Latest GSP furnace operation status

It is said that they have all been in operation; the space furnaces have been working for over a year now with no problems at all. They are far superior to foreign knockoff products like GSP

This post was last edited by shanxg on 2011-2-1 10:45. Operation status of the aerospace furnace gasification technology – Production application of the HT-L gasification technology. The HT-L gasification process is a simple, efficient, and practical gasification method developed by the 11th Aerospace Research Institute, which draws on advanced technologies from Shell in the Netherlands, GSP in Germany, and TEXACO in the United States, and utilizes a coil-type water-cooled wall gasifier of its own design. The application of this process in coal chemical projects is described as follows: I. Process Introduction 1. Coal grinding and drying system The process flow, operating principle, and control parameters of the coal grinding and drying system are identical to those of the SHELL process. Two such systems are operated in parallel, one as the active unit and the other as a backup; each system has a capacity of 35 tons per hour. The goal is to produce coal powder with a particle size of less than 90 microns, where over 80% of the particles are of this size, and the water content is less than 2%. No separate limestone is added to the system; instead, granular limestone is fed onto the coal conveyor belt using a belt scale and via ratio adjustment, where it then enters the coal grinder for grinding. 2. Pressurized conveying system: The process flow, operating principle, and control parameters of the pressurized conveying system are identical to those of the SHELL process. Its purpose is to use pressure differences to transport the prepared coal powder to the gasifier for combustion and gasification. The difference is that V1205 has three legs; these three lines convey the fluid, which then converges at the burner and is injected into the furnace chamber in a spiral pattern through the gaps in the burner ring. 3. Vaporization and purification: The burner design is the same as that of GSP; vaporization is achieved using a single burner in a top-firing configuration. The vaporization furnace employs the TEXACO quenching process. When the pressure in the furnace reaches 1 MPa, coal powder mixed with oxygen and steam enters the furnace at a specific oxygen-coal ratio. After stabilizing the pressure for 1 hour, slag formation occurs. There are 8 temperature monitoring points in the furnace, which can be used as references for the vaporization temperature as well as to assess the status of slag formation. The designed gasification temperature is 1400–1600°C, with a gasification pressure of 4.0 MPa. The hot crude gas is quenched together with the slag at the lower part of the gasifier, where they are separated as well. During this quenching process, the quenching water evaporates, and the gas becomes saturated with water vapor; its temperature upon leaving the gasifier is 199°C. After being washed in a Venturi scrubber and a scrubbing tower, the syngas, with a temperature of 194°C and a solid content of less than 0.2 mg/m3, is sent on to the shift reaction unit. 4. Sludge and ash water treatment system: The process flow, operating principle, and control parameters of the sludge and ash water treatment system are identical to those of the TEXACO process. The slag passes through a slag breaker, then through a high-pressure to low-pressure lock hopper, and is sent to a slag skimmer for slag-water separation; the water is recovered and reused ； The gray water passes through high-pressure flash evaporation and vacuum flash evaporation before reaching the sedimentation tank; the clear water is recovered as cooling water. The slurry is subjected to vacuum filtration to produce a filter cake. II. Technical Features 1. Adaptability of raw materials: According to the designers, this process is adaptable to a wide range of coal types; bituminous coal, anthracite, and lignite can all be gasified, and it is also suitable for coals with high ash content, high moisture, and high sulfur levels. Longyu has used two types of coal for production: Shenmu Carbon Plant coal and Yongmei Xinqiao coal. The operating conditions are stable, and the effective gas content generally meets the design requirements. However, since the coal from the Shenmu Carbon Plant has a low ash content (<10%), slag deposition is not very good; slag deposition is acceptable in the upper part of the furnace, but hardly occurs in the lower part. The operation time of Yongmei Xinqiao coal is relatively short, so it cannot fully reflect its slagging tendency. Coal quality analysis from Shenmu Carbon Factory and Yongmei Xinqiao: Moisture, sulfur content, ash content, volatile matter, and fixed carbon. For Shenmu Carbon Factory: 5.72, 0.83, 8.73, 35.88, 50.37; for Xinqiao Mine: 1.47, 0.84, 22.56, 8.84, 67.13. 2. Production capacity per unit: The designed production capacity of each gasification furnace is 42,000 NM3/h of useful gases (CO+H2), which allows for the production of 150,000–200,000 tons of methanol per year. Research is currently underway on gasification technologies and equipment that would enable an annual methanol production capacity of 350,000 tons. 3. The design yields a high carbon conversion rate of 98%, with the residual carbon in the slag kept at 1-2%; the actual residual carbon levels were 2.74%, 3.98%, and 1.59% ； The designed effective gas content is 90%, of which CO accounts for 70% and H2 accounts for 20%; the actual values can be seen in the syngas analysis below: Syngas, Oxygen, Nitrogen, Carbon Monoxide, Hydrogen, Carbon Dioxide. Shenmu Coal Plant: 0.01, 6.12, 52.57, 27.0, 14.3; Xinqiao Mine: 0.02, 2.53, 54.92, 27.13, 15.4. Note: The medium used for transporting coal powder is carbon dioxide, with a load of 60%. 4. Thermal efficiency: The overall thermal efficiency is 95–96%, while the actual efficiency of cold syngas is 80–83%. The steam production is only 3 T/H; most of the heat is carried away by the raw syngas and slag into the quenching water, resulting in heat loss. 5. Oxygen consumption: The designed oxygen consumption for producing each thousand cubic meters of useful gas is 330–360 Nm3. In actual production, coal from Xinqiao Mine is used, and the data on the amount of useful gas produced and the oxygen consumed are calculated at 60% load; the oxygen consumption per thousand cubic meters of useful gas is then 382.45 Nm3. 