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The excessive generation of plastic waste has become a major threat to the environment. Petroleum-based plastics, however, provided the opportunity for its re-conversion into fuel oil. In this study, polypropylene plastic was liquefied to produce liquid fuels in the presence of n-hexane solvent. The study was performed in a batch reactor at temperatures between 350 and 400 °C, reaction times between 0 and 150 min, and solvent-to-plastic mass ratios between 0:1–5:1. The effect of the different parameters was evaluated based on its yield amount and fuel quality. The results showed that the highest oil yield of 88.2 wt% was obtained at a temperature of 400 °C. A comparable oil yield of 88.0 wt% was also obtained at 150 min reaction time. The characterization results showed that the oil had density, viscosity and calorific value similar to the conventional gasoline. The GC–MS analysis showed that the oil was dominated by alkanes, alkenes and alcohol compounds with carbon numbers C6-C20, which is within the range of gasoline, kerosene and diesel fuel. In addition, the production of oil from the liquefaction of plastic could serve as an alternative source to the depleting fuel as well as increase the value of plastics, leading to fewer environmental problems caused by plastic waste. • Mild processing condition in liquefaction using n-hexane solvent • High oil yield in the absence of catalysts and at sub-critical solvent condition. • Organic solvents with low dielectric constants showed better performance in liquefaction process. [ABSTRACT FROM AUTHOR]

Co-Hydrothermal Carbonization (Co-HTC) was performed on a blended feedstock of coal and miscanthus. The main goal of this work was to evaluate the synergistic effects of miscanthus on coal during Co-HTC. Fuel quality was assessed for all hydrochars by evaluating mass yields, energy content, ultimate analysis, and proximate analysis. Calculation of combustion parameters showed experimental ignition and burnout indices of Co-HTC 260 °C hydrochar were 29.0% and 26.5% lower than theoretical, non-interacting indices, respectively. Hydrochars shared the benefits of low sulfur and low ash content of miscanthus but maintaining higher energy content of coal. Hydrochars produced at 260 °C had energy contents as high as coal (27.3 ± 0.6 MJ kg − 1 ) and 73% less ash content and 74% less sulfur than raw coal as a result of the more acidic environment produced by miscanthus decomposition. Furthermore, hydrochars were homogeneous as miscanthus-derived hydrochar was formed on coal surface according to SEM imaging and verified by the reduced pore width from nitrogen adsorption. Co-HTC hydrochars were pelletized in a single-press pellet press. Both mass and energy densities of Co-HTC pellets were increased with the increase of Co-HTC temperature. For instance, energy densities of pelletized Co-HTC hydrochars were increased to 32.4 GJ m − 3 , whereas HTC coal contains energy density of 28 GJ m − 3 . [ABSTRACT FROM AUTHOR]

Spray wall impingement in the early injection period has been proved be unavoidable in the diesel engine using early injection strategy. The formation of wall film directly affects fuel/air mixture formation, combustion, exhaust emissions and oil quality. In this study, experiments were carried out to investigate the wall film ratio of pure diesel, butanol/diesel, DME (Di Methyl Ether)/diesel and gasoline/diesel blended fuels. The variations of wall film ratio with different injection pressures, impingement distances, impingement angles and blending ratios were compared under both dry wall and wet wall conditions. For both dry wall and wet wall conditions, with increasing injection pressure and blending ratio, wall film ratio decreased, which is the opposite trend to impingement distance and impingement angle variations. Some dimensionless numbers also have been introduced in order to evaluate the effect of each impact factor on the variation of wall film ratio. Results showed that impingement momentum is the major impact factor on wall film ratio when varying the injection pressure or impingement distance. Impingement flow mass is the major impact factor when varying the impingement angle. For different blending ratios, the wall film ratio is mainly influenced by surface tension, followed by viscosity and saturated vapor pressure. In addition, the equations between the wall film ratio and Weber number of the impingement droplet were derived for each test fuel. [ABSTRACT FROM AUTHOR]

