Underground Pipeline Leakage Risk Assessment in an Urban City.

Underground pipeline safety is a concern among civilians in populated urban cities. Due to the potential for considerable damage from underground pipeline leakages, it is critical to identify potential risk areas. This study developed a simplified risk value using risk assessment software (ALOHA) and geography information systems (SuperGIS and Surfer) to produce potential risk maps for underground pipeline leakage in a major urban city. A risk assessment of areas affected by underground pipeline leakage was performed for vapor diffusion, thermal radiation from combustion, and overpressure from an explosion. The results are applicable to disaster management departments and agencies in highly populated cities.

Studies on the runaway reaction of ABS polymerization process.

Taiwan has the largest acrylonitrile-butadiene-styrene (ABS) copolymer production in the world. Preventing on unexpected exothermic reactions and related emergency relief hazard is essential in the safety control of ABS emulsion polymerization. A VSP2 (Vent Sizing Package 2) apparatus is capable of studying both normal and abnormal conditions (e.g., cooling failure, mischarge, etc.) of industrial process. In this study, the scenarios were verified from the following abnormal conditions: loss of cooling, double charge of initiator, overcharge of monomer, without charge of solvent, and external fire. An external fire with constant heating will promote higher self-heat rate and this is recommended as the worst case scenario of emulsion polymerization on butadiene. Cooling failure coupled with bulk system of reactant was determined to be the credible worst case in ABS emulsion polymerization. Finally, the emergency vent sizing based on thermokinetics from VSP associated with DIERS methodology were used for evaluating the vent sizing and compared to that of the industrial plants.