Transformation and commissioning of 200,000-ton coal-to-ethylene glycol gasification unit in Inner Mongolia

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Renovation and Commissioning of 200,000-ton Coal-to-Ethylene Glycol Gasification Unit in Inner Mongolia Author/Source: Date: 2016-04-27 Clicks: 18 At 2 p.m. on April 21, 2016, the Tongliao Jinmei Composite Powder Gasifier was successfully put into operation for the first time, producing qualified gas that was integrated into the system for normal production. To date, the gasifier has been operating stably and well. Tongliao Jinmei has adopted atmospheric pressure composite powder gasification technology to upgrade its existing gasification unit – the No. 3 Endler furnace. This approach takes full account of the use of the company’s existing equipment, aims to reduce investment costs, lower carbon dioxide emissions, increase the amount of usable gas, and address environmental issues related to ash and wastewater. Both the syngas purification unit and the ethylene glycol plant utilize the same technical solutions as the original plants. To improve the ethylene glycol production process, the ethylene glycol plant has been equipped with DMC and ethanol removal facilities; these additional facilities represent partial modifications to the existing plants and involve conventional distillation processes, so there are no technical risks associated with these modifications. The 200,000 tons per year coal-to-ethylene glycol plant of Tongliao Jinmei is the first production line in China to utilize coal-based oxalic acid technology, covering a total area of 3,000 square meters. The total planned investment is around 10 billion yuan, and the project is located in the million-ton ethylene glycol production base within the Tongliao Economic and Technological Development Zone. The first phase of the 200,000 t/a coal-based ethylene glycol project commenced construction in August 2007, was completed and put into operation by the end of 2009, and the production process was optimized in December 2009 to yield qualified products. Following the joint commissioning trial, qualified oxalic acid product was produced on May 3, 2010. Full production capacity was achieved on November 18, 2011. The composite powder gasification technology is characterized by its strong adaptability to coal types, being suitable for almost all types of coal. This process utilizes both fluidized-bed gasification and slag fluidized-bed gasification technologies in the same coal gasification unit. Since its primary furnace is a fluidized-bed gasification furnace, coal is fed in using a screw feeder, and there are very low requirements regarding the particle size of the raw coal (0–10 mm) and its moisture content (0–12%), so no special coal nozzles are needed. The two-stage furnace is a slag fluidized bed; it can use either hot-wall or water-cooled walls. It features a high gasification temperature, and the requirements regarding the activity of coal are relatively low. It is highly adaptable to various types of coal (with a calorific value of over 3,000 kcal), allowing almost any type of coal to be gasified. Since the secondary gasification furnace operates with high-temperature slag, all the organic matter in the feedstock is decomposed, and most of the carbon dioxide in the feed gas is converted into carbon monoxide, thereby becoming useful gas and reducing carbon dioxide emissions. This technology addresses the issues associated with existing coal gasification systems, such as complexity, high investment costs, difficulty in maintenance, and high operating expenses. The treatment of raw coal is simple, no special coal gasification nozzles are required, and the separation of gas from slag is easy, thereby reducing the energy consumption and operating costs of coal gasification systems.