Numerical simulation study on the formation and control of HCl during the gasification of industrial organic hazardous waste

The utilization of industrial organic waste instead of coal by high temperature gasification to produce syngas is a promising way to reduce carbon emissions. The distinct property of industrial hazardous waste is characterized as high content of chlorine and volatile organics, which is significantly different from coal-water slurry. Herein, novel numerical models were established to simulate to the formation and control of HCl in the Texaco gasifier, where the chlorine-containing substances were simplified as dichloromethane to describe the mass transfer during the gasification. The models presented a good accuracy with the minimum error of 0.55% in syngas components prediction. The simulation demonstrated that HCl was generated near the nozzle, and the increasing of CaO amount and the decreasing of its particle size had positive effect on dechlorination. However, excessively reducing the size of CaO below 0.1 mm decreased its promoting effect, and high temperature in flame zone inhibited the dechlorination reaction. Therefore, the models developed in this work provided the feasibility of the general numerical simulation method to optimize the operating conditions in order to reduce the corrosion of chlorine to equipment and improve the stability of operation during the gasification process of organic hazardous waste.

Automated summary

Replacing coal with industrial organic waste in high temperature gasification to produce syngas is a viable method to reduce carbon emissions. This study developed novel numerical models to simulate the formation and control of HCl in Texaco gasifier, taking chlorine-containing substances as dichloromethane for mass transfer description during gasification. The models showed good accuracy with a minimum error of 0.55% in predicting syngas components. The simulation revealed that HCl was mainly generated near the nozzle, and increasing CaO amount and decreasing particle size had a positive effect on dechlorination. However, excessively reducing CaO size below 0.1 mm decreased its promoting effect, and high temperature in the flame zone inhibited the dechlorination reaction. Therefore, the developed models provided feasibility for optimizing operating conditions and reducing chlorine corrosion and improving stability during the gasification of organic hazardous waste.