Shandong Weifang Fertilizer Plant Technical Transformation Office
Cao Fengwen
The urea production of our factory adopts CO2 stripping method. The original designed production capacity is 40,000 tons/year. After many technical transformations, it has reached an annual production capacity of nearly 80,000 tons. The consumption is obviously reduced, and the technical transformation has brought to the enterprise. Very good economic benefits. Compared with the aqueous solution full circulation method, the CO2 stripping process has outstanding advantages, short process flow, low energy consumption and simple operation, but it is difficult to expand and reform. There are four high-pressure equipments in the urea synthesis section of the CO2 stripping process. If you want to increase the output in the high-pressure circle, the investment is large and the equipment transformation is difficult. In order to achieve the purpose of increasing production, in 1998, we added a medium-pressure decomposition and recovery system in the urea decomposition and recovery section to strengthen the production of high-pressure system by enhancing decomposition and recovery and increasing the circulation of the circulation system. After the completion of the transformation, the effect is obvious. Urea increased from 155 tons to 215 tons. The ammonia consumption of urea per ton was reduced from 610KG to 605KG, but the steam consumption increased slightly. The pressure fluctuation of the medium and low pressure system was large. The liquid level of the absorption tower was difficult to control. The medium and low pressure decomposition towers were difficult to control. The outlet temperature is high, the concentration of methylammonium solution is increased, and the temperature is increased, and the load of the ammonium chloride pump is increased. Operators and technicians have spent a lot of effort and have not found the root cause of the problem. Later, from the relevant information, many manufacturers introduced new internal parts, high-efficiency fillers, and good results. Inspired by us, we first replaced the old-fashioned claw-type distributor in the decomposition tower and distillation tower, and installed a new disc-type distributor to ensure gas. The liquid distribution is uniform. After driving, the pressure fluctuations of the medium and low pressure systems are significantly reduced, the liquid level of the absorption tower is stable, and the gas phase temperature of the distillation column is reduced from 131 °C to 118 °C, and the operation condition is obviously improved. The reason for the analysis is that the load on the decomposition and recovery system is increased due to the increase in production. The original old-fashioned distributor and tower internals made the gas-liquid distribution uneven, resulting in gas phase entrainment, decomposition and absorption rate reduction, resulting in system fluctuations, unstable operation, and high steam consumption. In order to completely solve this problem, we used the 99-year overhaul to renovate the medium-pressure decomposition tower and the rectification column Packing, replacing the original Baole ring with a structured packing, and the tail gas absorption tower, the medium and low pressure absorption tower nozzles. The type distributor was changed to a disc type distributor, and the internals and packings of the tower were modified accordingly. After the completion of the transformation, the daily urea production reached 245 tons, the ammonia consumption per ton of urea reached 587 KG, the electricity consumption was 118 kwh, and the steam consumption (2.1 MPa) was 985 KG. The technical transformation has brought good economic benefits to our factory. Next, we are going to renovate the internal components of the urea synthesis tower. The effective volume of the urea synthesis tower of our plant is 16M3, and the current urea conversion rate is about 56%. According to the data, urea is introduced. The high-efficiency tray is selected for the synthesis tower, and its CO2 conversion rate can be increased by 2-3%. At present, there are many forms of high-efficiency trays. The new ball-capped high-efficiency trays designed and manufactured by Ningbo Far East Tower Engineering Co., Ltd. have been applied in urea plants in Sichuan Minfeng and Shandong Jinxiang, with good results and CO2 conversion rate. 65%. If our factory adopts new high-efficiency trays, the conversion rate of CO2 will reach 58%, then the steam consumption of tons of urea will be reduced by more than 20KG, the ammonia consumption and power consumption will be reduced accordingly, and the benefits will be objective. If this transformation can be achieved, then our plant's urea production will be on a new level.
Cao Fengwen
The urea production of our factory adopts CO2 stripping method. The original designed production capacity is 40,000 tons/year. After many technical transformations, it has reached an annual production capacity of nearly 80,000 tons. The consumption is obviously reduced, and the technical transformation has brought to the enterprise. Very good economic benefits. Compared with the aqueous solution full circulation method, the CO2 stripping process has outstanding advantages, short process flow, low energy consumption and simple operation, but it is difficult to expand and reform. There are four high-pressure equipments in the urea synthesis section of the CO2 stripping process. If you want to increase the output in the high-pressure circle, the investment is large and the equipment transformation is difficult. In order to achieve the purpose of increasing production, in 1998, we added a medium-pressure decomposition and recovery system in the urea decomposition and recovery section to strengthen the production of high-pressure system by enhancing decomposition and recovery and increasing the circulation of the circulation system. After the completion of the transformation, the effect is obvious. Urea increased from 155 tons to 215 tons. The ammonia consumption of urea per ton was reduced from 610KG to 605KG, but the steam consumption increased slightly. The pressure fluctuation of the medium and low pressure system was large. The liquid level of the absorption tower was difficult to control. The medium and low pressure decomposition towers were difficult to control. The outlet temperature is high, the concentration of methylammonium solution is increased, and the temperature is increased, and the load of the ammonium chloride pump is increased. Operators and technicians have spent a lot of effort and have not found the root cause of the problem. Later, from the relevant information, many manufacturers introduced new internal parts, high-efficiency fillers, and good results. Inspired by us, we first replaced the old-fashioned claw-type distributor in the decomposition tower and distillation tower, and installed a new disc-type distributor to ensure gas. The liquid distribution is uniform. After driving, the pressure fluctuations of the medium and low pressure systems are significantly reduced, the liquid level of the absorption tower is stable, and the gas phase temperature of the distillation column is reduced from 131 °C to 118 °C, and the operation condition is obviously improved. The reason for the analysis is that the load on the decomposition and recovery system is increased due to the increase in production. The original old-fashioned distributor and tower internals made the gas-liquid distribution uneven, resulting in gas phase entrainment, decomposition and absorption rate reduction, resulting in system fluctuations, unstable operation, and high steam consumption. In order to completely solve this problem, we used the 99-year overhaul to renovate the medium-pressure decomposition tower and the rectification column Packing, replacing the original Baole ring with a structured packing, and the tail gas absorption tower, the medium and low pressure absorption tower nozzles. The type distributor was changed to a disc type distributor, and the internals and packings of the tower were modified accordingly. After the completion of the transformation, the daily urea production reached 245 tons, the ammonia consumption per ton of urea reached 587 KG, the electricity consumption was 118 kwh, and the steam consumption (2.1 MPa) was 985 KG. The technical transformation has brought good economic benefits to our factory. Next, we are going to renovate the internal components of the urea synthesis tower. The effective volume of the urea synthesis tower of our plant is 16M3, and the current urea conversion rate is about 56%. According to the data, urea is introduced. The high-efficiency tray is selected for the synthesis tower, and its CO2 conversion rate can be increased by 2-3%. At present, there are many forms of high-efficiency trays. The new ball-capped high-efficiency trays designed and manufactured by Ningbo Far East Tower Engineering Co., Ltd. have been applied in urea plants in Sichuan Minfeng and Shandong Jinxiang, with good results and CO2 conversion rate. 65%. If our factory adopts new high-efficiency trays, the conversion rate of CO2 will reach 58%, then the steam consumption of tons of urea will be reduced by more than 20KG, the ammonia consumption and power consumption will be reduced accordingly, and the benefits will be objective. If this transformation can be achieved, then our plant's urea production will be on a new level.
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