Light Fuels Research Articles

Chemometric techniques in oil classification from oil spill fingerprinting

Extended use of GC–FID and GC–MS in oil spill fingerprinting and matching is significantly important for oil classification from the oil spill sources collected from various areas of Peninsular Malaysia and Sabah (East Malaysia). Oil spill fingerprinting from GC–FID and GC–MS coupled with chemometric techniques (discriminant analysis and principal component analysis) is used as a diagnostic tool to classify the types of oil polluting the water. Clustering and discrimination of oil spill compounds in the water from the actual site of oil spill events are divided into four groups viz. diesel, Heavy Fuel Oil (HFO), Mixture Oil containing Light Fuel Oil (MOLFO) and Waste Oil (WO) according to the similarity of their intrinsic chemical properties. Principal component analysis (PCA) demonstrates that diesel, HFO, MOLFO and WO are types of oil or oil products from complex oil mixtures with a total variance of 85.34% and are identified with various anthropogenic activities related to either intentional releasing of oil or accidental discharge of oil into the environment. Our results show that the use of chemometric techniques is significant in providing independent validation for classifying the types of spilled oil in the investigation of oil spill pollution in Malaysia. This, in consequence would result in cost and time saving in identification of the oil spill sources.

Light fuel demand and public policies in Brazil, 2003–2013

ABSTRACTThe main objective of this article is to evaluate determinants of demand for light fuels in Brazil between 2003 and 2013. Through a vector autoregression analysis, an effort was made to identify and quantify the impact of different economic variables and public policy measures adopted during this period on the surprising increase in energy consumption by Brazil’s light-vehicle fleet. The results suggest that demand for energy by the light-vehicle fleet was influenced by an increase in income, by a decrease in fuel prices associated with a policy designed to prevent increases in the price of gasoline from pushing the inflation rate up, by a higher availability of credit for buying vehicles, and by a drop in the real price of those goods, with emphasis on countercyclical measures to waive the tax on industrialized products levied on new vehicles during economic downturns in the automotive industry.

High and low frequency unfolded partial least squares regression based on empirical mode decomposition for quantitative analysis of fuel oil samples

Accurate prediction of the model is fundamental to the successful analysis of complex samples. To utilize abundant information embedded over frequency and time domains, a novel regression model is presented for quantitative analysis of hydrocarbon contents in the fuel oil samples. The proposed method named as high and low frequency unfolded PLSR (HLUPLSR), which integrates empirical mode decomposition (EMD) and unfolded strategy with partial least squares regression (PLSR). In the proposed method, the original signals are firstly decomposed into a finite number of intrinsic mode functions (IMFs) and a residue by EMD. Secondly, the former high frequency IMFs are summed as a high frequency matrix and the latter IMFs and residue are summed as a low frequency matrix. Finally, the two matrices are unfolded to an extended matrix in variable dimension, and then the PLSR model is built between the extended matrix and the target values. Coupled with Ultraviolet (UV) spectroscopy, HLUPLSR has been applied to determine hydrocarbon contents of light gas oil and diesel fuels samples. Comparing with single PLSR and other signal processing techniques, the proposed method shows superiority in prediction ability and better model interpretation. Therefore, HLUPLSR method provides a promising tool for quantitative analysis of complex samples.

Production of gasoline and diesel like fuels from waste tire oil by using catalytic pyrolysis

This study has dealt with the pyrolysis of waste tire by using catalytic distillation method to obtain engine fuels. WTO (Waste tire oil) product that had the 40% ratio was produced with 42% char, and the remaining 18% was released to atmosphere as gaseous by product. The WTO was mixed with two additives, namely naturel zeolite and lime, at different mass ratio. Each fuel sample was exposed to pyrolytic distillation to obtain light and heavy fuel products. Characteristics of the as-produced fuels were determined and their distillation tests were investigated. As a result of these tests, the lime mixture fuel sample at 10 wt% ratio of has shown the best results, has acquired the optimum distillation temperatures and was close to diesel fuel. This mixture was categorized as light and heavy fuels according to its distillation test results. Characteristics of those light and heavy fuels were resembled to those of gasoline and diesel fuel, which were named as GLF (gasoline-like fuel) and DLF (diesel-like fuel), respectively. Fractions of the as-produced fuels were 18 wt% of the WTO for the light fuel, and 70 wt% for heavy fuel. The other product was 12 wt% of the residues.

