Pujan Biswas

All Publications

• Multiwavelength Speciation in Pyrolysis of n-Pentane and Experimental Determination of the Rate Coefficient of nC5H12 = nC3H7 + C2H5 in a Shock Tube. The journal of physical chemistry. A Biswas, P., Choudhary, R., Hanson, R. K. 2023

  Abstract

  We report the application of a multiwavelength speciation strategy to the study of n-pentane (nC5H12) pyrolysis behind reflected shock waves in a shock tube. Experiments were conducted with 2% nC5H12/0.8%CO2/Ar (by mole) between 1150 and 1520 K in the pressure range of 1-2 atm. Utilization of laser absorption spectroscopy at eight wavelengths allowed time-resolved measurements of n-pentane, ethylene, methane, heavy alkenes, and temperature. The measured time histories were compared against the predictions of four recently developed chemical kinetic models for heavy hydrocarbons. It was found that none of the models reconciled the measured species time histories simultaneously. Sensitivity analysis was conducted to identify key reactions influencing the evolution of ethylene and other major pyrolysis products. The analysis revealed that the unimolecular decomposition of n-pentane into n-propyl and ethyl radicals has a dominating influence over the evolution of ethylene in the temperature range of 1150-1450 K. The rate coefficient of this reaction was then adjusted to match the measured ethylene time histories for each experiment. The rate coefficients thus determined, were fit against temperature using an Arrhenius expression given by k1(T) = 3.5 × 1014 exp(-67.2 kcal/RT) s-1. The average overall 2σ uncertainty of the measured rate coefficient was found to be ±35%, resulting primarily from uncertainties in the rate coefficients of secondary reactions. The measured rate coefficient, when used with the models, leads to a significant improvement in the prediction of species time histories. Further improvements in the model are possible if the rate coefficients of relevant reactions pertaining to small hydrocarbon chemistry are determined with an improved accuracy, and less uncertainty. To the best knowledge of the authors, this is the first experimental determination of the rate coefficient of C5H12 → nC3H7 + C2H5.

  View details for DOI 10.1021/acs.jpca.2c07538

  View details for PubMedID 36852653

• A mid-IR laser absorption diagnostic for measuring formaldehyde at high pressures and its demonstration in shock tubes COMBUSTION AND FLAME Biswas, P., Choudhary, R., Panda, A., Davidson, D. F., Hanson, R. K. 2022; 245

  View details for DOI 10.1016/j.combustflame.2022.112366

  View details for Web of Science ID 000862966000011

• Thermometry and speciation for high-temperature and -pressure methane pyrolysis using shock tubes and dual-comb spectroscopy MEASUREMENT SCIENCE AND TECHNOLOGY Pinkowski, N. H., Biswas, P., Shao, J., Strand, C. L., Hanson, R. K. 2021; 32 (12)

  View details for DOI 10.1088/1361-6501/ac22ef

  View details for Web of Science ID 000702061800001