Shuli Yan

 Ph.D ”An Investigation of Ca- and Zn-based Oxide Catalysts Used in the Transesterification of Oil with Methanol”  M.S ” Growth of Carbon Nanotubes from Methane by a Catalytic Chemical Vapor Decomposition Method” My Research in Sichuan University

 My dissertation  Using supported CaO catalysts for transesterfication (solid base catalyst)  Using ZnO and Al 2 O 3 binary metal oxide catalysts for transesterification (solid acid catalyst) My Research in Sichuan University Publicataions: One Patent and five papers Publications: One patent and three papers, and further more are in process

Supported CaO Catalysts Used in the Transesterification of Rapeseed Oil for the Purpose of Biodiesel Production Published on Energy and Fuel, DOI: /ef070105o

Introduction  Biodiesel Fig.1 The transesterification of triglyceride with methanol (1)

Fats and oils have quite big molecules with a spinal of glycerol on which are bond three fatty acid rests. By the transesterification, the fatty acid rests are removed from the glycerol and each is bond with methanol. The products are one mole glycerol and three mole of fatty acid methyl ester. Introduction

Various Catalysts used in Biodiesel Production Base Catalysts: NaOH, KOH, NaMeO Acid Catalysts: H 2 SO 4, PTSA, MSA, H 3 PO 4, Typical base concentrations are : NaOH/KOH – to 1.5 % Na MeO – % or less Sulfated Zeolites & Clays Hetro-poly acids Metal Oxides, Sulfates Composite materials Homogenous Heterogeneous

 Benefits - Heterogeneous Catalyst Catalyst Regeneration – Decrease of Catalyst Cost Simplification of separation process – Decrease of production cost Decrease of wastewater – Development of environmental friendly process Utilization of lower quality feed stocks for biodiesel production Introduction

 Literatures Ca-based catalysts  Goal Supporting CaO onto carriers  Content

Experimental Section  Oil refining process Fig. 2 Chemical refining process for raw oils

Experimental Section  Catalyst Samples MgO, CaO, SrO and BaO Samples 1–4 denote the catalysts using MgO, SiO2, Al2O3, and HY particles as carriers. Samples 5–9 denote the catalysts obtained by impregnation withdifferent concentrations of lime acetate solution.  Catalyst Characterization XRD, TPD, TG, BET, AAS, XPS

Experimental Section  Transesterification Process

Experimental Section  The FAME phase was analyzed by the gas chromatography method using GC9790 equipped with a column DEXIL-300 Japan Frontier.  The glycerol phase was analyzed by a chemical method according to the Chinese State Standard GB/T

Catalytic Activities of Alkaline Earth Metal Oxides. Table 1. Catalytic activities of some alkaline earth metal oxides and NaOH in the transesterification Catalyst PretreatmentReaction temperatu re o C Catalyst dosage % Methanol to oil ratio Reaction time hr Oil conversio n % MgO700 o C, N 2, 2 hr : 13.5< 5 CaO700 o C, N 2, 2 hr : SrO700 o C, N 2, 2 hr : BaO700 o C, N 2, 2 hr : NaOH\ :10.597

Catalytic activity of supported calcium oxide Catalyst PretreatmentReaction temperat ure o C Catalyst dosage % Methanol to oil ratio Reaction time hr Oil conversio n % NaOH\ : Sample 1700 o C, N 2, 2 hr : Sample 2700 o C, N 2, 2 hr : 1660 Sample 3700 o C, N 2, 2 hr : 1636 Sample 4700 o C, N 2, 2 hr : 1623 Table 2. Catalytic activity of supported calcium oxide

Characterization of supported calcium oxide Table 3. Physicochemical properties of some metal oxides SampleS BET m 2 /g X-ray structure CaO content (wt)% Alkalinity umol/m -2 sample 16.6Ca(OH) 2, MgO CaO1.5CaO, Ca(OH) MgO43.5MgO, Mg(OH) 2 \15.5

Transesterification catalyzed by CaO/MgO Figure 4. Catalytic activities of homogeneous catalyst NaOH a, CaO b, MgO b and a binary alkaline earth metal oxides Sample 1 c. 1

Effect of Ca loading on catalyst activity Table 5. Effect of Ca loading on catalyst activity Catalystsample 5sample 6sample 7sample 8sample 9 CaO content (wt)% Average crystal size of Ca(OH) 2 nm a Oil conversion % b, c a All samples showed the mixture of Ca(OH) 2 and MgO. Average crystal size was calculated from X- ray line broadening at θ angles for (0, 1, 1) plane of Ca(OH) 2. b Pretreatment: 700 o C, N 2, 2 hr c Experiment condition: 64.5 oC, 18:1molar ratio of methanol/oil, 2 % catalyst dosage, 3.5 hr.