Advantage of ethanol fuel for gas generator cycle air turbo ramjet engine

Performance analyses of Gas Generator cycle Air Turbo Ramjet (GG-ATR) engine are conducted to investigate the feasibility of ethanol fuel, as comparing Liquefied Hydrogen (LH2), Liquefied Natural Gas (LNG), and n-C12H26. Liquefied Oxygen (LOX) is considered as an oxidizer. Gas generator combustion temperature and compressor pressure ratio are selected as the analytical parameters, which are varied from 900 to 1700 K and from 2.0 to 4.0, respectively.In general, specific impulses of light molecule weight fuels, such as LH2 and LNG, are higher than those of large molecule weight fuel. For storable fuel, Isp of ethanol is larger than that of n-C12H26 when gas generator temperature is less than 1300 K, although specific heat release of ethanol is only two thirds of n-C12H26 heat release. The main chemical species of n-C12H26 gas generator (GG) combustion gas are CH4 and CO. On the other hand, ethanol GG combustion gas is mainly composed of H2 and CO, resulting in smaller molecular weight than n-C12H26. These characteristics contribute to larger Isp of ethanol than n-C12H26 and indicate the feasibility of ethanol for GG-ATR engine fuel.

Development of Kinetic and Process Models for the Oxidative Desulfurization of Light Fuel, Using Experiments and the Parameter Estimation Technique

The oxidative desulfurization (ODS) of light gas oil (LGO) is investigated with an in-house-designed catalyst consisting of cobalt oxide loaded on alumina (γ-Al2O3), in the presence of air as an oxidizing agent, under moderate operating conditions (temperatures of 403–473 K, liquid hourly space velocity (LHSV) = 1–3 h–1, initial concentration = 500–1000 ppm). The Incipient Wetness Impregnation (IWI) method of cobalt oxide over γ-alumina (2% Co3O4/γ-Al2O3) is used for the preparation of the catalyst. The optimal design of experiments is studied to evaluate the effects of several process variables (namely, temperature, LHSV, and concentration of dibenzothiophene) and their optimal values were found to be 473 K, 1 h–1, and 1000 ppm, respectively. For the conversion of dibenzothiophene to sulfone and sulfoxide, the results indicates that the IWI method is suitable to prepare this type of the catalyst. Based on the experiments, mathematical models that represent a three-phase reactor for describing the behavio...

Catalytic cracking of heavy oil over TiO2–ZrO2 catalysts under superheated steam conditions

Heavy oil upgrading was examined over titania–zirconia mixed oxide (TiO2–ZrO2) catalysts using fixed-bed flow-type reactors. Catalytic cracking of atmospheric residual oil (AR) and oil sand bitumen into lighter fuels such as gas oil and vacuum gas oil (VGO) was carried out in a superheated steam. The upgrading mechanisms were found to occur by carbon–carbon bond cleavage and naphthalene-ring opening caused by cracking, oxidation, or hydrogenolysis. The carbon–carbon bond cleavage reaction over acid sites is a well-known FCC (Fluid Catalytic Cracker) process, whereas coke formation on catalysts is a serious problem. Hence, repetition of the sequence of reactions over a short period of time and immediate regeneration of the catalyst is required. We previously developed a CeO2–ZrO2–Al2O3–FeOX iron oxide catalyst for heavy oil conversion into lighter fuels (Funai et al., 2010a,b; Kondoh et al., 2015). When this catalyst was applied to the degradation of heavy oil, the lattice oxygen in the catalyst was the main active site, and it decomposed the heavy oil through partial oxidative cracking. Although the catalyst showed a high upgrading activity, it was gradually deactivated due to carbon deposition. In contrast, we found TiO2–ZrO2 catalysts exhibited acidic cracking activity for heavy oil cracking under superheated steam conditions. In this study, we conducted experiments with TiO2–ZrO2 catalysts for upgrading heavy oil. The effect of the catalyst composition on the yield of the lighter fuels, catalyst activity, and stability after the reaction was examined. As a result, the yield of light fractions from AR decomposition reached 71mol%-C when using a TiO2–ZrO2 catalyst comprising TiO2 and ZrO2 in equimolar amounts and the catalyst structure remained intact after the reaction.

