现代生物柴油的生产工艺及产品质量

介绍了最新开发的，由植物油脂经酯交换，离心机分离连续生产生物柴油的CD-工艺方法。检测表明，经该法生产的生物柴油，各项技术指标与天然柴油极为相似，其各项燃烧指标优于或与普通柴油相仿，满足欧洲2号排放标准。     

生物柴油的标准和质量控制

标准能指导生产优质的生物柴油,同时也是市场准入的重要条件,生物柴油的发展刺激着标准的建立.对生物柴油的各项指标进行综述,讨论了生物柴油的稳定性.     

新一代生物柴油原料——微藻

生物柴油是指来自生物体的油脂经转酯作用而形成的单烷基脂肪酸酯。从目前的情况来看,以高等植物、动物等油脂为原料生产的生物柴油根本无法满足人们的需求。某些微藻因含油量高、易于培养、单位面积产量大等优点,而被视为新一代的、甚至是唯一能实现完全替代石化柴油的生物柴油原料。该文结合中国生物柴油的发展状况,剖析了利用微藻生产生物柴油的优势,并就其存在的劣势重点地从优良藻种的筛选、产油培养条件与技术的改进、生物柴油提炼方法与过程系统化等方面,提出了应对措施,并展望了其应用的前景。     

废动植物油脂工业化生产生物柴油的研究

以废动植物油脂为原料,在自制DYD催化剂作用下生产生物柴油,详细介绍了生产生物柴油的工艺过程、分析方法、产品质量以及在柴油机上的试验情况,通过正交试验确定了生产生物柴油的最优工艺条件,即醇油摩尔比4∶1,催化剂用量2%,反应温度75℃,反应时间8 h。测试结果表明,所生产的生物柴油各项性能指标都达到美国同类产品的标准(D6751-03a),在动力性、经济性基本不变的情况下,其环保性能指标明显改善,完全能在柴油机上应用。     

文冠果生物柴油的性质及与硅橡胶的兼容性

在制备文冠果生物柴油的基础上,以0~#柴油为对照,研究了文冠果生物柴油的性质及与硅橡胶的兼容性。结果表明:文冠果生物柴油不饱和脂肪酸含量高,其各项理化指标均符合我国生物柴油国家标准(GB/T 20828—2007);常温静态浸泡28 d过程中,文冠果生物柴油的密度和运动黏度仍满足国标要求,且硅橡胶对文冠果生物柴油的性质影响小于对0~#柴油的;硅橡胶在文冠果生物柴油中厚度最大变化率、质量最大变化率、拉伸强度最大变化率和扯断伸长率最大变化率分别达到11.99%、14.52%、-12.23%和7.69%,其值均小于0~#柴油中的变化率。文冠果生物柴油与0~#柴油对硅橡胶的溶胀作用主要发生在浸泡初期。     

生物柴油与石化柴油性能的比较分析

从生产方法和工艺、燃料特性和起动性能、发动机经济性和动力性、排放特性以及可再生性方面比较了生物柴油与石化柴油的差异.结果表明,生物柴油与石化柴油在生产方法和工艺方面存在很大差异,也有很多相似之处;生物柴油的燃料特性、起动性能以及发动机经济性、动力性接近或稍逊于石化柴油;生物柴油具有更好的排放性能和可再生性,因此生物柴油是一种综合性能优良的可替代石化柴油的燃料.     

废动植物油工业化生产生物柴油的研究

以废动植物油为原料,研究了在自制DYD催化剂作用下,生产生物柴油的原理和方法、最佳生产工艺、分析方法、产品质量以及在柴油机上的试验情况,在最佳工艺条件下,转化率达到97%以上.测试结果表明,所生产的生物柴油,其各项性能指标都达到美国同类产品的标准(D6751-03a),在动力性、经济性基本不变的情况下,其环保性能指标明显改善,完全能在柴油机上广泛应用.     

