High Heat Of Combustion Research Articles

Synthesis of 4,4′-spirobi[pentacyclo[5.4.0.02,6.03,10.05,9]undecane

4,4′-Spirobi[pentacyclo[5.4.0.02,6.03,10.05,9]undecane] (10) is first successfully prepared by a nine step synthetic scheme starting from the key intermediate (cyclopentadiene derivate, 2). This synthetic scheme avoids using the hardly obtainable spiro[4.4]nonatetraene (18) as the starting material. In the structure of 10, two polycyclic cages share one spiro-carbon so that it has high density (1.2663g/cm3) and high volumetric heat of combustion (53.353MJ/L).

The co-processing of municipal waste in a cement kiln in Mexico. A life-cycle assessment approach

A growing population and a high level of consumption generate increasing municipal waste, which requires integral and environmentally efficient waste management systems. In contrast, the cement industry has an inherent need for fuel with a high heat of combustion. Thus, municipal solid wastes with high calorific value are desirable as Refuse-Derived Fuel for thermal processes in the cement industry, which is an opportunity for both the waste sector and cement industry. However, the environmental viability must be objectively, systematically and holistically evaluated. For the last trait, a comparative Life Cycle Assessment was developed to evaluate the environmental impact from clinker production for two fuel scenarios: one considering a 100% petroleum coke and the other a 20% Refuse-Derived Fuel and 80% petroleum coke co-process. This study considers real operating data from waste management systems and the cement industry in Mexico. Both scenarios considered the impact of the raw material extraction, manufacture and transport of fuels, electricity generation and use air emissions, discharge and wastewater generated during the life cycle of the analyzed fuels. The evaluated impact categories were the abiotic resource depletion, acidification, eutrophication, global warming, stratospheric ozone depletion, photochemical smog and terrestrial toxicity based on the CML IO Baseline V3.01. The results indicate the co-processing scenario exhibited a lower environmental impact than using only petroleum coke as a fuel for all categories. Therefore, using Refuse-Derived Fuel from municipal waste in Mexican cement plants mitigates environmental impacts and could be a strategic alternative for waste management.

High-Density Renewable Diesel and Jet Fuels Prepared from Multicyclic Sesquiterpanes and a 1-Hexene-Derived Synthetic Paraffinic Kerosene

High-density renewable diesel and jet fuels have been generated by blending multicyclic sesquiterpanes with a synthetic paraffinic kerosene (5-methylundecane). The sesquiterpanes impart high density and volumetric net heat of combustion (NHOC) to the blends, while inclusion of the modestly branched paraffin decreases the viscosity and increases the cetane number of the blends. A surrogate diesel fuel comprising 65% sesquiterpanes and 35% 5-methylundecane had a cetane number of 45.7, a density of 0.853 g/mL, and a volumetric NHOC of 134.0 thousand British thermal units (kBtu)/gallon. By increasing the amount of paraffin to 60% by volume, a jet fuel surrogate was prepared with a cetane number of 57.0, a density of 0.806 g/mL, a −20 °C kinematic viscosity of 8.3 mm2/s, and a NHOC of 124.6 kBtu/gallon. The results show that full-performance and even ultraperformance fuels can be generated by combining bioderived sesquiterpanes and paraffins. The components of the fuel blends studied in this work can be genera...

Halogen-free fire retardant styrene–ethylene–butylene–styrene-based thermoplastic elastomers using synergistic aluminum diethylphosphinate–based combinations

Multicomponent flame retardant systems containing aluminum diethylphosphinate in thermoplastic styrene–ethylene–butylene–styrene elastomers are investigated (oxygen index, UL 94, cone calorimeter, and mechanical testing). Solid-state nuclear magnetic resonance, scanning electron microscopy, and elemental analysis illuminate the interactions in the condensed phase. Thermoplastic styrene–ethylene–butylene–styrene elastomers are a challenge for flame retardancy (peak heat release rate at 50 kW m−2 > 2000 kW m−2, oxygen index = 17.2 vol%, no UL-94 horizontal burn rating) since it burns without residue and with a very high effective heat of combustion. Adding aluminum diethylphosphinate results in efficient flame inhibition and improves the reaction to small flame, but it is less effective in the cone calorimeter. Its efficacy levels off for amounts >∼25 wt%. As the most promising synergistic system, aluminum diethylphosphinate/melamine polyphosphate was identified, combining the main gas action of aluminum diethylphosphinate with condensed phase mechanisms. The protection layer was further improved with several adjuvants. Keeping the overall flame retardant content at 30 wt%, aluminum diethylphosphinate/melamine polyphosphate/titanium dioxide and aluminum diethylphosphinate/melamine polyphosphate/boehmite were the best approaches. An oxygen index of up to 27 vol% was achieved and a horizontal burn rating in UL 94 with immediate self-extinction; peak heat release rate decreased by up to 85% compared to thermoplastic styrene–ethylene–butylene–styrene elastomers, to <300 kW m−2.