6. Coal consumption: The original design used Hebi coal with a fixed carbon content of 74% as the raw material, resulting in a coal consumption of 600 Kg/KNm3 of useful gas. In actual production, Xinqiao mine coal is used; calculations are based on the useful gas produced at 60% load, as well as data regarding coal and oxygen usage, showing that 693 Kg of coal is required per thousand cubic meters of useful gas. 7. Wastewater discharge: The design calls for 9.76 tons of wastewater to be discharged to the treatment facility per hour; in actual operation, the maximum discharge volume reaches 20 tons per hour, but the average discharge is less than 10 tons per hour, thus meeting the design requirements. 8. Water wall of the gasification furnace: The water wall of the gasification furnace is of coiled-tube type, with an inner diameter of DN40 for the water pipes, ensuring uniform distribution of water flow and preventing blockages that could lead to low water flow and subsequent pipe rupture. However, the resistance is high and the heat exchange efficiency is poor. III. Key Equipment and Instruments 1. Coal Grinding Mill: The coal grinding mill uses the Shenzhong G168 model, which performs well. At loads below 70%, the pressure on the grinding rollers is set at 6.5 MPa; at loads above 70%, this pressure increases to 7.5 MPa ； Over 80% of the coal powder produced through grinding is less than 90 um, with 3–27% being ≤40 um, and generally around 10%. The after-sales service is poor. 2. Burners: The burners of the HT-L gasification furnace are manufactured by the 11th Aerospace Research Institute itself; they are similar to the German GSP gasification burners, with only a slight change in the direction in which the coal powder is injected. An integrated pilot burner, startup burner, and coal burner is used, with the pilot burner located in the center. Natural gas at 0.2 MPa is utilized for the pilot burner, while natural gas at 1.7 MPa from the outlet of the natural gas compressor is used for the startup burner. Once the furnace pressure is raised to 1.0 MPa, coal is fed into the furnace through all three coal powder pipelines simultaneously (since there is only one oxygen pipeline, the oxygen-to-coal ratio is controlled based on the total amount). After coal feeding begins, the pilot burner is turned off. The designer said that the part of the burner that usually gets damaged is the burner tip, and this tip needs to be replaced every six months to a year (the price wasn’t specified). During the three months of testing, three burners have been replaced; it is said that there is nothing wrong with the burners themselves, but this was done to reduce the resistance posed by them as part of the testing process. 3. HT-L gasification furnace: The gasification furnace uses a top-fired design; as long as the pressure difference at the burner is maintained, the burner generally will not get damaged. The water wall is of the coiled type; the circulating water distribution tubes lead out four DN40 water pipes in a relatively even manner. These four pipes surround each other in parallel to form the water wall, with studs and fins between the pipes, onto which refractory material is attached. There are eight temperature measurement points in total in the furnace, with the temperature sensors embedded in the surface of the refractory material. The temperature readings can reach 1200°C, but the designers require that this temperature not exceed 1000°C; if it does exceed 1000°C, it indicates poor slag attachment or overheating of the furnace. It is reported that the temperature reading at the heating element in the aerospace furnace in Linquan, Anhui, showed 1800°C, and the water wall was quickly damaged. The lower part of the furnace utilizes TEXACO’s quenching process, which serves to wash and cool it. 4. Slag skimmer: The slag skimmer is from Qingdao Sizhou. Due to the short operating time, low load, and low ash content in the raw coal, no problems have arisen with the device itself. However, the capacity of the slag water pump is insufficient, which leads to overflow of slag water; therefore, it is planned to replace it with a slag water pump from a factory in Shijiazhuang (originally from Shanghai Kaiquan Pumps). 5. Coal powder mass flow meter: The coal powder mass flow meter uses the German SWR type, which relies on microwave measurement. Instead of using a speed meter and a density meter to obtain data separately and then performing calculations in the PLC, this device integrates both functions together, delivering data directly. The data collection is stable, but the values obtained are slightly lower than the actual values. The originally planned U.S.-made thermoelectric products were not used. 6. Coal powder control valve: The coal powder control valve uses the German brand SUFU, just like in our factory, but there has been one instance where the valve stem was damaged due to blockages by debris. 7. Coal powder three-way valve: The coal powder three-way valve is a product of Beijing Aerospace 11th Research Institute; it operates slowly, with a response time of more than 15 seconds on average. Our factory uses valves from Denmark, whose response time is around 10 seconds. 8. The steam flow meter in the gasification furnace does not give accurate readings; the operators at Longyu lack experience in controlling the oxygen-coal ratio based on steam production, so they rely on changes in furnace temperature and the composition of the syngas. IV. Issues: 1. The screw conveyor does not operate stably, and problems such as blockages and broken screws occur frequently; it is planned to replace it with one from Nanjing. 2. If one out of the three coal powder circulation pipelines fails, the furnace must be shut down to prevent uneven burning that could damage the water wall and burners; this poses significant difficulties for long-term operation. It is therefore essential to ensure that the coal powder remains clean and does not cause blockages in the coal powder valves. There was a case where the capacitive level gauge of V1204 failed, causing the coal powder valve to get clogged and leading to a shutdown. 