Cnooc (Qingdao) Heavy Oil Processing Engineering Technology Research Center Co., LTD
Equipment Maintenance Technology, Issue 32, 2021
Abstract: The continuous development of Chinese science and technology has promoted the development of various sectors of the society. At the same time, it has also effectively enhanced our economic strength and overall national strength. As an important part of the circuit steelmaking process, the needle coke is mainly used in the production of graphite electrodes. It plays an important role in the production of lithium battery products, as well as in the nuclear power industry and aviation fields. With the promotion of the background of science and technology, the continuous optimization and improvement of electric furnace steelmaking technology has been promoted, and the corresponding standards and requirements of needle coke in the research and development and production process have been constantly updated, in order to comply with the requirements of social production development. Due to the different raw materials used in the production process, needle coke is divided into petroleum series and coal series. According to the specific application results, it can be seen that petroleum series needle coke has stronger chemical activity than coal series. In this paper, we study the current situation of the petroleum needle-focus market and the problems in the research and production process of relevant technology, and analyze the difficulties in the production development and related technical difficulties of the petroleum needle-focus.
I. Introduction
Needle coke plays an important role in the production of graphite electrode. From the current development situation, foreign developed countries such as the United States and Japan started earlier in the research and development and production of needle coke, and the application of relevant technologies has tended to be mature, and they have mastered the core manufacturing technology of petroleum needle coke. In comparison, the independent research and production of the needle in the oil focus start late. But with the continuous development of our market economy, promoting the comprehensive expansion of various fields of industry, the research and development of the needle in the oil focus has made breakthrough in recent years, realizing industrial production. However, there are still some gaps in quality and use effect compared with imported products.Therefore, it is necessary to make clear the current market development status and technical difficulties in the petroleum system.
Ii. Introduction and analysis of the application of petroleum needle coke technology
(1) Analysis of the current development status of petroleum needle coke at home and abroad
Petroleum needle coke technology originated in the United States in the 1950s. But our country is officially open
The research on the technology and manufacturing of petroleum needling coke began in the early 1980s. Under the support of national policy on technology research and development, Chinese research institutes began to conduct various tests on petroleum needling coke and constantly explore and research a variety of test methods. In addition, in the 1990s, our country has completed a lot of experimental research on the preparation of needle-focused petroleum system, and applied for the relevant patent technology. In recent years, with the support of relevant national policies, many domestic Academy of Sciences and related enterprises have invested in research and development and promoted the development of production and manufacturing within the industry. The research and development level of petroleum needle-coke technology is also continuously improving. The main reason for this phenomenon is that there is a large domestic demand for petroleum needle-coke. However, domestic research and development and manufacturing can not meet the demand of the market, a large part of the domestic market is occupied by imported products. In view of the current development situation, although the current focus and attention for the petroleum needle-focus technology research and development and manufacturing is increasing, in terms of the level of technology research and development, there are some difficulties that make the relevant technology research and development obstacles, which leads to a big gap between our country and the developed countries.
(2) Technical application analysis of domestic petroleum needle coke enterprises
Based on the analysis of domestic and foreign product quality and application effect, it can be seen that the difference between them in the quality of petroleum needle coke is mainly due to the difference in the two indexes of thermal expansion coefficient and particle size distribution, which reflects the difference in product quality [1]. This quality gap is mainly caused by the production difficulties in the manufacturing process. Combined with the specific production process and method content of petroleum needle coke, its core production technology is mainly for the pretreatment level of raw materials. At present, only Shanxi Hongte Chemical Co., LTD., Sinosteel (Anshan) and Jinzhou Petrochemical have realized mass production. In contrast, Jinzhou Petrochemical Company’s production and manufacturing system of petroleum needle coke is relatively mature, the processing capacity of the device is continuously improved, and the related products produced can reach the middle and high level in the market, which can be used for high-power or ultra-high-power steel making electrodes.
Iii. Analysis of the domestic petroleum needle coke market
(1) With the acceleration of industrialization, the demand for needle coke is increasing daily
Our country is the big industrial production country in the world, which is mainly decided by the mode of our industrial structure.
Iron and steel production is also one of the important industries to promote the development of our economy. Under this background, the demand for needling is increasing every day. But at present, our technical research and development level and production capacity do not match market demand. The main reason is that there are few petroleum needle-focused enterprises that can actually produce quality standards, and the production capacity is unstable. Although the relevant technology research and development work is advancing at present, but want to meet the high power or ultra high power graphite electrode and there is a large gap, which leads to the obstacles in the quality control of petroleum needle-focused products. At present, the needle-measure coke market is divided into petroleum needle-measure coke and coal needle-measure coke. By contrast, petroleum needle-measure coke is slightly lower than coal needle-measure coke either in project development quantity or development level, which is also one of the main reasons to hinder the effective expansion of Chinese petroleum needle-measure coke. But along with the continuous improvement of the steel industry production technology level, the steel production and manufacturing demand for ultra-high power graphite electrode is increasing. This also highlights that with the continuous improvement of our industrial development level and the acceleration of the industrialization process, the demand for needle coke will be more and more large.
(2) Analysis of the floating price of needle coke market
According to the current level of industrial development and the adjustment of industrial structure and industrial content of our country, it is found that the petroleum series of needle-measure coking is more suitable for our country than coal series of needle-measure coking, which will further aggravate the domestic situation of imbalance between supply and demand of the needle-measure coking, in order to solve the situation of imbalance between supply and demand of the petroleum system, we can only rely on imports. From the analysis of the price fluctuation characteristics of imported products in recent years, it can be seen that the price of imported petroleum needle coke products has been on the rise since 2014. Therefore, for the domestic industry, with increasing supply gap and rising import price, petroleum needle coke will become a new investment hotspot in China’s needle coke industry [2].