餐厨废弃油脂制生物柴油的典型指标在储存期间的变化规律

为提高餐厨废弃油脂制生物柴油的储存稳定性,以餐厨废弃油脂为原料,采用生物酶法制备生物柴油,并向其中添加0.2%的抗氧化剂,测定其在90 d储存过程中酸值、水含量、硫含量及氧化安定性的变化。结果表明：酶法制备的生物柴油各项指标满足GB 25199—2017《B5柴油》中BD100生物柴油S10的技术要求,硫含量最低为2.1 mg/kg;当添加0.2%的抗氧化剂时,生物柴油的氧化安定性由3.6 h提高至12.0 h,储存90 d后,生物柴油的硫含量、酸值、水含量、氧化安定性仍符合国标要求。酶法制备生物柴油工艺易于控制产品的各项指标,且工艺更加绿色环保,通过添加抗氧化剂可提高生物柴油的储存稳定性。     

不同酸价原料油生产生物柴油方法探讨

在制取生物柴油时,原料油酸价是决定生物柴油生产工艺关键因素之一.该文介绍几种不同酸价原料油生产生物柴油方法,阐述各自工艺方法、特点和适应性,并提出在实际生产过程中应注意问题.对生物柴油生产具有一定指导意义.     

适于生产生物柴油的产油酵母菌的筛选

该文从土壤中筛选出10株产油脂的酵母菌,经摇床培养复筛确定其中2株优良产油酵母菌JM-B、JM-D。通过对2株菌生理生化特性的试验,进一步对其发酵性能进行研究并对酵母菌株油脂脂肪酸组成进行测定。菌株JM-D油脂脂肪酸组成与植物油相似,适合用于发酵生产生物柴油,是今后发酵生产生物柴油的优良菌株。     

从废油脂中制取生物柴油的反应动力学及工艺研究

本文根据碱催化甲醇酯化反应机理提出了甲醇酯化反应的动力学假设模型，并对模型做了适当的简化，然后对甲醇酯化制取生物柴油的反应动力学进行了模拟，并且提出了利用餐饮业废油脂生产生物柴油的方法工艺。     

Unregulated emissions from a heavy-duty diesel engine with various fuels and emission control systems

This study evaluated the effects of various combinations of fuels and emission control technologies on exhaust emissions from a heavy-duty diesel engine tested on an engine dynamometer. Ten fuels were studied in twenty four combinations of fuel and emission control technology configurations. Emission control systems evaluated were diesel oxidation catalyst (DOC), continuously regenerating diesel particulate filter (CRDPF), and the CRDPF coupled with an exhaust gas recirculation system (EGRT). The effects of fuel type and emission control technology on emissions of benzene, toluene, ethylbenzene, xylene (BTEX), and 1,3-butadiene, elemental carbon and organic carbon (EC/OC), carbonyls, polycyclic aromatic hydrocarbons (PAHs), and nitro-PAHs (n-PAHs) are presented in this paper. Regulated gaseous criteria pollutants of total hydrocarbons (THC), carbon monoxide (CO), oxides of nitrogen (NO(x)) and particulate matter (PM) emissions have been reported elsewhere. In general, individual unregulated emission with a CRDPF or an EGRT system is similar (at very low emission level) or much lower than that operating solely with a DOC and choosing a "best" fuel. The water emulsion PuriNO(x) fuel exhibited higher BTEX, carbonyls and PAHs emissions compared to other ultralow sulfur diesel (ULSD) fuels tested in this study while n-PAH emissions were comparable to that from other ULSD fuels. Naphthalene accounted for greater than 50% of the total PAH emissions in this study and there was no significant increase of n-PAHs with the usage of CRDPF.     

Biodiesel fuel production by transesterification of oils

Biodiesel (fatty acid methyl esters), which is derived from triglycerides by transesterification with methanol, has attracted considerable attention during the past decade as a renewable, biodegradable, and nontoxic fuel. Several processes for biodiesel fuel production have been developed, among which transesterification using alkali-catalysis gives high levels of conversion of triglycerides to their corresponding methyl esters in short reaction times. This process has therefore been widely utilized for biodiesel fuel production in a number of countries. Recently, enzymatic transesterification using lipase has become more attractive for biodiesel fuel production, since the glycerol produced as a by-product can easily be recovered and the purification of fatty methyl esters is simple to accomplish. The main hurdle to the commercialization of this system is the cost of lipase production. As a means of reducing the cost, the use of whole cell biocatalysts immobilized within biomass support particles is significantly advantageous since immobilization can be achieved spontaneously during batch cultivation, and in addition, no purification is necessary. The lipase production cost can be further lowered using genetic engineering technology, such as by developing lipases with high levels of expression and/or stability towards methanol. Hence, whole cell biocatalysts appear to have great potential for industrial application.     

