scholarly journals Combustion Study of Polyoxymethylene Dimethyl Ethers and Diesel Blend Fuels on an Optical Engine

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4608
Author(s):  
Jingjing He ◽  
Hao Chen ◽  
Xin Su ◽  
Bin Xie ◽  
Quanwei Li

Polyoxymethylene dimethyl ethers (PODE) are a newly appeared promising oxygenated alternative that can greatly reduce soot emissions of diesel engines. The combustion characteristics of the PODE and diesel blends (the blending ratios of PODE are 0%, 20%, 50% and 100% by volume, respectively) are investigated based on an optical engine under the injection timings of 6, 9, 12 and 15-degree crank angles before top dead center and injection pressures of 100 MPa, 120 MPa and 140 MPa in this study. The results show that both the ignition delay and combustion duration of the fuels decrease with the increasing of PODE ratio in the blends. However, in the case of the fuel supply of the optical engine being fixed, the heat release rate, cylinder pressure and temperature of the blend fuels decrease with the PODE addition due to the low lower heating value of PODE. The addition of PODE in diesel can significantly reduce the integrated natural flame luminosity and the soot formation under all injection conditions. When the proportion of the PODE addition is 50% and 100%, the chemical properties of the blends play a leading role in soot formation, while the change of the injection conditions have an inconspicuous effect on it. When the proportion of the PODE addition is 20%, the blend shows excellent characteristics in a comprehensive evaluation of combustion and soot reduction.

2017 ◽  
Vol 19 (10) ◽  
pp. 1099-1112 ◽  
Author(s):  
Magín Lapuerta ◽  
Juan José Hernández ◽  
José Rodríguez-Fernández ◽  
Javier Barba ◽  
Angel Ramos ◽  
...  

Tests with diesel/n-butanol blends (up to 20% by volume) were carried out in a Euro 6 engine following the New European Driving Cycle in a test bench. No decrease in engine efficiency was observed when n-butanol is used and fuel consumption increased proportionally to its lower heating value. Regarding emissions, total hydrocarbon and carbon monoxide increased when n-butanol is used. On the other hand, the use of n-butanol reduces the particle emissions down to a minimum value (for around 16% of n-butanol content) and then increases particle emissions again. This was observed in both mass and particle number. This trend occurs as a consequence of the compromise between the increase in oxygen content, which inhibits soot formation, and the increase in hydrocarbon emissions, especially under cold-engine conditions, which promotes liquid nucleation. Finally, NOX emissions remained unchanged as a consequence of the compensation between larger ignition delays and shorter combustion durations.


Author(s):  
Joshua A. Bittle ◽  
Jesse K. Younger ◽  
Timothy J. Jacobs

Biodiesel remains an alternative fuel of interest for use in diesel engines. A common characteristic of biodiesel, relative to petroleum diesel, is a lowered heating value (or per mass energy content of the fuel). For same torque engine comparisons, the lower heating value translates into a higher brake specific fuel consumption (amount of fuel consumed per unit of power produced). The efficiency at which fuel energy converts into work energy, however, may remain unchanged. In this experimental study, evaluating nine unique engine operating conditions, the brake fuel conversion efficiency (an assessor of fuel energy to work energy efficiency) remains unchanged between 100% petroleum diesel fuel and 100% biodiesel fuel (palm olein) at all conditions, except for high load conditions. Several parameters may affect the brake fuel conversion efficiency, including heat loss, mixture properties, pumping work, friction, combustion efficiency, and combustion timing. This article describes a study that evaluates how the aforementioned parameters may change with the use of biodiesel and petroleum diesel, and how these parameters may result in differences in the brake fuel conversion efficiency.


2021 ◽  
Author(s):  
Randall Boehm ◽  
Zhibin Yang ◽  
David Bell ◽  
John Feldhausen ◽  
Joshua Heyne

A detailed assessment is presented on the calculation and uncertainty of the lower heating value (net heat of combustion) of conventional and sustainable aviation fuels, from hydrocarbon class concentration measurements, reference molecular heats of formation, and the uncertainties of these reference heats of formation. Calculations using this paper’s method and estimations using ASTM D3338 are reported for 17 fuels of diverse compositions and compared against reported ASTM D4809 measurements. All the calculations made by this method and the reported ASTM D4809 measurements agree (i.e., within 95% confidence intervals). The 95% confidence interval of the lower heating value of fuel candidates that are comprised entirely of normal- and iso-alkanes is less than 0.1 MJ/kg by the method described here, while high cyclo-alkane content leads to 95% confidence bands that approach 0.2 MJ/kg. Taking a possible bias into account, the accuracy and precision of the method described in this work could be as high as 0.23 MJ/kg for some samples.


