing oxygen.

Description

[0051] FIG. 1 shows the yield of monocarboxylic acids (MCAs) and dicarboxylic acids (DCAs) in the catalytic cleavage of methyl oleate (>99%) with O.sub.2 using (Ce.sub.2)(Nb.sub.2O.sub.5) at different temperatures. Working conditions: catalyst loading 5.5% (% w/w), P.sub.O2=9 bar, t=3 h.

[0052] FIG. 2 shows the oxidative cleavage of methyl oleate with 7(CeO.sub.2) 7(Nb.sub.2O.sub.5) 3(La.sub.2O.sub.3) 1(K.sub.2O) 2(Bi.sub.2O.sub.3). The yields and selectivities towards azelaic acid (AA) and pelargonic acid (PA) are shown as function of the reaction time. Working conditions are: T=120° C., PO.sub.2=9 bar, catalyst loading=5.5% (w/w).

[0053] FIG. 3 shows the yield (mol/mol.sub.oeate %) for several products formed with time in the oxidation of methyl oleate with 7(CeO.sub.2) 7(Nb.sub.2O.sub.5) 3(La.sub.2O.sub.3) 1(K.sub.2O) 2(Bi.sub.2O.sub.3) with oxygen as oxidant.

EXAMPLES

[0054] The catalytic activity has been tested using methyl oleate or a low quality olive oil (a triglyceride called “lampante olive oil”). Using compressed air, at the same pressure than oxygen, the reaction is slower because oxygen is diluted by N.sub.2. Higher reaction rate is achieved by increasing the air pressure.

[0055] All catalysts, prepared as described below, gave good elemental analyses and where characterized for BET, acid and basic sites.

[0056] In all cases CeO.sub.2 and Nb.sub.2Os are STREM products, La.sub.2O.sub.3, Bi.sub.2O.sub.3 and K.sub.2CO.sub.3 are purchased from Sigma-Aldrich, and CuO is a Carlo Erba product.

Example 1—Preparation of Mixed Oxides x(CeO.SUB.2.) y(Nb.SUB.2.O.SUB.5.) z(La.SUB.2.O.SUB.3.) s(K.SUB.2.O) t(Bi.SUB.2.O.SUB.3.)

[0057] Mixed oxides where x=7, y=7, z=3, s=1, t=2, were prepared by milling 1.204 g of CeO.sub.2 with 1.860 g of Nb.sub.2O.sub.5, 0.138 g of K.sub.2CO.sub.3, 0.977 g of La.sub.2O.sub.3 and 0.931 g of Bi.sub.2O.sub.3. The final mixture after milling at 700 rpm for 30 min was calcined at 550° C. for 3 h.

Example 2—Preparation of Quaternary Mixed Oxides x(CeO.SUB.2.)y(Nb.SUB.2.O.SUB.5.)z(CuO)

[0058] Quaternary mixed oxides wherein x=2, y=1, z=1 were prepared by mixing 0.564 g of CeO.sub.2, 0.436 g of Nb.sub.2O.sub.5 and 0.130 g of CuO. The oxides were milled at the solid state using HEM (700 rpm for 30 min at room temperature). The final mixture was calcined at 550° C. for 3 h.

Example 3. Catalytic Oxidation of Methyl Oleate (>99%) with Ternary Mixed Oxides Using Oxygen (P.SUB.O2.=9 Bar)

[0059] Ternary mixed oxides x(CeO.sub.2)y(Nb.sub.2O.sub.5) with x/y=0.2÷10 have been prepared from CeO.sub.2 and Nb.sub.2O.sub.5. In particular, the following amounts were used 0.229 g of CeO.sub.2 and 1.771 g di Nb.sub.2Os; or 0.489 g of CeO.sub.2 and 1.511 g of Nb.sub.2Os; or 0.786 g of CeO.sub.2 and 1.214 g of Nb.sub.2Os; or 1.128 g of CeO.sub.2 and 0.871 g of Nb.sub.2Os; or 1.528 g of CeO.sub.2 and 0.472 g of Nb.sub.2Os; or else 1.732 g of CeO.sub.2 and 0.268 g of Nb.sub.2O.sub.5, for the desired molar ratio x. The oxides were milled at the solid state using HEM (700 rpm for 30 min at room temperature). Each final mixture was calcined at 550° C. for 3 h.