Effect of calcine temperature on CaO/MgO catalyst Figure 6. TG and DTG curves of sample 10.

Table 7. Effects of calcination temperatures on the CaO/MgO catalyst Catalyst samples Calcine temperature o C CaO content (wt) % X-ray structureMgO, Mg(OH) 2 MgO, CaCO 3 MgO, Ca(OH) 2 S BET m 2 /g Oil conversion % a, b < a Pretreatment: calcine temperature, N 2, 2 hr b Experiment conditions: 64.5 o C, 18:1molar ratio of methanol/oil, 2 % catalyst dosage, 3.5 hr.

Effects of storage and pretreatment conditions on CaO/MgO catalyst Table 8. Effects of storage conditions and pretreatment conditions on the catalytic activity of sample 15 CatalystStorage conditions Pretreatment conditions Oil conversion d % Sample 15N 2 flow a for 5 hr\< 5 N 2 flow a for 5 hr700 o C, N 2, 2 hr89 N 2 flow b for 5 hr\8 700 o C, N 2, 2 hr84 N 2 flow c for 5 hr\14 N 2 flow c for 5 hr700 o C, N 2, 2 hr81 air for 24 hr\< 5 air for 24 hr100 o C, N 2, 2 hr< 5 air for 24 hr200 o C, N 2, 2 hr16 air for 24 hr500 o C, N 2, 2 hr43 air for 24 hr700 o C, N 2, 2 hr91 a N 2 flow with 21 (vol) % O 2 b N 2 flow with 10 (vol) % CO 2 c N 2 flow with 4 (vol) % H 2 O d Experiment conditions: 64.5 o C, 18:1molar ratio of methanol/oil, 2 % catalyst dosage, 3.5 hr.

Fig. 9 IR spectrum of the poisoned sample 15

Effects of reaction conditions Table 6. Effect of reaction temperature on transesterification Reaction temperatures o C Rapeseed oil conversion %< Pretreatment: 700 o C, N 2, 2 h Reaction conditions: 12 hr, 1g of sample 1, 12 : 1 molar ratio, 50 g oils. Table 7. Effect of mole ratio of methanol/oil on transesterification Mole ratio of methanol/oil3 : 16 : 112 : 118 : 136 : 142 : 1 Rapeseed oil conversion % Pretreatment: 700 o C, N 2, 2 hr Reaction conditions: 12 hr, 1g of sample 1, 64.5 o C, 50 g oils.

Effects of reaction conditions Table 8. Effect of catalyst dosage on transesterification Catalyst dosage Rapeseed oil conversion % Pretreatment: 700 o C, N 2, 2 hr Reaction conditions: 12 hr, 64.5 o C, 12 : 1 molar ratio, 50 g oils. Table 9. Effect of stirring speed on transesterification Stirring speed r/min Rapeseed oil conversion % Pretreatment: 700 o C, N 2, 2 hr Reaction conditions: 6 hr, 1g of sample 1, 64.5 o C, 18 : 1 molar ratio, 50 g oils.

Effects of water and FFA in oil Figure 10. Effects of water and FFA on the equilibrium conversion ratio Pretreatment conditions: 700 o C, N 2, 2 hr. Reaction conditions: 64.5 o C, 12:1molar ratio of rapeseed oil to methanol, sample 1, 2 % catalyst dosage, 8hr.

Effects of water and FFA in oil Figure 11. Conversions against reaction time. 1: 0.5 (wt) % water addition; 2: FFA addition with acid value 2 mgKOH/g Pretreatment conditions: 700 o C, N 2, 2 hr. Reaction conditions: 64.5 o C, 12:1molar ratio of rapeseed oil to methanol, sample 1, 2 % catalyst dosage. 1 2

Effects of water and FFA in oil Figure 12. Transesterification of some commercial oils Pretreatment conditions: 700 o C, N 2, 2 hr. Reaction conditions: 64.5 o C, 18:1molar ratio of oil to methanol, sample 1, 2 % catalyst dosage, 8hr.