Mechanical performance of integrally bonded copper coatings for the long term disposal of used nuclear fuel

The preferred method for disposal of used nuclear fuel is underground emplacement in a Deep Geological Repository (DGR). Many countries have light water reactor fuels which require large Used Fuel Container or Canister (UFC) designs weighing up to 25 ton for containment. In contrast, Canada exclusively uses heavy water reactor fuel, which is substantially smaller. This has led the Nuclear Waste Management Organization (NWMO) to create a novel UFC, which uses standard pressure vessel grade steel for structural containment and a thick, integrally bonded copper coating applied to the exterior surface for corrosion protection. Currently, the coating is applied using two different methods: electrodeposition and gas dynamic cold spray. This novel copper coating needs to be fully validated to ensure adequate mechanical strength and chemical resistance for use under repository conditions. Detailed mechanical and corrosion testing programs were undertaken. Mechanical tests indicated that adhesion strengths exceeded 45MPa and tensile properties were comparable to wrought copper. A Finite Element Model (FEM) of the copper–steel composite was created and validated using three point bend tests. This model accurately predicts the response of the composite, including large deformation and debonding failure mechanisms. Now validated, this model will be used to assess the performance of the coating on the full-scale UFC under simulated DGR loading conditions.

Targeting Household Air Pollution for Curbing the Cardiovascular Disease Burden: A Health Priority in Sub-Saharan Africa.

Household air pollution (HAP) is a major public health problem, particularly in sub-Saharan Africa where most of the populations still rely on solid fuels for cooking, heating, and lighting. This narrative review highlights the direct and indirect evidence of the important role of HAP in cardiovascular disease, especially in sub-Saharan African countries where highest rates of major cardiovascular disease and death are observed, and thus provides ample reason for promotion of preventive interventions to reduce HAP exposures in the region. There is an urgent need for efficient strategies to educate populations on the health issues associated with this health hazard, to provide affordable clean cooking energy for poor people and to promote improved household ventilation. High-quality data on household energy practices and patterns of HAP and related health issues are still needed for efficient policy making in this region.

Uranium silicide pellet fabrication by powder metallurgy for accident tolerant fuel evaluation and irradiation

In collaboration with industry, Idaho National Laboratory is investigating uranium silicide for use in future light water reactor fuels as a more accident resistant alternative to uranium oxide base fuels. Specifically this project was focused on producing uranium silicide (U3Si2) pellets by conventional powder metallurgy with a density greater than 94% of the theoretical density. This work has produced a process to consistently produce pellets with the desired density through careful optimization of the process. Milling of the U3Si2 has been optimized and high phase purity U3Si2 has been successfully produced. Results are presented from sintering studies and microstructural examinations that illustrate the need for a finely ground reproducible particle size distribution in the source powder. The optimized process was used to produce pellets for the Accident Tolerant Fuel-1 irradiation experiment. The average density of these pellets was 11.54 ± 0.06 g/cm3. Additional characterization of the pellets by scanning electron microscopy and X-ray diffraction has also been performed. Pellets produced in this work have been encapsulated for irradiation, and irradiation in the Advanced Test Reactor is expected soon.

