Kinetics and modelling of heptane steam-cracking

Abstract

The kinetics and product distribution during the cracking of heptane in the presence of steam were investigated. The experiments were performed in a flow reactor under atmospheric pressure in a temperature range of 680–760°C with a mass ratio of steam to heptane of 3: 1. The overall decomposition of heptane is represented by a first-order reaction with activation energy of 249.1 kJ mol−1 and a frequency factor of 3.13 × 1013 s−1. The reaction products were analysed using gas chromatography, the main product being ethylene. The molecular reaction scheme, which consists of a primary reaction and 24 secondary reactions between primary products, was used for modelling the experimental product yields. The yields of ethylene and hydrogen were in good agreement; however the experimental yields of propylene were higher than the predicted yields.

Microwave discharge in liquid n‐heptane with and without bubble flow of argon

“…In the present work, among the products, acetylene and its homologs, as well as allene, absent in low‐temperature experiments were determined. Same products were fixed at temperatures of more than 800 °C in flow reactors and in the shock tube .…”

“…The results of experimental study of pyrolysis of n ‐heptane are partly summarized in the reviews . Processes were studied in a flow reactor when the reagent was diluted with nitrogen, argon, water vapor, and without dilution with a carrier gas; as well as processes in the shock tube . It was found that decomposition of n ‐heptane under the action of temperature is a radical‐chain process and is described by the Kosyakov‐Rice mechanism with additions .…”

“…It was found that decomposition of n ‐heptane under the action of temperature is a radical‐chain process and is described by the Kosyakov‐Rice mechanism with additions . The main products of pyrolysis of n ‐heptane are hydrogen, methane, ethylene, ethane, propylene . α ‐olefins C4‐C6 (butene‐1, pentene‐1, hexene‐1) are also always present in the product mixture, the first of them at moderate temperatures and small degrees of conversion belongs to the main products.…”

“…[30][31][32]34] The main products of pyrolysis of n-heptane are hydrogen, methane, ethylene, ethane, propylene. [34][35][36][37][38][39][40] α -olefins C4-C6 (butene-1, pentene-1, hexene-1) are also always present in the product mixture, the first of them at moderate temperatures and small degrees of conversion belongs to the main products. Among the products are also identified: butenes-2, butadiene-1,3, pentenes.…”

Microwave Discharges in Liquid Hydrocarbons: Physical and Chemical Characterization

“…The results of experimental study of pyrolysis of n-heptane are partly summarized in the reviews [53][54][55]. Processes were studied in a flow reactor when the reagent was diluted with nitrogen [57,58], argon [59,60], water vapor [61,62] and without dilution with a carrier gas [63], as well as processes in the shock tube [64,65]. It was found that decomposition of n-heptane under the action of temperature is a radical-chain process and is described by the Kosyakov-Rice mechanism with additions [53][54][55]57].…”