An inventory of some of the key research topics of coal chemical industry during the 13th Five-Year Plan

1.
Reviewing the development history of modern coal chemical industry during the "Twelfth Five-Year Plan" period, everyone agrees that the rapid development of modern coal chemical industry is one of the biggest bright spots in the development of the petrochemical industry
.
With the completion and commissioning of a number of coal chemical industry demonstration projects, modern coal chemical production equipment with independent intellectual property rights has begun to enter the stage of commercial operation from the laboratory
.
This is a milestone development stage.
On the one hand, major breakthroughs have been made in the core engineering technology, and on the other hand, it has been greatly developed in terms of product scale.
No matter from which level, China's modern coal chemical industry has been in the world.
At the forefront
.
1.
1 Major breakthroughs in core technology.
Coal gasification technology is a key technology of coal chemical industry.
Generally, poor production of coal chemical projects is related to stable production of coal gasification
.
Coal gasification: multi-nozzle opposed gasifiers, 109 gasifiers have been built, of which 40 have been put into operation; 72 space furnaces have been built, of which 24 have been put into operation; water wall Tsinghua furnace, Xi’an Thermal Engineering Institute two Sectional furnaces, five-ring furnaces, and Dongfang furnaces have all made major breakthroughs in key advanced coal gasification technologies.
According to relevant information, the modern coal gasification process is used to gasify about 200 million tons of coal
.
Coal-to-liquid: Shenhua coal direct liquefaction technology was successfully used in the Baotou 1 million t/a coal-to-liquid demonstration project; the coal indirect liquefaction technology jointly developed by the Shanxi Institute of Coal Chemistry of the Chinese Academy of Sciences and China Synthetic Oil, high temperature slurry bed FT Synthetic has carried out 160,000 t/a coal indirect liquefaction demonstration projects in Yitai, Lu'an and Shenhua Baotou, and has been successfully put into operation
.
Coal-to-methanol olefin aromatics: The DMTO methanol-to-olefins of the Dalian Institute of Chemical Technology has built a 600,000 t/a MTO demonstration project in Shenhua Ordos, which has achieved good benefits; Shenhua Ning’s 600,000 t/a MTP methanol-to-propylene was completed and put into production.
Obvious economic benefits have been achieved; the fluidized bed methanol-to-aromatics FMTA, methanol-to-propylene FMTP and other pilot plants developed by Tsinghua and Huadian and China Chemical have been successful.
The kerosene co-refining and hydrogenation process developed by Yanchang Petroleum Group has also been completed.
450,000 t/a demonstration project, with energy efficiency reaching more than 70%
.
Coal-to-ethylene glycol: The coal-to-ethylene glycol developed by the Institute of Fugou of Chinese Academy of Sciences, Pujing, Donghua, Wuhuan, and Sinopec has built more than ten sets of ethylene glycol projects, with a total production capacity of 1.
65 million t/a.
Natural gas: The first phase of 1.
3 billion m3/a natural gas constructed by Datang Keqi and Xinjiang Qinghua has been put into production
.
In short, modern coal chemical industry has contributed to the diversification of China's petrochemical products
.
1.
2 The ultra-large scale of coal chemical industry and the industrial clustering of modern coal chemical products during the "Twelfth Five-Year Plan" period, regardless of the structure and scale, have achieved rapid development
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Coal-to-olefins: 10 sets of olefin plants have been built and put into production, each with a capacity of about 600,000 t/a, and the total olefin production capacity is close to 5 million t/a; Coal-to-oil: 5 sets of coal-to-oil plants have been built and put into operation, with a total oil production capacity It has reached 2.
4 million t/a, and the single-series unit has a capacity of 1 million t/a; coal-to-natural gas: 5 sets of coal-to-natural gas plants have been built, and the scale of single-series units is 1.
3 billion m3/a, 2 billion m3/a and 40 100 million m3/a, with a total production capacity of 17 billion m3/a; coal-to-methanol: The built-up methanol plant has a capacity of about 40 million t/a, and a single-series unit has a capacity of 600,000 t/a, 1 million t/a and 150 10,000 t/a; coal-to-ethylene glycol: nearly a dozen sets of ethylene glycol demonstration projects have been built, with a single-series device capacity of 200,000 t/a, and a total ethylene glycol production capacity of 1.