Assessment of cost as a function of abatement options in maritime emission control areas

This paper assesses cost as a function of abatement options in maritime emission control areas (ECA). The first regulation of air pollutions from ships which came into effect in the late 1990s was not strict and could easily be met. However the present requirement (2015) for reduction of Sulfur content for all vessels, in combination with the required reduction of nitrogen and carbon emissions for new-built vessels, is an economic and technical challenge for the shipping industry. Additional complexity is added by the fact that the strictest nitrogen regulations are applicable only for new-built vessels from 2016 onwards which shall enter US or Canadian waters. This study indicates that there is no single answer to what is the best abatement option, but rather that the best option will be a function of engine size, annual fuel consumption in the ECA and the foreseen future fuel prices. However a low oil price, favors the options with the lowest capex, i.e. Marine Gas Oil (MGO) or Light Fuel Oil (LFO), while a high oil price makes the solutions which requires higher capex (investments) more attractive.

Optimal Design of a Trickle Bed Reactor for Light Fuel Oxidative Desulfurization Based on Experiments and Modeling

In this work, the performance of oxidative desulfurization (ODS) of dibenzothiophene (DBT) in light gas oil (LGO) is evaluated with a homemade manganese oxide (MnO2/γ-Al2O3) catalyst. The catalyst is prepared by the incipient wetness impregnation (IWI) method with air under moderate operating conditions. The effect of different reaction parameters such as reaction temperature, liquid hour space velocity, and initial concentration of DBT is also investigated experimentally. For developing a detailed and validated trickle bed reactor (TBR) process model that can be employed for design and optimization of the ODS process, it is important to develop kinetic models for the relevant reactions with high accuracy. The best kinetic model for the ODS process taking into account hydrodynamic factors (mainly, catalyst effectiveness factor, catalyst wetting efficiency, and internal diffusion) and the physical properties affecting the oxidation process is developed utilizing data from pilot plant experiments. An optimization technique based upon the minimization of the sum of the squared error between the experimental and predicted composition of oxidation process is used to determine the best parameters of the kinetic models. The predicted product conversion showed very good agreement with the experimental data for a wide range of operating conditions with absolute average errors less than 5%.

Nanostructure of metallic particles in light water reactor used nuclear fuel

An extraordinary nano-structure has been observed in the metallic (Mo–Tc–Ru–Rh–Pd) particles that are known to form during irradiated in light water nuclear reactor fuels. This structure points possible high catalytic reactivity through the occurrence of a very high surface area as well as defect sites. We have analyzed separated metallic particles from dissolved high burn-up spent nuclear fuel using scanning and transmission electron microscopy. The larger particles vary in diameter between ∼10 and ∼300nm and possess a hexagonally close packed epsilon-ruthenium structure. These particles are not always single crystals but often consist of much smaller crystallites on the order of 1–3nm in diameter with evidence suggesting the occurrence of some amorphous regions. It is possible that neutron irradiation and fission product recoils generated the unusual small crystallite size. The composition of the metallic particles was variable with low levels of uranium present in some of the particles. We hypothesize that the uranium may have induced the formation of the amorphous (or frustrated) metal structure. This unique nano-structure may play an important role in the environmental behavior of nuclear fuels.

Effects of Soret Diffusion on Premixed Counterflow Flames

Soret diffusion is a secondary mass diffusion and it affects laminar flames with very light or heavy species and large temperature gradients. To get a general understanding of Soret effects on stretched flames, we conduct theoretical analysis on a premixed counterflow flame with Soret diffusion. A deliberately idealized premixed counterflow flame model is analyzed asymptotically within the framework of large activation energy, potential flow, and thermal-diffusive model. A correlation among flame stretch rate, flame position, and flame temperature is derived and is used to assess the effects of Soret diffusion on counterflow flame structure, Markstein length, and extinction stretch rate. Results show that Soret diffusion quantitatively affects the premixed counterflow flame and that the influence of Soret diffusion strongly depends on Lewis number and stretch rate. For light fuels, the premixed counterflow flame becomes stronger after including Soret diffusion. The opposite trend occurs for heavy fuels. The influence of Soret diffusion is found to increase with the stretch rate. A linear change between normalized Markstein length and Soret diffusion coefficient is observed, indicating that flame becomes more sensitive to stretch rate after including Soret diffusion. Furthermore, Soret diffusion is shown to greatly increase the extinction stretch rate of light fuels. These results indicate that for highly-stretched premixed flames containing very light species, the impact of Soret diffusion cannot be neglected.

