Combustion calorimetry on samples of mass about 5 mg of substances containing chlorine with a CRMT rocking-bomb calorimeter. Application to the study ofp-chlorobenzoic acid

1995 ◽  
Vol 27 (6) ◽  
pp. 685-691 ◽  
Author(s):  
Raphaël Sabbah ◽  
Aaron Rojas Aguilar
Keyword(s):  
Combustion Calorimetry ◽  
Chlorobenzoic Acid ◽  
Bomb Calorimeter

Étude thermodynamique des trois isomères de l'acide chlorobenzoïque. Partie II

1995 ◽  
Vol 73 (9) ◽  
pp. 1538-1545 ◽  
Author(s):  
Raphaël Sabbah ◽  
Aaron Rojas Aguilar
Keyword(s):  
Nous Avons ◽  
Resonance Energy ◽  
Combustion Calorimetry ◽  
Enthalpies Of Formation ◽  
Condensed State ◽  
Thermodynamic Quantities ◽  
Chlorobenzoic Acid ◽  
Gaseous State ◽  
Calorimetric System ◽  
Experimental Values

Our isoperibol rocking-bomb calorimeter, previously described, has been modified to: (i) reduce and stabilize the heat exchange between the calorimetric system and its surroundings; (ii) change its thermometer; (iii) associate with it a computer program for the robotics of different steps of an experiment, data acquisition, and determination of the thermodynamic quantities. After testing these modifications and calibrating the calorimetric system, the enthalpies of formation in the condensed state and at 298.15 K of the three isomers of chlorobenzoic acid have been determined by combustion calorimetry. Associating these values with those of their enthalpies of sublimation previously measured, we determined their enthalpies of formation in the gaseous state. The experimental values of the thermodynamic functions [Formula: see text] [Formula: see text] are given for 2-chlorobenzoic acid, 3-chlorobenzoic acid, and 4-chlorobenzoic acid. From the experimental value of the enthalpy of atomization, it has been possible to determine an enthalpy value for the Cb—Cl bond. The experimental and theoretical values of the resonance energy of the three isomers are compatible. The relative stability of some monosubstituted derivatives of benzoic acid studied in our laboratory is also discussed. Keywords: thermodynamics, combustion calorimetry, differential thermal analysis; 2-chlorobenzoic acid, 3-chlorobenzoic acid, 4-chlorobenzoic acid, enthalpies of combustion, of formation, resonance energy, enthalpies of atomization, of intramolecular bonds, reference material.Notre calorimètre isopéribolique à bombe rotative, précédemment décrit, a été modifié: (i) en diminuant et en stabilisant les échanges thermiques entre le système calorimétrique et le milieu extérieur; (ii) en modifiant son thermomètre de mesure; (iii) en lui associant un système informatisé de robotique, d'acquisition et de traitement des signaux thermiques. Après avoir vérifié la bonne marche de l'appareil ainsi modifié et réalisé l'étalonnage du système calorimétrique, nous avons déterminé à 298,15 K et par calorimétrie de combustion les enthalpies de formation à l'état condensé des trois isomères de l'acide chlorobenzoïque. En associant ces valeurs à celles de leurs enthalpies de sublimation à 298,15 K, nous avons pu déterminer leurs enthalpies de formation à l'état gazeux. Les valeurs expérimentales des fonctions thermodynamiques [Formula: see text] [Formula: see text] sont données pour les acides 2-chloro-benzoïque, 3-chlorobenzoïque et 4-chlorobenzoïque. À partir de l'enthalpie d'atomisation expérimentale de ces trois acides, une valeur enthalpique a été proposée pour la liaison Cb—Cl dans ce type de composés. Les valeurs expérimentale et théorique de l'énergie de conjugaison sont compatibles. Une discussion sur la stabilité relative de quelques dérivés monosubstitués de l'acide benzoïque étudiés au laboratoire est aussi développée. Motsclés: thermodynamique, calorimétrie de combustion, analyse thermique différentielle; acide 2-chlorobenzoïque, acide 3-chlorobenzoïque, acide 4-chlorobenzoïque, enthalpies de combustion, de formation, énergie de conjugaison, enthalpies d'atomisation, de liaisons intramoléculaires, substance d'intercomparaison.