Four, our oil needle focus research and development and production technology difficulties analysis
(1) Analysis of raw material pretreatment difficulties
Through the analysis of the whole process of production and manufacturing of petroleum needle-coke, it can be seen that, for the pretreatment of raw materials, petroleum is the main raw material, because of the particularity of petroleum resources, crude oil needs to be mined underground, and the petroleum crude oil in our country will use various catalysts in the process of mining and processing, so that there will be a certain amount of impurities in petroleum products. This pretreatment method will bring adverse effects on the production of petroleum needle coke. In addition, the composition of the petroleum itself is mostly aliphatic hydrocarbon, the content of aromatic hydrocarbon is low, which is caused by the characteristics of the existing petroleum resources. It should be noted that the production of high-quality petroleum needle coke has strict requirements for raw materials, with a high proportion of aromatic hydrocarbon content, and chooses low sulfur, oxygen, asphaltene and other petroleum as raw materials, requiring that the mass fraction of sulfur is less than 0.3%, and the mass fraction of asphaltene is less than 1.0%. However, based on the detection and analysis of the original composition, it is found that most of the crude oil processed in our country belongs to the high sulfur crude oil, and the lack of oil suitable for the production of needle coke with high aromatic hydrocarbon content. It is a great technical difficulty to remove impurities in the oil. Meanwhile, Jinzhou Petrochemical, which is more mature in R&D and manufacturing at present, requires the raw materials suitable for the production of needle-oriented coke in the process of production and processing of petroleum needle-oriented coke. The shortage of raw materials and instability of quality are one of the main factors restricting the stability of quality of needle-oriented coke [3]. Shandong Yida New Material Co., Ltd. designed and adopted the pretreatment of raw materials for the production unit of petroleum needle coke
At the same time, a variety of methods were adopted to remove solid particulate matter. In addition to selecting heavy oil suitable for the production of needle coke, harmful substances in raw materials were removed before coking.
(2) Analysis of technical difficulties in the delayed coking process of petroleum needle coke
The production operation of needle coke is relatively complicated, and there are high requirements on the control of environmental temperature changes and operating pressure in the specific processing process. It is one of the difficulties in the coking process of needle coke production whether the pressure, time and temperature of coke can be truly controlled scientifically and reasonably, so that the reaction time can meet the standard requirements. At the same time, the better optimization and adjustment of coking process parameters and specific operating standards can also play an important role in the optimization and quality improvement of the entire needle coke production.
The main purpose of using heating furnace for temperature change operation is to carry out standard operation in accordance with the standard in the production process of needle coke so that the ambient temperature can reach the required parameters. In fact, the process of temperature change is to promote the coking reaction can be carried out in a slow and low temperature environment while delaying the coking reaction, so as to achieve aromatic condensation, ensure the ordered arrangement of molecules, to ensure that they can be oriented and solidified under the action of pressure, and promote the stability of the state. The heating furnace is an essential operation in the whole production process of petroleum needle coke, and there are certain requirements and standards for the specific temperature range parameters, which cannot be lower than the lower limit of 476℃ and cannot exceed the upper limit of 500℃. At the same time, it should also be noted that the variable temperature furnace is a large equipment and facilities, we should pay attention to the uniformity of the quality of each tower of needle coke: each tower in the feeding process, due to the temperature, pressure, air speed and other factors are changed, so the coke tower after coke is uneven, middle and lower quality. How to effectively solve the problem of quality uniformity of needle coke is also one of the problems that should be considered in the production of needle coke.
5. Analysis of the future development direction of petroleum needle coke
(a) Promote the continuous improvement of the quality of domestic petroleum system needle coke
The technology and market of needle focus has been dominated by the United States and Japan. At present, in the actual production of needle coke in China, there are still some problems, such as unstable quality, low coke strength and much powder coke. Although the produced needle coke has been used in the production of high-power and ultra-high-power graphite electrodes in large quantities, it cannot be used in the production of large-diameter ultra-high-power graphite electrodes in large quantities. In recent years, our research and development of needle focus has not stopped, and the product quality will continue to improve. Shanxi Hongte Coal Chemical Co., LTD., Sinosteel Coal measure needle coke, Jinzhou Petrochemical Co., LTD. Oil series needle coke units have reached 40,000-50,000 tons/year scale, and can run stably, constantly improve the quality.
(2) Domestic demand for petroleum needle coke continues to grow
The development of iron and steel industry requires a large number of ultra-high power electrodes and high power electrodes. In this context, the demand for needle coke for ultra high power electrode and high power electrode production is growing rapidly, estimated at around 250,000 tons per year. The output of electric furnace steel in China is less than 10%, and the world average output of electric furnace steel has reached 30%. Our steel scrap has reached 160 million tons. According to the current situation in the long run, the development of electric furnace steel is inevitable, the shortage of needle coke supply will be inevitable. Therefore, measures should be taken to increase the source of raw materials and improve the manufacturing method to meet the needs of production.
(3) The expansion of market demand promotes the improvement of domestic R&D technology level
The gap in quality and the increase in demand of the needle-scorch require an acceleration in the development of the needle-scorch. During the development and production of needle-scorch, researchers have become more and more aware of the difficulties in the production of needle-scorch, increasing research efforts, and building small and pilot test facilities to obtain experimental data to guide production. The processing technology of needle coke is constantly being improved to meet the growing demand. From the perspective of raw materials and manufacturing methods, the world oil shortage and the increasing sulfur content restrict the development of oil system needle coke. The new raw material pretreatment industrial production facility of oil series needle coke has been built and put into operation in Shandong Yida New Material Co., LTD., and the excellent raw material of oil series needle coke has been produced, which will effectively improve the quality and output of oil series needle coke.
Post time: Dec-07-2022