Oxygen Bomb Research Articles

Municipal solid waste higher heating value prediction from ultimate analysis using multiple regression and genetic programming techniques.

Municipal solid waste (MSW) management presents an important challenge for all countries. In order to exploit them as a source of energy, a knowledge of their calorific value is essential. In fact, it can be experimentally measured by an oxygen bomb calorimeter. This process is, however, expensive. In this light, the purpose of this paper was to develop empirical models for the prediction of MSW higher heating value (HHV) from ultimate analysis. Two methods were used: multiple regression analysis and genetic programming formalism. Both techniques gave good results. Genetic programming, however, provides more accuracy compared to published works in terms of a great correlation coefficient (CC) and a low root mean square error (RMSE).

Synthesis of Styrenated Sulfur- and Phosphorus-Free Organic Titanate and Evaluation of Its Tribological and Antioxidant Properties as an Additive in Poly-α-olefin

The styrenated sulfur- and phosphorus-free organic titanate (STAE) was synthesized via an in situ method with soybean oil, diethanolamine, and isopropyl titanate. The tribological and antioxidant behavior of the as-synthesized STAE as an additive in PAO was evaluated by a four-ball test, a rotary oxygen bomb test (ROBT), and differential scanning calorimetry (DSC), and its oxidative stability was estimated through thermogravimetric analysis (TGA). The as-synthesized STAE exhibits excellent antiwear and load-carrying capacities as well as good antiwear synergism with zinc dialkyldithiophosphate (ZDDP) in poly-α-olefin (PAO). STAE in PAO also showed good synergistic antioxidation effects with the traditional additive p,p-(dioctyldiphenylamine (DODPA). This is because STAE can effectively reduce the oxidation rate of DODPA, which was confirmed by the results of Fourier transform infrared spectroscopy (FTIR) and gas chromatography-tandem mass spectrometry (GC/MS).

Gross Calorific Value of Combustible Solid Waste in a Mass Burn Incineration Plant, Benin City, Nigeria

Some solid waste incinerators burn waste that does not possess enough calorific value that justifies the installation of an energy recovery facility, this implies that a substantial amount of energy would be provided by an auxiliary burner. Hence, the presentation of this paper was to evaluate the feasibility of setting up a mass burn incinerator with energy recovery facility using the gross calorific value (GCV) of waste generated in Benin City of Nigeria which is considered as case study. Solid waste samples (wood, leather rubber, plastic, paper, textile material etc.) were collected from Benin metropolis and their GCV were determined in a laboratory using an XRY-1A digital oxygen bomb calorimeter. The average calorific value of the waste samples calculated from the experiment was 20,198.89kJ/kg, this value is higher than the 7,000kJ/kg minimum average calorific value of solid waste required for setting up an incineration plant with energy recovery.Keywords: Incineration, Solid waste, Gross calorific value, Energy recovery

Characterization of mesoporous biochar produced from biogas digestate implemented in an anaerobic process of large-scale hog farm

Using a laboratory-scale pyrolyzer, porous biochars were produced at a wide operating temperature range from 300 to 800 °C for holding times of 30–120 min from biogas digestate (BD), which was derived from the anaerobic digestion unit in a large-scale pig farm. The resulting biochars were characterized by elemental analyzer, oxygen-bomb calorimeter, inductively coupled plasma-optical emission spectrometer (ICP-OES), pycnometer, surface area and porosity analyzer, and energy dispersive X-ray spectroscopy (EDS). The pore properties of the BD-based biochar products were on an increasing trend as pyrolysis temperature increased, indicating that operating temperature at about 800 °C seemed to be the optimal condition for producing biochar. The Brunauer-Emmet-Teller (BET) surface area of the optimal biochar was about 110 m2/g due to its mesoporous feature. Furthermore, the mineral elements of the optimal biochar were rich in calcium (Ca), phosphorus (P), magnesium (Mg), silicon (Si), iron (Fe), and potassium (K), which should be present in the forms of phosphates, carbonates, oxides, silicates, or their composites. Based on the pore properties and chemical characteristics, the BD-based biochar could be used as an excellent soil conditioner.

Synthesis of Ethyl-4-ethoxy Pentanoate by Reductive Etherification of Ethyl Levulinate in Ethanol on Pd/SiO2 -C Catalysts.

