Coal accounts for more than 75% of China's energy consumption, of which 80% is used for combustion, but more than 50% is directly used for industrial boilers, industrial kilns and household coal-fired furnaces, but the use of direct combustion has caused the utilization efficiency of coal to be very low, and it is also accompanied by pollutant emissions. In addition, with the improvement of the degree of mechanization of coal mining, the yield of block coal has dropped from 52 to 60% to 20 to 38%, which has aggravated the shortage of block coal and caused a long-term backlog of pulverized coal. In particular, a large number of low-grade coal, due to its high moisture content, low calorific value, as well as easy differentiation and difficult to transport, etc., lead to difficult processing and utilization, therefore, how to efficiently use low-grade pulverized coal has become an urgent problem in the field of coal utilization. Moreover, with the increasing domestic energy demand, the comprehensive conversion and utilization of low-grade coal, especially low-grade pulverized coal, is bound to become a strong support for future energy demand, in order to adapt to the trend and trend of market economic development, many alternative processes for oil have emerged quietly, these technologies mainly cover coal-to-oil, coal-to-olefin, biodiesel, fuel ethanol and so on. Among them, coal-to-oil in the alternative process has been proved to be significantly more prominent and widely used, but the coal indirect liquefaction oil production technology, has become the top priority, let's take a look at some important processes of coal indirect liquefaction oil production technology.
Coal indirect liquefaction oil production technology has the following requirements for the quality of coal:
1. Coal ash should be less than 13%;
2. The coal water content should be low, it should have good grindability, and it can be quickly milled;
3. Coal should have good pulping performance to meet the requirements of coal water slurry gas production process, and the concentration of coal water slurry should be higher than 60%,
4. To meet the requirements of coal gasification, it should have a high melting point. Although the indirect coal liquefaction oil production technology has a wide range of adaptability to coal resources, it should also take into account the maximization of economic benefits, according to different coal types, the use of different gasification methods, and do a good job in reducing sulfur and ash content of raw coal and washing and processing links.
F—T synthesis reactor
The F-1T synthesis reactor is the key core of indirect coal liquefaction oil production technology, and its applications on industrial scale are mainly slurry beds, fluidized beds and fixed beds.
(1) Slurry bed reactor
The slurry bed reactor has potential technical and economic advantages and good operability, and is recognized as the best F-T synthesis reaction process. Slurry bed reactors can be used to produce wax products and diesel oil, wax products are a linear alkane that do not contain aromatic hydrocarbons that are damaged to the human body, with a high melting point; diesel is a high cetane number and sulfur-free product. These advantages make the slurry bed reactor play an important role in the indirect liquefaction process of coal. After the hydrocarbon produced by the slurry bed reactor, after processing, kerosene, diesel, gasoline Germany can be obtained, and hard wax can also be produced, and its exhaust gas can be obtained after cryogenic separation treatment of low-carbon, high value-added olefins, after the oligomerization reaction, it can improve the oil yield, and can also form a synergy to form a gas to generate synthetic hydrocarbons, which are used for the synthesis of methanol, synthetic ammonia or fuel gas. In the field of petrochemical industry in the mainland, the oil processing technology is relatively mature, and the hydrocarbons produced by F-T basically do not contain impurities such as heterocyclic aromatic hydrocarbons, nitrogen and sulfur, the processing cost is very low, and the depth of hydrogenation is not high, but it is necessary to combine the characteristics of F-T synthetic hydrocarbons to develop corresponding catalysts.
(2) Fluidized bed reactor
Fluidized bed reactor can be divided into fixed fluidized bed and circulating fluidized bed, in terms of product distribution, heat transfer performance, production capacity, etc., fluidized bed reactor has obvious advantages. Circulating fluidized bed is mainly a gas flow carrying a fine powder catalyst for ascending reaction, continuous sedimentation in the branch pipe affected by cyclone separation, circulating under the reaction of the catalyst, the syngas conversion rate of the circulating fluidized bed is as high as 85%, the gas contains a large number of gasoline distillate hydrocarbons, wax and light oil production is less. The fixed fluidized bed is mainly a catalyst suspension reaction in the gas stream, which has good bed isothermal properties and high oil selection Majesty, and the reactor investment cost is low, suitable for high-temperature F-T synthesis
(3) Fixed bed reactor
The fixed bed reactor process is relatively simple, for liquid, gaseous or mixed synthetic products, the ambient temperature requirements are low, do not need to consider the separation of liquid products and catalysts, and the liquid products are easy to separate from the reactor outlet gas stream, which can be used for F-T wax production. The fixed bed reactor can adsorb a large amount of sulfur, effectively protect the lower bed and reduce the loss of catalyst activity.
catalyst
The use of catalysts directly affects the economic benefits of the indirect liquefaction process of coal, and is the key to reducing the cost of the oil production process. Coal indirect liquefaction oil production technology should use a catalyst that is efficient and cheap, has high wear strength, is green and environmentally friendly, and is easy to separate from the oil, and the catalyst can be recycled as much as possible and can be produced on a large scale. At present, the most commonly used catalysts for coal indirect liquefaction oil production technology are Ru, Ni, Co and Fe and other transition metals, these catalysts have a good hydrogenation effect, and are conducive to promoting the growth of the chain, which contains d orbital vacancies, can quickly receive electrons, and carbon atoms and hydrogen atoms produce a strong adsorption majesty, promote CO activity. Ru catalyst in the F-T synthesis process is less affected by factors, but its reserves are insufficient, expensive, can only be used for research, Ni catalyst has a strong hydrogenation effect, easy to produce methane and carbonyl nickel, in practical applications, co and Fe are the most widely used.
CNPC Jiuzhou Beidou is a state-owned energy and chemical sales company. Main business: light diesel, coal-based light diesel, heavy liquid paraffin wax, stable light hydrocarbons, blue charcoal, refined phenols, asphalt coke and other new energy coal chemical products and fuel card sales and promotion business.
The business model of CNPC Jiuzhou Beidou: Through the innovative business model of "Beidou + Internet + energy + logistics + finance", with the four major platforms of Beidou, oil merchants, yiyun and finance as the starting point, and the offline PetroChina refueling (refueling) station and logistics park as the carrier, the "ONLINE + offline" integrated "CNPC Jiuzhou Beidou Smart Logistics Ecosystem" is built.