Similar Heating Values Research Articles

Realization of Bio-Coal Injection into the Blast Furnace

The steel industry accounts, according to the International Energy Agency, for ~6.7% of global CO2 emissions, and the major portion of its contribution is from steelmaking via the blast furnace (BF) route. In the short term, a significant reduction in fossil CO2 emissions can be achieved through the introduction of bio-coal into the BF as part of cold bonded briquettes, by injection, or as part of coke. The use of bio-coal-containing residue briquettes was previously demonstrated in industrial trials in Sweden, whereas bio-coal injection was only tested on a pilot scale or in one-tuyere tests. Therefore, industrial trials replacing part of the pulverized coal (PC) were conducted. It was concluded that the grinding, conveying, and injection of up to 10% of charcoal (CC) with PC can be safely achieved without negative impacts on PC injection plant or BF operational conditions and without losses of CC with the dust. From a process point of view, higher addition is possible, but it must be verified that grinding and conveying is feasible. Through an experimentally validated computational fluid flow model, it was shown that a high moisture content and the presence of oversized particles delay devolatilization and ignition, lowering the combustion efficiency. By using CC with similar heating value to PC, compositional variations in the injected blend are not critical.

A Preliminary Study on the Use of Highly Aromatic Pyrolysis Oils Coming from Plastic Waste as Alternative Liquid Fuels.

In this work, the low-temperature pyrolysis of a real plastic mixture sample collected at a WEEE-authorised recycling facility has been investigated. The sample was pyrolysed in a batch reactor in different temperature and residence time conditions and auto-generated pressure by following a factorial design, with the objective of maximising the liquid (oil) fraction. Furthermore, the main polymers constituting the real sample were also pyrolysed in order to understand their role in the generation of oil. The pyrolysis oils were characterised and compared with commercial fuel oil number 6. The results showed that in comparison to commercial fuel oil, pyrolysis oils coming from WEEE plastic waste had similar heating values, were lighter and less viscous and presented similar toxicity profiles in fumes of combustion.

Investigation on pyrolysis and combustion characteristics of low quality lignite, cotton waste, and their blends by TGA-FTIR

In this study, lignite based fossil fuel and cotton waste based biofuel were selected as the main components of mixed energy resources due to their similar heating values. The effect of mixing ratio on pyrolysis and oxidation characteristics was investigated by thermal gravimetric analysis (TGA) equipped with Fourier transform infrared (FTIR) spectrometer. Synergy between the fuels was explained by comparing calculated and experimental findings of characteristic temperatures and gas evolution profiles. The results of the TGA and FTIR analyses revealed that cotton waste addition improves thermal decomposition reactivity of low quality lignite under the pyrolysis and combustion conditions. Although no synergy was found between lignite and cotton waste under pyrolysis condition, the best synergistic interaction between fuels was observed in 50% mixing ratio during combustion.

Fuel properties and emission characteristics of essential oil blends in a compression ignition engine

Essential oils are mostly used in aromatherapy and their popularity has grown rapidly for the last decade. However, the industry has a substantial low-value waste stream, because downstream industries require therapeutic-grade oil. These waste stream oils can be used in the transport and agricultural sectors. This study investigated the influence of various essential oil blends on the emission characteristics of a multi-cylinder diesel engine. Orange, eucalyptus and tea tree oil were blended with diesel at 5% and 10% by volume, neat diesel and a 10% waste cooking biodiesel-diesel blend were also tested for comparison. The major constituents of orange oil and eucalyptus oil are limonene and 1,8-cineole respectively, and the main constituents of tea tree oil are terpinen-4-ol, γ-terpinene and α-terpinene. Orange oil contains negligible amounts of oxygen, whereas eucalyptus oil and tea tree oil contain 8.4% and 5.4% respectively. Compared to neat diesel, all the essential oil blends exhibited similar or slightly higher density, similar heating value, lower viscosity, flash point, and cetane number, and higher surface tension. However, only orange oil and eucalyptus oil blends exhibited oxidation stability above the minimum standards. Interestingly, blending eucalyptus oil increased the oxidation stability of diesel. Tea tree oil blends emitted the most carbon monoxide (CO) while orange oil and eucalyptus oil blends emitted the least CO and nitrogen oxide (NOX). Although eucalyptus oil and tea tree oil blends contain similar levels of oxygen, they exhibited opposite NOX emission trends, which might be attributed to the dissimilar and complex bonding of oxygen molecules into the structures. Particle number emission of essential oils were load dependent, however, all essential oil belnds emitted higher particulate mass at all loads.

The case of Frictional Torrefaction and the effect of reflux condensation on the operation of the Rotary Compression Unit

This work introduces the process of Frictional Torrefaction and comes as a continuation to the previous work done on Frictional Pyrolysis, which is a novel method of pyrolysis that does not utilize heat but only friction and pressure. Both processes (i.e. Frictional Torrefaction and Frictional Pyrolysis) take place in a Rotary Compression Unit without and with a reflux condenser respectively. Rotating augers are used for the development of friction and the simultaneous increase of pressure. The following types of analysis were performed: TGA, BET, CHNS and HHV. Both products have similar heating values, around 21 MJ/kg. The elemental compositions are comparable but lower hydrogen content (3.5%) was measured for Frictional Torrefaction. BET analysis showed differences on the surface areas and porous sizes of the materials. Frictional Torrefaction has higher fixed carbon (31.23% vs 28.31%), higher surface area (58.16 m2/g vs 36.88 m2/g) and higher absorbance (35 cm3/g vs 26 cm3/g).

