Maoming Petrochemical: New technology reduces alkali consumption for LPG desulfurization by 90%

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Date: 2016-11-24 Source: Sinopec News Network As of November 23, the 1.4 million tons per year catalytic liquid film desulfurization upgrade project at Maoming Petrochemical had been in operation for one month. Since its commissioning, this project has not only ensured that the total sulfur content in the refinery liquefied gas remains stable at below 100 milligrams per cubic meter, but it has also reduced the consumption of alkali solutions by 90%, thereby significantly cutting the costs associated with subsequent environmental treatment processes. It thus offers significant social and economic benefits. Before the operation of this system, due to the high total sulfur content in the liquefied gas feed used by the No. 3 catalytic liquefied gas desulfurization unit in the refinery – averaging 2000 milligrams per cubic meter – there was no alkali solution regeneration system available. As a result, fresh alkali solution had to be replaced three times a week in order to maintain product quality, which often led to unsatisfactory sulfur levels in the liquefied gas. Additionally, about 1000 tons of fresh alkali solution were consumed each year, placing significant strain on subsequent purification and environmental treatment processes, while also resulting in high energy consumption and costs. In particular, since the new 1.5 million tons per year light hydrocarbon recovery unit came online at the beginning of this year, liquefied gas production has increased by about 60%, making it even more difficult for the existing liquefied gas desulfurization unit to meet the production demands. To address this bottleneck, Maoming Petrochemical began upgrading the liquefied gas liquid film desulfurization unit in June this year. The renovation project utilizes an advanced new technology for efficient oxidation and regeneration of alkali solutions through full contact. This technology not only ensures high efficiency in alkali solution regeneration but also results in less waste alkali slag. By maintaining the required quality standards for total sulfur content in liquefied gas, it significantly reduces the amount of fresh alkali solution needed; approximately 900 tons of alkali slag can be avoided each year, representing a reduction of 90% in waste generation. This not only alleviates the burden on environmental treatment efforts but also saves over 2 million yuan in alkali solution costs per month. On October 23, the project achieved a successful safe test run after the renovation. Since its commissioning one month ago, the unit has been operating smoothly, with a 100% compliance rate for the total sulfur content in the liquefied gas product, which is nearly 10 percentage points higher than the previous average level.