Optimization of operational parameters on performance and emissions of a diesel engine using biodiesel

This work investigates the influence of compression ratio on the performance and emissions of a diesel engine using biodiesel (10, 20, 30, and 50 %) blended-diesel fuel. Test was carried out using four different compression ratios (17.5, 17.7, 17.9 and 18.1). The experiments were designed using a statistical tool known as design of experiments based on response surface methodology. The resultant models of the response surface methodology were helpful to predict the response parameters such as brake specific fuel consumption, brake thermal efficiency, carbon monoxide, hydrocarbon and nitrogen oxides. The results showed that best results for brake thermal efficiency and brake specific fuel consumption were observed at increased compression ratio. For all test fuels, an increase in compression ratio leads to decrease in the carbon monoxide and hydrocarbon emissions while nitrogen oxide emissions increase. Optimization of parameters was performed using the desirability approach of the response surface methodology for better performance and lower emission. A compression ratio 17.9, 10 % of fuel blend and 3.81 kW of power could be considered as the optimum parameters for the test engine.     

Performance and pollutants analysis on diesel engine using blends of Jatropha Biodiesel and Mineral Turpentine as fuel

Performance and pollutants features of Jatropha–Mineral Turpentine blends along with diesel have been examined in a single-cylinder compression ignition engine. Vegetable oils have higher viscosities than diesel fuel, and it greatly disturbs the performance, durability, burning and discharge features of the compression ignition engine. The tests were performed with different blend combinations of Jatropha–Mineral Turpentine oil as fuel. The experimental outcome indicates that brake thermal efficiency of the blend of 80% Jatropha Biodiesel and 20% of Mineral Turpentine is nearby to diesel fuel at 75% load. Carbon monoxides, hydrocarbons and emission were reduced to the considerable amount, whereas the oxides of nitrogen increase with increase in part load and reduced with 75% and full load operations. The specific fuel consumption of Jatropha–Mineral Turpentine blends found to be slightly upper than diesel fuel. The heat release rate and cylinder pressure of Jatropha–Mineral Turpentine blends were closer to diesel fuel. The test results recommend that Jatropha–Mineral Turpentine blends might stay a decent auxiliary to diesel fuel in the near upcoming and it can be concluded that Jatropha–Mineral Turpentine oil blends could be utilized in a conventional compression ignition engine with no alteration.     

Data analysis of the flue gas emissions in the thermal-power plant firing fuel oil and natural gas

The thermal-power plant with combined heat and power (CHP) production located in the city of Zrenjanin (Serbia) is powered by two steam boilers with nominal power of 280 MW each. Considering the problem of increasing pollutant emissions that occur during fossil-fuel combustion process, which is recognized as an arising problem in the CHP Zrenjanin, the accredited Laboratory has been carrying out monitoring and control of the emission production. The emissions have been measured during winter season on boiler B1 for five working regimes of burners, by adjusting the fuel ratio between natural gas and fuel oil. The measurement has been done regarding carbon monoxide, sulphur dioxide, nitrogen oxides (NOx), particulate matter (PM), gaseous inorganic chlorine compounds denoted as hydrogen chloride, and gaseous inorganic fluoride compounds denoted as hydrogen fluoride. Data acquired from those measurements have shown that all parameters except NOx and PM did not exceed emission limits defined under current regulatory statute. According to data analysis of the flue gas emissions, first preventive actions are recommended, then possible actions that could be taken during combustion process, and as last but not least, actions that have to be applied in case when emission problems appears. Regarding CHP control and management problems, some advices are given emphasizing an integral approach to the analysis and optimization of the CHP as the best solution.     