Upgradation of Pyrolysis Oil and Vacuum Residue Obtained from the Fractional Distillation of Bio-Crude Oil: A Review

Rising demand of transportation fuels, petrochemicals and the ever rising heavy residues of crude oil have resulted in a renewed interest in the processing of this heavy residue to generate useful lighter fuels and chemicals. Not only these heavy residue but also oil generated by the pyrolysis can be upgraded into useful energy component by using appropriate processing technology. In this connection an attempt has been initiated to upgrade vacuum residue oil obtained from fractional distillation of bio crude oil and pyrolysis oil.

Renewable Energy Policies and Practice in Tanzania: Their Contribution to Tanzania Economy and Poverty Alleviation

Tanzania is facing challenges in energy provision with a lot of people leaving in rural areas experiencing energy poverty exhibited by lack of access to electricity, therefore relying on traditional fuels for cooking and lighting. In Tanzania, the electricity access has risen from 18.4% in 2013 to 24% in 2015. Power generation remained generally stable in 2013 which contributed 7.3% to the growth of the National economy. In 2014 the estimates shows that the National economy grew by 7.2%, and is projected to reach 7.4% in 2015. It is reported that, the electricity demand in Tanzania is about 7% per year over the past 10 years. A large proportion of majority of rural population is located far away from the National grid and it is un economical to connect to the grid. The main objective of this paper is to examine renewable energy policies and practices in Tanzania and their contribution to Tanzania economy and poverty alleviation. The study focused on content analysis of projects reports and policy in 10 years. Tanzania has drafted renewable energy policies so as to shift dependence from hydropower which is many times affected by draught and weather patterns and petroleum that have been affected by price fluctuation to solar, wind, biogas and other biomass which are renewable. However, the adoption rate of these renewable energy technologies is low because of financial constraints, lack of awareness, lack of coordination between the Government, non Governmental organizations and private sectors. Existing renewable energy policies should be harmonized and the current practice should be evaluated so as to upgrade the adoption rate of renewable technologies.

Effects of Soret diffusion on spherical flame initiation and propagation

Dynamics of spherical flame initiation and propagation with Soret diffusion are investigated using large-activation-energy asymptotic analysis. Under the assumptions of constant density and quasi-steady flame propagation, a general correlation between the flame propagating speed and flame radius considering Soret diffusion and external energy deposition is derived. Emphasis is placed on assessing the effects of Soret diffusion on spherical flame propagation speed, Markstein length, and critical ignition condition. The stretched flame speed is found to be increased and reduced by the Soret diffusion of light and heavy fuels, respectively. For both light and heavy fuels, the absolute value of Markstein length increases after including Soret diffusion, indicating that premixed flames become more sensitive to stretch rate with Soret diffusion. It is found that the Markstein length can be characterized by an effective Lewis number which includes the effects of Soret diffusion. Moreover, Soret diffusion is shown to affect the ignition process since the spherical flame kernel is highly stretched. For large hydrocarbon fuels with high Lewis numbers, the minimum ignition power becomes much larger after considering Soret diffusion.

Impact of Accident-Tolerant Fuels and Claddings on the Overall Fuel Cycle: A Preliminary Systems Analysis

This paper presents a preliminary systems analysis related to most of the currently proposed enhanced accident-tolerant fuel and cladding concepts: fully ceramic microencapsulated fuels, uranium-molybdenum fuels, uranium-nitride fuels, uranium silicide fuels, silicon carbide cladding, advanced steel cladding, and molybdenum cladding. The benefits drawn from the implementation of demonstrated accident-tolerant fuels on the future development of nuclear energy generation as well as public acceptance are difficult to quantify but would probably be very significant. The potential impacts of these innovative light water reactor fuels on the front end of the fuel cycle, on the reactor operation, and on the back end of the fuel cycle are succinctly described.

