Analyzing the effects of Gas-to-Liquid (GTL) diesel blending on the efficiency and emissions of petroleum refineries and transport fuels in the U.S. and Europe

The transport sector is fast changing with demand for distillates increasing amidst declining gasoline consumption in many markets especially in the developed world. Increasingly refineries are stretched to operate less efficiently and this is manifested through a drop in efficiency as a consequence of increasing diesel production via less efficient routes, particularly on the marginal barrel of diesel. It has been suggested that this decline in diesel production efficiency, as the ratio of gasoline to diesel (G/D) production drops, can partly be mitigated through the use of Gas-to-Liquid (GTL) diesel. In this paper we adopted refinery Linear-Programming models to represent the refining system in Europe as well as a district in the U.S. to investigate the effects of increased availability of GTL diesel to a refiner on the energy efficiency and GHG emissions of refineries. Here we showed that indeed there is an improvement in diesel production efficiency with increasing GTL concentrations, but this efficiency gain (<0.5%) is insufficient to counteract the higher energy consumption and emissions associated with the production of GTL, thus leading to an overall decline in life cycle efficiency (up to 5%), and an increase in life cycle GHG emissions (up to 2%).     

电力推进技术在渡船中的应用

近年来,国家陆续出台了关于长江生态保护的相关文件。随着电力推进技术在节能减排方面的优势显现,常规动力渡船存在的问题显而易见,如较长传动轴增加了能量损耗,降低了能源效率;柴油机的响应较慢,影响船舶的机动性;柴油机的燃烧不充分导致燃油的过多消耗,以及柴油机直驱渡船的动力推进装置占据了机舱的大部分空间。本文结合电力推进渡船的应用情况,针对上述常规推进渡船的缺点,对船舶动力系统进行了改进,采用全回转电力推进取代原先柴油机直驱,电站采用高压共轨电喷式柴油机带动发电机发电,经整流实现直流组网后,统一为全船提供动力和日常用电。     

液化天然气(LNG)汽车日常检查方法及维护技术综述

天然气是一种优质的替代燃料,具有污染小、安全系数高、运行费用低等优点。天然气已经成为城市公共交通领域应用最为成功和广泛的车辆替代燃料技术,为推动交通运输行业的节能减排做出了显著的贡献。液化天然气汽车,作为天然气汽车的一种类型,与传统汽柴油车相比,液化天然气汽车安装了包括液化天然气气瓶、气管路及各种控制阀门和仪表在内的专用装置,在对液化天然气汽车进行日常检查时需要针对液化天然气汽车的专用装置进行重点检查。本文则针对液化天然气汽车的特点,对液化天然气汽车的正确使用方法、日常检查方法及维护技术要求、以及相关注意事项三个方面进行了解读,为指导液化天然气汽车进行日常检查与定期维护提供了技术参考。     

Assessing the cost-optimal mileage of medium-duty electric vehicles with a numeric simulation approach

Electric freight vehicles have the potential to mitigate local urban road freight transport emissions, but their numbers are still insignificant. Logistics companies often consider electric vehicles as too costly compared to vehicles powered by combustion engines. Research within the body of the current literature suggests that increasing the driven mileage can enhance the competitiveness of electric freight vehicles. In this paper we develop a numeric simulation approach to analyze the cost-optimal balance between a high utilization of medium-duty electric vehicles – which often have low operational costs – and the common requirement that their batteries will need expensive replacements. Our work relies on empirical findings of the real-world energy consumption from a large German field test with medium-duty electric vehicles. Our results suggest that increasing the range to the technical maximum by intermediate (quick) charging and multi-shift usage is not the most cost-efficient strategy in every case. A low daily mileage is more cost-efficient at high energy prices or consumptions, relative to diesel prices or consumptions, or if the battery is not safeguarded by a long warranty. In practical applications our model may help companies to choose the most suitable electric vehicle for the application purpose or the optimal trip length from a given set of options. For policymakers, our analysis provides insights on the relevant parameters that may either reduce the cost gap at lower daily mileages, or increase the utilization of medium-duty electric vehicles, in order to abate the negative impact of urban road freight transport on the environment.     