Combustion Behaviour of Fe2O3-coated Zirconium Particles in Air

Abstract Zirconium metal powder is widely used in aerospace and military as a metal fuel because of its high combustion rate and heat. This powder is used to produce flash powder, fireworks, artillery shells, timing bomb fuses and solid propellant rocket fuel. To comply with the special requirements for aerospace and military applications, zirconium particles are coated with Fe 2 O 3 ferrite magnetite nanoparticles to form a core-shell structure. This process alters the combustion performance of the coated zirconium dust. In this study, the combustion behaviour of Fe 2 O 3 -coated zirconium particles in the air is explored. Scanning electron microscopy, X-ray diffraction, thermogravimetry and differential scanning calorimetry are used to examine the micromorphology, phase composition, crystal structure, thermal stability and reactivity of Fe 2 O 3 -coated zirconium particles. The combustion behaviour is presented, with the coating layer of Fe 2 O 3 -coated zirconium particles generating a replacement reaction with the inner core zirconium. The inner zirconium induced an oxidation-reduction reaction with oxygen and pure Fe was oxidised at high temperatures. The decomposition reaction was due to the residue of Fe 2 O 3 that did not react with zirconium.

Effect of Nano-Magnesium on the Thermal Decomposition of PTFE

Due to high reaction activity and high combustion heat release, magnesium is widely used in the field of explosives. The research focus of this article is the effect of magnesium powder size and content on the thermal decomposition of PTFE. Two different particle sizes of magnesium powder are regarded as research objects. The thermal behavior of Mg/PTFE energetic system was investigated by TG-DSC analyzer. The experimental results show that magnesium has a catalytic effect on the thermal decomposition of PTFE. With the increase of magnesium content , the decomposition peak temperature of PTFE decreased firstly and when passed the ratio 50% increased, the best mixing ratio is Mg: PTFE =50:50. Within nanopowder, the activation energy of PTFE decreased by 150kJ∙mol-1 compared to 112 kJ∙mol-1 by mixing with micro powder. Obviously nanopowder has a better reactivity than micro powder, so has a more obvious catalytic effect.

INVESTIGATION INTO THE INFLUENCE OF FLAME RETARDANT ADDITIVES ON SOME FIRE PROPERTIES OF POLYESTER MATERIALS APPLYING SMALL-SCALE TESTING TECHNIQUES

In order to investigate the impact of some inorganic additive flame retardants on the selected fire properties of the materials based on polyester resin Polimal 1033 APy, small-scale fire testing techniques have been used. Seven samples have been studied: unmodified PES, PES modified with MoO3 (7, 14 and 21 wt%) and PES modified with Sb2O3 (7, 14 and 21 wt%). The following flammable properties of materials have been determined: the heat of combustion (HOC), the ignition temperature of volatile thermal decomposition products (Tig), self-ignition temperature and oxygen index. A cone calorimeter method has been used for determining heat release rate (HRR), mass loss, specific extinction area (SEA) and other combustion parameters. The toxicological analysis of combustion products has been conducted. Based on the obtained results, the following conclusions have been made: (1) MoO3 and Sb2O3 added to the studied material change its flammable properties and fire parameters. It can be indicated by higher HOC, higher Tig and self-ignition temperature, as well as by lower HRR and SEA. Modified materials become safer in terms of fire hazard. (2) A significant reduction in HRRmax of approx. 40% in the content of 7 wt% has been observed. The lowest HRRmaxof approximately 300 kW/m2 and 450 kW/m2 have been obtained for 21 wt% in a range of 200–600 s at 30 kW/m2 and 100–400 s at 50 kW/m2 respectively. Except for a sample containing 7 wt% of Sb2O3, a clear local reduction in HRR (from 50 to 150 kW/m2), in case of all modified samples has been noticed. (3) Sb2O3 has a greater impact on the thermostability of the studied materials compared to MoO3 in all cases of heat flux density and additive concentrations. The effectiveness of Sb2O3, as a flame retardant is the most evident at 21 wt%.

