Fire and Explosion Characteristics of 3-Methyl Pyridine at 270°C with High Oxygen Concentrations

The mixture of 3-methyl pyridine (3-picoline) and steam is used in the production of vitamin B3 in the gas phase. The aim of this study was to investigate the influence of inert steam (H2O) on the flammability characteristics of 3-picoline in the manufacturing process. Four practical vapour mixing ratios of 3-picoline/steam mixtures, 5, 10, 30 and 100 vol% 3-picoline, were selected in this study. A series of flammability tests were employed for determining their fire and explosion characteristics. Fire tests H2O: 3-picoline 5,10, 30 and 100 vol% were carried out in a 20-L-Apparatus under simulated conditions of 760 mmHg, 270°C, together with high oxygen concentrations (42 and 21 vol%) used in the real process.The experimental results showed that the safety-related parameters and flammability hazard degrees were all able to be significantly reduced while substantial amount of steam was infused into the 3-picoline/steam system. While the steam proportion was up to 97 vol%, 3-picoline/steam would be non-flammable. As a result, dosing steam to the process is one of the effective methods to prevent the relevant processes from incurring fire and explosion hazards, not to mention its economical benefit.