The synthesis of biomass-derived ethers to be used as biofuels or biofuel additives has attracted much attention. Following the recently reported synthesis of etherified ester ethyl-4-ethoxy pentanoate (EEP) from γ-valerolactone (GVL) in ethanol catalyzed by H-beta zeolite, an alternative route to prepare EEP in high yield has been developed by reductive etherification of ethyl levulinate (EL) in ethanol at 140 °C under 0.5 MPa H2 with a silica-modified Pd/C catalyst. The ether production likely follows a tandem acetalization-hydrogenolysis process with ethyl-4,4-diethoxy pentanoate (EDEP) as the intermediate. The acetalization step can be favored by introducing acidic materials, such as SiO2 -carbon or beta zeolite, as a cocatalyst. The combination of the Pd/SiO2 -C and beta zeolite mixture leads to 100 % EL conversion and 93 % EEP selectivity under optimized reaction conditions. For the first time, the standard molar combustion enthalpy of as-prepared EEP is measured by using a static oxygen bomb, and the value of which is determined to be about -5658 kJ mol-1 , which is much larger than that of GVL (-2650 kJ mol-1 ).

High Azide Content Hyperbranched Star Copolymer as Energetic Materials

A series of star azide copolymers (b-POBs) with hyperbranched polyether cores (HBPO-c) and short linear poly(3,3′-bis-azidomethyl oxetane) arms (PBAMO-a) have been prepared. The polymers were characterized with FT-IR, 1H NMR, quantitative 13C NMR, gel permeation chromatography, MALDI-TOF, and X-ray diffractometry. Due to hyperbranched structures, the crystallinity (Wc) of b-POBs was significantly decreased, and the processability was greatly improved. The enthalpy of formation, obtained by oxygen bomb calorimetric measurements, high azide content, and heats of decomposition of b-POBs demonstrated their remarkable energy level. Furthermore, b-POBs had good resistance to pyrolysis up to 230 °C (T5%), and their mechanical sensitivities were also obviously lower than that of the PBAMO homopolymer, showing their good safety properties. Moreover, the mechanism for sensitivity reduction of b-POBs was established by analyzing the relationship between the activation course in mechanical stimulus and its crystallin...

Effect of heat treatment on hydrophobic silica aerogel.

Hydrophobic silica aerogels were heat treated under various conditions. Physical and chemical analyses were conducted to study the effect of the heat treatments on the silica aerogels. The O/Si and C/Si values in the hydrophobic silica aerogels increased and decreased, respectively, with the increase in the heating temperature. C-O, -OH, and CO were detected during pyrolysis. Pyrolysis of the silica aerogels in air could be divided into 3 steps: the hydroxylation of methyl groups, the splitting of the alcoholic hydroxyl, and the oxidisation of CO. When the heat treatment temperature was lower than 350 °C, the properties of the silica aerogels showed little change. With further increase in the heat treatment temperature, the variation in the relevant parameters became more prominent. The secondary particles coalesced with one another, and the mesopores were destroyed. Consequently, the thermal conductivity and bulk density rose greatly. The carbon within the silica aerogels was released after heat treatment. As a result, the heat released in the thermal gravimetry and oxygen bomb analyses dropped remarkably with the increase in the heat treatment temperature.

Experimental Evaluation of Fundamental and Phase Change Characteristics for Carbon-Based Suspensions

In this study, carbon-based materials prepared using an isoperibol oxygen bomb calorimeter of varying oxygen pressure were added to water to form carbon-based suspensions (CBSs). The thermal conductivity, viscosity, density, and contact angle of CBSs were measured by appropriate instruments to understand the fundamental characteristics of CBSs. A differential scanning calorimeter (DSC) was used to measure and analyze the phase change characteristics of CBSs to evaluate the feasibility of employing CBSs as phase change materials (PCMs) in ice-storage air-conditioning systems. The experimental results revealed that the thermal conductivity, viscosity, and density of CBSs did not significantly change but a significant reduction in the contact angle of sample’s droplets occurred compared with that of water. The CBS of S5 had the lowest melting temperature and subcooling degree (SD) and highest freezing temperature in the DSC experiments; thus, S5 was determined to be the most suitable CBS for use as a PCM in this study.

Preparation and Experimental Evaluation of Phase-Change Characteristics in Carbon-Based Suspensions.

In this study, micro/nanocarbon-based materials (MNCBMs) were prepared using the high-pressure combustion method (HPCM) with an isoperibol oxygen bomb calorimeter at different oxygen pressures (0.5–3.0 MPa). The prepared MNCBMs were added to water to form carbon-based suspensions (CBSs); sodium dodecyl benzene sulfonate (SDBS) and defoamer were added to the CBSs to enhance their stability. The thermal conductivity, viscosity, density, and contact angle of the CBSs were measured using appropriate instruments to determine their fundamental characteristics. The phase-change characteristics of the CBSs were measured and analyzed using a differential scanning calorimeter (DSC) to evaluate the feasibility of employing them as phase-change materials in ice-storage air-conditioning systems. The results revealed that the maximal change ratios of thermal conductivity, viscosity, density, and contact angle of the samples were −3.15%, 6.25%, 0.23%, and −57.03%, respectively, as compared with the water. The CBS of S5 (oxygen pressure of 2.0 MPa) had the lowest melting temperature and subcooling degree (SD) and the highest freezing temperature in the experiments conducted using the DSC; thus, S5 was determined to be the most suitable CBS for use as a phase-change material of cold energy storage in this study.