65 million t/a.
1.
3 Coal Chemical Industry Park Significant progress has been made in the construction of coal chemical industrial parks, mainly in coal-producing areas, such as Inner Mongolia, Shaanxi, Ningxia, Shanxi, and Xinjiang
.
In the coal chemical industry park, national policies, local government support, and the park’s flexible mechanism and development planning and other incentive measures have cultivated and formed a number of relatively dynamic large-scale coal chemical and energy construction bases
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For example, the Ordos coal chemical base in Inner Mongolia, the large-scale energy coal-electricity-olefin base in Ningdong, Ningxia, and the Xinjiang Zhundong Coal Chemical Industrial Park are very conducive to the integrated construction of the upstream and downstream industrial chains of modern coal chemical companies
.
2.
The key research topics of coal chemical industry during the 13th Five-Year Plan There are many topics to be studied in coal chemical industry, and only a part of the topics are listed here to meet the urgent needs
.
2.
1 Coal chemical industry planning and layout constraints The country has strict requirements on the layout of modern coal chemical projects.
Priority should be given to development zones and key development zones with coal resources; priority should be given to areas with relatively abundant water resources and good environmental capacity.
In line with the environmental protection plan; for the deployment of coal chemical projects in areas without environmental capacity, measures such as economic restructuring, coal consumption equivalent or reduction substitution and other measures should be carried out to free up environmental capacity, and advanced process technology and pollution control technology should be adopted.
Minimize the discharge of pollutants
.
2.
2 Water resources utilization bottleneck constraints China is a water-scarce country.
The distribution of coal resources and water resources do not match.
There is no water in areas with coal, and areas with water lack coal
.
The main coal production areas and the layout of coal chemical project bases are mostly distributed in areas where water resources are relatively scarce and the environment is relatively fragile
.
Coal chemical industry is an industry that consumes a large amount of water resources.
It mainly includes: process steam participates in chemical reactions, circulating cooling water evaporation or dripping loss requires system supplementary water, demineralized water supplementary water and fresh water for daily use.
At the same time, a large amount of fresh water will be produced.
Wastewater poses a huge threat to the environment
.
If no feasible water-saving measures are taken, such as open-loop cooling water system water-saving technology, air-cooling technology, closed-type condensate recovery technology, water cascade utilization and reuse technology, etc.
, the unit water consumption and waste water discharge will be reduced.
Can not be lowered, thus affecting the layout of coal chemical projects
.
2.
3 High-concentration organic wastewater discharge pollution issues High-concentration organic wastewater mainly comes from coal gasification process wastewater, etc.
It is characterized by COD as the main pollutant, generally above 2 000 mg/L
.
Typical high-concentration organic wastewater, petroleum/chemical wastewater, etc.
, for example, the COD mass concentration of the effluent from the main production sections is generally above 3 000~5 000 mg/L, and some sections even exceed 10 000 mg/L; The mixed water in the process section will generally be more than 2 000 mg/L, and some even as high as tens of thousands of mg/L.
The BOD of petroleum/chemical wastewater is also high
.
The ratio of BOD to COD is greater than 0.
3.
This type of wastewater is relatively easy to treat, but due to the large amount of water, incorrect selection of sewage treatment process, insufficient investment or high pollution concentration, the effluent is difficult to meet the standard, and most companies send it directly to evaporation Pond treatment will cause adverse effects on the surrounding environment
.
2.
4 The problem of high-concentration refractory organics wastewater treatment There are many types of refractory organics, and the main features are high concentration organics, high refractory organics, high toxic substances, high oil content, high ammonia nitrogen and other pollutants
.
The ratio of BOD to COD is far less than 0.
3.
For example, coking wastewater contains higher concentrations of ammonia nitrogen, as well as phenol and phenol homologs such as naphthalene, anthracene, benzopyrene and other polycyclic compounds, as well as cyanide.
, sulfide, cyanide and the like
.
The organics in this type of wastewater are mostly aromatic compounds and heterocyclic compounds, and also contain sulfides, nitrides, heavy metals and toxic organics, with high chroma, peculiar smell, pungent odor, strong acid and alkali; such as low-grade The composition of waste water produced by low-temperature coal gasification and pyrolysis processes is very complex, and it is difficult to treat with general biochemical processes.
