生物柴油生产和利用的环境影响评价

生物柴油作为清洁的、可再生的石化燃料的替代能源,在许多国家得到了快速发展.通过生命周期评估法,对以油菜籽和大豆为原料的生物柴油生产全过程,包括种子的筛选、种植到生物柴油的燃烧,进行了环境影响评价,并与石化柴油进行了比较.     

微藻生物柴油的生命周期能耗和排放评估

本研究基于可行的微藻柴油生产工艺,建立了一套开放式跑道池微藻柴油生产系统。并采用生命周期评估方法,对这套系统生产的微藻生物柴油进行了生命周期能耗和排放评估。结果显示:在不对副产品加以利用的情况下,该系统生产的微藻生物柴油的生命周期能耗和排放分别高达:101952.9MJ/ton和10226.3kg CO_2eq/ton,其中微藻的培养过程是整个生产过程中能耗和排放最为集中的过程,该过程的能耗和排放占比均超过总能耗和总排放的60%。     

生命周期评价在促进造纸行业清洁生产中的应用

利用生命周期评价(LCA)的方法,分析了中国造纸业不同生命周期阶段的资源消耗及环境排放,评价了造纸业对环境造成的潜在影响,并比较了不同的废纸利用率及使用不同的能源所造成的潜在环境影响,探索资源利用、环境保护和造纸行业协调发展的途径和方法.     

啤酒酿造阶段生命周期清单分析

生命周期评价（LCA）可对产品生命周期各个阶段能量和物质利用以及废物排放进行分析，啤酒生命周期一般包括啤酒酿造、副产品处理、运输销售、回收处理等单元。清单分析包括原材料消耗、能源消耗和环境排放结果分析，环境排放又包括废水排放和废弃物排放。（孙悟）     

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.     

源于淀粉和纤维素替代材料的4类绿色环保餐具评价

为了比较源于淀粉和纤维素替代材料的环境绩效,以餐饮外卖领域推广使用的生物基餐具(复合淀粉基材料、覆膜纤维基材料)与可降解塑料餐具(全淀粉材料、全纤维材料)为研究对象,分析产品生命周期中的各种资源、能源消耗和环境排放并评价其环境影响。以1000个外卖食品餐盒为基准流,利用环境评估软件建立绿色环保餐具的生命周期评价LCA模型。结果表明,源于淀粉的绿色餐盒碳排放和能量消耗主要集中于原料获取和废弃物处理两个阶段,源于纤维的绿色餐盒碳排放和能量消耗则主要集中在制品生产阶段。全淀粉可降解餐具的各项环境影响指标最低,其中累计释放CO239.91kg,消耗电能332.04 MJ,较全纤维可降解餐盒碳排放降低69.5%,节约电能416.23 MJ。     

淀粉基食品包装材料的生命周期评价

为了比较石油基材料和淀粉基材料的环境绩效,采用生命周期评价（LCA）方法分析两种材料对环境指标的影响,以及在原材料获取阶段、产品生产阶段的碳排放当量。通过环境评估软件,建立两种材料的生命周期评估模型。结果表明,淀粉基材料对环境的主要影响指标如气体排放、能耗和水耗均比纯石油基聚丙烯明显减少了27.79%,27.55%,21.29%;碳排放当量在原材料获取阶段影响最大,其次是产品生产阶段。说明选取淀粉基代替材料设计食品包装能有效减轻环境污染,助力双碳目标实现。     

锆-铝-钛鞣黄牛革全生命周期评价

根据生命周期评价(LCA)的原理及理论框架,采用亿科eFootprint数据平台,以全球变暖潜值(GWP)、水资源消耗(WU)等因素作为环境影响评价指标,对锆-铝-钛鞣黄牛革的产品加工过程进行了全生命周期评价.并将其与铬鞣黄牛革全生命周期评价进行对比,为制革清洁化生产提供数据支撑.继续完善制革行业LCA数据库,促进我国...     

基于生命周期评价（LCA）的纸产品碳足迹评价方法

结合我国纸产品生产的特点,基于生命周期评价法(LCA),研究了我国纸产品碳足迹评价的方法,包括启动阶段、纸产品碳足迹计算和结果解释三个步骤.     

