Emission characteristics during heating, evaporation, ignition and extinguishing of bitumen as a representative...

Accidents in storage tanks in oil refineries and chemical enterprises usually occur due to substantial volumes of flammable liquids, petroleum products, and fuels stored primarily in external floating roof tanks. It is vital to develop technologies and methods for predicting the consequences of industrial accidents in the incipient stages of a fire, specifically during ignition. The paper reports experimental research findings on flue gas concentrations, when a fire involving a typical liquid hydrocarbon (bitumen) is suppressed using various types of gas-saturated compressed foam (air, nitrogen, carbon dioxide, and hydrate). An MRU MGA 5 + gas analyzer was used to record the composition of gases produced by bitumen heating, evaporation, thermal decomposition, combustion, and fire suppression. The experiments were carried out in 0.1-m³ and 0.4-m³ test tanks, with mineral wool used for thermal insulation of walls. Specific aspects of release of combustion product components were identified in relation to the control area location and temperatures. A multi-criteria analysis revealed that the efficiency factor of carbon dioxide and hydrate foams was comparable with a 10-12% difference depending on the priority given to foam application. Using firefighting foams containing an inert gas and CO₂ hydrate increased the efficiency factor of foam application 1.3-2-fold compared to conventional compressed air foam. Relative indicators reflecting the greenhouse effects were calculated. A method for predicting the burnout time and amount of extinguishing agent required for industrial tank fire suppression was developed.