菜籽油酯交换制备生物柴油的工艺研究

为提高生物柴油的转化率和纯度,以菜籽油为原料,研究在KOH催化剂作用下与甲醇进行酯交换反应制备生物柴油的工艺,考察了甲醇用量、催化剂用量、反应温度和反应时间等操作条件对酯交换反应的影响。结果表明,该反应最适宜的工艺条件为：甲醇用量为菜籽油质量的20%,催化剂用量为菜籽油质量的1.2%,反应温度为65℃,反应时间为90～120 min;菜籽油制备的生物柴油品质达到美国ASTM和德国DINE生物柴油标准,其生物柴油的转化率为94.89%。若充分开发中国南方可利用的冬闲田和边际土地约1000万hm²种植油菜,按照此工艺条件加工菜籽油,则每年可加工生产生物柴油740万t,具有广阔的发展前景。     

中间锦鸡儿油酸脱氢酶基因的克隆与反义表达

高质量高得率的生物柴油要求植物脂肪酸拥有一个以上的双键,但数目尽可能要少,最好只有一个双键。但是现在绝大多数油料植物的多不饱和脂肪酸含量偏高,如中间锦鸡儿种子中多不饱和脂肪酸含量高达60%,迫切需要改良。以中间锦鸡儿枝、叶和种子为材料,根据Genbank中已登录的fad2基因同源序列,设计兼并性引物,利用PCR方法获得基因片段。在GenBank中Blast(GenBank登录号AY957 394),所得基因片段和同属豆科的Glycinemax Gm基因fad2-2a同源性达88%,属于fad2基因编码区中间片断。将所得片段经BamHI和SacI酶切后插入表达载体质粒pBI121,构建反义表达载体pBI121fad2,并利用农杆菌介导法转入烟草叶片,获得了抗卡那霉素和安苄青霉素的烟草再生植株。采用基因片段特异引物和表达载体pBI121上基因NPTⅡ引物双重检测均呈阳性的确认为烟草转基因植株,分别测定转基因烟草和对照种子脂肪酸。结果表明,与对照烟草比较,转基因烟草种子脂肪酸含量未见明显差异,而亚油酸减少了10.3%。研究结果为进一步进行柠条分子育种,获得高产单不饱和脂肪酸新品种及改造相关生物柴油用木本油料植物提供了科学依据。     

大豆油和地沟油制备生物柴油生命周期评价

该研究应用生命周期评价方法,以大豆油和地沟油分别制备1 t生物柴油为研究对象,计算生物柴油全生命周期过程中的能源消耗和周期排放,结果表明：以大豆油为原料制备生物柴油全生命周期总能耗约为地沟油的2.65倍,且以地沟油为原料制备生物柴油过程中CO2、SO2、NOx、CO和粉尘各项排放与大豆油为原料时相比分别降低了82.92%、45.68%、94.91%、53.40%和90.61%。通过对制备生物柴油生命周期排放的废气和废物对环境造成的影响进行量化分析,结果表明以大豆油为原料时生命周期环境影响潜值约为地沟油的11.70倍,其数值分别为8.42和0.72,大豆油制备生物柴油过程中对环境的影响主要是全球性的变暖,地沟油制备生物柴油过程中对环境的影响主要是地区性的酸化。     

我国小桐子生物柴油产业现状和发展探讨

生物柴油是清洁的可再生能源,受到世界各国的高度重视,也是我国未来较长时期内石油市场发展的焦点。小桐子制取生物柴油可行性高,将其形成产业化对于解决我国能源安全、改善生态环境、增加农民收入具有重要意义。     

国内外生物柴油研究进展

介绍生物柴油的优点、制备方法以及国内外研究发展现状,指出油葵作为生物柴油原料的优势及我国发展油葵生物柴油产业中存在的问题和解决措施,以为生物柴油的研究及应用提供参考。     

生物柴油产业发展的现状及前景

生物柴油是一种环保、高效、多功能、可再生能源.概述了生物柴油的周途优越性.及国外对生物柴油的研究现状,指出了我国在生物柴油研发和生产应用上存在的问题,展望了生物柴油产业的发展前景,并且提出了发展生物柴油的一些战略措施.     