Test substances for bomb combustion calorimetry. p-Chlorobenzoic acid

1972 ◽  
Vol 4 (2) ◽  
pp. 283-299 ◽  
Author(s):  
Andrew T. Hu ◽  
Gerard C. Sinke ◽  
Margret Månsson ◽  
Birgitta Ringnér
Keyword(s):  
Combustion Calorimetry ◽  
Chlorobenzoic Acid

Evaluasi Prediksi Higher Heating Value (HHV) Biomassa Berdasarkan Analisis Proksimat

2020 ◽  
Vol 4 (1) ◽  
pp. 1-7
Author(s):  
Made Dirgantara ◽  
Karelius Karelius ◽  
Marselin Devi Ariyanti, Sry Ayu K. Tamba
Keyword(s):  
Renewable Energy ◽  
Natural Gas ◽  
Key Words ◽  
Critical Analysis ◽  
Fossil Fuels ◽  
Calorific Value ◽  
Proximate Analysis ◽  
Heating Value ◽  
Bomb Calorimeter ◽  
Hhv Prediction

Abstrak – Biomassa merupakan salah satu energi terbarukan yang sangat mudah ditemui, ramah lingkungan dan cukup ekonomis. Keberadaan biomassa dapat dimaanfaatkan sebagai pengganti bahan bakar fosil, baik itu minyak bumi, gas alam maupun batu bara. Analisi diperlukan sebagai dasar biomassa sebagai energi seperti proksimat dan kalor. Analisis terpenting untuk menilai biomassa sebagai bahan bakar adalah nilai kalori atau higher heating value (HHV). HHV secara eksperimen diukur menggunakan bomb calorimeter, namun pengukuran ini kurang efektif, karena memerlukan waktu serta biaya yang tinggi. Penelitian mengenai prediksi HHV berdasarkan analisis proksimat telah dilakukan sehingga dapat mempermudah dan menghemat biaya yang diperlukan peneliti. Dalam makalah ini dibahas evaluasi persamaan untuk memprediksi HHV berdasarkan analisis proksimat pada biomassa berdasarkan data dari penelitian sebelumnya. Prediksi nilai HHV menggunakan lima persamaan yang dievaluasi dengan 25 data proksimat biomassa dari penelitian sebelumnya, kemudian dibandingkan berdasarkan nilai error untuk mendapatkan prediksi terbaik. Hasil analisis menunjukan, persamaan A terbaik di 7 biomassa, B di 6 biomassa, C di 6 biomassa, D di 5 biomassa dan E di 1 biomassa.Kata kunci: bahan bakar, biomassa, higher heating value, nilai error, proksimat  Abstract – Biomass is a renewable energy that is very easy to find, environmentally friendly, and quite economical. The existence of biomass can be used as a substitute for fossil fuels, both oil, natural gas, and coal. Analyzes are needed as a basis for biomass as energy such as proximate and heat. The most critical analysis to assess biomass as fuel is the calorific value or higher heating value (HHV). HHV is experimentally measured using a bomb calorimeter, but this measurement is less effective because it requires time and high costs. Research on the prediction of HHV based on proximate analysis has been carried out so that it can simplify and save costs needed by researchers. In this paper, the evaluation of equations is discussed to predict HHV based on proximate analysis on biomass-based on data from previous studies. HHV prediction values using five equations were evaluated with 25 proximate biomass data from previous studies, then compared based on error value to get the best predictions. The analysis shows that Equation A predicts best in 7 biomass, B in 6 biomass, C in 6 biomass, D in 5 biomass, and E in 1 biomass. Key words: fuel, biomass, higher heating value, error value, proximate 

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