林木生物质能源开发和利用

林木生物质能源作为生物质能源的一个重要分支,清洁性和可循环再生利用等特点使其在新世纪具有广阔发展前景。本文结合国外做法介绍了我国木质能源开发和利用现状,阐述了林木质能源开发和利用方式,并对发展前景和对策作了初步探讨。     

国外生物柴油的发展及其对我国林业产业的启示

随着能源消耗量的不断增加,有限的常规能源如煤、石油、天然气等,将日趋紧缺,我国石油资源不足的问题也将更为突出,目前我国已经成为世界第二石油进口大国,2004年全年石油进口量达1.4亿t,占总需求量的1/3多,我国石油供应对国际石油市场的依赖程度将不断加大。因此,寻找新的可持续的能源对于我国来说意义特别重大。本文总结了国外发展生物柴油的现状和经验,对我国林业生物柴油的发展提出了建议。     

生物柴油-柴油混合燃油的试验分析

进行生物柴油及生物柴油-柴油混合燃油应用于压燃式发动机上的外特性和负荷特性试验,研究分析了生物柴油-柴油混合燃油以不同比例混合时所表现出的动力性、经济性和排放性的差异,为生物柴油-柴油混合燃油的优化控制提供基础。     

豆油乙二醇乙醚酯生物柴油燃料特性研究

以乙二醇乙醚和精制大豆油在金属钠催化下合成出了豆油乙二醇乙醚酯生物柴油,考察了该生物柴油作为替代燃料在性能方面与柴油的差别;研究了作为柴油添加剂,其加入量对混合燃料性能的影响。结果表明,豆油乙二醇乙醚酯生物柴油的燃料特性达到了国外生物柴油生产标准,可以直接作为柴油使用,也可与矿物柴油掺合使用,提高了柴油的使用性能。     

改性生物柴油碳烟与NOx排放试验

针对生物柴油氧化安定性较差、NOx排放偏高的情况,添加抗氧化剂(BHA)对生物柴油进行燃料改性,分析了抗氧化剂对生物柴油氧化安定性的影响,讨论了改性前、后生物柴油粘度随温度的变化规律。测量了高压共轨柴油机燃烧改性生物柴油的排放污染物随转速、负荷的变化规律。探讨了抗氧化剂改善生物柴油碳烟、NOx排放的作用机理。研究结果表明:燃料改性后,生物柴油的氧化安定性大幅度提高,燃油粘度略有降低;发动机的碳烟、NOx排放均明显下降,特别是在中、高负荷时效果显著;燃烧过程中抗氧化剂抑制了脂肪酸长链分子的高温裂解,促进了自由基的淬熄效应,由此改变了碳烟与NOx排放之间此消彼长的关系。     

二步法催化高酸值大豆油制备生物柴油

采用两步法催化高酸值大豆油制备生物柴油.第一步在固定床反应器中,以002CR型阳离子交换树脂为催化剂,高酸值大豆油中游离脂肪酸和甲醇酯化生成脂肪酸甲酯(生物柴油);然后用氢氧化钾催化油中的甘油三酯和甲醇进行酯交换.结果表明,最佳酯化条件为:醇酸摩尔比2:1,反应温度60℃,进耕速度3 mL/min.该条件下大豆油酸值可降至1 mgKOH/g以下.酯交换条件为:催化剂用量1.5%,醇油摩尔比6:1,反应温度65℃.产品技术指标达到我国0#柴油(GB252-1994优级品)的要求.     

生物柴油氧化稳定性研究

采用烘箱法，将样品置于63℃±2℃的培养箱中，定时取样检测样品过氧化值、酸值、硫代巴比妥酸值，考察B5、B10、B20、B100菜籽油生物柴油（RME）、大豆油生物柴油（SME）、棕榈油生物柴油（PME）、废煎炸油生物柴油（FWME）和0#柴油氧化稳定性，同时考察金属介质对B100生物柴油氧化稳定性的影响。结果表明，4种生物柴油的氧化稳定性依次为FWME＞RME＞PME＞SME，而0#柴油氧化稳定性远优于生物柴油；B5、B10、B20生物柴油样品表现出较好的氧化稳定性，但随着样品中生物柴油添加比例的增加，其酸值也高，样品的氧化主要是生物柴油氧化导致的；金属铜对生物柴油和0#柴油的氧化均有催化作用，金属铁的催化作用不明显。     

我国生物柴油领域技术专利分析

利用上海知识产权（专利信息）公共服务平台,对我国生物柴油领域专利信息进行深度挖掘,分别从专利类型、专利申请量、重点专利技术及专利申请人等方面分析了我国生物柴油领域专利保护现状、发展趋势以及竞争态势,为我国生物柴油领域的技术创新和战略发展提供参考.     

Potential of Near- and Mid-infrared Spectroscopy in Biofuel Production

For many decades, near-infrared spectroscopy (NIRS) has been used to determine the composition of animal feedstuffs and grains. More recently, mid-infrared spectroscopy (mid-IR) has also been examined for similar determinations. These spectroscopic methods offer the potential for rapid and accurate determination of organic constituents, such as fiber components and protein, of forages, by-products, and grains at reduced cost and greatly increased speed (minutes instead of hours or days). Because they are nonchemical in nature, they result in a large reduction (90% or more) in the chemical wastes associated with standard chemical-based assay methods. The same components of interest for biofuel production (cellulose, hemicellulose, lignin, starch, protein, oil, etc.) are those that have already been determined by NIRS/mid-IR for evaluating grains and animal feedstuffs. Therefore, these techniques would appear to be a natural match for evaluating feedstocks for biofuels, and the literature shows that efforts in this direction are being successfully tested and instituted. For this discussion, an overview of where such efforts are and the potential for NIRS/mid-IR in producing biofuels will be covered. For example, while there are similarities between the needs of the biofuels industry and the analysis of animal feedstuffs, there are also both practical and technical differences between the two that will likely impact how NIRS/mid-IR is developed for biofuels. As an example, grain analysis for protein is performed on a large scale by government agencies such as the Canadian Grain Commission and U.S. Grain Inspection Service, while at least in the United States, animal feedstuff analysis is performed by state or independent laboratories for individual farmers. For biofuels, this might well result in most analysis being performed by the large corporations converting the feedstocks to biofuels, as opposed to the individual producer having analysis performed at an independent laboratory. Similarly for animal feedstuffs, measurements of fiber (neutral detergent fiber or NDF, acid detergent fiber or ADF, and lignin) and protein are carried out. These fiber measurements often consist of more than one type of fiber component with some being computed by difference (hemicellulose = NDF – ADF) and are empirical at best. Whether such empirical estimates will be sufficient for assessing biofuels or whether new spectroscopic methods for directly measuring the components of interest (cellulose, etc.) will need to be developed is a question to be answered when components other than starch for ethanol or oil for biodiesel become common.     

Characterization of biodiesel and bio-oil from Sterculia striata (chicha) oil

This work describes the mechanical and solvent extraction of Sterculia striata seed oil. It was determined that the seeds contain up to 41% in oil, which has an unusual composition. Indeed, up to 50% of the fatty acid contain cyclopropenoid ring. The oil was used as raw material to produce bio-oil and biodiesel and their physical-chemical properties were evaluated. Some of the studied physical-chemical properties of the S. striata biodiesel are in acceptable range for use as biodiesel in diesel engines, showing a promising economic exploitation of this raw material in semi-arid regions. It was also observed that the cyclopropenoid ring remains after transesterification and is decomposed during pyrolysis.