降低燃用生物柴油NOx排放量的分析

在YL4102型柴油机上分别燃用生物柴油、石化柴油、生物柴油和石化柴油的混合物测定NOx的排放情况,并对降低NOx排放量的措施进行了研究。结果表明,适当推迟喷油提前角会降低NOx的排放,在满负荷范围时,当喷油提前角为10°CA左右时NOx排放降低30％左右。燃用乳化生物柴油可降低NOx的排放,随着乳化生物柴油中水的增加,NOx的排放迅速下降,当水的体积分数为30％时,NOx排放降低40％左右。     

Biodiesel production in a semiarid environment: a life cycle assessment approach

While the use of biodiesel appears to be a promising alternative to petroleum fuel, the replacement of fossil fuel by biofuel may not bring about the intended climate cooling because of the increased soil N2O emissions due to N-fertilizer applications. Using a life cycle assessment approach, we assessed the influence of soil nitrous oxide (N2O) emissions on the life cycle global warming potential of the production and combustion of biodiesel from canola oil produced in a semiarid climate. Utilizing locally measured soil N2O emissions, rather than the Intergovernmental Panel on Climate Change (IPCC) default values, decreased greenhouse gas (GHG) emissions from the production and combustion of 1 GJ biodiesel from 63 to 37 carbon dioxide equivalents (CO2-e)/GJ. GHG were 1.1 to 2.1 times lower than those from petroleum or petroleum-based diesel depending on which soil N2O emission factors were included in the analysis. The advantages of utilizing biodiesel rapidly declined when blended with petroleum diesel. Mitigation strategies that decrease emissions from the production and application of N fertilizers may further decrease the life cycle GHG emissions in the production and combustion of biodiesel.     

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.     

Assessment of fuel-cycle energy use and greenhouse gas emissions for Fischer-Tropsch diesel from coal and cellulosic biomass

This study expands and uses the GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model to assess the effects of carbon capture and storage (CCS) technology and cellulosic biomass and coal cofeeding in Fischer-Tropsch (FT) plants on energy use and greenhouse gas (GHG) emissions of FT diesel (FTD). To demonstrate the influence of the coproduct credit methods on FTD life-cycle analysis (LCA) results, two allocation methods based on the energy value and the market revenue of different products and a hybrid method are employed. With the energy-based allocation method, fossil energy use of FTD is less than that of petroleum diesel, and GHG emissions of FTD could be close to zero or even less than zero with CCS when forest residue accounts for 55% or more of the total dry mass input to FTD plants. Without CCS, GHG emissions are reduced to a level equivalent to that from petroleum diesel plants when forest residue accounts for 61% of the total dry mass input. Moreover, we show that coproduct method selection is crucial for LCA results of FTD when a large amount of coproducts is produced.     

Greenhouse Gas Emission Evaluation of the GTL Pathway

Gas to liquids (GTL) products have the potential to replace petroleum-derived products, but the efficacy with which any sustainability goals can be achieved is dependent on the lifecycle impacts of the GTL pathway. Life cycle assessment (LCA) is an internationally established tool (with GHG emissions as a subset) to estimate these impacts. Although the International Standard Organization's ISO 14040 standard advocates the system boundary expansion method (also known as the "displacement method" or the "substitution method") for life-cycle analyses, application of this method for the GTL pathway has been limited until now because of the difficulty in quantifying potential products to be displaced by GTL coproducts. In this paper, we use LCA methodology to establish the most comprehensive GHG emissions evaluation to date of the GTL pathway. The influence of coproduct credit methods on the GTL GHG emissions results using substitution methodology is estimated to afford the Well-to-Wheels (WTW) greenhouse gas (GHG) intensity of GTL Diesel. These results are compared to results using energy-based allocation methods of reference GTL diesel and petroleum-diesel pathways. When substitution methodology is used, the resulting WTW GHG emissions of the GTL pathway are lower than petroleum diesel references. In terms of net GHGs, an interesting way to further reduce GHG emissions is to blend GTL diesel in refineries with heavy crudes that require severe hydrotreating, such as Venezuelan heavy crude oil or bitumen derived from Canadian oil sands and in jurisdictions with tight aromatic specifications for diesel, such as California. These results highlight the limitation of using the energy allocation approach for situations where coproduct GHG emissions reductions are downstream from the production phase.     

Combinatorial life cycle assessment to inform process design of industrial production of algal biodiesel

The use of algae as a feedstock for biodiesel production is a rapidly growing industry, in the United States and globally. A life cycle assessment (LCA) is presented that compares various methods, either proposed or under development, for algal biodiesel to inform the most promising pathways for sustainable full-scale production. For this analysis, the system is divided into five distinct process steps: (1) microalgae cultivation, (2) harvesting and/or dewatering, (3) lipid extraction, (4) conversion (transesterification) into biodiesel, and (5) byproduct management. A number of technology options are considered for each process step and various technology combinations are assessed for their life cycle environmental impacts. The optimal option for each process step is selected yielding a best case scenario, comprised of a flat panel enclosed photobioreactor and direct transesterification of algal cells with supercritical methanol. For a functional unit of 10 GJ biodiesel, the best case production system yields a cumulative energy demand savings of more than 65 GJ, reduces water consumption by 585 m(3) and decreases greenhouse gas emissions by 86% compared to a base case scenario typical of early industrial practices, highlighting the importance of technological innovation in algae processing and providing guidance on promising production pathways.     