[0060] The mixed oxides catalyst (50 mg of CeO.sub.2—Nb.sub.2O.sub.5) was introduced in a glass reactor with a magnetic stirrer and 1 mL of methyl oleate was added. The reactor was placed in a 75 mL autoclave, that was pressurized with O.sub.2 (9 bar) and heated to T=120° C. The reaction was carried out for t=15 h. At the end the autoclave was cooled down to ambient temperature and the mixture of products recovered by centrifugation. The reaction mixture was analysed via GC after methylation using a 3% mol H.sub.2SO.sub.4/CH.sub.3OH mixture (60 minutes at 80° C.), extraction in hexane and filtration on anhydrous Na.sub.2SO.sub.4.

[0061] The (CeO.sub.2) (Nb.sub.2Os) catalyst, where x=1, was active in solventless conditions in the range 120-160° C. Best results were obtained at 160° C. for short (3 h) reaction time or at 120° C. for longer reaction time (15 h). In such conditions the dicarboxylic acid yield is around 40% (mainly azelaic and suberic acid) (Table 1). Other catalysts (n=mol.sub.CeO2/mol.sub.Nb2O5; n=0.2, 0.5, 1, 2, 5, 10) produce lower yields depending on n. Data in Table 1, were obtained working at 120° C. A similar trend is observed at 160° C. for 3 h.

TABLE-US-00001 TABLE 1 Oxidation of methyl oleate with O.sub.2 using ternary mixed oxides. Working conditions: T = 120° C., t = 15 h; P.sub.O2 = 9 bar; catalyst loading = 5.5% w/w. No of 0.2(CeO.sub.2) 0.5(CeO.sub.2) (CeO.sub.2) 2(CeO.sub.2) 5(CeO.sub.2) 10(CeO.sub.2) Product C atoms (Nb.sub.2O.sub.5) (Nb.sub.2O.sub.5) (Nb.sub.2O.sub.5) (Nb.sub.2O.sub.5) (Nb.sub.2O.sub.5) (Nb.sub.2O.sub.5) Dicarboxylic total 30.0 34.8 41.1 36.0 35.4 30.9 acids ≤6 0.1 0.2 0.6 0.7 0.5 0.4 (DCAs) 7 2.4 3.8 5.9 5.0 5.0 4.2 8 9.3 11.0 13.7 11.8 13.1 11.0 9 18.2 19.8 20.7 18.5 16.8 15.3 10 0.0 0.0 0.1 0.0 0.0 0.0 Monocarboxylic total 29.1 34.7 35.7 31.2 34.8 30.1 acids ≤6 1.3 1.6 1.6 2.0 1.6 1.3 (MCAs) 7 3.7 5.3 5.1 4.6 5.4 4.9 8 8.9 10.9 9.3 7.8 9.5 8.3 9 15.1 16.6 19.3 16.4 17.4 15.3 10 0.2 0.3 0.4 0.4 0.8 0.2 Conversion % 100.0 100.0 99.8 99.9 99.8 99.7 Selectivity AA/DCAs 60.7 56.8 50.5 51.4 47.6 49.5 towards AA (%) Selectivity PA/MCAs 51.7 47.8 54.1 50.0 52.6 51.0 towards PA (%)

Example 4. Catalytic Oxidation of Methyl Oleate (>99%) with (CeO.SUB.2.)(Nb.SUB.2.O.SUB.5.) with PO.SUB.2=9 .Bar at Various Temperatures

[0062] The reaction system prepared as in Example 3 (ternary oxide with x/y=1) was reacted under 9 bar O.sub.2 at various temperatures in the range 120-180° C. for 3 h. At the end the autoclave was cooled the catalyst separated and the liquid phase analysed as in Example 3. Data in Table 2 and FIG. 1 suggest that the temperature has a key role in the reaction and 160° C. is the best temperature. Both at 140° C. and at 180° C. the yield of PA (pelargonic acid, C.sub.8H.sub.17COOH) and AA (azelaic acid, HOOC—C.sub.7H.sub.14—COOH) are reduced.

[0063] The experiments at variable temperature show that: i) increasing the temperature increases the conversion rate of methyl oleate, ii) increasing the temperature increases the yield of dicarboxylic acids with less than 9 carbon atoms, due to decarboxylation of the products. Best compromise is represented by 3 h reaction time at 160° C. (FIG. 1) at which the conversion is complete and the yield of C9 is maximized.