The selection of fuel is crucial for a Combined Heat and Power (CHP) plant in terms of cost and corrosion and the fuel will vary over time. The corrosiveness of different fuels has been studied extensively, however, not how a current corrosion attack is influenced by corrosion history (i.e. previous deposit buildup and oxide scale formation) instead of the influence of the current flue gas composition (i.e. the current fuel mix being used). This influence of the corrosion history effect can be called “corrosion memory”. To investigate the corrosion memory effect on boilers, a novel setup was used. Air-cooled probe AISI304L samples were exposed in two different boilers to mimic different fuels. One boiler was a biomass-fired boiler representing a moderate corrosive fuel and the other was a waste-fired boiler representing a highly corrosive fuel. A three-step exposure program was performed in which a reference probe was exposed in the biomass-fired boiler for all three steps while another probe was exposed in the biomass-fired boiler for steps 1 + 3 and in the waste-fired boiler for the second step. All samples were investigated with material-loss measurements and SEM/EDX. The findings show that the deposit and oxide scales formed on the samples in the biomass-fired boiler had a mitigating effect on the corrosion attack. Consequently, corrosion history affects the future corrosion rate. [ABSTRACT FROM AUTHOR]

Using fuel additives to improve fuel quality is considered to be a simple and cost-effective measure to energy saving and emission reduction. In this work, eleven additives including Iso-butanol, Ethyl tert-butyl ether, Iso-propyl ether, Aniline, Diethylamine, Dimethyl carbonate, Sec-butyl acetate, Iso-butyl acetate, Dimethyl malonate, P-methyl phenol, and P-tert-butyl phenol were chosen to study the effects of additives on physicochemical properties of China commercially 92# and 95# gasoline and vehicle performance using New European driving cycle. Results show that low octane gasoline is more significantly affected by additives. Alcohol, ether, amine, and ester additives mainly affect 50% evaporating temperature of gasoline, while phenolic additives mainly affect 90% evaporating temperature and increase Drivability Index. Ethyl tert-butyl ether improves research octane value greatly with little change in reid vapor pressure. All additives can improve the fuel economy and reduce CO emissions of 92# gasoline but have no significant effect on 95# gasoline. Most additives reduce THC emissions of 92# gasoline but increase THC emissions of 95# gasoline. All additives increase NOx emissions of 92 # gasoline, but Iso-butanol, Iso-butyl acetate, and P-methyl phenol reduce NOx emissions of 95 # gasoline. In addition, all additives improve the acceleration performance both 92# and 95# gasoline. • Low octane gasoline is more significantly affected by additives. • Phenolic additives affect 90% evaporating temperature and increase drivability index. • All additives improve the fuel economy and reduce CO emissions of 92# gasoline. • Most additives reduce 92#'s THC emissions but increase 95#'s THC emissions. • Iso-butanol, Iso-butyl acetate, and P-methyl phenol reduce NOx emissions of 95#. [ABSTRACT FROM AUTHOR]

During start-up operations of the new residue ebullated bed H-Oil hydrocracking unit in the LUKOIL Neftohim Burgas refinery oil incompatibility was registered in the process of production of heavy fuel oil. Тhat was the reason for obtaining high sediment off-spec heavy fuel oil product. The oil incompatibility was observed in the process of blending of high saturate, low asphaltene, high colloidal stability H-Oil unconverted vacuum residue with the high aromatic, and relatively high asphaltene visbroken residue. The use of antifouling additive was found to decrease the sediment level in the heavy fuel oil. However, it was not capable of reducing the heavy fuel oil sediment content after chemical and thermal artificial aging of the fuel oil. Considerable amount of high aromatic fluid catalytic cracking heavy cycle oil was needed to reduce the off-spec heavy fuel oil sediment content to the specified max. limit of 0.1% sediments. After deasphaltization of the visbroken residue with n-heptane and blending of the visbroken deasphalted oil with the H-Oil unconverted vacuum residue in a ratio of 1:1 the sediment content of the heavy fuel oil blend dropped from 2.5% to 0.01%. This suggests that the lower solubility of the visbroken residue asphaltenes in the high saturate H-Oil unconverted vacuum residue was the reason for the oil incompatibility during the production of off-spec heavy fuel oil in the LUKOIL Neftohim Burgas refinery when both the H-Oil residue hydrocracker and the visbreaker were in operation. [ABSTRACT FROM AUTHOR]