Identification of 'carbon hot-spots' and quantification of GHG intensities in the biodiesel supply chain using hybrid LCA and structural path analysis

It is expected that biodiesel production in the EU will remain the dominant contributor as part of a 10% minimum binding target for biofuel in transportation fuel by 2020 within the 20% renewable energy target in the overall EU energy mix. Life cycle assessments (LCA) of biodiesel to evaluate its environmental impacts have, however, remained questionable, mainly because of the adoption of a traditional process analysis approach resulting in system boundary truncation and because of issues regarding the impacts of land use change and N(2)O emissions from fertilizer application. In this study, a hybrid LCA methodology is used to evaluate the life cycle CO(2) equivalent emissions of rape methyl ester (RME) biodiesel. The methodology uses input-output analysis to estimate upstream indirect emissions in order to complement traditional process LCA in a hybrid framework. It was estimated that traditional LCA accounted for 2.7 kg CO(2)-eq per kg of RME or 36.6% of total life cycle emissions of the RME supply chin. Further to the inclusion of upstream indirect impacts in the LCA system (which accounted for 23% of the total life cycle emissions), emissions due to direct land use change (6%) and indirect land use change (16.5%) and N(2)O emissions from fertilizer applications (17.9%) were also calculated. Structural path analysis is used to decompose upstream indirect emissions paths of the biodiesel supply chain in order to identify, quantify, and rank high carbon emissions paths or 'hot-spots' in the biodiesel supply chain. It was shown, for instance, that inputs from the 'Other Chemical Products' sector (identified as phosphoric acid, H(3)PO(4)) into the biodiesel production process represented the highest carbon emission path (or hot-spot) with 5.35% of total upstream indirect emissions of the RME biodiesel supply chain.     

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.     

餐厨废弃油脂生物柴油对船舶柴油机性能、排放特性以及燃烧特性的影响北大核心CSCD

为探讨生物柴油应用于船舶柴油机的可行性,将餐厨废弃油脂生物柴油与柴油混合,在船舶柴油机上进行试验,测试其对船舶柴油机性能、排放特性和燃烧特性的影响。结果表明:生物柴油混合物的高黏度以及低热值会降低有效热效率,并导致燃油消耗率略有升高;由于生物柴油的高含氧量促进完全燃烧,相比于柴油,燃烧生物柴油混合物后,一氧化碳排放量最高下降17%,二氧化碳排放量最高下降5.1%,二氧化硫排放量最高下降41%,碳烟排放量最高下降36%;生物柴油过快的燃烧速率提高了气缸内的燃烧温度,以及高含氧量促进了氮氧化物的排放;生物柴油混合物燃烧时的缸内压力与柴油非常接近。餐厨废弃油脂生物柴油对船舶柴油机的性能、燃烧特性和排放特性均具有较好的表现,可以作为柴油的替代燃料用于船舶柴油机。     

Emissions of acrolein and other aldehydes from biodiesel-fueled heavy-duty vehicles

Aldehyde emissions were measured from two heavy-duty trucks, namely 2000 and 2008 model year vehicles meeting different EPA emission standards. The tests were conducted on a chassis dynamometer and emissions were collected from a constant volume dilution tunnel. For the 2000 model year vehicle, four different fuels were tested, namely California ultralow sulfur diesel (CARB ULSD), soy biodiesel, animal biodiesel, and renewable diesel. All of the fuels were tested with simulated city and high speed cruise drive cycles. For the 2008 vehicle, only soy biodiesel and CARB ULSD fuels were tested. The research objective was to compare aldehyde emission rates between (1) the test fuels, (2) the drive cycles, and (3) the engine technologies. The results showed that soy biodiesel had the highest acrolein emission rates while the renewable diesel showed the lowest. The drive cycle also affected emission rates with the cruise drive cycle having lower emissions than the urban drive cycle. Lastly, the newer vehicle with the diesel particulate filter had greatly reduced carbonyl emissions compared to the other vehicles, thus demonstrating that the engine technology had a greater influence on emission rates than the fuels.     

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.