Photosynthesis,fluorescence and mesophyll conductance responses to increasing salinity levels in Jatropha curcas at early vegetative stages

Salinity is often a great limitation in marginal environments with potential for developing alternative non-edible crops for biodiesel, and the physiological responses involved in the recovery of plants subjected to high salinity are poorly studied. The aim of this study on Jatropha curcas is to identify salinity tolerance responses of net photosynthesis rate under saturating irradiances (A_max), its recovery capacity and the role of mesophyll conductance (g_m) over A_max. Two experiments were performed with seedlings in pots under outdoor conditions and hydroponic conditions, respectively, with salinity intensities ranging from 3 to 12 dS/m, their isosmotic treatments with polyethylene glycol (PEG) and controls without abiotic stress. A_max and growth rate were mainly affected by salinity effects in all the ranges, with a drastic 60% drop in dry biomass under 6 dS/m, revealing a significant sensitivity of this species. However, a surprising increase in A_max was promoted by the presence of NaCl, with respect to their respective isosmotic treatments with PEG, although it was still lower than the unstressed plants. This advantage disappeared from 9 dS/m, but negative effects of NaCl toxicities were never detected. The photochemical apparatus resulted extremely resistant in this species, since Fv/Fm and leaf greenness were affected only at 12 dS/m. So, g_m was strongly and linearly associated with A_max. This association derives from the overall range of stress intensities tested, thus appearing as the main useful trait for enhancing photosynthesis depletion under salinity stress, without losses of the water use efficiency. A drastic 75% drop was also detected in the electron use for photosynthesis, revealing that A_max would also be modulated by metabolic impairments under salinity. Moreover, full recovery after only 8 days was observed, confirming the high resistance of the species to NaCl stress even under very high salinities. This study contributes to a better understanding of the physiological processes involved in the response of J. curcas to salinity during early vegetative stage, generating possibilities for improving tolerance of this species under environments exposed to salinity.     

热带木本生物质能源树种——油棕

油棕是一种重要的热带木本生物质能源树种,具有结果期长、产量和含油量高等特点。随着原油价格的不断上涨,生物柴油的发展日益受到关注。而棕榈油由于生产成本低廉,成为生产生物柴油最具竞争力的原料。本文分别综述了油棕的基本特性、全球及我国棕榈油生产贸易和消费状况、我国发展油棕产业的重要意义,在此基础上对我国发展油棕产业的可行性和前景进行了探讨。     

The energy value of biodiesel glycerine products fed to broilers at different ages

The objective of this study was to determine the apparent metabolisable energy corrected for nitrogen balance (AMEn) of some products containing glycerine from soybean oil (GOIL), a mixture of frying oil and lard (GMIX) and a semi‐purified process (GSP) in broilers of different ages (10, 20, 30 and 40 days post‐hatching), using two methodologies. In trial 1, the basal diets were replaced with 100 g/kg of each studied glycerine product and the diets were supplied ad libitum. Three hundred broilers were used in five replicates, with five, four, three and three animals per cage in each age group, respectively. The AMEn was calculated for each experimental unit. In trial 2, dietary treatments included the addition of glycerine at 0, 40, 80 or 120 g/kg for each crude glycerine product, with 900 broilers in six replicates, using the same number of animals per cage as described in trial 1. Depending on the experimental unit, the feeding was restricted in 88%, 92%, 96% and 100% of estimated intake according to the Cobb guide. The AMEn was determined using linear regression between the feed intake and the AMEn of each diet. In both trials, the total excreta collection method was used. Because of the chemical composition, GMIX was not considered crude glycerine. The mean AMEn values of the products were 20.55 MJ/kg, 15.80 MJ/kg and 15.05 MJ/kg for GMIX, GSP and GOIL, respectively. There was a linear decrease (p < 0.01) in the AMEn values with the increasing age of the broilers. Numerically, it was observed that the AMEn values decreased until 28–30 day post‐hatching and then remained constant until the finishing phase. It is concluded that products containing glycerine can be used as an energy source for broilers, but that AMEn values can vary according to age. Younger broilers have a higher capacity of energy utilisation from these feedstuffs.     

基于差示扫描量热法和热力学模型的生物柴油结晶行为分析

棕榈酸甲酯(C16:0)、硬脂酸甲酯(C18:0)和油酸甲酯(C18:1)是生物柴油的主要组成部分。为了深入探究生物柴油的结晶行为,该文基于差示扫描量热法(differential scanning calorimetry,DSC)分析了这3种脂肪酸酯的物性参数,研究发现饱和脂肪酸甲酯C16:0和C18:0的熔点和熔化焓远远高出不饱和脂肪酸甲酯C18:1的值,C16:0和C18:0的熔点分别为301.57、310.92 K,C18:1的熔点为255.01 K。对脂肪酸酯组成的二元溶液进行DSC扫描,DSC曲线出现了2个放热峰,并且溶液的结晶点要低于首先析出的饱和脂肪酸酯纯物质时的熔点;随着饱和脂肪酸酯质量分数的增加溶液的结晶点温度也相应提高。将生物柴油当作由多元脂肪酸甲酯的混合溶液时,C16:0和C18:0等饱和脂肪酸甲酯作为溶质,C18:1等不饱和脂肪酸甲酯作为溶剂,建立了热力学模型计算溶液的结晶点温度。将脂肪酸甲酯的混合溶液近似为理想溶液时对此模型进一步简化,并利用简化模型计算得到4种生物柴油的结晶温度,与实测值进行比较得到了很好的验证效果。该研究可为优化生物柴油低温流动性的技术措施提供参考。