Fuel quality is one of the most critical variables in determining the heat rate, efficiency, and performance of power plants. The drive to leverage fuel switching and/or blending to meet more stringent SO 2 and NO x emission requirements has, in many cases, led to both a reduction in power station efficiency and a poorer net plant heat rate (NPHR). In addition, fuel switching and/or blending can lead to a significant reduction in operating margins and increase the risk of unit derates. To maintain boiler efficiency and performance, there is a strong incentive to manage or mitigate this risk. A first step in evaluating fuel options is using the spreadsheet-based Fuel Quality Advisor . The Advisor incorporates fuel quality information, furnace operating conditions, as well as some basic furnace design information to estimate the maximum boiler load potential, fuel cost/MWh, deposition tendency, mercury compliance, ash resistivity, corrosion potential, and backpass erosion potential. The basics of the Fuel Quality Advisor have been presented earlier; this paper presents results from a major US utility who used the Advisor to evaluate over 70 fuels and fuel blends for 10 of their larger coal-fired boilers. Combining the estimated performance from the Fuel Quality Advisor with actual operating experience using the new fuels or fuel blends has permitted the Advisor to be tailored to each specific unit — thus increasing the reliability of the estimations. This paper discusses the use of the Fuel Quality Advisor by the utility as well as several of the resulting estimations and comparisons to actual operations. [ABSTRACT FROM AUTHOR]

The present study explored a novel oxidative desulfurization (ODS) method of light gas oil fuel, which combines a catalytic oxidation step of the dibenzothiophene compound directly in the presence of molecular air as oxidant to obtain high quality fuel for light gas oil. In chemical industries and industrial research, catalysis plays a significant role. Heightened concerns for cleaner air together with stricter environmental legislations on sulfur content in addition to fulfill economic have created a driving force for the improvement of more efficient technologies and motivating an intensive research on new oxidative catalysts. As the lower quality fuel becomes more abundant, additional challenges arise such as more severe operation conditions leading to higher corrosion of the refinery installations, catalyst deactivation and poisoning. Therefore, among the technologies to face these challenges is to develop catalysts that can be applied economically under moderate conditions. The objective of this work is to design a suitable synthetic catalyst for oxidative desulfurization (ODS) of light gas oil (LGO) containing model sulfur compound (dibenzothiophene (DBT)) using air as oxidant and operating under different but moderate operating conditions. The impregnation method is used to characterize two homemade catalysts, cobalt oxide (Co 3 O 4 /γ-Al 2 O 3 ) and manganese oxide (MnO 2 /γ-Al 2 O 3 ). The prepared catalysts showed that the manganese oxide has a good impregnation (MnO 2 = 13%), good pore size distribution and larger surface area. A set of experiments related to ODS of dibenzothiophene has been carried out in a continuous flow isothermal trickle bed reactor using light gas oil as a feedstock utilizing both catalysts prepared in-house. At constant pressure of 2 bar and with different initial concentrations of sulfur within dibenzothiophene, the temperature of the process was varied from 403 K to 473 K and the liquid hourly space velocity (LHSV) was varied from 1 to 3 h − 1 . The results showed that an increase in reaction temperature and decreasing in LHSV, higher conversion was obtained. Although both catalysts showed excellent catalytic performance on the removal of molecule sulfur compound from light gas oil, the catalyst MnO 2 catalyst exhibited higher conversion than Co 3 O 4 catalyst at the same process operating conditions. [ABSTRACT FROM AUTHOR]