Influence of nozzle hole diameter and orifice diameter on dme spray to get the similar heat value with diesel spray using the constant volume chamber

Low heating value (LHV) of di-methyl ether (DME) is lower than that of diesel. To get the similar heat value with diesel from the diesel engine operation, single injection quantity of DME should be increased. This investigation was tried to increase the injection quantity of DME by the modified diesel injector and investigated the penetration length and spray angle of DME spray. DME was injected by using three-type modified diesel injectors those nozzle-hole diameters (Injector 1: 1.66 mm, Injector 2 and 3: 0.25 mm) and orifice diameters were different (Injector 1 and 2: 0.6 mm, Injector 3: 1 mm). Spray characteristics of DME was investigated with a various ambient pressures (2.5, 5.0 MPa) in the constant volume chamber and a fuel was injected by varied injection pressure from 35 to 70 MPa by interval of 5 MPa using a DME common rail fuel injection system. The result shows that DME injection quantity by Injector 3 was 1.69 ~ 2.02 times larger than that of diesel injection quantity by Injector 1. In this case, DME spray got the similar heat value compared with diesel spray. The penetration speed of DME spray by Injector 3 was the fastest, thus when the spray development was end, the penetration length of DME spray by Injector 3 was the longest compared with the other cases. In case of the spray angle, Injector 2 and 3 had the similar spray angle and these were larger than that of diesel and DME sprays by Injector 1. As the result, Injector 3 was the solution for how to solve the low heating value of DME.

Effect of nozzle dimensions and fuel type on flame lift-off length

Flame lift-off length of diesel fuel has significant influence on fuel–air mixture and soot formation. The results of the investigation on flame lift-off length are presented in this study. Experimental and numerical studies were conducted on a constant volume combustion chamber. To investigate the influence of injector nozzle geometry, four different types; namely divergent, straight, straight–rounded and convergent–rounded nozzles, were used in the experiments. Experiments were carried at 825K and 3.5MPa ambient conditions. To investigate the effect of fuel type, diesel fuel, n-heptane and a mixture of hexadecane–heptamethylnonane CN65 (cetane number 65) were injected by straight–rounded nozzle. The experimental results showed that the nozzle with smaller diameter and divergent shape has shorter flame lift-off length, that is thought to be related to lesser amount of injected fuel. Other nozzles have almost the same flame lift-off length. The experiments, conducted with fuels of different cetane number but similar heating values, showed that fuel type has insignificant effect on flame lift-off length. This result can be attributed to similar adiabatic flame temperature obtained after flame stabilization. In order to explain the driving parameters of flame lift-off length, KIVA3V CFD code was used in the numerical simulations which were carried under different ambient temperature and oxygen concentrations. It was concluded that the location of flame stabilization is effected by the flame temperature and the reverse motion of high temperature gas of combustion zone.

The Effect of the Position of Oxygen Group to the Aromatic Ring to Emission Performance in a Heavy-Duty Diesel Engine

In this paper the soot-NOx trade-off and fuel efficiency of various aromatic oxygenates is investigated in a modern DAF heavy-duty diesel engine. All oxygenates were blended to diesel fuel such that the blend oxygen concentration was 2.59 wt.-%. The oxygenates in question, anisole, benzyl alcohol and 2-phenyl ethanol, have similar heating values and cetane numbers, but differ in the position of the functional oxygen group relative to the aromatic ring. The motivation for this study is that in lignin, a widely available and low-cost biomass feedstock, similar aromatic structures are found with varying position of the oxygen group to the aromatic ring. From the results it becomes clear that both the soot-NOx trade-off and the volumetric fuel economy (i.e. ml/kWh) is improved for all oxygenates in all investigated work points. In general, the improvement in the soot-NOx trade-off correlated with the position of the functional oxygen group to the ring, with better overall emission behavior observed as the oxygen group was further from the ring. No distinct trend was observed with respect to fuel economy

Observations on the Smith–Glasser index for self-heating of bituminous coal

Self-heating of coal depends partly on intrinsic, coal-related factors. This article aims to discuss the Smith–Glasser index as a potential indicator of the self-heating propensity of a large set of bituminous coals with similar heating value but different origins. For this purpose, recorded properties and experience were reviewed for 7.5 million tonnes of coal delivered to the same power plant operator. The results suggest that the propensity to self-heat can be conveniently indicated by Smith–Glasser index that only involves routinely measured moisture and volatile contents of coal. The results appear consistent with the observed incidences of self-heating in storage.

Rheology and stability of coal—oil and coal—oil—alcohol dispersions

Studies on the effect of various surfactants on the stability of coal—oil mixtures (COM) have been carried out and a few of them were identified as most effective stabilizing agents. Rheological studies on coal dispersions in hexadecane were undertaken as a model system to elucidate the role of these surfactants on COM stability. Viscosity measurements of COM with various percentages of coal revealed that there is a marked increase in viscosity above 40% of coal concentration. At low concentrations of surfactants (< 1%) considerable decrease in viscosity of COM was observed. It was concluded that these surfactants are effective in the concentration range 0.1–0.5%, above which the effect levels off. The shear thinning behavior was evident both in the presence and absence of surfactants. Fuel oil is highly viscous and requires elevated temperatures to exhibit suitable flow characteristics. Methanol or ethanol was found to be immiscible with the fuel oil used in the present study. However, upon the addition of an appropriate amount of a lower chain hydrocarbon or kerosene, a stable single phase mixed fuel system (fuel oil + alcohol + alkane = alcofuel) was formed. The coal + oil mixtures prepared with alcofuels exhibited much lower viscosity than those prepared with fuel oil No. 6. Both types of COMs showed similar heating values. The advantages of alcofuels as compared to those of conventional fuel oils are emphasized in relation to COM technology.