“Which field in “cold and heat in the chemical industry” is seeing growth?

Thread Content

This post was last edited by liaifeng on 2018-8-18 at 10:09. Currently, the coal chemical industry is experiencing both downturns and upsides. The previously highly popular coal-to-olefins, coal-to-oil, and coal-to-gas projects have quietly lost their momentum. According to data released by the China Petroleum and Chemical Federation in August 2011, the planned capacity under construction was as high as 28 million tons, 40 million tons, and 150 billion cubic meters respectively. However, according to reports by journalists, based on the current preliminary work and projects under construction, by the end of the 13th Five-Year Plan period, China’s actual production capacity for coal-based olefins, coal-based oil, and coal-based gas is unlikely to exceed 15 million tons, 20 million tons, and 68 billion cubic meters respectively, representing a halving of the projected capacities. In sharp contrast to this, the utilization of coal in a differentiated manner, led by coal pyrolysis and previously not given much attention, has seen a quiet rise. According to reports by journalists, the coal pyrolysis capacity that is already in operation, under construction, or planned for construction in China exceeds 180 million tons. Among them, the production capacity of the medium- and low-temperature coal tar hydrogenation project that came online this year alone is 2 million tons, with a corresponding pyrolysis capacity of over 20 million tons. In 2016, an additional 1.6 million tons of capacity for the hydrogenation of medium- and low-temperature coal tar, as well as over 16 million tons of capacity for coal pyrolysis, was brought online. People must ask why there has been a turnaround in the differentiated use of coal One by one, the constraints have been overcome. On July 12, the integrated gasification-lower rank coal pyrolysis technology (CGPS), jointly developed by Shaanxi Coal and Chemical Technology Research Institute Co., Ltd. and Beijing Collinsda Technology Development Co., Ltd., passed the evaluation of scientific and technological achievements organized by the China Petroleum and Chemical Industry Federation in Beijing. The appraisal panel, composed of 9 experts including Xie Kechang, Ni Weidou, and Jin Yong, who are members of the Chinese Academy of Engineering, concluded that this technology utilizes the coupling of pyrolysis and semi-coke gasification techniques; by using the high-temperature gas generated from the gasification of semi-coke powder as a heat carrier for reverse cascade direct-contact pyrolysis, it enables efficient and rational utilization of the sensible heat in that high-temperature gas, as well as staged pyrolysis of low-rank coal. The process flow of its 10,000-ton industrial test facility features an advanced and rational main unit as well as automated control systems, ensuring easy operation and stable performance. This entire set of technologies has advanced the research and development of techniques for producing high-quality tar and gas through the directed pyrolysis of low-grade coal; it represents an international first and is at the leading level. This is another advanced coal pyrolysis technology developed in our country in less than 20 days. On June 25, the process technology for producing anthracite through the rotary pyrolysis of low-rank coal powder, jointly developed by Shenmu Tianyuan Chemical Co., Ltd. of Shaanxi Coal and Chemical Industry Group and Hualu Engineering Technology Co., Ltd., successfully passed the evaluation of scientific and technological achievements organized by the Shaanxi Provincial Department of Science and Technology. The appraisal panel, headed by Academician Jin Yong, concluded that this technology has overcome the key technologies and equipment needed for the clean and selective utilization of pulverized coal in the field of low-temperature coal pyrolysis, with the overall technology reaching an internationally advanced level. The above two technological achievements are merely a microcosm of the rapid progress in coal fractionation technology in our country. In fact, in recent years, new technologies in China’s field of coal utilization based on coal pyrolysis have emerged one after another. In 2010, Shenmu Tianyuan Chemical Company integrated the lightening technology for medium- and low-temperature coal tar that it had developed independently with medium- and low-temperature pyrolysis technology for lump coal, as well as delayed coking technology for coal tar, to build an industrial demonstration plant with an annual production capacity of 1.35 million tons of lump coal pyrolysis products and 500,000 tons of naphtha and diesel fractions obtained through coal tar hydrogenation, successfully overcoming the challenges associated with the large-scale application of lump coal pyrolysis, hydrogen production from waste gas, and fixed-bed hydrogenation technology for medium- and low-temperature coal tar ； In 2011, Henan Longcheng Group successfully developed the rotary bed pyrolysis technology for low-grade coal and built an industrial plant with an annual capacity of 300,000 tons ； On April 27, 2013, the industrialized technology for the full-range hydrogenation of medium/low-temperature coal tar to produce large quantities of intermediate distillate oil (FTH), developed by Shenmu Fuyou Energy Technology Co., Ltd. under Shaanxi Coal and Chemical Industry Group, was recognized by an evaluation panel headed by Xie Kechang, an academician of the Chinese Academy of Engineering, as \"a world-first innovation at the leading level.\" The industrial plant with an annual capacity of 120,000 tons built using this technology has been operating stably for over two years now, and it constitutes the world’s first industrial demonstration plant for the full-range hydrogenation of coal tar using a fixed-bed process ； In July 2015, the 150,000-ton-per-year full-range hydroprocessing unit for medium- and low-temperature coal tar developed by Hebei Xinqiyuan Energy Technology Development Co., Ltd., using the low-quality oil full-mixing fluidized-bed hydrogenation technology jointly developed by Shanghai Xinyou Energy Technology Co., Ltd. and Hebei Xinqiyuan Energy Technology Development Co., Ltd., was successfully commissioned for operation with stable performance from the very beginning ； On August 20, 2015, the world’s first industrial facility for the hydrocracking of coal tar using the slurry bed hydrogenation catalytic cracking technology (VCC), developed through a collaboration between Yanchang Petroleum Group and the U.S.