Even if tar removal, ammonia and recovery facilities are set up for pretreatment, the COD of organic wastewater after pretreatment is still Higher, poorer biodegradability
.
The reason for the difficulty in biological treatment is essentially determined by the characteristics of its refractory species
.
In addition to the external environmental conditions (such as temperature, pH, etc.
) that did not reach the optimal conditions for biological treatment during the treatment, there is also an important reason that the chemical composition and structure of the compound itself are very complex, and there is no specific treatment in the microbial community.
The enzymes of the compound make it resistant to degradation; at the same time, the wastewater contains substances (organic or inorganic) that are toxic to microorganisms or can inhibit the growth of microorganisms, so that organic substances cannot be rapidly degraded
.
2.
5 High-strength brine treatment and recovery subject High-strength brine wastewater is characterized by high salt content
.
The salt in the saline wastewater mainly comes from the gas washing wastewater during the production process, the drainage of the circulating water system, the drainage of the desalinated water system, the reuse of the concentrated water of the system, and the supplementary fresh water, etc.

.
For example, a coal-to-natural gas project supplements the Yellow River water source, and the amount of salt brought in by fresh water exceeds about 60% of the salt amount of the entire system, followed by the production process and the amount of salt produced by adding chemicals to the water system, which are 29% and 13.
6%, respectively.
The total salt content (TDS) of salt-containing wastewater from coal chemical industry is usually 500~5 000 mg/L, or even higher
.
If the coal chemical industry achieves "zero emissions", the final result will be miscellaneous salts, which contain a variety of inorganic salts and a large amount of organic matter
.
This kind of coal chemical industry evaporates and crystallizes the miscellaneous salt to be included in the hazardous waste for strict control
.
This kind of miscellaneous salt is extremely soluble, and its stability and curing properties are poor.
It can seep out with rain and cause secondary pollution.
At present, there are few ready-made hazard treatment centers that can receive these miscellaneous salts.
The treatment cost is It is also very high
.
2.
6 The topic of homogenization of coal chemical products The coal chemical industry has a short start-up time and a short R&D time, coupled with limited investment resources, and the core technology and equipment cannot be fully mastered, resulting in serious similarities in the intermediate products of the coal chemical industry, and the industrial chain is not long.

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Some end products are low-end products, such as polyethylene, polypropylene and other intermediate raw materials, which are not very competitive.
If they do not take a differentiated development path, a new round of overcapacity will be formed
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2.
7 Low oil and gas prices impact technical and economic issues Under the premise of high oil and gas prices, there is no doubt about the competitiveness of coal chemical industry
.
However, in the era of low oil prices, such as when it is below 60 USD/bbl and 50 USD/bbl, the competitive cost advantage of coal chemical industry has encountered great challenges.
How to take countermeasures and the central government's supporting policies are very important
.
2.
8 The key technological innovation topics of coal chemical industry.
The first is modern coal chemical pollutant control technology (three waste treatment and disposal and waste recycling environmental protection technology, energy and water saving technology); the second is modern coal chemical upgrading core technology (modern coal gasification, synthesis Gas purification, synthesis, coal quality classification and comprehensive utilization technology); the third is modern coal chemical follow-up product chain technology (synthetic materials, synthetic resins, synthetic rubber and other high-end new material technologies, fine chemicals specialization, high value-added technologies) ; Fourth, the modern coal chemical industry coupling integration technology (product coupling technology, catalyst upgrading technology, information control technology and localized large-scale equipment technology) still has a lot of room for technological innovation to open up and develop in this industry
.
3.
Rules that must be followed in the "13th Five-Year" coal chemical industry 3.
1 Basic principles to be followed by modern coal chemical industry During the "13th Five-Year Plan" period, the tasks of the modern coal chemical industry are to focus on energy efficiency, environmental protection, water conservation, and the autonomy of technical equipment.
Content Carry out industrialization project demonstration, rely on demonstration projects to continuously improve the independent innovation technology of modern coal chemical industry, accelerate the transformation of clean coal utilization, and provide strong support for the green and comprehensive utilization of coal
.
