本文選題：生物柴油 + 固體酸堿��； 參考：《合肥工業(yè)大學(xué)》2011年博士論文

【摘要】：我國生物柴油生產(chǎn)普遍采用的液體酸堿兩步催化法首先是使用濃硫酸(H_2SO_4)催化油脂中游離脂肪酸生成脂肪酸甲酯(生物柴油),再利用氫氧化鈉(NaOH)催化甘油三酯生成脂肪酸甲酯,催化劑溶于反應(yīng)體系,反應(yīng)后需要中和、水洗和干燥,造成過多的廢水排放和能量消耗。而固體酸堿催化劑不溶于反應(yīng)體系當中,反應(yīng)后離心即可去除催化劑,以固體酸堿催化劑代替H_2SO_4和NaOH,生產(chǎn)過程中的廢水排放和能量消耗會顯著減少,生產(chǎn)成本也相應(yīng)降低。 本論文分別選用Na_3PO_4和Zr(SO_4)_2·4H_2O為活性化合物,γ-Al_2O_3和硅藻土為載體,進行了新型負載型固體堿催化劑Na_3PO_4/γ-Al_2O_3和固體酸催化劑Zr(SO_4)_2-Kieselguhr的制備和表征研究,并利用自制的固體酸和固體堿催化劑在20 L中試規(guī)模裝置上進行放大試驗,制備了符合GB/T20828-2007的生物柴油產(chǎn)品。主要內(nèi)容和結(jié)果如下: (一)以磷酸鈉(Na_3PO_4)為催化劑,考查了其在催化菜籽油與甲醇的轉(zhuǎn)酯化反應(yīng)中的催化特性。 考察了Na_3PO_4在不同反應(yīng)條件下的轉(zhuǎn)酯化效果,比較了Na_3PO_4和文獻上發(fā)表的一些固體和液體催化劑在催化生物柴油制備上的活性;檢測了不同反應(yīng)條件下Na_3PO_4在相應(yīng)產(chǎn)物中的殘留;考察了催化劑的重復(fù)使用效果。結(jié)果表明在在催化劑用量3 wt%,醇油摩爾比9:1,反應(yīng)溫度343 K和攪拌轉(zhuǎn)速600 rpm的條件下,20 min內(nèi)生物柴油的產(chǎn)率就可以達到95%,與液體堿催化劑的活性相近;Na_3PO_4在生物柴油中的殘留很少,催化劑能夠重復(fù)使用8次。 (二)以四水合硫酸鋯(Zr(SO_4)_2·4H_2O)為催化劑,催化菜籽油脂肪酸主要組成成分-油酸與甲醇的酯化反應(yīng)制備油酸甲酯(脂肪酸甲酯的主要組成部分)。 考察了Zr(SO_4)_2·4H_2O在不同反應(yīng)條件下催化酯化反應(yīng)得活性并利用建立的一種擬均相反應(yīng)動力學(xué)模型擬合實驗結(jié)果;考察了Zr(SO_4)_2·4H_2O在甲醇中的溶解;考察了Zr(SO_4)_2·4H_2O的重復(fù)使用效果以及不同方法對催化劑的活性恢復(fù)效果。Zr(SO_4)_2·4H_2O在在催化劑用量3 wt%,反應(yīng)溫度333 K,醇酸摩爾比12:1以及攪拌轉(zhuǎn)速600 rpm條件下能轉(zhuǎn)化95%以上的油酸為油酸甲酯, SO42-能溶于甲醇當中導(dǎo)致催化劑在重復(fù)使用4次后活性下降,通過硫酸(H_2SO_4)負載的方法能恢復(fù)Zr(SO_4)_2·4H_2O的活性。 (三)以Na_3PO_4為活性化合物,γ-Al_2O_3為載體,浸漬法制備Na_3PO_4/γ-Al_2O_3負載型催化劑。 考察了制備條件(Na_3PO_4負載量、焙烤溫度和焙烤時間)對催化劑活性的影響,通過各種儀器表征方法考察了制備條件對催化劑結(jié)構(gòu)的影響,探索活性與結(jié)構(gòu)之間的關(guān)系;以活性最高的Na_3PO_4/γ-Al_2O_3為催化劑,催化菜籽油與甲醇反應(yīng)制備生物柴油,考察反應(yīng)溫度、催化劑用量和醇油摩爾比對生物柴油產(chǎn)率的影響;考察了催化劑的重復(fù)使用效果,利用XRF等方法探索了催化劑在重復(fù)使用過程中的失活原因并建立了活性再生方法。