双低油菜籽资源综合开发产业化

双低油菜籽作为一种新的油料资源，具有广阔的应用前景。分析测定了双低油菜籽主要成分及蛋白质、植酸、硫甙和单宁的溶解度，并与普通油菜籽的组成成分进行了比较。着重论述了双低油菜籽综合开发产业化的几种主要途径：油菜籽脱皮、挤压膨化(低温压榨)、浸出制油新工艺；菜籽浓缩蛋白的制备；天然复合氨基酸粉的制备；菜籽皮壳的利用以及生物柴油的生产。     

Brassica carinata as an alternative oil crop for the production of biodiesel in Italy: engine performance and regulated and unregulated exhaust emissions

A comparison of the performance of Brassica carinata oil-derived biodiesel with a commercial rapeseed oil-derived biodiesel and petroleum diesel fuel is discussed as regards engine performance and regulated and unregulated exhaust emissions. B. carinata is an oil crop that can be cultivated in coastal areas of central-southern Italy, where it is more difficult to achieve the productivity potentials of Brassica napus (by far the most common rapeseed cultivated in continental Europe). Experimental tests were carried out on a turbocharged direct injection passenger car diesel engine fueled with 100% biodiesel. The unregulated exhaust emissions were characterized by determining the SOOT and soluble organic fraction content in the particulate matter, together with analysis of the content and speciation of polycyclic aromatic hydrocarbons, some of which are potentially carcinogenic, and of carbonyl compounds (aldehydes, ketones) that act as ozone precursors. B. carinata and commercial biodiesel behaved similarly as far as engine performance and regulated and unregulated emissions were concerned. When compared with petroleum diesel fuel, the engine test bench analysis did not show any appreciable variation of output engine torque values, while there was a significant difference in specific fuel consumption data at the lowest loads for the biofuels and petroleum diesel fuel. The biofuels were observed to produce higher levels of NOx concentrations and lower levels of PM with respect to the diesel fuel. The engine heat release analysis conducted shows that there is a potential for increased thermal NOx generation when firing biodiesel with no prior modification to the injection timing. It seems that, for both the biofuels, this behavior is caused by an advanced combustion evolution, which is particularly apparent at the higher loads. When compared with petroleum diesel fuel, biodiesel emissions contain less SOOT, and a greater fraction of the particulate was soluble. The analysis and speciation of the soluble organic fraction of biodiesel particulate suggest that the carcinogenic potential of the biodiesel emissions is probably lower than that of petroleum diesel. Its better adaptivity and productivity in clay and sandy-type soils and in semiarid temperate climate and the fact that the performance of its derived biodiesel is quite similar to commercial biodiesel make B. carinata a promising oil crop that could offer the possibility of exploiting the Mediterranean marginal areas for energetic purposes.     

Emissions of EC, OC, and PAHs from cottonseed oil biodiesel in a heavy-duty diesel engine

Biodiesel fuels, made from renewable resources, have emerged as viable alternatives to conventional diesel fuel, but their impact on emissions is not fully understood. This study examines elemental carbon (EC), organic carbon (OC), and polycyclic aromatic hydrocarbons (PAHs) emissions from cottonseed oil biodiesel (CSO-B100). Relative to normal diesel fuel, CSO-B100 reduced EC emissions by 64% (±16%). The bulk of EC emitted from CSO-B100 was in the fine particle mode (<1.4 μm), which is similar to normal diesel. OC was found in all size ranges, whereas emissions of OC(1.4-2.5) were proportionately higher in OC(2.5) from CSO-B100 than from diesel. The CSO-B100 emission factors derived from this study are significantly lower, even without aftertreatment, than the China-4 emission standards established in Beijing and Euro-IV diesel engine standards. The toxic equivalency factors (TEFs) for CSO-B100 was half the TEFs of diesel, which suggests that PAHs emitted from CSO-B100 may be less toxic.     