3. Due to the low steam output and inaccurate flow measurement, when using carbon dioxide to transport coal powder, there are no reference parameters available for adjusting the oxygen-to-coal ratio, resulting in arbitrary operation. 4. After two flashes, the temperature of the gray water drops to 70–80°C; after sedimentation, it is sent to a vacuum filter. The high water temperature can cause the filter cloth to deform, shift out of place, or get damaged as a result of folding. 5. Due to the low steam production and thus low pressure in the external steam pipeline network, no attempts have been made yet to increase the gasification load. 6. The mass flow rate meter for coal powder is in tons per hour, which causes excessive fluctuations in the oxygen-to-coal ratio during cascade control; therefore, the control of the oxygen-to-coal ratio is now done manually. V. Promotion and Application Analysis 1. The HT-L coal gasification process is a pulverized coal pressurized gasification technology independently developed by the 11th Academy of Aerospace, tailored to China’s national conditions. Although there is no pilot plant, the technology for each individual unit relies on a well-developed design foundation and extensive operational experience, enabling direct industrial production without any design flaws or operational bottlenecks. 2. Low investment required. The total investment for Henan Longyu’s 150,000-ton methanol project is 640 million yuan, of which 310 million yuan is allocated to the gasification unit; this amount is one-third less than the investment required for a SHELL-based plant of similar scale. Simple structure and easy to operate. 3. High degree of localization. Many of the equipment in the HT-L gasification unit, such as the pulverized coal lock-hopper valve, slag breaker, burner, gasification furnace, pulverized coal circulation three-way valve, slag-water circulation pump, quenching water pump, boiler water circulation pump, and hot air stove, were designed, manufactured, or commissioned for manufacture by the 11th Academy of Aerospace Science and Technology in Beijing. These devices operate smoothly and are easy to maintain, and they have also promoted the development of related industries; they hold great significance for advancing China’s economic and technological progress. 4. Although the HT-L gasification process has low thermal efficiency and high heat losses, technical improvements can be made during subsequent operation and design by adding waste heat utilization devices to reduce energy consumption. In summary, the HT-L gasification process is economical and reliable, making it worthy of promotion and application. 2. Issues encountered during the plant’s commissioning: From the second feeding attempt, it can be seen that the plant’s operational performance was generally stable, with all parameters meeting the design requirements. However, there were still some issues, mainly including: (1) too many system interlocks, which, combined with the operators’ lack of proficiency, led to multiple shutdowns of the plant. (2) Issues with the flow meter of the coal feeder caused the furnace temperature to reach 1800°C, resulting in the damage of the insulation pins at the upper part of the furnace. (3) Key equipment such as powder furnace nozzles and special valves has not yet undergone long-term operation, and further testing is required. (4) The operation is unstable, and the carbon content in the slag and furnace ash is relatively high. (5) Fine ash and slag have a high water content, making subsequent treatment more difficult. (6) Coal consumption: The designed coal consumption is 1.4 t/t (5000 Kcol/kg); due to unstable operation, the current coal consumption is 1.5–1.6 t/t. III. Insights and recommendations regarding the operation of the plant: 1. There are too many interlocks in the space furnace system, and especially during commissioning, changes in data can lead to shutdowns of the system. It will need to be figured out through future operations. 2. The trial operation time of the space furnace is very short; currently, the operating cycle is only 12 days, and the maximum load is only 75%. The operational data and consumption figures need to be further verified through subsequent operations to determine whether they meet the design requirements. 3. In accordance with the design requirements of the space furnace, the nozzles inside the furnace need to be inspected and maintained every 6 months. That is, the space furnace needs to be shut down every 6 months for maintenance of the nozzles. 4. The operating temperature of the space furnace is 1400–1900°C. To prevent the temperature sensing elements from being damaged, the sensing point is located 1 centimeter inside the insulation layer of the water-cooled wall within the furnace. The actual combustion temperature inside the space furnace is much higher than the operating temperature. The service life of the nozzles, the insulation materials used for the water-cooled walls, and other components in the furnace still needs to be tested. 5. The steam generated as a by-product in the space furnace is entirely saturated steam; if superheated steam is required, it can only be used after reducing the pressure. It causes certain difficulties for the steam balance of the entire plant. 6. The space furnace has not yet been tested under long-term continuous operation. 7. There are few domestic manufacturers that produce complementary products such as black water valves, self-regulating valves, oxygen valves, and other special types of valves. At present, although the domestic pressurized coal gasification technology using space furnace systems has many advantages when compared with advanced foreign coal gasification technologies such as TEXACO’s water-coal slurry pressurized gasification technology and SHELL’s pressurized coal gasification technology, there is still no record of long-term operation. It is recommended to conduct further and more thorough evaluations of various operational parameters of these space furnace systems, particularly by gathering actual operational data after a period of use. Additionally, it is necessary to observe more closely the stability of the gasification system and special valves over long periods of operation, in order to understand their actual performance in practice.