A new offline optimization approach for designing a fuel cell hybrid bus

In this study a hydrogen powered fuel cell hybrid bus is optimized in terms of the powertrain components and in terms of the energy management strategy. Firstly the vehicle is optimized aiming to minimize the cost of its powertrain components, in an official driving cycle. The optimization variables in powertrain component design are different models and sizes of fuel cells, of electric motors and controllers, and batteries. After the component design, an energy management strategy (EMS) optimization is performed in the official driving cycle and in two real measured driving cycles, aiming to minimize the fuel consumption. The EMS optimization is based on the control of the battery’s state-of-charge. The real driving cycles are representative of bus driving in urban routes within Lisbon and Oporto Portuguese cities. A real-coded genetic algorithm is developed to perform the optimization, and linked with the vehicle simulation software ADVISOR. The trade-off between cost increase and fuel consumption reduction is discussed in the lifetime of the designed bus and compared to a conventional diesel bus. Although the cost of the optimized hybrid powertrain (62,230 €) achieves 9 times the cost of a conventional diesel bus, the improved efficiency of such powertrain achieved 36% and 34% of lower energy consumption for the real driving cycles, OportoDC and LisbonDC, which can originate savings of around 0.43 €/km and 0.37 €/km respectively. The optimization methodology presented in this work, aside being an offline method, demonstrated great improvements in performance and energy consumption in real driving cycles, and can be a great advantage in the design of a hybrid vehicle.     

Well-to-wheel analysis for electric, diesel and hydrogen traction for railways

This paper derives the energy efficiencies and CO₂ emissions for electric, diesel and hydrogen traction for railway vehicles on a well-to-wheel basis, using the low heating value and high heating value of the enthalpy of oxidation of the fuel. The tank-to-wheel and well-to-tank efficiency are determined. Gaseous hydrogen has a WTW efficiency of 25% low heating value, if produced from methane and used in a fuel cell. This efficiency is similar to diesel and electric traction in the UK, US, and California. A reduction of about 19% in CO₂ is achieved when hydrogen gas is used in a fuel cell compared to diesel traction, and a 3% reduction compared to US electricity.     

The role of nano additives for biodiesel and diesel blended transportation fuels

The energy crisis is due to two reasons, one is the rapid increase in worldwide population and the other is changing living style of human beings. The fossil fuel is also a major contributor to add the harmful pollutants into the atmosphere. Fuel modifications play a major role in increasing engine efficiency and reducing emissions. In the present investigation focused on fuel modifications in diesel engine. Initially the single cylinder diesel engine was operated with 20MEOM, 40MEOM, 60MEOM, 8MEOM and 100MEOM without additives with diesel at different loads at constant rated speed. From the experimental study proved that 20MEOM is the best fuel ratio compared to other blends. In second phase based upon first phase results the engine was operated 20MEOM blended fuel with adding 50 ppm copper oxide nano additives with diesel using solgel process. From the results, the brake thermal efficiency was 2.19% improved compared than 20MEOM blend without additive at full load condition. Emissions of HC, CO and smoke were considerably reduced. The present analysis reveals that the biofuel from mahua oil with nano additives is quite suitable as an alternate fuel for diesel engine.     