Assessing the fire risk of electrical cables using a cone calorimeter

The presented study deals with the fire risk of electrical cables. Samples of three-core electrical power cables and two-core electrical control cables were investigated. The influence of the mutual spacing between the cables and the thermal conductivity of the material under the cables (underlying material) on fire risk was assessed in the study. The fire risk was determined using a cone calorimeter (at a heat flux of 50 kWm−2) and an oxygen bomb calorimeter. The fire risk was assessed based on parameters quantifying the released heat, toxicity and amount of combustion products and flashover category. The heat release rate, total heat release and the effective heat of combustion increase with increased spacing between the cables and decreased thermal conductivity of the underlying material. The carbon monoxide yield increases with the increase in the thermal conductivity of the underlying material. The influence of the spacing between cables on the carbon monoxide yield (in the interval 0–1800 s) depends on the thermal conductivity of the underlying material. At low thermal conductivity, the carbon monoxide yield decreases as the spacing decreases, with the opposite trend (with some exceptions) at high thermal conductivity. Smoke yield decreases with increasing thermal conductivity of the underlying material and also increases with increased spacing between cables. Neither the thermal conductivity of the underlying material nor the spacing between cables has an influence on the flashover category of the cables investigated.

Paradoxes and paradigms: observations on pyrohydrolysis, oxygen bomb combustion, and alkaline carbonate fusion, most frequently used decomposition methods for subsequent determination of fluorine and accompanying thermochemistry

Pyrohydrolysis, oxygen bomb combustion, and alkaline carbonate fusion are the most frequently used methods for decomposition of fluorine containing materials. The efficiency of these methods was proven by the determination of fluorine content in certified reference materials of clay and vegetation. Possible reactions proceeding during decomposition were suggested and accompanying thermochemistry discussed. The Gibbs energies were estimated to establish if suggested reactions are thermodynamically favorable or not. In addition, linear relationships between the enthalpies of formation of metal fluorides and the balanced values of the enthalpies of formation of the plausible reaction products (metal tungstates, metal oxides, or metal carbonates), electronegativity of metals, and number of fluorine atoms in metal fluorides were established. These equations were suggested for the estimation of the enthalpies of formation of metal tungstates, metal oxides, or metal carbonates, for which experimental data are not available.

Thermodynamic properties of 2–methylindole: Experimental and computational results for gas-phase entropy and enthalpy of formation

Abstract Measurements leading to the calculation of thermodynamic properties in the ideal-gas state for 2-methylindole (Chemical Abstracts registry number [95–20–5]) are reported. Experimental methods were adiabatic heat-capacity calorimetry, differential scanning calorimetry (d.s.c.), comparative ebulliometry, inclined-piston manometry, and oxygen bomb calorimetry. The critical temperature of 2-methylindole was determined experimentally with d.s.c. Molar thermodynamic functions for the condensed and ideal-gas states were derived from the experimental results. Statistical calculations were performed based on molecular geometry optimization and vibrational frequencies using B3LYP hybrid density functional theory with the def2-TZVPPD basis set. Excellent accord between computed and experimentally-derived ideal-gas entropies is shown. The enthalpy of formation for 2-methylindole in the gas phase was computed with an atomization-based protocol described recently, and excellent agreement with the experimental values is seen. The experimental literature for enthalpies of formation in the gas phase for 1- and 2-ring pyrrollic compounds is reviewed, and comparisons with computed values further support the findings here. All experimental results are compared with property values reported in the literature, where possible.

