以油菜籽和甲醇为原料,在甲醇的超临界状态下进行原位萃取-酯交换反应制备生物柴油,研究了产物的主要组成以及反应温度、反应压力和原料比对生物柴油产率的影响。结果表明,产物主要由亚油酸甲酯、油酸甲酯、棕榈酸甲酯、硬脂肪酸甲酯和...以油菜籽和甲醇为原料,在甲醇的超临界状态下进行原位萃取-酯交换反应制备生物柴油,研究了产物的主要组成以及反应温度、反应压力和原料比对生物柴油产率的影响。结果表明,产物主要由亚油酸甲酯、油酸甲酯、棕榈酸甲酯、硬脂肪酸甲酯和亚麻酸甲酯构成;并发现反应温度、反应压力以及菜籽与甲醇的质量比是影响甲酯产率的主要因素,在菜籽与甲醇质量比为1∶4,反应压力和反应温度分别为14 MPa和280℃时,萃取和酯交换反应可同时在10 m in内完成,且油菜籽中所含的油脂转化率可达到94.3%。展开更多
以棉籽油脂肪酸与甲醇为原料,采用超临界甲醇非催化法制备生物柴油。考察了反应温度、反应时间、脂肪酸与甲醇体积比对产物中亚油酸、油酸、亚油酸甲酯和油酸甲酯含量的影响。结果表明,产物中亚油酸甲酯和油酸甲酯在反应温度超过280℃...以棉籽油脂肪酸与甲醇为原料,采用超临界甲醇非催化法制备生物柴油。考察了反应温度、反应时间、脂肪酸与甲醇体积比对产物中亚油酸、油酸、亚油酸甲酯和油酸甲酯含量的影响。结果表明,产物中亚油酸甲酯和油酸甲酯在反应温度超过280℃后呈下降趋势;反应时间超过15 m in后有降低趋势;脂肪酸与甲醇体积比超过1∶3后呈降低趋势。说明在超临界甲醇法制备生物柴油过程中反应温度不宜太高,反应时间不宜过长。展开更多
Depolymerization of polybutylene terephthalate (PBT) in supercritical methanol was studied using a stainless stirred batch\|type autoclave under high temperature (453～533?K) and high pressure (7～12?MPa) conditions.T...Depolymerization of polybutylene terephthalate (PBT) in supercritical methanol was studied using a stainless stirred batch\|type autoclave under high temperature (453～533?K) and high pressure (7～12?MPa) conditions.The main depolymerization products were dimethyl terephthalate (DMT) monomer and ethylene glycol.The effects of different reaction temperature and pressure on depolymerization of PBT were investigated by analysis of the solid phase and liquid phase products.Considering the critical point of methanol (512 6?K,8 09?MPa),the reaction pressure was varied with in the range of 7～12?MPa.The results showed that the reaction pressure had little influence on the depolymerization and the depolymerization rate was affected greatly by the reaction temperature.The depolymerization of PBT was only 30% in 40?min at lower temperatures (453～463?K) but reached 100% in 20?min when the temperature was above 513?K.Depolymerization kinetics of polybutylene terephthalate in supercritical methanol was studied.The results showed that the depolymerization reaction rate constant ( k 1) in the temperature range of 513～533?K was much larger than the rate constant ( k 2) in the range of 453～483?K.The dissolution characteristics of PBT in supercritical methanol were the critical factors for depolymerization of PBT in a short time.These findings suggest that the supercritical methanol treatment for depolymerization of polymers such as PBT will be potential for obtaining useful chemicals.展开更多
文摘以油菜籽和甲醇为原料,在甲醇的超临界状态下进行原位萃取-酯交换反应制备生物柴油,研究了产物的主要组成以及反应温度、反应压力和原料比对生物柴油产率的影响。结果表明,产物主要由亚油酸甲酯、油酸甲酯、棕榈酸甲酯、硬脂肪酸甲酯和亚麻酸甲酯构成;并发现反应温度、反应压力以及菜籽与甲醇的质量比是影响甲酯产率的主要因素,在菜籽与甲醇质量比为1∶4,反应压力和反应温度分别为14 MPa和280℃时,萃取和酯交换反应可同时在10 m in内完成,且油菜籽中所含的油脂转化率可达到94.3%。
文摘以棉籽油脂肪酸与甲醇为原料,采用超临界甲醇非催化法制备生物柴油。考察了反应温度、反应时间、脂肪酸与甲醇体积比对产物中亚油酸、油酸、亚油酸甲酯和油酸甲酯含量的影响。结果表明,产物中亚油酸甲酯和油酸甲酯在反应温度超过280℃后呈下降趋势;反应时间超过15 m in后有降低趋势;脂肪酸与甲醇体积比超过1∶3后呈降低趋势。说明在超临界甲醇法制备生物柴油过程中反应温度不宜太高,反应时间不宜过长。
文摘Depolymerization of polybutylene terephthalate (PBT) in supercritical methanol was studied using a stainless stirred batch\|type autoclave under high temperature (453～533?K) and high pressure (7～12?MPa) conditions.The main depolymerization products were dimethyl terephthalate (DMT) monomer and ethylene glycol.The effects of different reaction temperature and pressure on depolymerization of PBT were investigated by analysis of the solid phase and liquid phase products.Considering the critical point of methanol (512 6?K,8 09?MPa),the reaction pressure was varied with in the range of 7～12?MPa.The results showed that the reaction pressure had little influence on the depolymerization and the depolymerization rate was affected greatly by the reaction temperature.The depolymerization of PBT was only 30% in 40?min at lower temperatures (453～463?K) but reached 100% in 20?min when the temperature was above 513?K.Depolymerization kinetics of polybutylene terephthalate in supercritical methanol was studied.The results showed that the depolymerization reaction rate constant ( k 1) in the temperature range of 513～533?K was much larger than the rate constant ( k 2) in the range of 453～483?K.The dissolution characteristics of PBT in supercritical methanol were the critical factors for depolymerization of PBT in a short time.These findings suggest that the supercritical methanol treatment for depolymerization of polymers such as PBT will be potential for obtaining useful chemicals.