Raw biomass washing prior to pyrolysis treatment has been employed to mitigate the ash-related problems encountered during resultant biochar combustion. However, wide-spread application of this approach is limited by high energy consumption and low washing efficiency. In the present study, the biochar washing instead of raw biomass washing was attempted to overcome aforementioned problems, and fuel qualities of washed biochars were investigated for the first time. The results showed that major ash forming metals can be efficiently removed by all tested washing agents (de-ionized water (DW), acetic acid (AA) and citric acid (CA)), especially for acid washing agents AA and CA. As a consequence, the ash content of the biochars decreased, and the slagging and fouling issues were dramatically mitigated. Due to metal removal, the washed biochars exhibited improved combustion properties, especially for the biochars derived from agricultural biomass. In addition, noticeable decreases in nitrogen and sulfur contents were observed following washing treatment, suggesting the additional benefit of reducing emissions of nitrogen and sulfur pollutants during washed biochar combustion. Compared to raw biomass washing prior to pyrolysis, the significantly increased washing efficiency and fuel quality and decreased hydrophilicity of the biochars indicate that pyrolysis combined with subsequent biochar washing is more suitable to produce solid fuel biochars with high fuel quality from different source of waste biomass. [ABSTRACT FROM AUTHOR]

Abstract: There have been great strides in understanding the fundamental underpinnings of the slagging and fouling phenomena. Unfortunately as fuel quality changes due to coal pricing, mine closures, government regulations, market forces, etc., boilers and boiler operators continue to be plagued by poorer operating performance than desired. While improvements have been made, the need to address fundamental coal quality issues and how they affect deposition, emissions, handling, and combustion continues to be relevant. This paper presents the results of a study to assess how prevalent coal quality issues are to the power generation industry. A survey of selected EPRI members was made to determine the major areas where coal quality effects power generation and a reliability and availability assessment of the NERC GADS database for the years 1995 to 2004 was completed. This database was used to determine the lost generation through either forced outages, forced derates or planned outages and derates due to coal quality or slagging and fouling issues. The results clearly demonstrated that slagging, fouling, corrosion and fuel blending continue to be the leading coal quality concerns of utility personnel. Ash chemistry resulting from fuel blending and new coals being utilized continue to be the main area for needed utility support. A minimum estimated annual economic impact of over $1.2 billion was calculated for all coal- and lignite-fired boilers in the US based on coal quality and deposition occurrences. While this annual economic loss is huge, these outages and derates account for only about 1.6% of the total number of outages and derate occurrences and 2.5% of the total lost MW-hour generation. An annual evaluation of the coal quality and deposition-based outages and derates did not show a clear trend. In fact, the coal quality-based outages and derates generally increased over the ten-year period. [Copyright &y& Elsevier]

The technology of distillation and the technology of co-hydroprocessing with liquid biomass are combined for a more effective and sustainable LCO upgrading. The first technology is to separate the LCO hydrocarbons via distillation to obtain the fraction with boiling point up to 350 °C, rendering a light LCO fraction (LCO_cut). The second technology involves the integration of the LCO_cut with Waste Cooking Oil (WCO) towards a joined hydrotreatment step. The choice of the two aforementioned technologies is based on the claim that the distillation will exempt LCO from refractory properties and the co-hydroprocessing with WCO will led to a paraffinic product that could approach diesel fuel quality. The results show that concerning sulfur content, an improvement presented in the case of LCO_cut/ WCO product in comparison with the corresponding ones of LCO/ WCO. Moreover, the LCO_cut/ WCO product of the intermediate temperature presented the optimal aromatic content, density and cetane number in comparison with the corresponding ones of LCO/ WCO. In summary, the two degraded feedstocks; LCO and WCO, are converted to improved products, indicating the potential of integrating these feedstocks within a refinery. Unlabelled Image • Distillation and co-hydroprocessing technologies are combined for LCO upgrading. • 90% v /v of distilled LCO with 10%v/v of WCO are led to the co-hydroprocessing. • Two degraded feeds (LCO and WCO) are converted to useful product. [ABSTRACT FROM AUTHOR]