Preparation and characterization of sintered B/MgB2 as heat release material

Sintered B/MgB2 (S-B/MgB2) was originally prepared by introducing Mg to B and sintering the system under appropriate temperature and atmosphere. During the sintering process, B2O3 layer was depleted by Mg reduction and the product was characterized by XRD and SEM methods. The XRD results show that the constituents of S-B/MgB2 are B, B6O, MgB2 and MgO. Coupled with EDS, it is noticed that Mg has a desirable distribution in the particles, indicating a uniform configuration of S-B/MgB2. TG-DSC method was applied to verify the microstructure and study the oxidation processes of S-B/MgB2. It is noticed that S-B/MgB2 enjoys a high thermal stability due to the protection from MgB2/MgO shell. In addition to that, because of the absence of B2O3 layer and increased active B content, the length and rate of the oxidation reaction increase, resulting in a boost of reaction ratio and heat release in TG-DSC. Accompanied with theoretical calculation and oxygen bomb test results, it appears that S-B/MgB2 also enjoys a heat release which is not evidently affected by external conditions. Therefore, S-B/MgB2 has a promising future as heat release material.

Nitrogen‐Rich Salts based on 1,1’‐Dihydroxy‐5,5’‐Azobistetrazole: aNew Family of Energetic Materials with Promising Properties

AbstractA series of nitrogen‐rich energetic heterocyclic 1,1’‐dihydroxy‐5,5’‐azobistetrazole (AZO) salts are synthesized with ethylenediammonium (1), hydrazinium (2), semicarbazidium (3), guanidinium (4), 1‐amino‐1,2,3‐triazolium (5), 4‐amino‐1,2,4‐triazolium (6) and 5‐amino‐tetrazolium (7). The salts have characterized through elemental analysis, Fourier Transform infrared spectroscopy (FT‐IR) spectroscopy, 1H NMR, 13C NMR and mass spectrometry. The crystal structures determined by single crystal X‐ray diffraction. The thermal decomposition behaviors investigated by using the DSC and TG‐DTG technologies. The enthalpies of formation are calculated through the combustion heat data measured through the oxygen bomb calorimetry. All the salts have acceptable thermal stability with the highest decomposition temperature of 301.8 °C, excellent high positive formation enthalpies ranging from 350.5 kJ mol−1 to 1500.3 kJ mol−1, and good insensitivity to outer stimuli compared to the traditional RDX. The promising detonation parameters of the salts yield detonation velocities (D) and pressures (P) are ranging from 7327 m s−1 to 8931 m s−1, and from 21.7 GPa to 32.7 GPa. Considering the advantage, it is possible to prepare these nitrogen‐rich energetic salts as promising energetic materials. It's hoped that the present author's research contributed to the expansion and application of the chemistry of 1,1’‐dihydroxy‐5,5’‐azobistetrazole.

The debrominated and lightweight oil generated from two stage pyrolysis of WPCBs by using compound chemical additives

Abstract The effect of employing compound additives were investigated for application to the catalytic pyrolysis of waste printed circuit boards (WPCBs), in order to recycle low brominated and lightweight oils. The study included the analysis of three-phase product yields; organic and inorganic bromine distributions; oil content; and the boiling point of experimental product fractions. Bromine distributions were analyzed using ion chromatography (IC) and oxygen bomb calorimeter, with oil products analyzed using gas chromatography-flame ionization (GC/FID) and gas chromatography-mass spectrometry(GC/MS). Results show that the pyrolysis liquid up to 27.04 wt.% by using CaCO3 + 4A; the total bromine content(include organic and inorganic) of pyrolysis liquid was reduced to 4.68 wt.% through Fe3O4 + 4A; Using Fe3O4 + Al2O3 can increase the water content(68.76 wt.%) of pyrolysis liquid; the application of Fe3O4 + 4A can cut down the organic bromine to 1.59 wt.%; Fe3O4 + 5A can increase the 150–200 °C fraction(gasoline) to 53.25%; the phenol fraction can be increased to 46.01% applied Fe3O4 + 5A; the bromophenol less than1.30% and bisbromophenol was not detected. Thererfore, using Fe3O4 + 5A to recycle the low brominated and lightweight pyrolysis oil have a huge significance,which can use as potential fuel.

Investigation on standard molar enthalpy of combustion, specific heat capacity and thermal behavior of methionine

The standard molar enthalpy of combustion of methionine was determined to be − 6661.03 kJ mol−1 by XRY-1C microcomputer oxygen bomb calorimeter. The standard molar enthalpy of formation was calculated to be 3121.35 kJ mol−1 based on the standard molar combustion enthalpy. The thermal stability behavior of methionine was studied by the thermal gravimetric analysis. The results show that melting process of methionine was accompanied by the decomposition reaction in the temperature range of 500.15–520.15 K, displayed one-stage decomposition process. The absorb heat of methionine was obtained to be 974.34 kJ mol−1 (6530.00 J g−1) at 550.51 K by DSC-60 differential scanning calorimetry. Moreover, the specific heat capacity of methionine from 373.15 to 453.15 K in the solid state was measured, and then the relationship between the constant pressure specific heat capacity Cp and the temperature has been established. These data provide a thermodynamic basis for process development, engineering design and industrial production of methionine.