-based company KBR, was put into operation at Yanchang Anyuan Chemical Co., Ltd., with a capacity of 500,000 tons per year for the hydrocracking of medium- and low-temperature coal tar… To date, Shaanxi Coal and Chemical Industry Group alone has carried out research on coal pyrolysis technologies in six different areas. Three of these studies have completed pilot-scale testing, while the other three have achieved breakthroughs in key technologies. ”Hua Wei, a deputy to the National People’s Congress and Party secretary of Shaanxi Coal and Chemical Group, said to the reporters with pride. He told reporters that the concept of differentiated utilization of coal was first proposed by Shaanxi Coal and Chemical Group. The overall concept is as follows: Low-rank coal with a high oil content (over 5%) is subjected to pyrolysis at moderate to low temperatures (550–850°C), during which light components such as tar and gas are extracted, while yielding semi-coke, a clean material with a high calorific value. Gas is used to produce hydrogen or methane ； Coal tar, after treatments such as phenol extraction, undergoes catalytic cracking with hydrogen to produce naphtha and diesel fractions ； Semicoke from which the volatile components have been removed has a higher calorific value and is cleaner than raw coal. It can be used for gasification to produce syngas, which in turn can be used to manufacture chemical products. It also serves as a high-quality fuel for domestic use and in power plants, and can replace bituminous coal as a feedstock for blast furnaces in steelmaking processes, thereby enabling efficient and clean utilization of coal on a differentiated basis. The differentiated utilization of coal, with pyrolysis as the key technique, has attracted attention from various countries since the 1930s. To date, nearly 20 coal pyrolysis technologies have been developed worldwide. China successfully developed the vertical furnace lump coal pyrolysis technology in the late 1980s, which has been in use to this day. Currently, the national coal pyrolysis capacity exceeds 80 million tons per year. However, vertical furnaces have disadvantages such as the requirement to use lump coal as raw material, low effective content and calorific value of gas, and low production capacity per furnace, which limit their further adoption and make it difficult to truly achieve the efficiency and cleanliness associated with the differentiated use of coal. For this reason, in recent years, coal or bituminous coal pyrolysis technology has become a field that many enterprises and research institutions are competing to develop. Among these, the separation of oil dust from high-temperature gas, the treatment and resource utilization of high-concentration pyrolysis wastewater (containing tar, phenols, benzene, ammonia nitrogen, and COD), and the scaling up of the equipment represent the three major challenges in coal or pulverized coal pyrolysis; they are also the three hurdles that must be overcome for the differentiated use of coal. Now, thanks to the unremitting efforts of scientific and technical personnel, relatively reasonable solutions have been found for all three of the aforementioned major challenges. Among them, the process technology developed by Shenmu Tianyuan Company and Hualu Company for producing anthracite through the rotary pyrolysis of low-grade coal dust enables the use of hot flue gas to dry the coal dust, simultaneously expelling coal dust with a particle size of less than 0.2 millimeters. This significantly reduces the amount of coal dust in the coal tar produced during the subsequent pyrolysis process. By making use of high-speed centrifugal separation technology, the tar containing a small amount of coal dust can be effectively separated, thus solving the problem of difficulty in separating oil and dust during the coal dust pyrolysis process. CGPS technology feeds fines with a particle size of less than 25 millimeters into the belt furnace through graded distribution, thereby forming multi-layer moving particle beds. By utilizing a moving filter layer composed of different layers of particle coal, and based on filtration principles such as inertial collision, diffusion deposition, gravitational deposition, direct interception, and electrostatic attraction, it achieves efficient self-dust removal from the pyrolysis gas (with a dust removal efficiency of over 96%, and the dust content in the tar reduced to below 0.32 grams per cubic meter). In the field of treatment of pyrolysis wastewater, Shenmu Tianyuan Company has developed viable solutions by integrating and combining various advanced water treatment technologies. After demulsification, membrane treatment, and biochemical treatment, all the reclaimed water obtained from this process is returned to the system for reuse, thereby achieving zero discharge of coal pyrolysis wastewater; it has already been validated using a pilot-scale installation. The 120 tons per hour industrial plant under construction has completed its unit testing, and joint commissioning is set to begin in September. By then, the long-standing problem of treating pyrolysis wastewater, which has posed challenges to the differentiated use of coal, will also be resolved. As for the issue of scaling up pyrolysis facilities, the low-rank coal rotary bed pyrolysis technology developed by Henan Longcheng Group has seen two industrial plants with a capacity of 800,000 tons per year built and put into operation ； The belt-type furnace thermal pyrolysis technology for coal (or lignite) developed by Beijing Collinsda Company can handle a capacity of up to 1 million tons per year per furnace ； The modular process developed by Shaanxi Coal Chemical Technology Research Institute Co., Ltd. enables each module to process 3 million to 4 million tons of coal per year... Moreover, several processes including CGPS use oil washing in place of the traditional water washing method, which significantly reduces the generation of pyrolysis wastewater and makes the resulting semi-coke (or coke powder) cleaner. Furthermore, the pyrolysis gas produced by these processes contains over 80% of useful gas components such as carbon monoxide, hydrogen, methane, and olefins; it features high calorific value, high content of useful gases, and excellent quality. It can be used to produce hydrogen, liquefied natural gas, as well as high-value chemical products, thereby enabling the full utilization of all resources contained in the gas. The FTH technology developed by Shenmu Fuyou Company, the fluidized bed hydrogenation technology developed by Shanghai Xinyou Energy Technology Company, and the VCC technology developed by Yanchang Petroleum Group can all enable full-range hydrogenation treatment of low-quality coal tar, thereby significantly increasing the yield of liquid products in the coal tar hydrogenation process as well as the economic benefits for enterprises. “The previous concern regarding the disposal of semi-coke (or coke powder) obtained from coal pyrolysis now has an ideal solution. ”Hua Wei revealed to the reporters.