Effect of biodiesel on particulate numbers and composition emitted from turbocharged diesel engine

In present study a turbocharged, medium duty compression ignition engine was alternatively fuelled with biodiesel to investigate the changes in particulate matter composition, relative to that taken with diesel fuel. The engine was operated on an AC electrical dynamometer in accordance with an 8-mode, steady-state cycle. The numbers of particles were estimated through electrical low pressure impactor, while sulfates and trace metals were analyzed by ion chromatography and inductively coupled plasma-atomic emission spectroscopy, respectively. Nitric oxides and nitrogen dioxides were measured separately using SEMTECH-DS. Experimental results revealed that, on account of elevated ratios of nitrogen dioxide to nitrogen oxides, mean accumulation mode particles were 42 % lower with biodiesel. On the other hand, nuclei mode particles were higher with biodiesel, owing to heterogeneous nucleation and accounting for an increase in sulfate emissions up to 8 % with biodiesel as compared to diesel. On the average, trace metal emissions were significantly reduced showing 65–85.4 % reduction rates with biodiesel, relative to its counterpart. Further to this, individual congeners such as iron, calcium, and sodium were the predominant elements of the trace metals emitted from engine. The mean relative decrease in iron and calcium was 89–97.8 and 77.6–87 %, respectively, while the relative rise in sodium was in the range of 29–46 % with biodiesel. Further, elements such as zinc, chromium, and aluminum showed substantial abatement, whereas potassium, magnesium, and manganese exhibited irregular trends on account of variable engine loads and speeds during the various modes of cycle.     

Laboratory-scale analysis of transportation and natural attenuation of diesel fuel in aquifer

Processes that control the distribution and natural attenuation (NA) of petroleum hydrocarbons dissolved from the released diesel fuel in a bench-scale model aquifer were evaluated. The experimental results obtained in two-dimensional aqueous-phase petroleum hydrocarbon concentrations indicated that the total petroleum hydrocarbon (TPH) in the aquifer migrated in longitudinal and lateral directions. The TPH plume of 2 mg L^?1 spread to the entire area of the aquifer, and the maximum concentration at the center of the plume was 44.15 mg L^?1 after 90 days of release. After diesel fuel release, the NA of TPH was evaluated and quantified. Experimental data indicated that the NA of TPH was immediately implemented to prevent migration of the plume into the downgradient of the aquifer, but controlling the TPH plumes using NA mechanisms requires a long time.     

Comparative performance study of diesel and electric face-haulage vehicles

Summary Results of a performance study of diesel ram-dump cars and electric cable-reel shuttle cars, conducted at an underground coal mine in the Warrior Basin of Alabama, are presented. Time-study data, obtained over a one-year period, show that the average load and discharge times of the diesel cars are slightly less than those of the electric cars, while the average travel-loaded, travel-empty, in, and out speeds of the diesel cars are slightly greater.Computer simulations, based on frequency distributions from the cycle-time data, show average shift productions for both vehicle types to be very close for two-car and three-car configurations with a haul distance of two crosscuts. However, as the haul distance increases, the diesel cars outproduce the electric cars.Results of a maintenance-cost comparison are presented for the sake of general interest and should not be considered as valid comparison, since the electric cars are approximately three years older than the diesel cars. The results show preventive maintenance costs to be much greater for a diesel car on both permonth and per-ton bases, and the total maintenance cost for a diesel car to be significantly higher on a permonth basis, but significantly less on a per-ton basis.     

Evaluating the production and bio-stimulating effect of 5-methyl 1, hydroxy phenazine on microbial fuel cell performance

The role of endogenous redox mediators has considerable importance in electron shuttling reactions and associated performance of microbial fuel cell. Single-chamber microbial fuel cell-II with dual air-cathode assembly (area = 18.84 cm²) supported highest bacterial (Pseudomonas aeruginosa) density (6.7 × 10⁹) and active biomass [4.4 ± 0.3 mg cm^?2 (carbon content = 0.48 ± 0.1 mg cm^?2)] on anode thereby resulting in maximum production of redox metabolite, 5-methyl 1, hydroxy phenazine (301 ppm) and voltage (595 ± 5 mV) than similar cells with relatively less surface area of cathode. It was further revealed that 5-methyl 1, hydroxy phenazine production was positively correlated with chemical oxygen demand removal rate (77 ± 2.5%) and power generation (66.6 ± 2.2 mW cm^?2) efficiency of single-chamber microbial fuel cell-II. Maximum power density of 258 ± 4.5 mW cm^?2 was generated when reactor was supplemented with 2 ml crude extract of 5-methyl 1, hydroxy phenazine metabolite, whereas power output was about 229 ± 2.5 mW cm^?2 when reactor was bio-stimulated with 1 ml pure extract of 5-methyl 1, hydroxy phenazine. With this concentration, the electrochemical response of mixed culture biofilm (sediment) was enhanced by 99.3%. However, further increase in concentration of endogenous mediator proved to be limiting on reactor performance. Pyrosequencing and phylogenetic analysis on the basis of partial 16S rRNA sequences demonstrated both culturable and unculturable bacterial species in anodic biofilm and relative abundance of family Pseudomonadaceae was found to be maximum, i.e., 61.7% followed by Rhodocyclaceae 19.2%, Xanthomonadaceae 6.3% and Opitutaceae 3.18%.     

