On September 4, the “Atmospheric Pressure Oxygen-Enriched Circulating Fluidized Bed High-Alkaline Coal Gasification for Syngas Production” technology, developed jointly by the Institute of Engineering Thermophysics of the Chinese Academy of Sciences, Xinjiang Yihua Chemical Co., Ltd., and CAS Hefei Coal Gasification Technology Co., Ltd., was evaluated in Beijing. The evaluation was organized by the China Petroleum and Chemical Industry Federation.
The expert panel, consisting of renowned professionals such as Jin Yong, academician of the Chinese Academy of Engineering, and Gu Zongqin, president of the China Nitrogen Fertilizer Industry Association, unanimously agreed that the technology is internationally advanced, particularly in the field of high-alkaline coal gasification, and holds great significance for the development of Xinjiang's high-alkaline coal resources and the local economy.
Experts noted that the Zhundong coal field in Xinjiang is the largest consolidated coal field in China, with an estimated reserve of 390 billion tons. This technology expands the applicability of circulating fluidized bed coal gasification to high-alkaline coals, providing a complete set of technologies and equipment for the efficient and clean utilization of Xinjiang's vast high-alkaline coal reserves.
According to Zhu Zhiping, Director of the Circulating Fluidized Bed Laboratory at the Institute of Engineering Thermophysics, the high-alkaline coal from Zhundong has characteristics such as poor fusibility, poor slurry formation, and high alkali metal content, making air-blown fluidized bed gasification unsuitable. Additionally, the coal's high volatile content would generate large amounts of tar if using fixed-bed technologies, leading to significant environmental challenges.
Zhu explained that their developed technology innovates in areas such as furnace temperature zoning, flow field and reaction control, waste heat recovery system temperature matching, and dry slag discharge through gas-seal pipes. These innovations have significantly improved the gasification efficiency, overall energy efficiency, and furnace reliability, while reducing wastewater discharge and eliminating tar and phenolic wastewater pollution.
Yang Xiaoqin, Chief Engineer of Xinjiang Yihua Chemical Co., Ltd., reported that the technology has been successfully applied to upgrade the syngas production section of Xinjiang Yihua's ammonia synthesis system. The project uses three sets of 720 tons/day units, replacing 20 existing atmospheric pressure fixed-bed oxygen-enriched continuous gasifiers. The system produces syngas from locally sourced high-alkaline coal to produce ammonia, methanol, melamine, and other chemicals. The project achieved successful ignition on September 6, 2020, and has since operated stably, with individual gasifiers running for 210 days continuously, and each of the three gasifiers exceeding 330 days of annual operation.
The installation passed a 72-hour continuous operation evaluation organized by the China Petroleum and Chemical Industry Federation from July 10-13. Liu Ying, Senior Engineer at YK Xinjiang Coal Chemical Co., Ltd., noted that the unit's technical indicators, including coal, oxygen, and water consumption per product, are all superior, particularly the water consumption, which is just 0.89 tons per kNm3 of (CO+H2) produced, including water for by-product steam.
