Design Optimization And Experimental Research On A Sulfur Recovery Reactor For The Desulfurization System Of FLNG

The FLNG must be equipped sulfur recovery unit due to the environmental and safety requirements.The Land-based sulfur-recovery technology has become more mature.However,there are some higher demands have been put forward for the equipment and process development of FLNG sulfur-recovery due to the limitations of special maritime operating environment.?1?The equipment should be compact,light-weight;?2?The operating environments should be stable under shaking conditions;?3?The process flow should be concise and the sulfur-recovery efficiency should be high.Firstly,comparing the more mature sulfur-recovery technology,it is preferable to apply the complex iron liquid-phase oxidation-reduction method to the desulfurization method under floating condition.According to the regeneration mode of the desulfurization catalyst,we design two types of regeneration process of air oxidation and electrochemistry.Through the desulfurization experiment of a small desulfurization prototype,three kinds of complex iron catalysts were optimized.It was found that when using catalyst A as a desulfurizer during a long period of desulfurization,no hydrogen sulfide was detected in the exhaust gas,and the desulfurization effect was optimal.According to the designed requirements of FLNG sulfur-recovery device,we have designed the sulfur recovery reactor with three returns and optimized key structure of the core desulfurization reactor by applying Fluent simulation software.Through Fluent numerical simulation,the final determination of the inner casing diameter is 25 mm,the middle casing diameter is 100 mm.The size of the combination as a result of optimized device,which hold the best gas-liquid mass transfer effect.After designing and optimizing core desulfurization reactor,the further study should be explored through experiments.The desulfurization experiment under the static condition of middle-scale machine was used to determine the treatment capacity of the device.Under air regeneration conditions,when the flow rate of the catalyst in the completely rich liquid state is 2.0m³/h,the middle sampler can handle the mixed gas?25%H₂S+75%CO₂?with a flow rate is 18L/min,and the critical gas-liquid ratio is 1.85?0.3 for electrochemical regeneration conditions?.When the flow rate of the catalyst in the completely rich liquid state is2.0-2.5m³/h,the middle sampler can process pure hydrogen sulfide gas with the flow rate is8-9L/min,and the critical gas-liquid ratio is 4 at the same time?0.83 for electrochemical regeneration conditions?.In the sloshing mode of trim,roll,heading,traverse,lift,and forward 6 degrees of freedom and their free combination,the H₂S concentration in the tail gas can be stably maintained below 3ppm through desulfurization experiments,verifying its stability under shaking conditions and different techniques.