新型冷拌冷铺沥青混合料路用性能研究

为了提高普通乳化沥青混合料的路用性能,将乳化沥青与水性环氧树脂有机结合,得到一种新型复合材料——水性环氧乳化沥青。通过试验研究水性环氧树脂用量对混合料的力学强度、水稳定性以及温度稳定性的影响。结果表明：混合料的初期强度、后期强度以及高温稳定性随着水性环氧树脂用量的增加而提高,但其水稳定性和低温稳定性随着水性环氧树脂用量的增加先增大后减小,分别在水性环氧树脂用量为10%和15%时达到最佳提升效果。在实际工程应用中将水性环氧树脂用量控制在10%~15%之间。     

Isolation and characterization of a novel native Bacillus strain capable of degrading diesel fuel

The ability of native bacteria to utilize diesel fuel as the sole carbon and energy source was investigated in this research. Ten bacterial strains were isolated from the oil refinery field in Tehran, Iran. Two biodegradation experiments were performed in low and high (500 and 10000 ppm, respectively) concentration of diesel fuel for 15 days. Only two isolates were able to efficiently degrade the petroleum hydrocarbons in the first test and degraded 86.67% and, 80.60 % of diesel fuel, respectively. The secondary experiment was performed to investigate the toxicity effect of diesel fuel at high concentration (10000 ppm). Only one strain was capable to degrade 85.20 % of diesel fuel at the same time (15 days). Phenotype and phylogeny analysis of this strain was characterized and identified as diesel-degrading bacteria, based on gram staining, biochemical tests, 16S rRNA gene sequence analysis. These results indicate that this new strain was Bacillus sp. and could be considered as Bacillus Cereus with 98 % 16 S rRNA gene sequence similarity. The results indicate that native strains have great potential for in situ remediation of diesel-contaminated soils in oil refinery sites.     

Development and evaluation of biodiesel fuel and by-products from jatropha oil

Biodiesel is an environmentally friend renewable diesel fuel alternative. Jatropha seeds can be a feedstock to produce a valuable amount of oil to be converted to biodiesel using transesterification reaction. Jatropha plant has been successfully grown in southern Egypt using primary treated municipal wastewater for its irrigation. Abench scale production of biodiesel from Jatropha oil (using methyl alcohol and sodium hydroxide as catalyst) was developed with methyl esters yield of 98 %. Biodiesel was produced on a pilot scale based on the bench scale experiment results with almost the same methyl esters yield of 98 %. The produced biodiesel was evaluated as a fuel and compared with petroleum diesel according to its physical and chemical parameters such as viscosity, flash point, pour point, cloud point, carbon residue, acid value and calorific value. The experimental techniques and product evaluation results show that such properties of the produced biodiesel are near to that of petroleum diesel. A mass balance representing the transesterification process is presented in this study. Glycerol of 85 % purity was produced and evaluated as a valuable byproduct of the process. Free fatty acids and sodium phosphate salts which have industrial interesting are also produced and evaluated.     

The effect of the pore space microstructure on hydrophobization of oil and gas reservoirs

The results of theoretical and experimental studies of the effect of the microstructure of the pore space on the hydrophobization of oil and gas reservoirs are presented. A possible mechanism of formation of the microstructured wettability is described, which demonstrates that hydrophobization of the inner pore space in mixed wettability can be associated either with large or small pore sizes. It was proven experimentally that the process of hydrocarbon adsorption depended on the shape, size, and distribution of pores, the mineralogical composition (particle composition and size, presence of clay), as well as on the time of contact of hydrocarbons with the inner pore surface. The concept of the hydrophilic nature of rock prior to the migration of oil into it can be considered as accurate. However, as was shown in the experiments, oil could be present in the small pores (up to 10 μm), which was especially significant for the carbonate reservoirs.     