TABLE-US-00002 TABLE 2 Yields of MCAs and DCAs in the catalytic oxidation of methyl oleate (>99%) using (CeO.sub.2)(Nb.sub.2O.sub.5) at various temperatures. Working conditions: catalyst loading 5.5% (w/w), P.sub.O2 = 9 bar, t = 3 h. No of Product C atoms 120° C. 140° C. 160° C. 180° C. Dicarboxylic total 3.6 21.5 42.3 14.3 acids ≤C6 — 0.2 3.6 0.1 C7 — 1.9 9.9 1.7 C8 0.7 6.6 11.5 4.1 C9 2.8 12.8 17.3 8.5 C10 — — 0.0 — Monocarboxylic total 6.2 21.5 42.6 16.5 acids ≤C6 0.1 1.2 4.9 1.6 C7 0.6 2.9 6.7 3.0 C8 2.2 6.3 9.8 5.1 C9 3.3 9.8 18.2 6.5 C10 — 0.4 3.2 0.3 Conversion % 49.8  93.2 99.6 99.4 Selectivity AA/DCAs(%) 77.8  59.5 40.9 59.4 vs. AA Selectivity PA/MCAs(%) 53.2  45.6 42.7 39.4 vs. PA

Example 5. Catalytic Oxidation of Methyl Oleate (>99%) with the Mixed Oxide 7(CeO.SUB.2.) 7(Nb.SUB.2.O.SUB.5.) 3(La.SUB.2.O.SUB.3.) 1(K.SUB.2.O) 2(Bi.SUB.2.O.SUB.3.) under P.SUB.O2.=9 Bar

[0064] In order to improve the stability of the catalyst and its activity, multiple mixed oxides were prepared. The mixed oxide 7(CeO.sub.2) 7(Nb.sub.2O.sub.5) 3(La.sub.2O.sub.3) 1(K.sub.2O) 2(Bi.sub.2O.sub.3), prepared according to Example 1, showed excellent stability in catalysis and good reaction rate and selectivity. The catalyst (50 mg) was placed in a glass reactor, kept in vacuo for 30 min to eliminate humidity and added with methyl oleate (1 mL) under N.sub.2. The reactor was placed in a stainless steel autoclave that was closed, evacuated, charged with O.sub.2 (9 bar) and heated to T=120° C. for a time variable between t=0.66 and 15 h. At the end the catalyst was recovered by centrifugation and the liquid processed as reported in Example 3.

[0065] Table 3 shows that MCAs and DCAs are maximized at 15 h (44.3% and 53.1%, respectively). Interestingly, the multiple catalyst is more active than the ternary one described in examples 3-4 and its composition remains unchanged at the end of the catalytic run (and EDX analysis showed the total absence of metals in the liquid phase at the end of the catalytic run). The catalyst was recovered and re-used after short calcination at 550° C. showing the same activity.

[0066] At short reaction times, the acids with Cn lower than 9 were formed in a low yield, but the conversion of methyl oleate was also low. After 45 min short chain acids were almost absent and grew with time. A time of 15 h seemed to be a good compromise between conversion and selectivity. Longer times can produce decarboxylation of the acids.

[0067] FIG. 3 and data in Table 4, give useful information about the kinetics and mechanism of conversion of the methyl oleate into the carboxylic acid. Within first 45 min, the cleavage produced oxo-derivatives that were subsequently converted into the end products. In the time interval 0.66-3 h the formation of MCAs and DCAs was observed. Me-oleate was partially converted into epoxy-derivatives (EOAs) which could afford diols and then the acids end products. After 3 h, methyl oleate was completely converted, while the formation of MCAs and DCAs continued from intermediates epoxides and diols, which concentration decreased with time. The gas phase showed the presence of CO.sub.2 and H.sub.2 formed by decarboxylation and dehydrogenative oxidation of cleavage products of methyl oleate.

