An effective way to reduce the amount of fresh alkali used in the alkali washing tower

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The construction scale of the Shenhua Baotou coal-to-olefins project is as follows: 1.8 million tons per year of coal-to-methanol, 600,000 tons per year of methanol-to-olefins, 300,000 tons per year of polyethylene, and 300,000 tons per year of polypropylene. The core technology employed is the DMTO process, which possesses independent intellectual property rights in China; the pilot run of this process was successful in August 2010. The separation technology in its alkali washing system utilizes the Lummus process from the United States. From the time the plant began operating until 2014, the MTO unit was shut down for maintenance once a year. To maximize economic benefits, the planned maintenance period for the Shenhua Baotou MTO unit in 2015 was set at one and a half years; the scheduled maintenance date was April 1, 2016. However, by December 2015, the strong-alkali section of the alkali washing tower had become severely clogged, resulting in a sharp increase in the tower pressure difference to 21 KPa (the design value being 10 KPa), a significant reduction in the circulation rate of the alkali solution to 4.5 t/h (the design value being 60 t/h), and a severe decline in the liquid dropping capacity of the tower trays. The tower pressure differences in the other alkali sections also increased to varying degrees, and the circulation rate of the alkali solution could no longer be maintained within the design range. As a result, the alkali washing tower could not operate properly and stably. The plant tried various solutions such as increasing the amount of butter inhibitor added and reducing the alkali concentration in the tower, but these measures were not very effective, and the situation continued to deteriorate. Shutdown for maintenance was imminent, and the outlook was not favorable. Butter discharge in waste alkaline solutions: Faced with the urgent situation of an impending shutdown, and in order to ensure the long-term stable operation of the alkali scrubbing tower in the MTO unit and enable a shutdown for maintenance over a period of one and a half years, Shenhua Baotou Coal Chemical Co., Ltd. conducted technical discussions and a series of experiments on the problem of blockages in the alkali scrubbing tower together with Tianjin Ruide Sain New Material Development Co., Ltd. Ultimately, thanks to its strong research capabilities and years of experience in the successful application of alkali scrubbing tower-related products, Ruide Sain New Material Company was able to provide a solution to the Shenhua MTO unit, which was on the verge of shutdown – an alkali scrubbing tower cleaner. Tianjin Ruide Sain New Material Development Co., Ltd., based on the blockage issues in the caustic washing tower of Shenhua Baotou’s MTO plant and a professional analysis of the relevant process parameters, developed a targeted \"phased\" cleaning solution that enabled rapid removal of the grease causing blockages in the tower while ensuring the stable operation of the plant. After a month of trial use, the alkali circulation rate in the section with the most severe clogging was increased from 4.5 t/h to 22 t/h, while the average tower pressure difference was reduced to 0.8 KPa ； The filter screen of the circulation pump yielded a large amount of solid butter during cleaning, showing a significant effect in removing the butter ； In the spent alkali solution, butter is in a liquid state, resulting in a significant increase in its fluidity ； The circulation volume and liquid level in each alkali section remain within normal ranges, effectively reducing the blockage of the trays in the alkali scrubber tower. Comparison of butter discharge in waste lye before and after testing; blockage of the filter screens in the strong-alkali section. After the product was tested, according to feedback from the Shenhua MTO plant, the maximum circulation rate of the lye in the strong-alkali section continued to increase, while both the pressure difference and liquid level remained stable, with no occurrence of liquid carryover. This demonstrates that the \"Quick-Acting Heart Rescue Pill\" – an alkali cleaning agent developed by Tianjin Ruide Sain New Material Development Co., Ltd. – not only successfully resolved the emergency shutdown issues caused by blockages in the alkali cleaning towers at the Shenhua Baotou MTO plant, but its active ingredients also provided a sustained effect in removing the butter that caused these blockages. As a result, a planned shutdown for maintenance period of one and a half years was possible; it is truly an effective solution to the severe blockage problems in the alkali cleaning towers of the Shenhua MTO plant!