Adhere to water measurement and strictly control project construction in water-deficient areas; adhere to clean and efficient transformation of energy efficiency, resource consumption and pollutant discharge in compliance with legal access requirements; adhere to demonstration first, focus on promoting the construction of demonstration projects, and grasp the pace of industrial development; adhere to science and rationality Layout, prohibit the construction of coal chemical projects in ecologically fragile and environmentally sensitive areas; adhere to the autonomy of technology and equipment, and promote the application of technologies and equipment with independent intellectual property rights
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3.
2 Modern coal chemical industry should follow strict industrial layout.
The red line coal chemical industry layout should be set up in the industrial park and meet the requirements of park planning and environmental impact assessment
.
Do not set up factories in the following areas, such as: areas that have reached or exceeded the total pollutant control indicators, total water resources control indicators, or energy consumption control indicators; the restrictions and prohibitions on the development of key ecological systems determined in the "National Plan for Major Function Zones" Functional areas, and other areas that need special protection; within 2 km outside the boundaries of the urban planning area, within 1 km on both sides of the main rivers, roads, and railways, and within the sanitary protection distance of residential areas
.
The wrong site selection will lead to serious consequences of a veto of the Hyundai Coal Chemical Environmental Impact Report
.
Coal chemical projects with serious environmental impacts cannot be approved
.
3.
3 Modern coal chemical industry should follow stricter water-saving standards.
Modern coal chemical industry should strengthen water-saving measures and reduce fresh water consumption
.
Where conditions permit, priority should be given to mine drainage and reclaimed water; coastal areas should use seawater as circulating cooling water; water-deficient areas should prioritize water-saving measures such as air cooling and closed circulation; surface water should not be used to squeeze ecological water and domestic water And agricultural water; it is forbidden to use groundwater as production water
.
Through the use of water-saving technologies and equipment such as air cooling, closed circulation, and wastewater pulping, the water efficiency can be improved as much as possible
.
The reuse rate of industrial water should not be less than 97%, and the recycling rate of cooling water should not be less than 98%.
For new projects, in addition to referring to the actual data of the demonstration projects that have been put into operation, water conservation optimization should be carried out in the design link, and follow the "high water and high The principle of “Utilization, Low Water and Low Utilization, Clean Pollutant Diversion, and Cascade Utilization”
.
3.
4 Modern coal chemical industry must comply with stricter exhaust gas emission standards.
Coal chemical industry exhaust gas emissions must take into account the local environmental capacity.
According to the Action Plan for Clean and Efficient Utilization of Coal (2015-2020), “air pollutants and sewage discharge must meet the strictest standards”.
Environmental protection requirements", implement the "Petrochemical Industry Pollutant Discharge Standard" (GB 31571-2015)
.
Strictly control the amount of new pollutant emissions, regard the total amount of pollutant emissions as a precondition for environmental review and approval, and determine the project based on the total amount
.
Newly built projects that emit sulfur dioxide, nitrogen oxides, industrial smoke and dust, and volatile organic compounds must be replaced by pollutant emission reductions to increase production and reduce emissions
.
For key control areas and cities where the atmospheric environmental quality exceeds the standard, new projects will be replaced by 2 times the reduction of active sources in the area, and 1.
5 times the reduction in general control areas.

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3.
5 Modern coal chemical industry should refer to the effective control standards for volatile organic compounds.
It should strictly refer to the “Comprehensive Remediation Plan for Volatile Organic Compounds in the Petrochemical Industry” issued by the Ministry of Environmental Protection in 2014.
Refining Industry Pollutant Emission Standard [3] or GB 31571 "Petrochemical Industry Pollutant Emission Standard" related requirements to control, attach great importance to coal chemical project volatile organic compound (VOCs) emission control
.
Based on this, comprehensively verify the volatile organic compound emission status
.
Measures should be taken for the equipment dynamic and static sealing points, organic liquid storage and loading and unloading, sewage collection and temporary storage and treatment systems, coal preparation, coal storage and other links to effectively control the escape of volatile organic compounds (VOCs), malodorous substances and toxic and harmful pollutants And emissions
.
Improve the control measures for unorganized emissions of volatile organic compounds from gas/water separation, phenol ammonia recovery, water storage tanks, gasification, purification, and sulfur recovery devices
.
In the process of sewage treatment equipment, specific measures should be taken according to the concentration of volatile organic compounds.
During the collection, storage and treatment of waste water, waste liquid, and waste residue, effective sealing and collection measures should be taken for the main links of volatile organic compounds emitted.
