This project was to study the relationship between the composition of waste streams in flare stacks and their heating values for EPA establishing the standard method. In this study, ethylene (with low carbon number), xylene (with high carbon number), dichloro ethane (with halogen atom), hydrogen sulfide, and ammonia were selected for a serious of experiments, including individual composition experiments, mixed composition experiments, and moisture interference experiments. Based on our results, the ratios of measured values to their theoretical values were within 0.8~1.2. In addition, the real-time monitor system of heating value was established. The optimal measurement conditions, such as analytical parameters, scopes, and interference, were studied. The data obtained were qualified with the quality specification, including multi-point calibration, accuracy and precision tests.The restriction and interference of this stoichiometric combustion method were also studied. To compare this stoichiometric combustion system with the GC system, 12 field experiments were carried out in petrochemical plants. The ratios of the data obtained from stoichiometric combustion system to GC system were within 0.9-1.1 in 11 field experiments, except to one due to the unusual emission. Furthermore, the auto-sampling system for high heating value emission gases was developed, and the technology diffusion was completed. In summary, this project has established analytical method for heating value in flare stacks using stoichiometric combustion system for EPA to establish the standard operation procedure, and to audit the flare stacks in petrochemical plants. For unusual emissions, the emission gases will be sampled by the auto-sampling system, and further be analyzed to identify species. For the plants using GC system, this stoichiometric combustion system can be used to check the accuracy.

Flare Stack, Heating Value, Petrochemical Plants