The effect of oil films on water evaporation and oxygen content in sea water

The paper covers some results of laboratory and nature experiments on studying the effect of oil films on water evaporation rate and oxygen concentration in sea water. It is demonstrated that oil films on the sea surface reduce the rate of water evaporation by 15 to 33% due to diffusion resistance of oil film as well as energy resistance of monolayer of surface active substances at the film-water interface. Large oil spots may cause, in areas oversaturated with oxygen, increase of oxygen concentration in sea water under the oil spot due to decrease of gas exchange rate at the sea-atmosphere interface.     

Ground penetrating radar imaging and time-domain modelling of the infiltration of diesel fuel in a sandbox experiment

Ground penetrating radar (GPR) is a non-destructive method which, over the past 10 years, has been successfully used not only to estimate the water content of soil, but also to detect and monitor the infiltration of pollutants on sites contaminated by light non-aqueous phase liquids (LNAPL). We represented a model water table aquifer (72 cm depth) by injecting water into a sandbox that also contains several buried objects. The GPR measurements were carried out with shielded antennae of 900 and 1200 MHz, respectively, for common mid point (CMP) and constant offset (CO) profiles. We extended the work reported by Loeffler and Bano by injecting 100 L of diesel fuel (LNAPL) from the top of the sandbox. We used the same acquisition procedure and the same profile configuration as before fuel injection. The GPR data acquired on the polluted sand did not show any clear reflections from the plume pollution; nevertheless, travel times are very strongly affected by the presence of the fuel and the main changes are on the velocity anomalies. We can notice that the reflection from the bottom of the sandbox, which is recorded at a constant time when no fuel is present, is deformed by the pollution. The area close to the fuel injection point is characterized by a higher velocity than the area situated further away. The area farther away from the injection point shows a low velocity anomaly which indicates an increase in travel time. It seems that pore water has been replaced by fuel as a result of a lateral flow. We also use finite-difference time-domain (FDTD) numerical GPR modelling in combination with dielectric property mixing models to estimate the volume and the physical characteristics of the contaminated sand.     

砂砾卵石土高速公路路基填筑试验研究

为研究砂砾卵石土混合料作为路基填料压实后的压实效果,通过室内筛分试验、重型击实试验、CBR试验得到砂砾卵石土的颗粒级配组成,最大干密度、最佳含水率与粗颗粒含量的关系,CBR值与粗颗粒含量、击实次数的关系。试验结果表明,最大干密度随着粗颗粒含量的增加先增大后减小,CBR值随着粗颗粒含量的增加而增大。进一步分析砂砾卵石土作为路基填筑材料的压实机制,通过现场碾压试验,确定砂砾卵石土路基填筑施工工艺,利用压实度、CBR、弯沉、回弹模量等现场检测手段和现场沉降观测数据检验压实效果,通过比较分析各种检测方法的可靠性,提出适合砂砾卵石土压实质量的检测方法,运用统计学方法得到沉降差检测标准值,确定采用碾压遍数与沉降差双重控制保证压实质量,得到一些有益的结论。     

Weathering of fuel oil spill on the east Mediterranean coast, Ashdod, Israel

Residual fuel oil spilled into the sea from the Eshkol power station on 8 February, 1998 contaminated about 9 km of the foreshore north of the Ashdod harbour. A study of the aliphatic, polycyclic alkane and polyaromatic hydrocarbon (PAH) composition of the spilled oil shows rapid weathering in the early stages followed by gradual slowdown after about three months. Weathering of isoprenoids and PAH compounds and variation in Pr/Ph ratio appear to occur almost contemporaneously with that of n-alkanes, at a relatively moderate level of degradation, when much of the >C₂₀ n-alkane envelope is still well preserved. Depletion of various compounds in accordance with molecular size rather than molecular structure appears to imply that physical weathering processes, i.e. evaporation and perhaps flushing due to wave energy, might have played an important role in the degradation of the spilled residual fuel oil in this study case.     