重庆市内河船舶污染物排放现状及LNG动力船舶推广效益分析

重庆地处长江上游经济带核心地区,水运发达,随着客货运量逐年增加,通行的内河船舶尾气排放严重影响港口及航道附近大气环境,已成为重庆大气污染的主要来源之一,颗粒物、NO_x的排放分别占重庆市总排放的4.3%、21.9%,SO_2占年排放的7.4%(14.8%。在大气环境问题日益严峻的情况下,LNG动力船舶因其可明显降低排气污染物,越发受到社会关注,对重庆市单LNG动力示范船舶尾气排放进行实测,对比柴油动力船舶,颗粒物、NO_x、SO_2减排显著,减排率分别达99.94%、72.69%、100%。因此,LNG动力船舶的推广表现出明显的环境效益,同时,综合分析了当前LNG动力船舶推广存在问题及困难。     

Life cycle ownership cost and environmental externality of alternative fuel options for transit buses

This paper assesses alternative fuel options for transit buses. We consider the following options for a 40-foot and a 60-foot transit bus: a conventional bus powered by either diesel or a biodiesel blend (B20 or B100), a diesel hybrid-electric bus, a sparking-ignition bus powered by Compressed Natural Gas (CNG) or Liquefied Natural Gas (LNG), and a battery electric bus (BEB) (rapid or slow charging). We estimate life cycle ownership costs (for buses and infrastructure) and environmental externalities caused by greenhouse gases (GHGs) and criteria air pollutants (CAPs) emitted from the life cycle of bus operations. We find that all alternative fuel options lead to higher life cycle ownership and external costs than conventional diesel. When external funding is available to pay for 80% of vehicle purchase expenditures (which is usually the case for U.S. transit agencies), BEBs yield large reductions (17–23%) in terms of ownership and external costs compared to diesel. Furthermore, BEBs’ advantages are robust to changes in operation and economic assumptions when external funding is available. BEBs are able to reduce CAP emissions significantly in Pittsburgh’s hotspot areas, where existing bus fleets contribute to 1% of particulate matter emissions from mobile sources. We recognize that there are still practical barriers for BEBs, e.g. range limits, land to build the charging infrastructure, and coordination with utilities. However, favorable trends such as better battery performance and economics, cleaner electricity grid, improved technology maturity, and accumulated operation experience may favor use of BEBs where feasible.     

The influence of locomotive diesel engine transient operating modes on energy usage

This paper analyzes the influence of transient operating modes in the Cat 3512B-HD and MTU 4000 R41 locomotive diesel engines on their energy usage. This analysis represents an integral component of the technological research and development performed at Lietuvos Geležinkeliai AB (JSC Lithuanian Railways) with the objective of increasing the efficiency of freight transportation with the upgraded 2M62M and modern ER20CF/2ER20CF diesel locomotives. The influence of transient modes on the operating variables of the locomotive diesel engines was evaluated under operational load-cycling conditions to aid in the selection of appropriate parameters (e.g., the train weight, the diesel locomotive type, and the technical characteristics of the diesel locomotive to be modeled) for freight transportation on Lithuanian railway lines. It was determined that the engine’s electronic control system compensates for the negative effects of transient operations on the engine’s energy usage. As a result, the increase in fuel consumption is less than 3% during transient operation when compared to steady-state operation. Through this research, methodological foundations have been formulated and adapted for the use of the mathematical modeling of the transient modes of locomotive diesel engines to optimize freight transportation, resulting in an expected decrease of 10–15% in fuel consumption.     

Energy consumption,pollutant production,and dollar costs of diesel suburban commuter trains

The results presented in this report are based on data obtained from Chicago's three largest diesel commuter railroads. Those aspects of their operations that relate to energy and pollution are described. Service characteristics, such as average occupancy and average trip distance, are presented. Energy consumption results are presented and discussed. With energy efficiency measured in passenger-miles per Btu, it is found that trips by diesel commuter train are 3.5 times more energy efficient than Chicago Central Area auto trips. The total trip from home to suburban station, then by train to a downtown terminal, is found to be 2.2 times more energy efficient than Chicago Central Area auto trips. Pollutant production rates are presented for five pollutants. For every pollutant except sulfur oxides, trains are found to be less polluting per passenger-mile than autos. Per passenger-mile pollutant emissions from trains are, overall, less damaging by a factor of 5.5 than the per passenger-mile emissions from autos. Travel on these diesel commuter trains is less costly to society than auto travel (1972 suburban-based autos). This is the case whether one compares the train trip alone with an auto trip or the home-to-suburb an-station-tlien-to-a-downtown-terminal trip with a home-to-downtown auto trip.     

