【Ten Years of Great Progress in Chemical Engineering Technology】010-2023 SinoTech Double-Bed 20,000 Nm3/h Circulating Fluidized Bed Gasification Unit

“The technological innovation of the “Zhongke Double-Bed” furnace: The “Zhongke Double-Bed” furnace represents a significant technical upgrade built on the industrial application experience of over 70 sets of “Zhongke Single-Bed” furnaces. Its main innovation lies in the addition of a pyrolysis furnace to the circuit of the “Zhongke Single-Bed” gasification furnace; the method of feeding coal is changed from using the gasification furnace to using the pyrolysis furnace, thereby enabling separate operation of the pyrolysis and gasification processes. As the name implies, this results in a “double-bed” operation mode. This technology enables free switching between the “double-bed” operation mode and the “single-bed” operation mode by changing the coal feeding position. When the coal feeding location is switched from the pyrolyzer to the gasifier, the pyrolyzer becomes the material passage, allowing the \"double-bed\" operation mode to be changed to the \"single-bed\" operation mode. According to the data collected at the project site, in the \"double-bed\" operation mode, the average calorific value of the gas reaches 1550 kcal/Nm3, which is more than 20% higher than that in the \"single-bed\" operation mode; as a result, coal consumption can be reduced by up to 4%. This technology can also increase the calorific value and the content of useful gases in coal gas through oxygen-enriched oxidation, and can be widely applied to meet the needs in areas such as coke oven gas replacement, natural gas substitution, chemical raw materials, and industrial hydrogen production.

【Ten Years of Great Progress in Chemical Technology】 series of summary posts – continuously being updated! https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=3594069 (Source: Haichuan Network – Huahai Chuanliu)

“Technical principle of the “Zhongke Double-Bed” furnace: The core design concept of the “Zhongke Double-Bed” furnace is to achieve staged conversion of coal through the decoupling of pyrolysis and gasification processes. The technical principle is shown in Figure 2, while the process flow is illustrated in Figure 3. By feeding coal in the pyrolysis section, the volatiles in the coal enter the gasification and reduction zone directly after pyrolysis, thereby preventing high-calorific-value volatiles from coming into contact with oxygen at the bottom of the gasifier and being wasted through unproductive combustion ； The recycled semi-coke after pyrolysis exhibits significantly increased reactivity; it undergoes combustion and gasification reactions with the gasifying agent at the bottom of the gasifier. The reaction gases mix with the pyrolysis gases in the reduction zone, where the small amount of large-molecule substances present in the pyrolysis gases are further cracked, increasing the content of H2, CH4, C2H4, and other hydrocarbons in the syngas. Therefore, the calorific value of gas can be increased by 10%-20%, with a coal savings of over 3%. “The technical performance indicators of the \"Zhongke Twin-Bed\" furnace are advanced, and it offers significant benefits in terms of energy conservation and emission reduction. It represents the future development direction of circulating fluidized bed gasification technology, opening up a new path for the clean and efficient use of coal as well as sustainable development in China.

“Technical features of the “Zhongke Twin-Bed” furnace: The six key features of the “Zhongke Twin-Bed” furnace are cleanliness, high efficiency, safety, reliability, scalability, and low cost. “\"Cleaning\" is mainly reflected in the fact that the gas contains no large-molecule organic substances such as tar and phenol ； Dry dust removal results in a low dust content in the gas, with the dust level being less than 10 mg/Nm3 ； It consumes little water and produces no organic wastewater. “\"High efficiency\" is primarily achieved through key technologies such as high-rate carbon circulation, decoupling of gasification and pyrolysis, preheating of hot air, efficient waste heat recovery, and re-ignition of residual carbon, thereby enabling a cold gas efficiency of 75% ； The calorific value of gas is increased by 10%-20% compared to the Zhongke single-bed technology, resulting in a coal savings of over 3% ； The air vaporization heat value exceeds 1500 Kcal/Nm3 ； The system-wide carbon conversion rate can exceed 98%. “\"Safety\" and \"reliability\" are primarily reflected in the fact that the device has few moving parts and vulnerable components, resulting in low maintenance needs; it operates stably, is easy to use, features a high degree of automation, has a high rate of safe interlock activation, is less susceptible to human interference, and can operate continuously for over 8,000 hours per year. “The low cost is mainly reflected in the fact that this technology has good adaptability to different types of coal; lignite, bituminous coal, and steam coal can all be used as feedstock for gasification. By utilizing inexpensive pulverized coal and undergoing efficient, clean conversion through this technology, the cost of produced gas is much lower than that of similar technologies. This cost advantage is even more significant for users who currently rely on natural gas. “\"Larger scale\" is mainly reflected in the variety of gasification furnace types available; customers can choose from furnaces with a gas production capacity ranging from 10,000 Nm3/h to 80,000 Nm3/h, which can meet the needs of various large-scale gas users.

The Department of Science and Technology of the Xinjiang Uygur Autonomous Region recently released the list of projects proposed for approval under the third batch of key research and development tasks for the autonomous region in 2022 – projects that involve collaboration between departments as well as between departments and local authorities. The project \"Research and Development of Key Technologies for CSIC Gasification\", submitted by Xinjiang Xinye State-owned Assets Operation (Group) Co., Ltd. (referred to as \"Xinye Group\"), is included among them. Once selected, this project will be given priority for implementation by the autonomous region and will receive 5 million yuan in financial support for research activities. The project \"Research and Development of Key Technologies for CSL Furnace Gasification\" submitted by Xinye Group represents an innovative approach to the conversion of low-grade coal into oil and gas, with the CSL furnace as its core component. This approach aims to overcome the current challenges in coal-to-gas production, such as high investment costs, low overall energy efficiency, and low resource conversion efficiency, thereby exploring new ways for the clean and efficient utilization of long-flame coal in Xinjiang. Innovations and features of Zhongke furnace gasification: 1. Achieves the coupling of intensified dry distillation and gasification in a fixed-bed gasifier. Integration of key technologies such as fixed-bed gas-solid phase distribution internals, slag discharge, and overall furnace automation programs. 2. The cold gas efficiency of Zhongke’s furnace gasification technology is greater than 83%, while the coal conversion rate is greater than 99.8%. Achieving a high methane content based on the regulation of the composition of raw gas is particularly suitable for coal-to-natural gas and oil and gas projects. 3. Compared with fixed-bed gasification, the Zhongke furnace exhibits a higher coal gasification efficiency and significant advantages in terms of scale-up. Low wastewater and carbon dioxide emissions throughout the entire process. Next step. The group company will, in accordance with the requirements for managing scientific research projects, increase investment and accelerate progress to facilitate the early implementation of pilot testing for this project.