TABLE-US-00003 TABLE 3 Yield (% in mol) in MCA and DCA in the catalytic oxidation of methyl oleate with 7(CeO.sub.2) 7(Nb.sub.2O.sub.5) 3(La.sub.2O.sub.3) 1(K.sub.2O) 2(Bi.sub.2O.sub.3) in solvent- free conditions at 120° C. as function of reaction time. Working conditions: P.sub.O2 = 9 bar; catalyst loading = 5.5% w/w. Alifatic chain length Reaction times (h) Product (No of C atoms) 0.66 1.5 3 6 15 MCAs total 1.6 12.9  21.6 29.6 44.2 ≤5 — — n.d. n.d. n.d. 6 — 0.4 0.7 1.1 2.0 7 — 0.7 2.0 3.1 5.0 8 0.4 3.1 6.1 8.3 11.4 9 1.2 6.3 9.2 12.0 17.6 10 — — 0.1 0.2 0.8 DCAs total 1.0 11.4  23.1 30.0 53.2 ≤5 — — — n.d. n.d. 6 0.0 0.0 0.2 0.4 0.9 7 0.0 0.0 1.8 3.1 6.8 8 0.3 4.3 8.3 10.6 17.5 9 1.0 7.1 12.6 15.6 27.5 10 0.0 0.0 0.2 0.3 0.4 Conversion of oleate % 28.5  69.8  97.1 98.8 98.8 Selectivity vs AA AA/DCAs(%) 76.9  62.6  54.4 52.1 51.8 Selectivity vs PA PA/MCAs(%) 75.0  64.3  55.4 52.6 51.8

TABLE-US-00004 TABLE 4 Yield (mol/mol.sub.oleate %) of compounds formed in the oxidation of methyl oleate with O.sub.2 in presence of 7(CeO.sub.2) 7(Nb.sub.2O.sub.5) 3(La.sub.2O.sub.3) (K.sub.2O) 2(Bi.sub.2O.sub.3) (P.sub.O2 = 9bar) with time Reaction time (h) Compound 0 0.66 1.5 3 6 15 MCAs — 1.6 12.9 21.6 29.6 44.2 DCA — 1.0 11.4 23.1 30.0 53.2 Aldehydes — 11.8 14.6 3.9 0.8 0.3 Oxo-acids — 9.1 12.4 2.4 0.2 0.0 Oxiranes — 16.7 44.1 51.0 26.6 5.8 Diols — 0.0 0.0 5.4 10.3 2.8 Oleate 99.8 71.3 30.0 2.7 1.0 1.0

Example 6. Catalytic Oxidation of Methyl Oleate with Compressed Air in Presence of 7(CeO.SUB.2.) 7(Nb.SUB.2.O.SUB.5.) 3(La.SUB.2.O.SUB.3.) 1(K.SUB.2.O) 2(Bi.SUB.2.O.SUB.3.)

[0068] The autoclave set was prepared as in Example 5 and loaded with air at 6 bar (or 40 bar) and the reaction run for 15 h at 120° C. The reaction mixture was worked up as reported in Example 3. Table 5 shows the conversion of the reagent and the yield of MCAs and DCAs with the air pressure. When the pressure of 40 bar was used, the O.sub.2 pressure (8 bar) was close to that used with pure O.sub.2(9 bar). At 6 bar the conversion of oleate was not complete. A better conversion was observed at 40 bar, but it was not quantitative.

[0069] Oxiranes are present in significant amount at the end of the reaction.

TABLE-US-00005 TABLE 5 Catalytic cleavage of methyl oleate with compressed air at two different pressures using 7(CeO.sub.2) 7(Nb.sub.2O.sub.5) 3(La.sub.2O.sub.3) 1(K.sub.2O) 2(Bi.sub.2O.sub.3). Working conditions: T = 120° C., t = 15 h, P(air) = 6 or 40 bar, catalyst loading 5% w/w. Conversion/Yield Conversion/Yield Compound at 6 bar at 40 bar C6 0.2 0.7 C7 0.9 1.9 C8 3.2 5.7 C9 4.2 8.5 C10 0.4 0.1 MCAs (mol % tot) 8.9 16.9 Selectivity vs PA 47.3 50.3 (% mol PA/mol MCAs) C6 0.0 0.2 C7 0.2 1.8 C8 2.6 8.2 C9 4.0 12.5 C10 0.2 0.2 DCAs (mol % tot) 7.1 22.9 Epoxystearates (mol %) 42 22 Selectivity vs Azelaic acid 56.5 54.6 (% mol AA/mol DCAs) Conversion (%) 61.9 94.0

Example 7. Catalytic Cleavage of Lipids (Olive Oil) Under O.SUB.2 .in Presence of 7(CeO.SUB.2.) 7(Nb.SUB.2.O.SUB.5.) 3(La.SUB.2.O.SUB.3.) 1(K.SUB.2.O) 2(Bi.SUB.2.O.SUB.3.)