, To ensure that the exhaust gas meets the requirements of relevant standards after collection and treatment
.
The abnormally discharged waste gas should be sent to special equipment or torch and other facilities for treatment, and direct discharge is strictly prohibited
.
3.
6 Modern coal chemical industry should follow strict CO2 emission reduction standards.
Modern coal chemical projects should reduce CO2 emissions as much as possible through measures such as optimizing processes and improving energy efficiency, and should give full play to the advantages of high CO2 concentration and easy capture of modern coal chemical projects.
, Actively explore treatment methods such as gas flooding oil recovery, geological storage, microalgae oil production, such as urea, ammonium bicarbonate, dimethyl carbonate, methanol, PC, degradable plastics, CO2 oxygen-enriched CO conversion, natural gas methanol carbon supplement (flue gas recycling CO2) and consumption and so on
.
3.
7 Modern coal chemical industry should follow stricter wastewater discharge standards.
Modern coal chemical wastewater treatment and discharge should follow the principles of clean/sewage separation, sewage/sewage separation, advanced treatment, and quality reuse.
Design wastewater treatment plans and select industrialized applications Or pilot-scale mature, economically feasible technology
.
In the construction of modern coal chemical projects in areas with sewage bodies, the discharge of wastewater (including salt-containing wastewater) shall meet the requirements of relevant pollutant discharge standards, and ensure that surface water bodies meet the requirements of downstream water use functions
.
Construction of modern coal chemical project in the absence of receiving water body area, not to pollute groundwater, air and soil
.
The miscellaneous salt crystallized from the high-concentration wastewater of coal chemical industry is classified as hazardous solid waste because it contains organic matter and trace heavy metals
.
These miscellaneous salts should all be used or safely treated.
The current miscellaneous salt resource utilization technology is still in the research stage, and downstream product standards also have restrictions such as inapplicability.
Highly attention should be paid to the effective treatment of high-salt wastewater and the use of technologies
.
3.
8 Modern coal chemical industry shall increase the upgrading and innovation of core process technology.
Modern coal chemical industry shall further increase the innovation of core process technology, engineering technology and environmental protection control technology, and make breakthroughs in key and core technologies
.
The process technology, engineering technology and environmental protection, energy saving and emission reduction control technology of the project shall meet the requirements of the national industrial policy, and adopt an upgraded process with high energy conversion rate and low pollutant emission intensity
.
In the industry demonstration stage, environmental protection demonstration tasks should be undertaken in the aspects of coal quality and efficient utilization, resource and energy coupled utilization, pollution control technology development (such as wastewater treatment technology, wastewater treatment plan, crystalline salt utilization and disposal plan), etc.
, and demonstration technologies should be proposed Countermeasures that fail to achieve the expected results
.
At the same time, strictly restrict the use of coal with high content of aluminum, arsenic, fluorine, oil and other rare elements that are not yet mature in processing technology, pollution prevention technology or comprehensive utilization technology as raw coal and fuel coal
.
4.
"Thirteenth Five-Year" coal chemical industry demonstration technology upgrade breakthrough modern coal chemical pollutant control technology; modern coal chemical core process technology; modern coal chemical follow-up product chain technology; modern coal chemical industry coupling integration technology constitutes a modern "13th Five-Year Plan" The key to the development and survival of coal chemical industry
.
Focus on solving environmental issues, survival issues, technical and economic issues, and core competitiveness issues
.
During the "Thirteenth Five-Year Plan" period, it is necessary to advance the modern coal chemical industrialization and technological upgrading demonstration projects in an orderly manner, standardize the calibration and evaluation work, and achieve three good results.

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The first is to master the main indicators of material consumption, energy consumption, water consumption and three wastes emissions of the calibration demonstration project, such as the energy conversion efficiency of the demonstration project and the emission intensity of sulfur dioxide (SO2), nitrogen oxides (NOx) and carbon dioxide (CO2); the second is to master the demonstration The production load of the project and the operating conditions of each unit and rotating equipment, product varieties and quality indicators, safety and environmental protection measures, investment intensity and economic benefits, determine whether the above indicators have reached the design value; the third is to grasp the operation experience of the demonstration project and summarize, search and analyze Existing problems provide reliable data basis for further optimization of operation and technological upgrading and transformation
.