Treated and untreated foam core particleboards with intumescent veneer

The effectiveness of treatments for the surface layer of novel foam core particleboards was evaluated by means of Cone calorimeter tests. Foam core particleboards with variations of surface layer treatment, adhesives, and surface layer thicknesses under similar processing conditions were used to produce the test specimen for the Cone calorimeter tests. Ignitability, heat release rate profile, peak of heat release rate, total heat released, effective heat of combustion, mass loss rate, gaseous emissions, and specific extinction area were measured using the cone irradiance of 50 kW m−2. Additional analysis of this data provided fuel composition information that could reveal the pyrolysis events of the composite boards. Thermocouples at various depths were used to provide further verification of pyrolysis events. The unprotected foam core panels generally had much higher heat release rates, somewhat higher heat of combustion and much higher smoke production due to the polymeric foam component of tested panels, whereas time to ignition and total heat release were not pronounced from the veneer treated boards. Adding the commercial fire retardant veneer to the face particleboard provided a dramatic improvement to the measured flammability properties. It worked sufficiently well with a 3 mm thick surface layer to improve the predicted flame spread rating of the foam core particleboards.

Biomass derived motor fuels with higher combustion heat, ecological and chemmotological characteristics

High pour point and low combustion heat were defined as the major disadvantages of biodiesel type motor fuels. We have proposed to add wood biomass derived bicyclic compound hydrocarbon (1S,5S)-6,6-dimethyl-2-ethylenebicyclo [3.1.1] heptane (C10H16) into fat acids methyl esters (FAME) type biofuel to improve its performance and ecological qualities. A novel blended 100% biofuel is thus obtained. For a comparision we have studied performance properties of the methyl ester of rape oil (MERO) mixture with mineral diesel fuel. It was determined that the optimal performance characteristics of such fuel mixture is near 30% of MERO. Density, kinematic viscosity, pour point and combustion heat of the blends were investigated: measured, calculated, and analyzed.

Fire performances of foam core particleboards continuously produced in a one-step process

For further progress of novel foam core particleboards, their fire performance was examined with cone calorimetry tests (ASTM E 1354-11a). Specimens with varying surface layer thicknesses, foam densities (polystyrene foam), and processing temperatures were tested. Using the initially recommended cone irradiance of 35 kW/m2, different flammability parameters were measured. In comparison to particleboards, the foam core panels generally had much higher heat release rates, somewhat higher heat of combustion and much higher smoke production due to the EPS-foam component of tested panels. The time to ignition and total heat release did not vary significantly among the samples, although certain trends could be explained. The effects of variations in specimen foam densities and processing temperatures on the flammability parameters were not very significant. However, the flammability properties improved towards that of the reference particleboard as the surface layer thickness increased from 3 to 5 mm.

Experimental Study on the Thermodynamic Properties of Thermites

In order to study the thermites systematically, six different thermites were chosen and prepared, then the thermodynamic properties were measured. It was found that Mg+MnO2, Al+Fe3O4 and Mg+CuO combusted steadily and slowly, while Mg+MnO2 had a high combustion temperature; Mg+CuO, Mg+Fe3O4 and Mg+MnO2 had lower starting reaction temperature, higher releasing heat, and reacted easily; Mg+MnO2, Mg+CuO and Al+CuO had higher combustion heat and complete combustion capacity. Mg+MnO2 and Mg+CuO are two ideal thermites, have bright practical application prospect.

Altitudinal variation in leaf construction cost and energy content of Bergenia purpurascens

It is still unknown if the variation of leaf energy content across altitudinal gradients is caused by varying climatic factors or species replacement. We test whether there is an altitudinal increase in leaf energy properties within a single species, which is mainly due to the decreasing air temperature with altitude. We collected samples for Bergenia purpurascens Engl. (an evergreen herb) at every 10 m in altitude from outside the timberline forest (4320 m) to the hilltop (4642 m) in the Sergyemla Mountains, southeastern Tibet. We measured mass- and area-based leaf construction cost (CCm, CCa) and their components: nitrogen concentration (Nmass), ash concentration (AC), the heat of combustion (HC), and specific leaf area (SLA), as well as leaf lignin concentration (LC) and new leaf dry mass per plant (NLDM). As altitude increased, CCm, CCa, HC, and LC increased, whereas Nmass, SLA, AC, and NLDM decreased. CCm and CCa were positively correlated with HC and LC but negatively with Nmass, SLA, AC and NLDM. CCm, CCa and HC were negatively correlated with mean air temperature. The data indicated that some high-HC constituents like lignin rather than protein contributed to the observed pattern of leaf energy properties. For high-altitude plants, having relatively high leaf CCm and HC can be regarded as a growth strategy for sustaining carbon gain and maximizing nitrogen-use efficiency. Since CC tends to decrease with increasing air temperature, evergreen herbs at high altitude are expected to construct relatively “cheaper” leaves in response to global warming.

