Yunnan Dada Ammonia Production Company achieved a successful one-time startup of its plant after maintenance

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Successful One-Time Startup of the Plant After Overhaul at Yunnan Dawa Ammonia Production Company / Author/Source: Yunnan Dawa Ammonia Production Co., Ltd. Date: 2020-09-28 Clicks: 46 Progress of the Overhaul and Startup (as of 8:00 on September 28, 2020) With the guidance and assistance of Yuntianhua Group, as well as the joint efforts of all employees of the company and external contractors, all tasks related to the overhaul were completed safely and successfully, and the plant was brought online in just one attempt. The progress of the driving work is as follows: On September 17 at 5:20, the supply of primary water throughout the plant was restored to normal. Among them, the water supply pipeline for Huashan Reservoir was put into normal operation at 12:50 on September 18 after its renovation was completed. At 7:45 on September 19, the circulating water in the ammonia synthesis system was started normally. At 13:06 on September 19, Boiler No. 4 was ignited. At 15:18 on September 20, Boiler No. 5 was started up to increase its temperature and pressure while leaks were being checked; the boiler had to be shut down at 23:00 due to a leak in the gasket on the right side of the steam drum access panel. At 23:53 on September 20, Boiler No. 3 was ignited, and at 06:00 on September 21, it was connected to the steam system. At 21:30 on September 20, the warm valve box of the MAN unit was activated; the MAN unit was started up at 3:34 on the 21st. At 9:08, it stopped operating due to a high-level interlock triggered by shaft vibration V*-1179, and the unit was cooled for inspection. The MAN unit was restarted at 20:34 on September 22, and air drying was carried out in the cold box at 1:00 on the 23rd; the expansion machine system was started up at 13:36 to drain accumulated coolant. At 18:20 on September 24, qualified nitrogen was supplied by the air separation unit; leaks were checked in unit U1200, and the conversion system was inspected for leaks and any issues that needed to be resolved; liquid nitrogen was used for washing, drying, and cooling ； 23:22 Flue gas desulfurization startup. At 3:10 on September 25, Boiler No. 2 was started up for heating, and steam connection was achieved at 10:30. At 9:06 on September 25, the nitrogen product compression unit was started up via air separation, and it operated normally ； 12:00-19:24 Coal gasification and grinding; 15:40 Temperature increase in the steam system, leak inspection in the gasification system ； 13:18 Raise temperature of conversion catalyst ； 16:45 – The synthesis gas compressor was started up; on September 26 at 3:20, its speed was increased to 5300 RPM and it operated normally. On September 26 at 21:43, ammonia was introduced into the synthetic refrigeration system; at 23:37, the ammonia compressor was started up. On September 27 at 1:15, the ammonia compressor was put under load and operated normally. At 6:30 on September 27, the methanol circulation was established in the methanol washing unit; at 7:00, the heating process for the shift catalyst was completed ； 9:58 – Gasification ignition; 10:20 – Coal feeding; 11:00 – Gas diversion for conversion; 11:25 – Gas diversion for methanol washing; 14:00 – Temperature increase for sulfur recovery; 16:11 – Gas diversion for liquid nitrogen washing; 17:17 – Acid gas introduced for sulfur recovery operation; 17:20 – Gas diversion from the synthesis tower; 19:20 – Ammonia production commenced successfully. At 20:41 on September 27, air was introduced into Carbonization Tower No. 6 of the caustic soda production plant; caustic soda was produced at 22:00. Air was introduced into Carbonization Tower No. 5 at 23:40, and caustic soda was produced at 0:50 on September 28. The unit has now moved from major maintenance to normal operation; all units are requested to strengthen inspections to ensure its safe and stable operation.