Efficient utilization of lignite
Thread Content
Lignite is the type of coal with the lowest degree of coalification. Lignite has a high moisture content (30%–50%), a high volatile matter content (15%–30%), and low calorific value. It is prone to weathering and cracking, as well as oxidation and spontaneous combustion; therefore, it is not suitable for long-distance transportation or utilization. Additionally, its direct combustion generates large amounts of dust, causes severe environmental pollution, and results in low heat efficiency. To date, China has not carried out large-scale development or use of lignite. Some experts believe that the appropriate lignite processing technology should be selected based on the quality and properties of the lignite as well as the market positioning of the products. For high-quality lignite with low ash content, and given its scarcity, it is recommended to use medium- and low-temperature carbonization processes to produce high-quality reducing agents, which can replace metallurgical coke as raw materials for the production of ferroalloys and calcium carbide ； Carbonaceous adsorbents are produced from pyrolyzed semi-coke; these activated carbon products have predominantly large and medium pores, which not only gives them a high sulfur adsorption capacity but also makes them suitable for treating various industrial wastewater. Given the increasing scarcity of water resources in our country, it is of great significance to develop such coal-based activated carbon ； For lignites with high ash and sulfur content, experts recommend that low-temperature coal tar can be produced while improving the quality of these lignites using mild pyrolysis techniques. The composition and properties of low-temperature lignite tar are similar to those of heavy oil; it is a highly valuable resource, and through further processing it is possible to extract phenolic chemicals with high added value and strong market demand. By subjecting the distillate obtained after defooling to processes such as hydrocracking, reforming, and refining, a variety of liquid fuels with satisfactory properties can be produced. Therefore, it is feasible to develop an integrated processing technology for fuels, lubricants, and chemicals in order to make effective use of the various resources present in low-temperature lignite tar. At present, the processing and utilization of lignite have begun in China, but the industrial production technology for producing semi-coke through lignite pyrolysis is not yet mature and requires further development and improvement. In the field of coal gasification, China has successfully developed technologies such as the Ende powder coal gasification process that uses lignite as raw material, as well as the Dutch Shell pressurized coal gasification process; multiple coal gasification units have already been built and put into operation. Among the various lignite pyrolysis technologies under research and development in China at present, the ones that have been put into industrial pilot production include: the rapid pyrolysis technology using solid heat carriers for lignite developed by Dalian University of Technology, the low-temperature dry distillation modification technology for lignite developed by Anshan Thermal Energy Research Institute, and the low-temperature drying and modification technology to improve the quality of lignite developed by Beijing Collinsda Energy Technology Development Company. These three technologies employ different drying methods and processing temperatures, resulting in variations in product designs and performance; industrial pilot production facilities have been established in all domestic lignite-producing areas. Experts believe that developing technologies to upgrade lignite and produce semi-coke can not only address the issues of severe environmental pollution and low thermal efficiency associated with the direct combustion of lignite, but also yield various coal-based products such as coal tar and coke oven gas. It represents an important approach for the efficient and low-pollution utilization of lignite, and is fully in line with China’s strategy of developing clean coal technologies and diversifying energy sources. Coupled with high coal prices, this has created excellent opportunities for the development of this technology. Recently, Inner Mongolia Tiancheng Oil and Electricity Company has utilized its abundant lignite resources, employing solid heat carrier pyrolysis technology to fully transform low-quality and inexpensive lignite. The products obtained after this transformation are diverse in type, thereby increasing their added value. We hope netizens can share their views on the comprehensive utilization of lignite and the above viewpoints.
Regarding the information provided by the original poster, there are two points that interest me greatly, and I hope more detailed information can be provided: 1. The poster mentioned that \"in the field of coal gasification, China has successfully developed technologies such as the Ensdorf coal gasification process using lignite as raw material, as well as the Shell pressurized coal gasification process from the Netherlands; several coal gasification plants have already been built and put into operation.\" ”Where is Shell’s facility for brown coal gasification? What technology is used for lignite drying? 2. Could you provide some more detailed information on the projects of Inner Mongolia Tiancheng Oil and Electricity Company?
Inner Mongolia Tiancheng Oil and Electricity Company: A project invested by Huo Mei Yicheng Energy Co., Ltd., located in the Zahanaoer Industrial Park in Zhalut Banner, Tongliao City. Other more detailed items to be checked!
The lignite of the Tang Dynasty was processed using Shell’s gasification technology. The factory is located in Inner Mongolia; I’m not sure of the exact location. The lignite processing process is also under consideration
The lignite of the Tang Dynasty was processed using Shell’s gasification technology. The plant is located in Duolun County, Inner Mongolia – it’s the coal-to-olefins project, and it is now in the later stages of construction!
Our company has now set up operations in other regions as well; it’s not clear what the economic benefits will be from using their raw materials for production
Our company uses four-nozzle technology, employing a mixed use of high-quality coal and lignite in proportion
This is indeed a good solution. May I ask what the pulping concentration for your blended coal can reach? By the way, what’s the price of high-quality coal you mentioned? Is it more cost-effective to use mixed coal as raw material after mixing it with lignite, compared to using plain coal alone?
Hehe, let’s wait and see. This post was last edited by jacksonme on 2008-6-27 09:01]
Why extract these resources that are not yet mature or do not yet have favorable conditions for utilization? Why bother racking one’s brains over these issues? Is it possible to turn lime into flour? Just like humans, coal’s strengths are truly its strengths – it’s not up to anyone else or some authority to decide that! I believe that lignite can serve as a backup option for coal resources; it’s best not to exploit it in the short term. At present, we make use of both fossil resources of good and poor quality, which is highly detrimental to human beings as well as China’s future energy security. To achieve sustainable exploitation and utilization of coal resources, we must act this way – we cannot sacrifice long-term interests for short-term gains. Not exploiting lignite means keeping a backup option, and I think this approach should be adopted in this regard. What the Chinese lack is a sense of social responsibility; they will not hesitate to cause others financial losses for their own or immediate interests! As new coal chemical industry professionals, I believe we should cultivate and promote a sense of social responsibility in the new era. This is just my personal opinion; different views are welcome! Last edited by GSP on 2008-6-25 09:05 in this post.]
I’m a bit confused. Since Shell technology is being used, it means powder coal gasification; then what’s the purpose of drying it and shaping it afterward? Also, can a moisture level of 15% meet the requirements for transporting pulverized coal? Will it get clogged in the coal hopper? Also, I would like to ask what the temperature is for drum drying? Are there any issues with volatile matter release and tar during pilot testing?