4.
1 EBA process technology to treat high-concentration refractory organic waste water.
The current coal gasification process adopts low-rank coal gasification at low temperature, such as Lurgi furnace, etc.
The light components in the coal are converted into tar, phenol, and ammonia during the gasification process.
, Alkanes, aromatic hydrocarbons, heterocyclics, ammonia nitrogen and cyanogens, arsenic, alkyl pyridines and other substances are produced at the same time as coal gas
.
In the subsequent gas washing, cooling, and purification process, most of the above-mentioned substances enter the gas water, which is a typical high-concentration refractory organic waste water, and the composition of the large quantity, toxic and harmful substances is complex and difficult to treat
.
The EBA process is used for exploratory treatment of high-concentration phenol-ammonia wastewater produced by Lucci furnace, BGL furnace and low-temperature cracking.
Although the high-concentration phenol-ammonia wastewater is treated by the phenol-ammonia recovery process, the composition of the wastewater entering the biochemical treatment system is still complex and toxic Harmful, in which the mass concentration of phenolic compounds can reach 200~1 000 mg/L, and the mass concentration of ammonia nitrogen can reach 100~300 mg/L.
This process is used to improve the biodegradability of wastewater, reduce wastewater toxicity, and improve sludge activity.
The high-concentration phenol-ammonia wastewater treatment effluent can meet the reuse water standard
.
As a processing path, this technology needs to be further verified and improved
.
4.
2 Closed air-cooled circulating cooling water water-saving technology Closed air-cooled circulating cooling water system uses soft water or demineralized water as cooling water, absorbs heat from process heat exchange equipment, increases the temperature, and enters energy-saving water film air cooler or combined air cooling The inside of the tube is pre-cooled, and then it enters the spray tube section to be absorbed by the air and spray water outside the tube.
After cooling, it is pressurized by the circulating water pump to the process heat exchange equipment
.
The soft water is circulated for use in a closed circulation system, and does not contact the outside air to complete the heat transfer process of heat absorption and heat release
.
This process replaces the traditional industrial circulating cooling water system, and replaces the cooling water tower with an energy-saving water film air cooler or a combined air cooler, which not only ensures the cooling water temperature to meet the requirements of various processes, but also saves water and reduces scaling of pipeline equipment , Improve the service life of equipment, and provide a treatment path for water saving, which needs to be further verified and improved
.
4.
3 Comprehensive utilization technology of high-concentration brine crystallization and salt separation treatment The technology of multi-stage evaporation and crystallization of high-concentration brine into miscellaneous salt has been verified to a certain extent in the fertilizer project of China Coal Tuke (BGL furnace), but the comprehensive utilization of this miscellaneous salt There are still problems
.
In view of the difficulty of comprehensive utilization of crystalline salt in coal chemical industry, the research on evaporative crystallization salt separation proposed to realize the harmlessness and resource utilization of crystalline salt produced by "zero discharge" is a direction, and pilot experiments are needed
.
After the technical and economic feasibility and operational reliability of various pollution prevention and control measures have been fully demonstrated, the admission can be determined
.
Crystallization and salt separation, comprehensive utilization technology, through the step-by-step crystallization method to separate sodium chloride, sodium sulfate, and how to dispose of the large amount of organic matter contained in the concentrated brine.
There are no experimental data on the effect of the step-by-step crystallization, and at present, China’s chlorine The product quality standards of sodium sulfide and sodium sulfate are not applicable to the production of salt from industrial wastewater
.
When this technology provides a path for the comprehensive utilization of high-concentration brine, it needs further verification
.
4.
4 Comprehensive utilization technology of low-rank coal (lignite) by quality classification and comprehensive utilization of low-rank coal (lignite) pretreatment, gasification, synthesis, power generation, heating and other technologies It is a modern coal chemical technology with development prospects.
It researches and develops low-rank (medium temperature, high temperature) fast (medium speed) heat carrier entrained bed (fixed bed, fluidized bed) pyrolysis process of low-rank coal to extract tar and dry distillation gas.
He semi-coke is a development trend in the classification and upgrading of the main products and the classification and transformation technology
.
This technology can derive a variety of technical combinations.