内河船用柴油机冷却水系统节能探讨

内河船用柴油机在工作时,其燃油经济性能、动力性能和环境性能直接受到冷却系统性能的好坏的限制。本文对内河船用柴油机冷却水系统节能进行了探讨,提出了对冷却水温度进行恒温控制必将成为冷却水系统设计的重点。     

Demand forecasting of diesel passenger car considering consumer preference and government regulation in South Korea

Changing market regulations in South Korea have allowed diesel-fueled passenger cars in the domestic market. The diffusion of diesel cars is tied to issues of environmental impact, energy supply and demand, and changes in tax revenue. Policymakers can influence demand for diesel vehicles to protect social welfare and to observe international environmental protection laws. On the supply side, carmakers need to know consumer preferences regarding new vehicles to arrive at development strategies.This study uses microsimulated demand forecasting to address these issues and predict consumer demand for diesel passenger cars. The model accommodates governmental policies and car attributes such as price and engine efficiency. We find that consumers will likely prefer diesel passenger cars to gasoline ones due to the low operation costs of the former in spite of high purchase price when diesel is relatively cheaper than gasoline. Finally we find that diesel passenger cars will capture a 42% market penetration ratio under the pricing system suggested by the Ministry of Environment of Korea.     

油气长输管道节能技术研究

为了解国内外节能技术应用的现状,更好地采用节能技术以不断降低管道能耗,对比了近年来国内外油气长输管道在输送工艺、运行设备及新能源3个方面的各种节能技术。结果表明：油品输送减阻剂技术、含蜡原油降凝剂技术、天然气管道减阻剂技术、输油泵变频调速技术、超声波防/除垢技术以及太阳能阀室供电等技术在油气长输管道上的应用有着明显的节能效果。因此,开发并利用新的节能技术,特别是新能源技术,将是油气长输管道节能降耗发展的方向。     

新加坡C902地铁隧道工程项目6640mm铰接式土压平衡复合盾构的研制

盾构设计的合理性和科学性是盾构设备安全可靠和高效施工的基础。文章通过对新加坡C902地铁隧道工程项目6 640 mm铰接式土压平衡复合盾构的技术研究和工程应用,介绍其设计条件及主要技术参数,着重对该盾构及其相关设备组成部分进行了详细论述。此复合盾构在系统优化及设计理念的先进性上比原先的盾构有很大的提高,尤其是增加了很多人性化的设计。     

用PLC实现热媒炉自动控制

在管道输送石油的生产过程中,热媒炉是给原油进行加热的设备。设计的控制系统能否正常运行,关系到输油的安全、节能。以铁大线的加热炉为例,用PLC逻辑控制器实现热媒炉自动化控制,结合热媒炉工作原理,以S7-300PLC为炉控系统,实现热媒炉助燃空气和燃料油的自动控制与优化燃烧,达到了节能、降耗、保安全的目的。     

Energy conservation in urban public transport

Urban public transport energy use is determined largely by the weight of the vehicle, and frequency of intermediate stops, imposing repeated acceleration/steady running/braking cycles, in which much of the kinetic energy is dissipated. Energy consumed for the same capacity and vehicle performance may be reduced by coasting, cutting vehicle weight, and use of regenerative braking, on electrically‐powered systems, to convert the otherwise wasted braking energy into useful form. Particular attention is paid to the last‐named, identifying results of past experience and recent simulations. Practical constraints limiting the amount of energy actually recovered are discussed, including proportion of vehicle weight braked electrically, receptivity of the supply system, stop spacing and number of vehicles operated simultaneously. Reference is also made to battery vehicles and flywheel energy storage.