結(jié)果表明固體堿催化劑的堿性、堿量、孔徑尺寸,Na_3PO_4中所含結(jié)晶水個數(shù)對活性有影響;Na_3PO_4/γ-Al_2O_3在最優(yōu)條件下的生物柴油轉(zhuǎn)化率超過95%;催化劑能夠重復(fù)使用4次,在使用過程中Na_3PO_4逐漸轉(zhuǎn)變?yōu)镹a_2HPO_4和NaH2PO4,通過堿洗把它們轉(zhuǎn)變回Na_3PO_4后,活性得到恢復(fù)。 (四)以Zr(SO_4)_2·4H_2O為活性化合物,硅藻土為載體,制備了Zr(SO_4)_2-Kieselguhr固體酸催化劑。 考察了制備條件(Zr(SO_4)_2負載量、焙烤溫度和焙烤時間)對催化劑活性的影響,并把活性變化與催化劑結(jié)構(gòu)、活性化合物的變化聯(lián)系起來;以活性最高的Zr(SO_4)_2-Kieselguhr為催化劑,催化油酸與甲醇反應(yīng)制備油酸甲酯,考察反應(yīng)溫度、催化劑用量和醇酸摩爾比對油酸甲酯產(chǎn)率的影響;利用XRF等方法考察了催化劑重復(fù)使用過程中的活性變化,探索了催化劑失活原因并建立了活性再生方法。催化劑的酸性、酸量、孔徑和Zr(SO_4)_2中結(jié)晶水個數(shù)對活性影響較大,最理想條件下Zr(SO_4)_2-Kieselguhr催化的最佳酯化產(chǎn)率可達95.2%,催化劑在重復(fù)使用4次過程中SO_4~2-逐漸流失導(dǎo)致失活,重新負載Zr(SO_4)_2后活性得到恢復(fù)。 (五)分別以Na_3PO_4/γ-Al_2O_3和Zr(SO_4)_2-Kieselguhr為固體酸堿催化劑,固體酸堿兩步法催化菜籽毛油與甲醇反應(yīng)制備生物柴油。 在酸催化中考察了催化劑用量、反應(yīng)溫度和醇油摩爾比對生物柴油產(chǎn)率的影響;在堿催化中考察了催化劑用量、反應(yīng)溫度、醇油摩爾比、酸催化時間和甲醇添加方式對生物柴油產(chǎn)率的影響,并利用二次旋轉(zhuǎn)正交法優(yōu)化堿催化反應(yīng)。建立了生物柴油固體酸堿兩步法20 L中試工藝和生物柴油后處理工藝,本工藝所制備的生物柴油產(chǎn)率可達97.6%,產(chǎn)品符合國家標準GB/T20828-2007,與液體酸堿兩步法比較,該工藝可節(jié)省熱能7.6%,節(jié)省電能43.6%,廢水排放降低一半。
[Abstract]:The two - step catalytic method of liquid acid and alkali used in biodiesel production in China firstly uses concentrated sulfuric acid ( H _ 2SO _ 4 ) to catalyze free fatty acid in oil to produce fatty acid methyl ester ( bio - diesel oil ) , then uses sodium hydroxide ( NaOH ) to catalyze triglyceride to form fatty acid methyl ester . The catalyst is dissolved in the reaction system . After the reaction , the catalyst can be removed . The solid acid - base catalyst is not dissolved in the reaction system . After the reaction , the catalyst can be removed . The solid acid - base catalyst can replace H _ 2SO _ 4 and NaOH , and the wastewater discharge and energy consumption in the production process can be reduced significantly , and the production cost is correspondingly reduced .