Social Impact of Solar Home System in Rural Bangladesh: A Case Study of Rural Zone

The Initial research on the Solar Home System (SHS) was related to an evaluation o f its present ci rcumstances in Bangladesh. Aft erwards, considering its increasing d emand, a signi ficant research study was condu cted to find standardi zed qualifi cation testing procedures fo r SHS components. Sequentially, the following re- search deals with the socio-economic impact and sustainable development in rural areas o f Bangladesh using SHS. A combination of qualitative and quantitative meth- odological tactics, were used to provide descriptive evidence concerning electricity's impact on the assess able so cio-economic dat a. Qualitative consultations with the specialists involved in the SHS propagation method, delivered overall inform ation related to SHS packages and exposed the pro fessional's individual opinion regarding socio-economic impacts of solar elect ricity in a rural part o f Bangl adesh. To finalize this inform ation with field -level data, a p ervasive household survey and individual short interviews with shop-k eep ers were perform ed in a rural area near Dh aka city. SHS's contribute to sustainable dev elopment mainly through the improv ement o f social aspects in rural life. The implementation of SHS's in rural Bangladesh, causes optimistic impacts, particularly in the areas o f edu cation, health, in formation, com- munication, social security and household works. Moreover, the plummeting of CO 2 emissions through the substitution o f traditional lighting fu els has to be mentioned as a positive environment al impact. The economic impacts o f the SHS's are limited to an increas e in income o f shops. Previously SHS's were mostly used by house- holds who possessed high in comes however by now focusing on the poorer hous e- holds has extended the opportunity of dev eloping both socio-economic groups. Dur- ing the last few decad es, the implementation rate of SHSs are much notable than any other ren ewable energy system. This is especially so in rural areas. Showing the im- pact on rural development, this research will amplify the opportunity of SHS's in the long run having adequate government subsidy.

A cross-sectional study of household biomass fuel use among a periurban population in Malawi.

The Global Burden of Disease Study suggests almost 3.5 million people die as a consequence of household air pollution every year. Respiratory diseases including chronic obstructive pulmonary disease and pneumonia in children are strongly associated with exposure to household air pollution. Smoke from burning biomass fuels for cooking, heating, and lighting is the main contributor to high household air pollution levels in low-income countries like Malawi. A greater understanding of biomass fuel use in Malawi should enable us to address household air pollution-associated communicable and noncommunicable diseases more effectively. To conduct a cross-sectional analysis of biomass fuel use and population demographics among adults in Blantyre, Malawi. We used global positioning system-enabled personal digital assistants to collect data on location, age, sex, marital status, education, occupation, and fuel use. We describe these data and explore associations between demographics and reported fuel type. A total of 16,079 adults participated (nine households refused); median age was 30 years, there was a similar distribution of men and women, 60% were married, and 62% received secondary school education. The most commonly reported occupation for men and women was "salaried employment" (40.7%) and "petty trader and marketing" (23.5%), respectively. Charcoal (81.5% of households), wood (36.5%), and electricity (29.1%) were the main fuels used at home. Only 3.9% of households used electricity exclusively. Lower educational and occupational attainment was associated with greater use of wood. This large cross-sectional study has identified extensive use of biomass fuels in a typical sub-Saharan Africa periurban population in which women and people of lower socioeconomic status are disproportionately affected. Biomass fuel use is likely to be a major driver of existing communicable respiratory disease and the emerging noncommunicable disease (especially respiratory and cardiovascular) epidemic in this region. Our data will help inform the rationale for specific intervention studies and the development of appropriately targeted public health strategies to tackle this important and poverty-related global health problem.