Mesoporous silica nanoparticles-loaded methyl 3-(3,5-di- tert -butyl-4-hydroxyphenyl) propanoate as a smart antioxidant of synthetic ester oil

Methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoate (brand name T512) was loaded by mesoporous silica nanoparticles (MSNs) to afford the antioxidant for synthetic ester lubricant oil. Rotary oxygen bomb tests, pressure differential scanning calorimetry and oven oxidation tests were conducted to investigate the effect of the as-prepared antioxidant on the antioxidant stability of di-iso-octylsebacate (denoted as DIOS). When MSNs are combined with T512 at a properly selected mass ratio, the oxidation of the DIOS base oil is greatly slowed down while the oxidation induction time is significantly prolonged. This may be attributed to the gradual release of T512 from the MSNs and the adsorption of the oxidation products into the channels of MSNs.

Influence of Jatropha Fruit Maturity on Seed Oil Yield, Composition and Heat of Combustion of Derived Biodiesel

Maturity of Jatropha fruits has influence on oil yield, chemical composition and physicochemical properties of derived biodiesel. Oil yield was determined using soxhlet extraction while biodiesel was prepared through the process of transesterification. Fatty acid profile was determined according to test method EN 14103 using Agilent Technologies GC System 7890. The calorific value of biodiesel was determined using Oxygen Bomb Calorimeter, IKA C200 according to test method ASTM D5865. Results showed that Yellow Jatropha fruit seeds have the highest oil yield and energy content, coupled with the best mix of fatty acid methyl esters.

Core–shell type multi‐arm azide polymers based on hyperbranched copolyether as potential energetic materials in solid propellants

AbstractA series of novel multi‐arm azide copolymers (POGs) with the same hyperbranched poly[3‐ethyl‐3‐(hydroxymethyl)oxetane] core (PEHO‐c) and different content of linear glycidyl azide polymer shell (GAP‐s) have been synthesized by sequential cationic ring‐opening polymerization and azidation. Detailed structural information of these copolyethers was deduced from Fourier transform infrared, 1H NMR and inverse gated decoupled 13C NMR spectroscopies, matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry, gel permeation chromatography and elemental analysis. The molecular weight of POG having GAP‐s and PEHO‐c with a molar ratio 14.95:1 (Rs/c) was around 31 000 g mol−1, far above that of linear GAP (around 4000 g mol−1). The apparent viscosity and glass transition temperature (−51 to −23 °C) decreased first and then slightly increased with increasing molecular weight. Thermal analysis revealed that all the obtained POGs exhibited excellent resistance to thermal decomposition up to 220 °C. Moreover, the energetic properties, investigated using oxygen bomb calorimetric measurements, indicated that the enthalpy of formation of the POGs was higher than that of general linear GAP, but similar to that of branched GAP under reasonable Rs/c. The compatibilities of the POGs with common materials used in solid propellants were studied using differential scanning calorimetry and the results indicated that the POGs had good compatibility with these materials. © 2017 Society of Chemical Industry

Biomass Briquette Investigation from Pterocarpus Indicus Leaves Waste as an Alternative Renewable Energy

Indonesia is a tropical country located in Southeast Asia. Indonesia has a lot of variety of plant species which are very useful for life. Pterocarpus indicus are commonly used as greening and easily found everywhere in Surabaya city because of its characteristics that they have dense leaves and rapid growth. Pterocarpus indicus leaves waste would be a problem for residents of Surabaya and disturbing the cleanliness of the Surabaya city. Therefore, the Pterocarpus indicus leaves waste would be used as biomass briquettes. This research investigated the calorific value of biomass briquettes from the Pterocarpus indicus leaves waste, the effect of tapioca as an adhesive material to the calorific value of biomass briquettes from the Pterocarpus indicus leaves waste, the optimum composition for Pterocarpus indicus leaves waste biomass briquette as an alternative renewable fuel and the property of the optimum resulted biomass briquette using ultimate analysis and proximate analysis based on the ASTM standard. The calorific value biomass briquettes from the Pterocarpus indicus leaves waste were performed using an oxygen bomb calorimeter at various composition of Pterocarpus indicus from 50% to 90% rising by 10% for each experiment. The experimental results showed that the 90% raw materials (Pterocarpus indicus leaves waste)-10% adhesive materials (tapioca) mixtures is the optimum composition for biomass briquette Pterocarpus indicus leaves waste. The lower the percentage of the mass of tapioca in the biomass briquettes, the higher calorific value generated.