Cold Vent Dispersion Analysis for PSV Cold Stack of Assam Bio Refinery Private Limited

Assam Bio Refinery Private Limited is India’s first Bio-fuel refinery which uses Bamboo as a feed stock for Ethanol production, located near Numaligarh Refinery Ltd. The bio-fuel Refinery also produces chemicals such as Furfural alcohol, acetic acid and Bio coal, which enables the Refinery’s operations to be entirely powered by renewable energy. Exhaust and cold venting of gas poses a danger to both personnel and equipment if the gas spreads to unwanted places. Flow and dispersion modelling gives a clear picture of how the gas spreads under various wind conditions, and this helps in designing the facility and constructing rules for various activities. IFluids Engineering has been entrusted to carry out the Vent dispersion analysis study for PSV Cold Stack of the Assam Bio Refinery Private Limited.

Dispersion modeling is conducted to evaluate the effect distances of the released material from vent scenarios and their impact on dispersion. The Dispersion study is carried to estimate and identify the quantity of material release from the vents to atmosphere, potential hazards and its effects, occurrence of hazards during the process.

A vapour cloud may be formed when a liquid is having potential to liberate vapours at a specific condition for a particular duration. If the gas cloud does not immediately ignite, it disperses based on the prevalent wind direction, speed and stability category (i.e. degree of turbulence).

The cloud dispersion simulation is carried out to provide the distance (from the leak) at which the concentration of flammable material falls below the Lower Flammability Limit (LFL) and toxic material in the permissible toxic gas limits. Based on these estimations, a suitable height is recommended for open vents through dispersion modelling.