Estimation of petrol and diesel adulteration with kerosene and assessment of usefulness of selected automobile fuel quality test parameters

Kerosene is common adulterant utilized for mixing with diesel. Five fuel-adulterant mixtures in different proportions by volume were prepared and individually tested for density and kinematic viscosity. The mixtures were administered to six light cargo vehicles and the tail pipe exhaust emission was tested for opacity value. No appreciable density variation at different levels of adulteration was observed. Density was within the prescribed value even at higher adulteration. Considerable decrease in kinematic viscosity, a departure from prescribed viscosity, was noted at higher adulteration level. The percent opacity value decreased sharply even at small level of adulteration. The probable amount of kerosene present as an adulterant in diesel dispensed at filling stations in Kathmandu city ranged between 35% and 50%. The observations suggest density test is not a good indicator of diesel adulteration. Kinematic viscosity and opacity value are useful diesel adulteration test parameters. Existing diesel adulteration warrants initiation of strict compliance regulation.     

Facile regeneration and modification of industrial used chelating resin for fuel oil desulfurization

A systematic study was carried out on the preparation and application of metal-loaded polypropylene-divinyl benzene resin for dibenzothiophene adsorption. Amidoxime groups over used industrial polypropylene-divinyl benzene chelating resin were regenerated through a chemical graft reaction, and the highest regeneration efficiency of about 90 % can be reached. Different metal phases (Zn, Ni, Cu, Fe, Bi, and Ag) were introduced to the regenerated resin via an incipient-wetness impregnation method to examine their desulfurization efficiency. The desulfurization efficiency of ca. 86.3 % can be gained over Zn-loaded resin (Zn-R) under optimized reaction conditions. The order of different desulfurization influencing factors was further verified according to the orthogonal experiments, that is, desulfurization temperature > metal loading content > space velocity > organic sulfur concentration. Distribution of adsorption products was analyzed, and the results reveal that the metal-modified resins can effectively remove the organic sulfur compounds in diesel oil without loss of its octane value. The desulfurization effect of metal-contained resins is primary determined by the π-complexation.     

碱渣与粉煤灰拌合物的岩土工程及环境特性研究

碱渣是氨碱法生产纯碱时产生的工业废料,仅天津碱厂历年堆积的碱渣占地已达数平方公里。碱渣与其它材料（如粉煤灰等）拌和可制成工程土,代替一般工程土作为道路基础或大面积填垫材料的途经。对碱渣制工程土的化学成分,岩土工程性质和对环境的影响进行了研究,对碱渣土回填场地的地基承载能力和长期稳定性进行了测试。研究成果可以使这种工程土得到合理利用,从而减轻工业废料-碱渣的堆积和污染问题     

冻土区土石混合体冻融交界面剪切性能研究

随着全球气候变暖,多年冻土加速退化,冻土区土石混合体边坡稳定性问题日益突出。为探究不同含水率和碎石含量对土石混合体冻融交界面剪切强度的影响。开展土石混合体冻融交界面直剪试验,得出含水率(21%、24%、27%、30%)和含石率(0%、10%、20%、30%、35%、40%)对土石混合体冻融交界面抗剪强度变化的影响规律。试验结果表明:含水率对土石混合体冻融交界面强度的影响可分为快速下降和缓慢下降两个阶段。当含水率从21%增加到27%的过程中,土石混合体冻融交界面强度下降迅速。当含水率从27%增加到30%的过程中,界面抗剪强度继续下降,但下降速率减慢,即含水率对界面强度影响的阈值在27%左右。随着碎石含量增加,界面抗剪强度一直处于增长趋势。当含石率为10%的交界面强度相比不含石的交界面强度有明显增加,最大增长幅度为33%。当含石率大于30%时,土体抗剪强度增长迅速,即含石率对界面强度影响的阈值在30%左右。当含石率一定时,交界面处摩擦角随着含水率增加逐渐减小,在含水率达到27%后变化缓慢,而交界面黏聚力在含水率达到27%前快速减小后趋于缓慢下降。当含水率一定时,随着含石率增加,交界面摩擦角...