Energy Balance and Offgas Utilization of Ilmenite Smelting in a 30 MVA Direct Current Electric Arc Furnace

Energy balance and offgas utilization of ilmenite smelting in 30 MVA direct current electric arc furnace (DC furnace) of a Yunnan company were investigated to make sure safety production, and to save energy and reduce pollution. The total input energy in the DC furnace was 2,000 kWh per ton of ilmenite, in which 1,003.31 kWh per ton of ilmenite was used to carbothermic reduction and other energy was consumed as heatloss. Based on energy conservation, the whole system heatloss in physical production should be controlled at 1,000 kWh per ton of ilmenite. With high combustion heat, the offgas discharged from furnace after treatment could be used to ilmenite drying, anthracite drying, titanium slag drying, and casting ladle baking. The offgas design flow ranged from 5,000 to 8,000 Nm3/h with the mean of 6,500 Nm3/h. The combustion heat quantity of offgas in the plant was 82,160 MJ per hour, which could save 480,276.8 kWh of electrical energy per day, and thus lower carbon emission of the whole production line.

Boosted HCCI Combustion Using Low-Octane Gasoline with Fully Premixed and Partially Stratified Charges

High-load HCCI combustion has recently been demonstrated with conventional gasoline using intake pressure boosting. The key is to control the high combustion heat release rates (HRR) by using combustion timing retard and mixture stratification. However, at naturally aspirated and moderately boosted conditions, these techniques did not work well due to the low autoignition reactivity of conventional gasoline at these conditions. This work studies a low-octane distillate fuel with similar volatility to gasoline, termed Hydrobate, for its potential in HCCI engine combustion at naturally aspirated and low-range boosted conditions. The HCCI combustion with fully premixed and partially stratified charges was examined at intake pressures (Pin) from 100 to 180 kPa and constant intake temperature (60°C) and engine speed (1200 rpm). First, the key parameters for high-load HCCI operation were investigated, including 1) intermediate temperature heat release (ITHR), which determines the potential of using combustion retard to control the HRR, and 2) φ-sensitivity, which determines the effectiveness of mixture stratification for controlling the HRR. It is found that consistent with the low octane number, Hydrobate shows strong ITHR and φ-sensitivity even at Pin = 100 kPa. However, the ITHR of Hydrobate is not enhanced by increasing intake pressure, which is different from gasoline at Pin = 100-180 kPa, but similar to gasoline at Pin ≥ 180 kPa. For high-load operation, it is found that with a fully premixed charge, Hydrobate allowed higher loads than conventional gasoline for Pin < 160 kPa, mainly due to the lower intake temperature allowing a higher fueling rate. However, for Pin ≥ 160 kPa, the maximum load reached by Hydrobate was lower than gasoline due to the higher level of EGR required, which limited the oxygen available for combustion. On the other hand, higher thermal efficiency was consistently observed with Hydrobate at all Pin tested, mainly due to the lower intake temperature and more advanced combustion phasing. Applying partial fuel stratification to Hydrobate combustion further improved thermal efficiency compared to the fully premixed case, since it allowed even more advanced combustion phasing; however, it only slightly extended the high-load limit, again due to the limited oxygen availability. This work indicates that low-octane gasoline is a superior HCCI fuel for naturally aspirated and modestly boosted operations. Copyright © 2012 SAE International.

Synthesis and characterization of water borne intumescent fire retardant varnish based on phosphate resin acid cold cured amino resin

In this research, a water borne intumescent fire retardant varnish based on phosphate resin acid (PRA) cold cured amino resin was synthesized. Infrared (IR) spectrum proved that PRA was from 1,4-butanediol diglycidyl ether (BDE) and epoxy resin E-51 (E-51) via the reaction between epoxy group and POH of phosphate ester acid of N-butyl alcohol (BA) and pentaerythritol (PT). The introduction of BDE and E-51 improved water resistance and flexibility of painted film. The fire retardancy test demonstrated that a higher phosphorus content is beneficial to the intrinsic fire retardancy of painted films, but the high quality char formation is another key of fire retardancy of painted films. The TG and DTA proved: E-51 and PT are true carbon source that is beneficial to form a high quality charred layer, but their high combustion heat is detrimental to the intrinsic fire retardancy of painted film material. BDE is beneficial to increase the intrinsic fire retardancy of painted film material, but detrimental to form a high quality charred layer. The conclusion also is showed directly by the scanning emission microscopy (SEM). To achieve high performance painted film, all the components need to be balanced perfectly.

