A thermochemical concept-based equation to estimate waste combustion enthalpy from elemental composition

Waste combustion is an interesting alternative for waste management and energy recovery. Knowledge of the waste higher heating value (HHV) is important for judging it’s worth as fuel. This work introduces a new equation, based on thermochemical concepts, to calculate HHV from elemental composition. This equation is expressed in terms of mass percentages on a dry basis of carbon (%C), hydrogen (%H), oxygen (%O), nitrogen (%N), and sulfur (%S); the HHV is computed in MJ/kg. The equation is as follows: HHV=(1−(%H₂O/100))(−0.3708(%C)−1.1124(%H)+0.1391(%O)−0.3178(%N)−0.1391(%S)). The thermochemical concept on which this expression is based involves a wide applicability. This equation neglects the inorganic carbon, hence it is not very adequate when there is a significant concentration of it. The predictions from this approach were contrasted against those proceeding from equations currently used in combustion technology, and also against bomb calorimeter data. The new equation is clearly competitive with respect to other formulations, and it can be very helpful for presenting a waste HHV value based on different derivation suppositions.     

PSI’s 1 kW imaging furnace—A tool for high-temperature chemical reactivity studies

A new experiment has been installed to conduct studies at temperatures as high as 2500 K on chemical reactions that involve solids or melts and the release of condensable gases. The sample is radiatively heated by a 1 kW xenon short arc lamp placed in the upper focus of a vertically oriented ellipsoid of revolution. The optimal optical configuration has been determined by a Monte-Carlo Ray tracing method. Several methods to machine the reflector have been evaluated by experimentally determining the optical quality of the surface of plane test pieces. In the imaging furnace the sample is placed on a water-cooled support and heated by the concentrated radiation. This arrangement allows for fast heating and impedes the reaction of the sample with crucible material. A remotely controlled hammer allows for freezing the high-temperature composition of the sample by a fast quench. Thus, the sample can be later analyzed by conventional methods such as XRD or TEM. To allow for measurements under defined atmospheres and to protect the ellipsoidal reflector from liberated condensable products, the entire sample stage is enclosed by a hemispherical glass dome. The dome itself is protected from condensable compounds by a laminar flow of inert gas. Experiments with an incense cone at the place of the sample to visualize the gas flow showed that a steady layer of inert gas protects the dome from smoke, if the inert gas flow is properly adjusted. Measured peak flux densities clearly exceed 500 W cm⁻² required to access temperatures of at least 2500 K. Decomposition experiments on copper sulfides confirmed the operation of the furnace. In the near future flash assisted multi-wavelength pyrometry (FAMP) will be implemented to measure sample temperatures online. Though the imaging furnace was developed to study the decomposition of metal sulfides it is obviously suited to conduct high-temperature studies on most materials relevant for high-temperature solar technology.     

Enthalpies of mixing of liquid Ag–Ga,Cu–Ga and Ag–Cu–Ga alloys

Using MHTC 96 Setaram high temperature drop calorimeter, partial and integral enthalpies of mixing of liquid alloys were determined in the Ag–Ga, Cu–Ga and in the ternary Ag–Cu–Ga system. The ternary alloys were investigated along two cross-sections at two different temperatures: 1128 K and 1273 K, respectively. Experimental data were used to find ternary interaction parameters by applying the Redlich–Kister–Muggianu model for substitutional solutions, and a full set of parameters describing the concentration dependence of the enthalpy of mixing was derived. The experimental data indicate that the heat of mixing in this system is slightly temperature dependent, at least in the measured temperature range.     

Two-Phase Calorimetry. II. Studies on the Thermodynamics of Cesium and Strontium Extraction by Mixtures of H+CCD− and PEG-400 in FS-13

Abstract

Thermochemical characterization of the partitioning of cesium and strontium from nitric acid solutions into mixtures of the acid form of chlorinated cobalt dicarbollide (H⁺CCD^?) and polyethylene glycol (PEG-400) in FS-13 diluent has been completed using isothermal titration microcalorimetry and radiotracer distribution methods. The phase transfer reaction for Cs⁺ is a straightforward (H⁺ for Cs⁺) cation exchange reaction. In contrast, the extraction of Sr²⁺ does not proceed in the absence of the co-solvent molecule PEG-400. This molecule is believed to facilitate the dehydration of the Sr²⁺ aquo cation to overcome its resistance to partitioning. The phase transfer reactions for both Cs⁺ and Sr²⁺ are enthalpy driven (exothermic), but partially compensated by an unfavorable entropy. The results of the calorimetry studies suggest that the PEG-400 functions as a stoichiometric phase transfer reagent rather than acting simply as a phase transfer catalyst or phase modifier. The calorimetry results also demonstrate that the extraction of Sr²⁺ is complex, including evidence for both the partitioning of Sr(NO₃)⁺ and endothermic ion pairing interactions in the organic phase that contribute to the net enthalpic effect. The thermodynamics of the liquid-liquid distribution equilibria are discussed mainly considering the basic features of the ion solvation thermochemistry.     