Author(s):  
Ziedonis Miklašēvičs

The methodology in Latvia forest industry provide to determine the quality of energy chips only in long- term storage places before selling. Due to the lack of hard empirical data about the quality parameters of energy chips in different phases of manufacturing process, this research paper consists of: - the identification and analyses of the factors that influenced the values of energy chips quality features such as: bulk density, moisture content, ash content, higher and lower heating value according to actual moisture content and per dry mass of the chips; - the methodology for determination the quality parameters of energy chips by analysis the wood moisture content and by choice the method of the manufacturing of energy chips.


2019 ◽  
Vol 137 ◽  
pp. 01018 ◽  
Author(s):  
Jing Luo ◽  
Ogechi Emelogu ◽  
Tatiana Morosuk ◽  
George Tsatsaronis

Allam cycle is a novel cycle that capitalizes on the unique thermodynamic properties of supercritical CO2 and the advantages of oxy-combustion for power generation. It is a high-pressure supercritical carbon dioxide cycle designed to combust fossil fuels such as natural gas or syngas (from coal gasification systems) with complete CO2 separation at a high-efficiency and zero atmospheric emissions. This semi-closed cycle produces sequestration-ready/pipeline quality CO2 by-product, and thus eliminates the need for additional CO2-capture system. The Coal-fueled Allam cycle is targeted to deliver between 51-52% net efficiency (lower heating value) for coal gasification. In this study, the expected energetic efficiency is verified by simulating the system in Ebsilon professional software and the result showed that the net efficiency of the simulated coal-fired plant is 30.7%, which is significantly lower than the targeted value. The lower efficiency maybe as a result of the missing heat integration in the system, the high power demand of the oxidant compressor and CO2 compressors. And an exergy analysis based on published cycle data is employed, to investigate the cycle performance, identify the sources of the cycle’s thermodynamic inefficiencies at the component level; a sensitivity analysis is also performed to study the effects of selected thermodynamic parameters on the overall performance of the coal-fired Allam cycle.


2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Halina Pawlak-Kruczek ◽  
Agnieszka Urbanowska ◽  
Weihong Yang ◽  
Gerrit Brem ◽  
Aneta Magdziarz ◽  
...  

Abstract Currently, the reclamation and reuse of water have not reached their full potential, although more energy is needed to obtain and transport freshwater and this solution has a more serious environmental impact. Agricultural irrigation is, by far, the largest application of reclaimed water worldwide, so the proposed concept may result in the production of water that can be used, among others, for crop irrigation. This paper describes a novel installation for the recovery of the agricultural water from the digestate, along with the results of initial experiments. Currently, water is wasted, due to evaporation, in anaerobic digestion plants, as the effluent from dewatering of the digestate is discharged into lagoons. Moreover, water that stays within the interstitial space of the digestate is lost in a similar fashion. With increasing scarcity of water in rural areas, such waste should not be neglected. The study indicates that hydrothermal carbonization (HTC) enhances mechanical dewatering of the agricultural digestate and approximately 900 L of water can be recovered from one ton. Dewatered hydrochars had a lower heating value of almost 10 MJ/kg, indicating the possibility of using it as a fuel for the process. The aim of this Design Innovation Paper is to outline the newly developed concept of an installation that could enable recovery of water from, so far, the neglected resource—i.e., digestate from anaerobic digestion plants.


Author(s):  
Marcus Thern ◽  
Torbjo¨rn Lindquist ◽  
Tord Torisson

Ethanol from bio-products has become an important fuel for future power production. However, the present production technology is rather expensive. This paper focuses on how to lower the production cost of ethanol extraction from mash, and to use the ethanol as a primary fuel in gas turbines for heat and power production. Today, ethanol is produced during distillation by supplying energy to extract the ethanol from the mash. Using the evaporation process in the evaporative gas turbine to extract the ethanol from the mash before the distillation step, a lot of energy can be saved. In the evaporation process, the ethanol is extracted directly from the mash using energy from low-level energy sources. The evaporation technology is therefore expected to reduce the cost for the ethanol production. Simultaneous heat and mass transfer inside the ethanol humidification tower drives a mixture of ethanol and water into the compressor discharge air. To investigate the evaporation of a binary mixture into air at elevated pressures and temperatures, a test facility was constructed and integrated into the evaporative gas turbine pilot-plant. The concentration of ethanol in the mash is not constant but depends on the sugar content in the feedstock used in the fermentation process. Tests were therefore conducted at different concentrations of ethanol in the ethanol-water mixture. Tests were also performed at different temperature and flow conditions to establish the influence of these parameters on the lower heating value of the produced low calorific gas. It has been shown that this technology extracts about 80% of the ethanol from the mash. It has also been shown that the composition of the resulting gas depends on the temperatures, flow rates and composition of the incoming streams. The tests have shown that the produced gas has a lower heating value between of 1.8 to 3.8 MJ/kg. The produced gas with heating values in the upper range is possible to use as fuel in the gas turbine without any pilot flame. Initial models of the ethanol humidification process have been established and the initial test results have been used for validating developed models.


Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5107 ◽  
Author(s):  
Magdalena Dołżyńska ◽  
Sławomir Obidziński ◽  
Jolanta Piekut ◽  
Güray Yildiz

Agri-food waste is generated at various food cycle stages and is considered to be a valuable feedstock in energy systems and chemical syntheses. This research identifies the potential and suitability of a representative agri-food waste sample (i.e., plum stones) as a solid fuel. Ground plum stones containing 10, 15, and 20 wt.% of rye bran were subjected to pelletization. The pelletizer was operated at 170, 220, and 270 rpm, and its power demand for the mixture containing 20 wt.% of rye bran was 1.81, 1.89, and 2.21 kW, respectively. Such pellets had the highest quality in terms of their density (814.6 kg·m−3), kinetic durability (87.8%), lower heating value (20.04 MJ·kg−1), and elemental composition (C: 54.1 wt.%; H: 6.4 wt.%; N: 0.73 wt.%; S: 0.103 wt.%; Cl: 0.002 wt.%; O: 38.2 wt.%). Whole plum stones and pellets were subjected to combustion in a 25 kW retort grate boiler in order to determine the changes in the concentrations of NO, SO2, CO, CO2, HCl, and O2 in the post-combustion flue gas. Collected results indicate that plum stone–rye bran pellets can serve as effective substitutes for wood pellets in prosumer installations, meeting the Ecodesign Directive requirements for CO and NO.


e-xacta ◽  
2016 ◽  
Vol 9 (2) ◽  
Author(s):  
Letícia Fabri Turetta ◽  
Andréa Oliveira Souza da Costa

<p>A indústria siderúrgica produz quatro subprodutos com significativa capacidade de geração de energia. Esses subprodutos podem ser utilizados como combustível na caldeira siderúrgica, equipamento da central termoelétrica. O objetivo deste estudo é propor uma modelagem para estimar a temperatura adiabática da chama da fornalha de uma caldeira siderúrgica com a variação de ar e combustível disponível. A técnica empregada consiste no princípio da Primeira Lei da Termodinâmica. O balanço de energia do sistema foi proposto definindo assim o modelo. A solução do modelo possibilita estimar a temperatura adiabática do sistema. Na indústria, a temperatura adiabática é determinada pelo poder calorífico inferior dos combustíveis. A metodologia proposta neste estudo faz com que não sejam necessários levantamentos experimentais do poder calorífico inferior. Os valores da temperatura adiabática simulados indicam que utilizar condições operacionais distintas na alimentação do combustível e do ar podem afetar significativamente o valor deste parâmetro. Nas simulação com a variação de ar, nota-se que a temperatura adiabática decresce com o acréscimo do excesso de ar. Tal resultado é esperado, uma vez que o aumento da massa, contida no sistema, diminui a eficiência energética do processo. Conclui-se que a metodologia proposta provou ser eficaz de descrever o sistema quando diferentes condições de alimentação são adotadas.</p><p> </p><p>ABSTRACT</p>Steel industry produces four by-products with significant capacity of energy generation. These products can be used as fuel at steel boiler, equipment thermoelectric plant. The objective of this study is to propose a modeling to estimate the adiabatic flame temperature furnace’s of an industrial boiler steelmaking with the variation of available air and fuel. The technique employed consists in principle of the First Law of Thermodynamics. The system's energy balance was proposed thus defining the model. The solution’s model enables to estimate the system’s  temperature of the adiabatic. In industry, the adiabatic temperature is determined by the fuel’s lower heating value. The methodology proposed in this study makes is not necessary experimental surveys of the lower heating value. The values at the adiabatic temperature simulated to indicate that use different operating conditions in the feed of fuel and air can significantly affect the value of this parameter. In the simulation with the variation in air, it is noted that the adiabatic temperature decreases with the increase of excess air. This result is expected since the increase of the mass contained in the system decreases the energy efficiency of the process. It is concluded that the methodology proved to be effective to describe the system when different air and fuel feed are adopted.


2020 ◽  
Vol 157 ◽  
pp. 01003 ◽  
Author(s):  
Vitaliy Asabin ◽  
Alexey Roslyakov ◽  
Leyla Kurmanova ◽  
Sergey Petukhov ◽  
Maxim Erzamayev

This research paper contains the results of analysis of a range of variation of the lower heating value of gas during the process of conversion of diesel locomotive engines to operation on natural gas as motor fuel. It was demonstrated in this paper that the range of variation of the lower heating value at the various fields considered in it varied within the limits to 32.4%. A proposal was made to take into consideration the so-termed lower heating value of diesel fuel and natural gas when running diesel locomotive engines on liquid-gas fuel complementary to atmospheric conditions.


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