The preparation and characterization of Na _ 3PO _ 4 / 緯 - Al _ 2O _ 3 and solid acid catalyst Zr ( SO _ 4 ) _ 2 - Kipling were carried out by using Na _ 3PO _ 4 and Zr ( SO _ 4 ) _ 2 路 4H _ 2O as the active compound .


( 1 ) The catalytic properties of sodium phosphate ( Na _ 3PO _ 4 ) in the transesterification of rapeseed oil and methanol were investigated .


The transesterification effects of Na _ 3PO _ 4 under different reaction conditions were investigated . The activities of Na _ 3PO _ 4 and some solid and liquid catalysts in the preparation of biodiesel were compared . The results showed that the yield of the biodiesel was 95 % under the conditions of 3 wt % of catalyst , 9 : 1 molar ratio of alcohol oil , 343 K of reaction temperature and 600 rpm , and the activity of the catalyst was similar to that of the liquid base catalyst . The residual of Na _ 3PO _ 4 in biodiesel was little , and the catalyst could be reused 8 times .


( 2 ) The main components of methyl oleate ( fatty acid methyl ester ) were prepared by esterification of oleic acid with methanol by using zirconium sulfate tetrahydrate ( Zr ( SO _ 4 ) _ 2 路 4H _ 2O ) as catalyst .


The effects of Zr ( SO _ 4 ) _ 2 路 4H _ 2O on the catalytic esterification of Zr ( SO _ 4 ) _ 2 路 4H _ 2O in methanol were investigated . The effect of Zr ( SO _ 4 ) _ 2 路 4H _ 2O on the activity of Zr ( SO _ 4 ) _ 2 路 4H _ 2O was investigated . The activity of Zr ( SO _ 4 ) _ 2 路 4H _ 2O was investigated . The activity of Zr ( SO _ 4 ) _ 2 路 4H _ 2O was recovered by means of sulfuric acid ( H _ 2SO _ 4 ) loading .


( 3 ) Na _ 3PO _ 4 / 緯 - Al _ 2O _ 3 supported catalyst was prepared by impregnation method with Na _ 3PO _ 4 as active compound and 緯 - Al _ 2O _ 3 as carrier .


The effects of the preparation conditions ( Na _ 3PO _ 4 loading , baking temperature and baking time ) on the activity of the catalyst were investigated . The effects of the preparation conditions on the catalyst structure were investigated by various instrument characterization methods . The results showed that the conversion of Na _ 3PO _ 4 / 緯 - Al _ 2O _ 3 in the process of reuse was more than 95 % . The results showed that the activity of Na _ 3PO _ 4 / 緯 - Al _ 2O _ 3 was more than 95 % .


( 4 ) Zr ( SO _ 4 ) _ 2 路 4H _ 2O as active compound and diatomite as carrier , Zr ( SO _ 4 ) _ 2 - Kilowsolid acid catalyst was prepared .


The effects of preparation conditions ( Zr ( SO _ 4 ) _ 2 loading , baking temperature and baking time on the activity of catalyst were investigated . The effects of reaction temperature , catalyst dosage and molar ratio of alcohol and acid on the yield of methyl oleate were investigated by reaction of oleic acid with methanol .


( 5 ) Using Na _ 3PO _ 4 / 緯 - Al _ 2O _ 3 and Zr ( SO _ 4 ) _ 2 - Kip1 as solid acid - base catalyst , the solid acid - base two - step method was used to catalyze the reaction of rapeseed crude oil with methanol to prepare biodiesel .


The effects of catalyst dosage , reaction temperature and molar ratio of alcohol and oil on the yield of biodiesel were investigated in acid catalysis . The effects of catalyst dosage , reaction temperature , molar ratio of alcohol and oil , acid - catalyzed time and methanol addition on the yield of biodiesel were investigated .
【學(xué)位授予單位】：合肥工業(yè)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2011
【分類號】：TE667;TQ426.95

【引證文獻】

相關(guān)碩士學(xué)位論文 前1條

1 邢春梅;新型固體堿的合成及催化酯交換性能的研究[D];黑龍江大學(xué);2012年

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本文編號：1956999