| The liquid acid-base two step catalysis is widely applied in biodiesel production of China,free fatty acid in the oil was firstly esterified into fatty acid methyl ester (FAME) catalyzed by concentrated sulfuric acid (H2SO4) and then triglyceride was transesterified into FAME by sodium hydroxide (NaOH), catalysts are dissolved in the reaction system and need to be neutralized and washed away by water after reaction. In liquid two steps technology, extra waste water is discarded and more energy is required to dry the product; Solid acid and base does not dissolve in the reaction system, they can be removed by centrifugation after reaction,. Less water will be let out and more energy will be consumed if solid acid and base are employed.Na3PO4/γ-Al2O3 solid base catalyst and Zr(SO4)2-Kieselguhr solid acid catalyst were developed in the paper using Na3PO4, Zr(SO4)2·4H2O as active species andγ-Al2O3, Kieselguhr as carriers, biodiesel which meets Chinese standard GB/T20828-2007 was perpared in 20 L scale by esterification with Zr(SO4)2-Kieselguhr and transesterification with Na3PO4/γ-Al2O3. The work was done as follows:(1) Catalyst activity of sodium phosphate (Na3PO4) was tested via rapeseed oil transesterification with methanol to produce biodiesel.Biodiesel yield was determined to study the effects of reaction conditions on reaction; Na3PO4 content was monitored in the products under different reaction conditions, Na3PO4 was compared with other catalysts on activity; Na3PO4 was used repeatedly and biodiesel yield in each repetition was determined. Results indicated that under the reaction condition of catalyst loading 3 wt%, methanol to oil molar ration 9:1, reaction temperature 343 K and rotation speed 600 rpm, transesterification catalyzed by Na3PO4 was finished in 20 min, which was as active as homogeneous catalyst, Na3PO4 dissolved in product was ignorable and the catalyst can be used repeatedly for 8 times.(2) Catalyst activity of Zirconium sulfate tetra-hydrate (Zr(SO4)2·4H2O) was tested via esterification of oleic acid with methanol to produce methyl oleate.Effects of reaction condition on methyl oleate yield were investigated and a psedou-homogeneous kinetic model was built to simulate the experiment results; Zr(SO4)2·4H2O dissolution in methanol was observed; Zr(SO4)2·4H2O catalyst activity during repeated uses was watched and different regeneration methods were researched. More than 95% oleic acid was esterified into methyl oleate in catalyst loading 3 wt%, reaction temperature 333 K, methanol to acid molar ratio 12:1 and rotation speed 600 rpm, deactivation after 3 repeated uses was obeserved because SO42- was dissolved in methanol, but catalyst activity can be restored by SO42- repregnation. (3) Na3PO4/γ-Al2O3 catalyst was prepared by impregnation of Na3PO4 onγ-Al2O3 carrier.It was investigated of the effects of Na3PO4 amount on catalyst, calcination temperature and calcination time on catalyst activity and studied of catalyst structure and active species change under different prepared conditions; Na3PO4/γ-Al2O3 was used to catalyze the transesterification of rapeseed oil with methanol, biodiesel yield was curbed by reaction temperature, catalyst loading and methanol to oil molar ratio; Catalyst activity was lost gradually during recycled uses, the deactivation mechanism was proposed and regeneration method was developed by XRF and so on. Catalyst activity was influenced by alkaline strength, alkaline amount, pore size and crystal water on Na3PO4. Biodiesel yield can exceed 95% under optimum reaction conditions. Na2HPO4 and NaH2PO4 formed during repeated uses, so catalyst was deactivated, Na2HPO4 and NaH2PO4 can be changed back into Na3PO4 after wash by base and the activity was restored.(4)Zr(SO4)2-Kieselguhr solid acid was prepared by supporting Zr(SO4)2·4H2O on Kieselguhr.Preparation conditions such as Zr(SO4)2 amount on catalyst, calcination temperature and calcination time tuned structure and active species of the catalyst, and so had an influence on catalyst activity; Zr(SO4)2-Kieselguhr catalyst was used in the esterification of oleic acid with methanol, effects of reaction temperature, catalyst loading and methanol to oleic acid molar ratio on methyl oleate yield were studied; Catalyst activity decrease during recycled uses was observed, the deactivation reason was explored and the regeneration method was built by XRF and so on. Acid strength and amount, pore size and crystal water on Zr(SO4)2 had large effects on esterification; methyl oleate yield can reach to 95.2% under optimum reaction conditions; SO42- was lost after repeated uses and so the activity was also lost, activity can be restored by SO42- repregnation.(5)Biodiesel was produced from crude rapeseed oil with methanol by solid acid-base two steps catalysis, solid acid was Zr(SO4)2-Kieselguhr and solid base was Na3PO4/γ-Al2O3.In solid acid catalysis, effects of catalyst loading, reaction temperature and methanol to oil molar ratio on biodiesel yield was investigated; In solid base catalysis, effects of catalyst loading, reaction temperature, methanol to oil molar ratio, esterification time and methanol addition method on biodiesel yield were studied, solid base catalysis was then optimized by quatratic votary combination method. Based on the study mentioned above, solid acid-base two steps catalysis technology was developed for biodiesel production on 20L pilot scale. Post-reaction separation technology was built. Biodiesel yield was 97.6% using our technology and the product meets the standard of China. 7.6% of heat, 43.6% of electricity and half water were saved by using solid acid-base two steps catalysis technology compared to liquid acid-base two steps catalysis...
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