Through the coupling of pyrolysis and semi-coke gasification technology, the high-temperature coal gas generated by the gasification of semi-coke powder is used as the heat carrier, and the reverse cascade direct contact pyrolysis can be realized.
Efficient and reasonable utilization of heat and cascade pyrolysis of low-rank coal
.
Especially for low-rank coal with high oil content, it is pyrolyzed at medium and low temperature (550~850 ℃) to extract light components such as tar and coal gas, and at the same time obtain clean materials with higher calorific value; coal gas is used for hydrogen production Or methane; after phenol extraction, coal tar reacts with hydrogen catalytic cracking to produce naphtha and diesel fractions; the semi-coke from which volatiles is removed has a higher calorific value and cleaner than raw coal.
It can be gasified to produce syngas, and then The production of chemical products can also be used as high-quality civil fuels and power plant fuels, so as to realize the high-efficiency and clean utilization of coal according to quality and classification
.
4.
5 Coal tar refining and preparation technology.
Coal tar obtained through pyrolysis and coking of low-rank coal has three major problems in its refining: high-temperature gas dust removal, pyrolysis wastewater treatment and tar refining technology have a significant impact on comprehensive utilization
.
Due to the oil/dust separation in the high-temperature coal gas, the treatment and resource utilization of high-concentration (containing tar, phenol, benzene, ammonia nitrogen, COD) pyrolysis wastewater, and the large-scale equipment have become the three major constraints on the pyrolysis of pulverized coal or whole coal.
The problem is also the three barriers that must be crossed for the grading and utilization of low-rank coal
.
For example, the low-rank pulverized coal rotary pyrolysis technology to produce anthracite will blow out coal dust with a particle size of less than 0.
2 mm while drying the pulverized coal with hot flue gas, which greatly reduces the amount of coal dust in the coal tar during the subsequent pyrolysis process , The use of high-speed centrifugal separation technology to efficiently separate the tar containing a small amount of coal dust, which better solves the problem of difficult separation of oil dust in the pyrolysis process of pulverized coal
.
The medium and low temperature coal tar lightening technology integrates the coal tar delayed coking technology to integrate and couple the tar hydrogenation to produce naphtha and diesel fractions to break through the lump coal pyrolysis, raw gas hydrogen production, and medium and low temperature coal tar fixed bed hydrogenation devices Large-scale application problems; medium/low temperature coal tar full-distillate hydrogenation and more middle distillate technology (FTH) has become the world's first coal tar fixed-bed full-distillate hydrogenation industrialization demonstration device; CGPS ​​technology will reduce the particle size of coal tar with a particle size of less than 25 mm.
The coal enters the belt furnace through the graded cloth to form a multi-layer mobile particle bed.
The mobile filter layer composed of different particle coal layers is used to realize the pyrolysis through the filtering principles of inertial collision, diffusion deposition, gravity deposition, direct interception, and electrostatic attraction.
High-efficiency self-dust removal technology for coal gas (dust removal rate is over 96%, and the dust content in tar is reduced to less than 0.
32 g/m3)
.
4.
6 Large-scale clean coal coal gasification technology with low energy consumption.
Modern coal gasification is the core technology in coal chemical plants.
How to choose raw coal will directly affect the energy efficiency, environmental protection, safety, investment and benefits of modern coal chemical projects
.
The development trend and direction of modern coal gasification should conform to the characteristics of China's many types of coal and complex composition
.
We must always pursue a gasification upgrade process that has high coal conversion rate, high gasification efficiency, high effective yield, low energy consumption, low cost, and green environmental protection
.
Dry coal powder/coal water slurry/crushed gas fluidized bed/moving bed pressurized gasification technology should be further upgraded, integrated, coupled and equipment large-scale, such as the development of 3 000 t/d and above multi-nozzle opposed pulverized coal pressurization Entrained-flow technology, stable production, long-term operation, and reduced investment; development of 3 000 t/d and above dry pulverized coal pressurized chilled entrained-flow technology to improve coal conversion rate, gasification efficiency and high effective yield, stable production and lower investment Cost; development of 1 600 t/d and above crushed coal pressurized fixed bed technology, increase the carbon conversion rate, utilization rate and equipment large-scale of crushed coal pressurized gasification, reduce steam consumption, reduce waste water discharge and treatment volume; develop 3,000 The wet coal-water slurry gasification technology of t/d and above realizes low investment, stability, long cycle, large-scale, wide coal types, and lower consumption
.