Approach for energy saving and pollution reducing by fueling diesel engines with emulsified biosolution/ biodiesel/diesel blends

The developments of both biodiesel and emulsified diesel are being driven by the need for reducing emissions from diesel engines and saving energy. Artificial chemical additives are also being used in diesel engines for increasing their combustion efficiencies. But the effects associated with the use of emulsified additive/biodiesel/diesel blends in diesel engines have never been assessed. In this research, the premium diesel fuel (PDF) was used as the reference fuel. A soy-biodiesel was selected as the test biodiesel. A biosolution made of 96.5 wt % natural organic enzyme-7F (NOE-7F) and 3.5 wt % water (NOE-7F water) was used as the fuel additive. By adding additional 1 vol % of surfactant into the fuel blend, a nanotechnology was used to form emulsified biosolution/soy-biodiesel/PDF blends for fueling the diesel engine. We found that the emulsified biosolution/soy-biodiesel/PDF blends did not separate after being kept motionless for 30 days. The above stability suggests that the above combinations are suitable for diesel engines as alternative fuels. Particularly, we found that the emulsified biosolution/soy-biodiesel/PDF blends did have the advantage in saving energy and reducing the emissions of both particulate matters (PM) and polycyclic aromatic hydrocarbons (PAHs) from diesel engines as compared with PDF, soy-biodiesel/PDF blends, and emulsified soy-biodiesel/ PDF blends. The results obtained from this study will provide useful approaches for reducing the petroleum reliance, pollution, and global warming. However, it should be noted that NO(x) emissions were not measured in the present study which warrants the need for future investigation.     

Emissions of PCDD/Fs, PCBs, and PAHs from a modern diesel engine equipped with catalyzed emission control systems

Exhaust emissions of 17 2,3,7,8-substituted chlorinated dibenzo-p-dioxin/furan (CDD/F) congeners, tetra-octa CDD/F homologues, 12 2005 WHO chlorinated biphenyls (CB) congeners, mono-nona CB homologues, and 19 polycyclic aromatic hydrocarbons (PAHs) from a model year 2008 Cummins ISB engine were investigated. Testing included configurations composed of different combinations of aftertreatment including a diesel oxidation catalyst (DOC), catalyzed diesel particulate filter (CDPF), copper zeolite urea selective catalytic reduction (SCR), iron zeolite SCR, and ammonia slip catalyst. Results were compared to a baseline engine out configuration. Testing included the use of fuel that contained the maximum expected chlorine (Cl) concentration of U.S. highway diesel fuel and a Cl level 1.5 orders of magnitude above. Results indicate there is no risk for an increase in polychlorinated dibenzo-p-dioxin/furan and polychlorinated biphenyl emissions from modern diesel engines with catalyzed aftertreatment when compared to engine out emissions for configurations tested in this program. These results, along with PAH results, compare well with similar results from modern diesel engines in the literature. The results further indicate that polychlorinated dibenzo-p-dioxin/furan emissions from modern diesel engines both with and without aftertreatment are below historical values reported in the literature as well as the current inventory value.     

Evaluation of the Impacts of Biodiesel and Second Generation Biofuels on NO(x) Emissions for CARB Diesel Fuels

The impact of biodiesel and second generation biofuels on nitrogen oxides (NO(x)) emissions from heavy-duty engines was investigated using a California Air Resources Board (CARB) certified diesel fuel. Two heavy-duty engines, a 2006 engine with no exhaust aftertreatment, and a 2007 engine with a diesel particle filter (DPF), were tested on an engine dynamometer over four different test cycles. Emissions from soy- and animal-based biodiesels, a hydrotreated renewable diesel, and a gas to liquid (GTL) fuel were evaluated at blend levels from 5 to 100%. NO(x) emissions consistently increased with increasing biodiesel blend level, while increasing renewable diesel and GTL blends showed NO(x) emissions reductions with blend level. NO(x) increases ranged from 1.5% to 6.9% for B20, 6.4% to 18.2% for B50, and 14.1% to 47.1% for B100. The soy-biodiesel showed higher NO(x) emissions increases compared to the animal-biodiesel. NO(x) emissions neutrality with the CARB diesel was achieved by blending GTL or renewable diesel fuels with various levels of biodiesel or by using di-tert-butyl peroxide (DTBP). It appears that the impact of biodiesel on NO(x) emissions might be a more important consideration when blended with CARB diesel or similar fuels, and that some form of NO(x) mitigation might be needed for biodiesel blends with such fuels.