The Puyang HT-L furnace has been in operation for over 2 years. It is said that the burner can operate continuously for 146 days, while the overall operational cycle of the device is 100 days. Its performance was poor in 2008 and 2009, but it worked well in 2010.

Reply to 5# Under the Yimeng Mountains – learned something new! Why does the investment for a 750t/d space furnace amount to 310 million yuan? Is air separation included in this cost? I heard it’s around 250 million!

Reply to 5# Under the Yimeng Mountains: The report is written very professionally; I’ve learned a lot from it. This report was written a year ago; now, the space furnace has been in operation for almost two years. By 2010, the operational rate of the demonstration unit of this space furnace had reached 93%, and a large amount of data on long-term operation has been accumulated. This data will serve as a guide for the operation of other space furnace units in the future.

Reply to 5# Under the Yimeng Mountains: Reading this article from two years ago makes it seem more in line with the actual situation. It’s clear at a glance that the author is an insider and an expert in the field. But there is a small issue in the text: in reality, the space furnace does not have a backup furnace, and it has now achieved long-term stable operation. In 2010, it operated for nearly 340 days throughout the year; calculated on a 365-day basis, the operational rate was around 93%.

Reply to 10# Yipian Tian: If I’m not mistaken, the person above knows a lot about the operation of space furnaces! Share your thoughts; let’s learn* learn*!

　The Space Furnace (HT2L) pressurized coal gasification technology (hereinafter referred to as the Space Furnace technology) belongs to the pressurized fluidized bed process. It is a novel type of pressurized coal gasification technology that has been independently developed by Beijing Aerospace Wanyuan Coal Chemical Engineering Technology Co., Ltd., based on the design concepts of Shell, Texaco, and GSP pressurized gasification processes, and features unique innovation. Without undergoing pilot or pilot-scale tests, this technology was used to build industrial demonstration projects directly based on the process design; in 2008, two demonstration units with a daily coal input of 720 tons per furnace were constructed in Linquan, Anhui, and Longyu, Henan. Based on the current operation status, it basically meets the design requirements, with the longest continuous operating time reaching 128 days.

Reply to 12# mrwu20022002: The designed coal feeding amount should be around one thousand

The space furnace projects that have been completed or are under construction currently mainly feature two types of furnaces: the type with a diameter of 2800, which can process 750 tons of coal per day； It is a furnace with a diameter of 3200, consuming 1500 tons of coal per day.