At 6:06 PM on September 18, Xinjiang Yihua Chemical Co., Ltd. (hereinafter referred to as "Xinjiang Yihua") successfully produced its first batch of urea products for trial operation of its 4060 project. This marked the successful commissioning of the Xinjiang Yihua coal gasification unit project, undertaken by ZHGAS.
This project is an upgrade and renovation of the gasification section of Xinjiang Yihua's ammonia synthesis system. It utilizes three single 60,000 Nm3/h atmospheric pressure circulating fluidized bed oxygen-enriched gasifiers to replace the original 20 atmospheric pressure fixed-bed oxygen-enriched continuous gasifiers for syngas production. It is a circulating fluidized bed gasification unit that uses high-alkali coal as feedstock for syngas production.
Xinjiang Yihua Chemical Co., Ltd. is a wholly-owned subsidiary registered by Yihua Group in Jimusar County, Changji Hui Autonomous Prefecture, Xinjiang, to implement Xinjiang's advantageous resource transformation strategy and promote local economic development. It is also the first large-scale enterprise to enter the Zhundong area of Xinjiang, with a production capacity of 400,000 tons of ammonia and 600,000 tons of urea.
Previously, Xinjiang Yihua's gasification section used anthracite lump coal from other regions as feedstock, producing syngas through 20 atmospheric pressure fixed-bed oxygen-enriched continuous gasifiers. This process suffered from high raw coal costs, low single-furnace load, difficult tar treatment, and high emissions of "three wastes" (waste gas, waste water, and industrial residue), which did not meet national environmental protection requirements. The Zhundong area is rich in coal resources, but most of it is high-alkali coal, characterized by strong fouling, easy coking, large fluctuations in ash melting point, and poor slurry formation, making fixed-bed slagging, entrained flow gasification with coal-water slurry, or entrained flow gasification with pulverized coal unsuitable.
Adhering to the principle of fully utilizing local coal resources and considering the characteristics of Zhundong high-alkali coal, Zhonghe Gasification's R&D personnel conducted feasibility studies and designed the construction of three single pulverized coal gasifiers, each with a capacity of 60,000 Nm3/h, using circulating fluidized bed oxygen-enriched coal gasification technology. The gasification process does not produce hazardous wastes such as tar or phenol-cyanide wastewater. Additionally, customized designs, including optimizing the oxidant feeding method, establishing high-throughput material recirculation, and enhancing waste heat recovery, reduce material coking and lower heat loss. The successful commissioning of this project will significantly reduce Xinjiang Yihua's gasification costs, potentially lowering the cost per ton of ammonia by 200 to 400 yuan. The byproduct, high-temperature steam, can provide heat for the plant's production lines.
Since entering the site after the Chinese New Year, the project team has actively overcome various challenges such as the complex climate in Xinjiang, time zone constraints, and epidemic prevention and control. They successfully completed tasks including high and low-temperature furnace drying, "Three Checks and Four Determinations" (a standard industrial safety/quality review), PSSR (Pre-Startup Safety Review), single-unit commissioning, linked commissioning, and no-load commissioning. On September 6, the gasification unit was successfully ignited, officially signaling the start of feedstock trial operation. On September 8, the syngas met the specified quality standards (effective gas ≥ 64%), satisfying the requirements for subsequent ammonia synthesis production. On September 16, the ammonia synthesis system produced qualified liquid ammonia. On September 18, urea products came off the production line.
During the trial production period, the gasification unit operated stably overall, with uniform furnace temperature (axial temperature difference ≤ 0°C) and flexible load adjustment. The gasification unit, waste heat recovery unit, dust removal unit, cooling water unit, slag discharge unit, coal conveying unit, and ammonia stripping unit all met or even exceeded design specifications. During operation, the operating load was ≥95%, cold gas efficiency was ≥76%, oxidant preheating temperature was ≥700°C, and the byproduct of 3.8 MPa, 400°C medium-pressure steam was ≥60 tons/h.
"This set of equipment represents the most advanced new coal gasification technology in the national industry, specifically adapted to the coal quality of the Zhundong Development Zone. Furthermore, to produce ammonia and urea, coal gasification is the first process, serving as the 'dragon head' for the entire process," said Yang Xiaoqin, Party Committee Member and Chief Engineer of Xinjiang Yihua. He stated that through innovative treatment, this equipment has resolved specific challenges associated with Zhundong sub-bituminous coal, such as high sodium and potassium content, high moisture, low ash content, low ash melting point, oil content, unique viscosity-temperature characteristics, and poor slurry formation, making it the most suitable choice for large-scale new coal gasification using Zhundong sub-bituminous coal as feedstock.
The successful commissioning of the Yihua project fully demonstrates the strong adaptability of CGAS technology to different coal types, providing a feasible process pathway for small and medium-sized ammonia synthesis enterprises to reduce coal consumption costs. It also offers technical and equipment support for the efficient and clean utilization of Xinjiang's vast reserves of high-alkali coal.
This project is ZHGAS 's second successful commissioning in the ammonia synthesis field. The advantages of CGAS technology, such as low operating costs, low construction investment, good environmental benefits, and short renovation cycles in similar projects, are becoming increasingly apparent. In the future, ZHGAS will continue to expand the application of CGAS technology in this field, lead industry technological innovation, and provide efficient, environmentally friendly, and economical solutions for ammonia synthesis and coal chemical enterprises.