It is suggested that considerable scope exists in urban electric rail operation for reduced energy consumption, as existing fleets are replaced by lighter weight vehicles, fitted for regenerative braking. Further savings may come from use of inverter equipment. Rate of fleet renewal may be an important factor. Buses are already much more energy efficient, and dramatic gains are unlikely. However, there is some scope for use of flywheel energy storage, and regenerative braking on trolleybuses.     

Characteristics of gaseous and particulate pollutants exhaust from logistics transportation vehicle on real-world conditions

On-road vehicle tests of three heavy duty diesel trucks were conducted by a portable emission measurement system (PEMS) in Chengdu, China. SEMTECH-ECOSTAR provided by Sensors Inc. was employed to detect gaseous emissions and MI2, an emissions measuring instrument powered by the Pegasor Particulate Sensor (PPS) was used to detect particulate emissions during the tests. The impacts of speed, acceleration and engine load on emissions were analyzed. The average nitrogen oxides (NOx) emission factors of the heavy duty diesel truck (HDDT), medium-duty diesel truck (MDDT), light duty diesel truck (LDDT) were 7.29, 5.29 and 5.53 g/km. The particulate emission factors were 0.60, 0.30 and 0.14 g/km respectively, higher than the similar reported in the previous studies. Both gaseous and particulate emission exhibit significant correlations with the change in vehicle speed, acceleration and power demand. The highest emission was generally in high VSPs and higher loads. High engine load caused by aggressive driving was the main factor of high emissions for the vehicles on real-world conditions.     

特种装备项目的节能评估方法研究

特种装备的购置及改造项目属于固定资产投资范畴,在审批环节中应进行节能审查。本文以科学考察船为例,基于分析科学考察船与其他类固定资产的不同,阐述了科学考察船建设方案的节能评估、能源消费种类及能耗测算方法,并就评估过程中存在的问题提出了相关建议。     

Electric vehicle parking in European and American context: Economic,energy and environmental analysis

The transportation sector faces increasing challenges related to energy consumption and local and global emissions profiles. Thus, alternative vehicle technologies and energy pathways are being considered in order to overturn this trend and electric mobility is considered one adequate possibility towards a more sustainable transportation sector.In this sense, this research work consisted on the development of a methodology to assess the economic feasibility of deploying EV charging stations (Park-EV) by quantifying the tradeoff between economic and energy/environmental impacts for EV parking spaces deployment. This methodology was applied to 4 different cities (Lisbon, Madrid, Minneapolis and Manhattan), by evaluating the influence of parking premium, infrastructure cost and occupancy rates on the investment Net Present Value (NPV). The main findings are that the maximization of the premium and the minimization of the equipment cost lead to higher NPV results. The NPV break-even for the cities considered is more “easily” reached for higher parking prices, namely in the case of Manhattan with the higher parking price profile. In terms of evaluating occupancy rates of the EV parking spaces, shifting from a low usage (LU) to a high usage (HU) scenario represented a reduction in the premium to obtain a NPV = 0 of approximately 14% for a 2500 € equipment cost, and, in the case of a zero equipment cost (e.g. financed by the city), a NPV = 0 was obtained with approximately a 2% reduction in the parking premium. Moreover, due to the use of electric mobility instead of the average conventional technologies, Well-to-Wheel (WTW) gains for Lisbon, Madrid, Minneapolis and Manhattan were estimated in 58%, 53%, 52% and 75% for energy consumption and 66%, 75%, 62% and 86% for CO₂ emissions, respectively.This research confirms that the success of deploying an EV charging stations infrastructure will be highly dependent on the price the user will have to pay, on the cost of the infrastructure deployed and on the adhesion of the EV users to this kind of infrastructure. These variables are not independent and, consequently, the coordination of public policies and private interest must be promoted in order to reach an optimal solution that does not result in prohibitive costs for the users.