Magnetic behavior and physicochemical properties of Ni and NiO nano-particles

A series of nano-crystalline Ni/NiO particles was synthesized by a combustion route depending upon the glycine–nitrate process. The as prepared samples were characterized by X-ray diffraction (XRD), scanning electron micrograph (SEM), transmission electron micrograph (TEM), nitrogen adsorption isothems at 77 K and vibrating sample magnetometer (VSM) techniques.The XRD results revealed that the Ni powder crystallizes was formed with the cubic phase when the molar ratio of glycine to nitrate is 1.5. Above or below that molar ratio, NiO phase coexists as an impurity along with the Ni phase. The SEM and TEM measurements of the as synthesized powders showed that the particles are irregular in shapes and have porous morphology. Increasing the ratio between glycine and Ni–nitrate resulted in slightly agglomeration and grain growth of nano-particles with subsequent decrease in the value of surface area depending upon high combustion heat. The magnetization value of Ni measured at room temperature is very close to the value observed for commercial Ni powder.

Fuel Properties of a Two-Phase Biodiesel Emulsion

Biodiesel is one of the most promising alternative clean fuels to fossil fuel, which can effectively reduce the emissions from fossil fuel burning. The high oxygen content in biodiesel can promote the burning process, but it can also increase NOx formation simultaneously, when biodiesel is used as fuel. Fuel emulsification is considered to be effective in reducing NOx emissions. In this study, soybean oil was used as raw oil to produce biodiesel by transesterification reaction. The biodiesel product was then emulsified with water and emulsifying surfactant to form water-in-oil (w/o) biodiesel emulsion. The biodiesel emulsion composed of 1.5% polyoxyethylated castor oil (EL-12), 0.7% lethicin and 0.5% cetylpyridinium chloride (CPC) was proved to have the better emulsifying activity (EA) and emulsifying stability (ES) values, and higher combustion heat than those of the neat biodiesel and reference biodiesel emulsion (with 2.7% EL-12 as the emulsifying surfactant).

Comparison of methods of predicting the higher thermal combustion of coal

Formulas for predicting the higher heat of combustion of coal on the basis of technical analysis (the yield of volatiles), elementary analysis, and petrographic analysis are verified. It is found that the formulas are only valid for the samples used in their derivation. Statistical analysis of data for coal from the Donetsk and Lvov-Volynsk basins shows that the higher heat of combustion of such coal is most accurately described by a mathematical formula in which the predictors are petrographic characteristics of the initial coal components, including the reflection coefficient of vitrinite. The mean higher heat of combustion may be determined for vitrinite at different metamorphic stages (for ranks from D to T) and also for liptinite and the sum of fusinized (lean) components in Ukrainian Donetsk and Lvov-Volynsk coal.

Review of Theory and Practice on Natural Gas Hydrate

Research on Natural Gas Hydrate（NGH）is very popular in recent years. NGH is a potential, new and clean energy with the characteristics of high energy density, high combustion heat, high proven reserves, no pollution, wide distribution and shallow burial and so on. It has been identified that NGH is widely distributed in the plateau, arctic permafrost and some eligible areas in the seabed of epicontinental and continental slope all around the world. According to the research data on NGH at home and abroad, the mineralizing, formation, distribution and exploration technology of NGH are introduced as well as the NGH research status of countries in the world, including China. Many theories and techniques about the exploitation of NGH are not mature yet. Numerous problems still exist in industrial mining NGH, such as environmental, geological problems induced by mining NGH and storage and transportation problems after mining. Finally, the application and mining prospects of NGH are and prospected and summarized to provide a relatively comprehensive reference to this research field.

Evaluation of low-cost cathode catalysts for high yield biohydrogen production in microbial electrolysis cell

As an ideal fuel due to the advantages of no pollution, high combustion heat and abundant sources, hydrogen gas can be produced from organic matter through the electrohydrogenesis process in microbial electrolysis cells. But in many MECs, platinum is often used as catalyst, which limits the practical applications of MECs. To reduce the cost of the MECs, Ni-based alloy cathodes were developed by electrodepositing. In this paper hydrogen production using Ni-W-P cathode was studied for the first time in a single-chamber membrane-free MEC. At an applied voltage of 0.9 V, MECs with Ni-W-P cathodes obtained a hydrogen production rate of 1.09 m3/m3/day with an cathodic hydrogen recovery of 74%, a Coulombic efficiency of 56% and an electrical energy efficiency relative to electrical input of 139%, which was the best result of reports in this study. The Ni-W-P cathode demonstrated a better electrocatalytic activity than the Ni-Ce-P cathode and achieved a comparable performance to the Pt cathode in terms of hydrogen production rate, Coulombic efficiency, cathodic hydrogen recovery and electrical energy efficiency at 0.9 V.