[0070] Olive oil was used instead of methyl oleate in the oxidative cleavage. In order to have a complete conversion a higher temperature (140° C.) was used than with methyl oleate (120° C.). After 15 h at 140° C. using 9 bar of O.sub.2 the total conversion of the oil was observed. The catalyst was recovered by centrifugation and the liquid phase worked up as in Example 3. The formed acids are shown in Table 6.

TABLE-US-00006 TABLE 6 Oxidative cleavage of olive oil with 7(CeO.sub.2) 7(Nb.sub.2O.sub.5) 3(La.sub.2O.sub.3) 1(K.sub.2O) 2(Bi.sub.2O.sub.3) under 9 bar O.sub.2 at 140° C. for 15 h (MCAs = monocarboxylic acids; PA = pelargonic acid; DCAs = dicarboxylic acids; AA = azelaic acid). Selectivity Selectivity Compound (%) Yield (%) Yield (No of C atoms) PA/MCA % MCAs AA/DCAs % DCA ≤5 — 38.1 6.9 43.4 6 5.8 3.5 7 16.1 6.2 8 11.5 12.8 9 21.9 23.2 10 2.2 0.9 Tot 57.5 53.4

Example 8. Catalytic Cleavage of Methyl Oleate Under O.SUB.2 .in Presence of Quaternary Mixed Oxides 2(CeO.SUB.2.)(Nb.SUB.2.O.SUB.5.)(CuO)

[0071] The catalyst prepared according to Example 2 (50 mg) was placed in a glass reactor, under Nitrogen flux, and was kept in vacuo for 30 minutes before the addition of two different substrates (Fatty Acid methyl Esters (FAMEs), 1 mL; see composition in Table 6). The mixture was left under vacuum for a further 30 minutes and then introduced into a steel autoclave which was charged with oxygen (9 bar). The mixture was allowed to react at 120° C. for 15 h. After the reaction, the autoclave was cooled in an ice bath and the resulting mixture was recovered and separated from the catalyst by centrifugation. Reaction mixtures were prepared for GC/MS analysis by direct methylation catalyzed by H2SO4. Mixture A, containing a small amount of polyunsaturated acids, was more readily oxidized than the mixture B (methyl oleate 96%; see Table 7). Indeed, although in both cases the conversion of unsaturated FAMEs was almost quantitative within 3 hours, in the case of mixture B the main part is still composed of epoxies and di-hydroxystearates which in the case of mixture A have already disappeared after 3 hours. The oxidation of Mixture A yielded 44% dicarboxylic acids after 3 hours. The DCAs yields decreased to ≈38% after 15 h, probably due to the decomposition of the alkyl chains. The oxidation of mixture B yielded only 22-23%, but most of the mixture was still composed of partial oxidation products which could be further oxidized. Therefore, mixture B requires longer reaction times.

TABLE-US-00007 TABLE 7 Composition (mol %) of the FAMEs starting mixtures (A: Methyl oleate, technical grade; B: methyl oleate 96%). Unsaturated Monounsaturated Mixture C14:0 C16:0 C16:1 C18:0 C18:1 C18:2 (%) (%) A 3.2 5.2 5.1 1.3 73.7 10.8 89.7 78.8 B — — — 4.0 96.0 — 96.0 96.0

TABLE-US-00008 TABLE 8 Catalytic cleavage with O.sub.2 in presence of 2(CeO.sub.2)(Nb.sub.2O.sub.5)(CuO). Working conditions: T = 120° C., P.sub.O2 = 9 bar, catalyst loading 5.5% (w/w). tot tot Mixture t(h) C4 C5 C6 C7 C8 C9 C10 MCAs C6 C7 C8 C9 C10 DCAs A 3 1.1 2.5 5.8 5.2 8.0 11.2 0.8 34.6 2.6 3.4 14.9 17.2 5.9 44.0 A 15 1.3 2.9 5.9 5.8 6.9 10.6 0.6 34.0 2.2 3.4 12.5 16.7 3.5 38.3 B 3 0.3 0.5 0.9 3.1 7.8 9.7 0.3 22.7 1.0 2.4 7.6 10.1 1.3 22.3