Stability and regeneration of CaO/MgO catalyst Figure 13. Reusability of CaO/MgO catalyst. Pretreatment conditions: 700 o C, N 2, 2 hr. Reaction conditions: 64.5 o C, 12:1molar ratio of rapeseed oil to methanol, sample 1, 2 % catalyst dosage, 1.8 hr.

Active sites on the surface of CaO crystal Fig.14 Particle of cubic CaO, exhibiting three crystallographics surfaces. （ ） （ ） （ ） Ca O

Active sites on the surface of CaO crystal Fig.15 Active sites on the (110) surface of CaO minicrystal. Mg 2 ＋ replacing sites, oxygen vacancies, and CO 2, H 2 O, O 2 displacing oxygen vacancies. Mg O O O O H H H H C C C O Oxygen vacancy Ca O

Active sites on the surface of CaO crystal Fig. 16 Methanol molecular was actived on the surface of CaO crystal.

Mechanism of CaO-catalyzed transesterification of triglyceride with methanol (2) (1) (4) (3) (5) Fig. 17 Mechanism of CaO-catalyzed transesterifica tion of triglyceride with methanol

Conclusion  Supported CaO catalysts are active in the transesterification reaction for biodiesel production.  The basic carrier MgO, a Ca loading of 16.5 (wt)% and a calcination temperature of 700 o C  pretreatment before use is important  When the CaO/MgO catalyst was operated at the boiling temperature of methanol, 64.5 oC, with an 18:1 molar ratio of methanol/oil and 1 g catalyst, the conversion of rapeseed oil reached 92 %.  High content of water and FFA in oil could inhibit its transesterification.

Shuli Yan

Using solid acid catalysts in oil transesterification Fig. 6 － 7 Comparison of the transesterification processes in presence of samples 1, 2, 3, 4, NaOH, H 2 SO 4 and in absence of catalyst respectively. Reaction conditions: g refined rapeseed oil, 10 g methanol, NaOH 1.2 (wt) %, atmosphere, 64.5 o C; 2. H 2 SO 4 2 (wt) %, others are the same as 1; g refined rapeseed oil, 100 g methanol, no catalyst, 3.4MPa, 200 o C; 4. 42:1 molar ratio of methanol to rapeseed oil, no catalyst, 43 MPa, 350 o C [35] ; 5. Sample 1, 1.4 (wt) %, 3.3 MPa, others are the same as 3; 6. Sample 2, 1.4 (wt) %, others are the same as 5; 7. Sample 3, 1.4 (wt) %, others are the same as 5; 8. Sample 9, 1.4 (wt) %, others are the same as 5;

Using solid acid catalysts in oil transesterification Fig. 6 － 8 Effect of reaction temperature on oil conversion Reaction conditions: g refined rapeseed oil, 100 g methanol, ZnO, 1.4 (wt)%, 2hr; g refined rapeseed oil, 100 g methanol, Zn- Al-LDO, 1.4 (wt)%, 1hr; g refined rapeseed oil, 100 g methanol, no catalyst, 1hr;

Using solid acid catalysts in oil transesterification Fig. 3 Effects of FFA content on oil conversions. Reaction conditions: 〇 g refined rapeseed oil, 10 g methanol, 1.2 (wt) % g NaOH catalyst/g oil, atmosphere, 64.5 o C, 1 hr; █ g refined rapeseed oil, 100 g methanol, 1.4 (wt) % g ZnO catalyst/g oil, 3.3 MPa, 200 o C, 6 hr; ▲ g refined rapeseed oil, 39 g methanol, 2 (wt) % g H 2 SO 4 catalyst/g oil, atmosphere, 64.5 o C, 90 hr.

Using solid acid catalysts in oil transesterification Fig. 4 Effects of water content on oil conversions. Reaction conditions: 〇 g refined rapeseed oil, 10 g methanol, 1.2 (wt) % g NaOH catalyst/g oil, atmosphere, 64.5 o C, 1 hr; █ g refined rapeseed oil, 100 g methanol, 1.4 (wt) % g ZnO catalyst/g oil, 3.3 MPa, 200 o C, 6 hr; ▲ g refined rapeseed oil, 39 g methanol, 2 (wt) % g H 2 SO 4 catalyst/g oil, atmosphere, 64.5 o C, 90 hr.

Using solid acid catalysts in oil transesterification Fig Three reactions involved in the treatment of oils with methanol containing some water and FFA.

Using solid acid catalysts in oil transesterification Fig. 6 － 13 Mechanism of ZnO-catalyzed transesterificatio n of triglyceride with methanol （1）（1） （2）（2）