Various modern coal gasification technologies should have new breakthroughs and developments in major technical fields such as wastewater treatment, waste residue recycling, and high-concentration brine reduction
.
The overall coal gasification should be coupled with coal chemical industry, combined cycle power generation, and large-scale ultra-supercritical power generation; major breakthroughs should be made in the integration of coking, low-temperature pyrolysis and different coal gasification technologies and the integration of pollutant control technologies.
Mainly include: high-efficiency dust removal, sulfur recovery, denitrification technology; phenol ammonia recovery, wastewater pulping, activated carbon adsorption and other sewage treatment technologies; combined cycle power generation and large-scale supercritical power generation and other coupling technologies; coking, low-temperature pyrolysis and different coal gasification technologies Major breakthroughs should be made in pollutant control technologies such as the combined application technology between the two
.
In terms of high-efficiency dust removal, desulfurization, denitrification, phenol-ammonia recovery, wastewater pulping, activated carbon adsorption and other sewage treatment, as well as large-scale gasifiers, pyrolysis furnaces, synthesis towers, waste heat boiler technologies, it is necessary to form a clean coal gasification upgrade core with independent intellectual property rights technology
.
4.
7 Large-scale synthesis gas purification series technologies integrate and innovate on the basis of digesting and absorbing domestic and foreign gas purification technologies to form large-scale synthesis gas purification technologies with independent intellectual property rights
.
Upgrade and improve the conversion process content such as: (1) Develop high-content carbon monoxide conversion large-scale technology, improve sulfur tolerance, wide-temperature conversion catalyst activity and service life, optimize integration to adapt to various clean coal gasification synthesis gas process parameters, and meet various requirements Products have different requirements for conversion, increase carbon monoxide conversion rate, reduce steam consumption and energy consumption, and reduce investment; (2) carbon dioxide removal technology, develop a large-scale low-temperature methanol washing process with a single series of purified synthesis gas and alcohol conversion of more than 1 million t/a, Form a low-temperature methanol washing process that can meet the requirements of large-scale carbon dioxide removal, as well as supporting large-scale absorption towers and other equipment
.
Coupling integration technology of different purification technology, comprehensive utilization of carbon dioxide for oil displacement and gas displacement technology
.
Large-scale air separation technology of more than 70 000 m3/h, as well as large-scale domestically produced gas compressors, circulating gas compressors and large-scale dynamic equipment technologies; (3) Development of desulfurization and sulfur recovery, as well as carbon monoxide and carbon dioxide separation technologies, through adsorption, PSA, membrane The combination of separation, cryogenic rectification and other processes can meet the gas separation requirements of different products, different scales, and different components
.
4.
8 Large-scale methanol synthesis technology The synthesis process characterized by by-product steam isothermal synthesis is the mainstream of methanol synthesis technology development
.
The development of large-scale methanol synthesis technology should focus on the following aspects: (1) Digest and absorb the methanol synthesis reactor process with multi-stage adiabatic and inter-stage heat exchange, master the process design of two towers in series, and have a large-scale methanol reactor Develop and break through the largest scale; (2) The methanol synthesis reactor process for quenching between digestion and absorption sections can reduce methanol synthesis energy consumption while being super-large; (3) Research and develop the slurry-bed methanol synthesis reactor process Demonstration device to improve the heat exchange capacity of the methanol reactor and prolong the life of the catalyst
.
Concluding Remarks During the "Twelfth Five-Year Plan" period, technological innovation has always been the highlight of the development of modern coal chemical enterprises.
During the "Thirteenth Five-Year Plan" period, technological innovation will surely become the top priority
.
Technological innovation lies not only in original inventions, but also in technological integration with great application value
.
Through the integration and reorganization of the coal chemical industry's single process technology, engineering technology, information technology and environmental protection control technology, we will obtain a new set of upgraded technology with unified overall functions, and strive to form a new brand of modern coal chemical industry
.
Modern coal chemical industry will face more, greater, and more difficult new challenges under the new normal, but at the same time it will also usher in possible strategic opportunities to realize the leap-forward development of China’s petroleum and chemical industry from a big country to a powerful country.
Make a positive contribution
.