The standard enthalpies of formation of some intermetallic compounds of early 4d and 5d transition metals by high temperature direct synthesis calorimetry

The standard enthalpies of formation of some intermetallic compounds of early 4d and 5d transition metals have been measured by high temperature direct synthesis calorimetry at 1373±2 K. The following results (in kJ/mol of atoms) are reported: ZrMn₂(−24.7±2.7); ZrMo₂(−5.8±5.3); Zr₁₁Os₄(−8.9±2.1); HfCr₂(−4.8±4.3); HfMn₂(−20.3±2.0); HfMo₂(−6.4±4.3); NbRh₃(−21.6±1.8); TaRh₃(−14.0±4.0).     

海上稠油低温热化学机理研究与应用

稠油油田存在汽窜、含水率上升、低产低效井等问题。针对存在问题,提出了低温热化学技术,利用自主研发的适应于海上稠油油田高效开发化学体系-磺酸盐类化学体系L⁃B,协同低温蒸汽的热作用,达到降本增效并提高驱油效率的目的。该体系的静态洗油效率达28.7%。在56 ℃与原油的界面张力为0.086 mN/m,相比于原油与地层水的界面张力降低了99.3%。120 ℃驱油效率可达65.00%,相比于同等温度蒸汽驱提高了8.50%,达到了200 ℃的驱油效果。该技术在渤海某油田应用后,单井最高日产油达32 m3,提高了52.4%,对海上稠油油田提高原油采收率研究具有一定的指导和借鉴意义。     

A brief history of heat measurements by calorimetry with emphasis on the thermochemistry of metallic and metal-nonmetal compounds

A brief summary of the history of heat measurements is assessed from the Graeco-Roman time period to the first quantitative heat measurement in the 18th century. The concept of heat as energy is emphasized as a milestone in the development.The development of the modern calorimeters are summarized. Illustrations show the different types of equipment as designed for a variety of aims and purpose. In chronological order we illustrated the calorimeters by Lavoisier(1789), by Kawakami(1927), by Kubaschewski and Walter(1939), by Calvet(1950), by Kleppa(1955–2006), by Ticknor and Bever(1954), by Gachon(1979), by Cacciamani(1995), by Jung(2003) and by Navrotsky(2016).We discussed the theoretical and practical significance of calorimetry. The types of calorimetry measurements are briefly described. We also illustrated the international aspect of the use of this technique by showing some of the countries having actively participated in this effort.As a conclusion we compared to what extent the experimental measurements agree with theoretical predictions.     

某些著名营养药物促菌的热化学研究

使用微量量热计确定了灵芝、鹿茸对金黄色葡萄球菌的促茵作用的热功率-时间曲线,对不同浓度营养药液的发热量进行了计算,并由Q-C曲线得出了营养药液的最佳浓度,这项工作对营养药物的筛选有很大帮助.     

Thermochemistry of the combustion of gas phase and condensed phase detonation products in an explosive fireball

This paper uses the thermochemical behaviour of reacting species to differentiate between the combustion of gas phase and condensed phase detonation products in the fireball of an explosion. Experiments were carried out involving the detonation 15 g charges of C-4 and Detasheet-C explosives in a closed vessel. The initial partial pressure of oxygen in the vessel was varied in order to control the extent of the secondary afterburn reactions, and the total heat release was measured using the calorimeter that contained the closed vessel. A simple model that independently describes the evolution of heat from the gas phase and condensed phase detonation products as a function of oxygen consumption was developed, and was used to show that condensed phase products react much more effectively in the fireball than gas phase reactions, because the transport properties of particulates entrained in a turbulent flow gives them an advantage when it comes to the manner in which they mix with the surrounding air. An additional set of trials employing the entrainment of an external combustible material further confirms the importance of particle combustion in explosive fireballs.     

Thermochemistry and Thermodynamics of Trinitrophloroglucinol Dissolved in DMF and EtOH at 298.15 K

The enthalpies of solution of 2,4,6‐trinitro‐1,3,5‐trihydroxybenzene (trinitrophloroglucinol, TNPG) in N, N‐dimethylformamide (DMF) and EtOH are determined. The thermodynamics of these processes are also studied. The experiments are carried out by a SETARAM C80 calorimeter at 298.15 K. The empirical formulas for enthalpies of solution of TNPG in both DMF and EtOH are calculated by polynomial expressions. The resulting formulas are: (in DMF), and (in EtOH).