(A) the resource constraints of oil shale development and utilization
Resource constraints include reserve base, resource endowment, geological conditions and geographical environment.
1. Insufficient proven reserves.
The proven reserves of oil shale with exploitation value are the basis for the development of shale oil industry. From the national macro point of view, the most important limiting factor for the development and utilization of oil shale in China is the shortage of oil shale with a certain grade (such as oil content ≥5%). By the end of 2008, the estimated geological resources of oil shale in China were as high as 739 1× 108t, and the proven oil shale reserves were only 85 108t, of which the remaining recoverable reserves of shale oil with oil content above 5% were only 2.78× 108t, accounting for only 65,438 of the remaining proven economic recoverable reserves. This shows that China is rich in oil shale resources, but the degree of exploration is low and the exploitable reserves are insufficient.
At present, the known large-scale proven reserves are Fushun oil shale mine in Liaoning, Maoming oil shale mine in Guangdong and Danzhou oil shale mine in Hainan. The proven reserves of oil shale are 2.3 billion tons, accounting for 89% of the proven reserves of oil shale in China, which can be mined in open pit. The oil content of Fushun and Maoming oil shale mines is about 6% ~ 7%, of which oil shale with oil content ≥5% accounts for more than 90%. The oil content of Danzhou oil shale mine is about 5%, of which oil shale with oil content ≥5% accounts for 73%. Fushun Mining Bureau mines millions of tons of oil shale in Fushun West Open-pit Mine every year, which will be converted into oil shale in East Open-pit Mine in a few years. Fushun and Maoming shale oil production has good economic and social benefits, and expanding production has good development prospects.
There are more than ten proven oil shale mines worth developing in China, such as Huadian in Jilin, Luozigou in Wangqing, and small shale oil plants in Huangxian (Longkou) in Shandong, all of which have been put into production and refined by Fushun furnace. There is also a company in Yaojie, Gansu Province, which is building a gas retort refining square furnace, Daqing Oilfield is building a granular shale retort refining device in Liushuhe Basin, and Longjiang Harbin Coal Chemical Company is building an oil shale fluidized retort refining device in Dalianhe, with an annual output of only tens of thousands of tons of shale oil. Because the proven reserves of these oil shale mines are not large, it is impossible to have great development.
2. Poor resource endowment
Experience shows that under the current economic and technical conditions in China, as far as shale refining is concerned, it is required that the oil content of open-pit oil shale is ≥5% and that of underground oil shale is ≥8%. Only in this way can shale oil refining be economical. The oil content of oil shale used in German shale power plant is 4% ~ 4.5%, so it is speculated that the oil shale resources with oil content of 3.5% ~ 5% in China can be considered for shale combustion power generation. The calorific value of oil shale for power generation should also be considered.
Statistics show that China's oil shale resource endowment is poor. The average oil content of oil shale resources in China is only 6.59%, which is far lower than the average oil content of oil shale in most foreign countries of 8%- 13%. Only 54% of oil shale resources in China have oil content ≥5%. Of the 8/kloc-0 oil shale mining areas in China, only 75% are oil shale mining areas with average oil content ≥5%, and only 17% are oil shale mining areas with average oil content ≥8%. In 36% mining areas, less than 70% resource oil shale has an oil content of ≥5%, and in 25% mining areas, less than 50% resource oil shale has an oil content of ≥5%.
The top ten oil shale mining areas in China are Songnan in Jilin, Tongchuan-Zichang in Shaanxi, Songbei in Heilongjiang, Lunpola Basin and Biluocuo in Tibet, the northern foot of Bogda Mountain in Xinjiang, You Xiang in Qinghai, Wucheng in Henan, Maoming Basin in Guangdong and Bagmaode in Inner Mongolia. The total of oil shale geological resources accounts for 93.6% of the whole country. However, the average oil content of oil shale in Songnan, Tongchuan-Zichang, Songbei and Bagmaode, which account for 64.7% of the national oil shale resources, is less than 5%, and the resources with oil content ≥5% are less than 35%. The mining areas with higher average oil content are Lunpola Basin (1 1.28%), the northern foot of Bogda Mountain (10.02%), You Xiang (9.72%) and Biluocuo (9. 18%), followed by Wugeda Mountain.
The largest oil shale mining area in China is located in Songnan, Jilin Province (formerly Nong 'an, Songnan, Denglouku, Changling and other mining areas), with proven resource reserves as high as 766× 108t. However, according to the limited analysis data, although the oil shale in Songnan mining area is deeply buried, the coal seam is thin, the average oil content is only 4.8%, and the oil shale resources with oil content ≥5% account for only about 34%. Oil shale resources in Songnan mining area have not been developed and utilized so far.
Therefore, for China, oil shale resource endowment (or resource grade, mainly referring to oil content and calorific value) is a very important unfavorable factor. If the taste is too low, it will lose the value of development and utilization.
Only high-grade oil shale resources have the value of development and utilization. For example, the proven oil shale in Huadian, Jilin and Huangxian (Longkou), Shandong, has an oil content exceeding 10%. Although it is deeply buried and needs underground mining, the mining cost is high, but it still has mining value because of its good grade, and some enterprises have begun to develop it. But the proven reserves are not large, only a few hundred million tons.
3. The geological conditions are not ideal
The geological conditions affecting the development and utilization of oil shale mainly include the thickness of oil shale coal seam, buried depth, resource abundance and geological complexity.
Oil shale has few coal seams and large thickness, which is beneficial to mining. Large and medium-sized oil shale mines in China are characterized by many layers and thin coal seams. 25% of oil shale deposits have more than 5 layers and 60% have more than 2 layers. There are 32 layers of oil shale in Wucheng, Henan. Fushun oil shale mine has two layers, Maoming oil shale mine has two layers, Huadian oil shale mine has 13 layers, and Luozigou oil shale mine has 27 layers. The cumulative thickness of oil shale deposits in China is only 0.72m, and the maximum thickness is 160m (at the northern foot of Bogda Mountain in Xinjiang). 55% of the ore-bearing areas are thicker than 10m, and only 3 1% of the ore-bearing areas are thicker than 20m. Among the top ten oil shale-bearing mining areas in China, except the oil shale mine at the northern foot of Bogda Mountain in Xinjiang, the thickness of oil shale coal seams in the other nine mining areas is basically within the range of 10 ~ 35m, generally within the range of 10~35m ~ 25m.
Oil shale is shallow buried, which is beneficial to mining. Generally speaking, the depth of oil shale mining is less than 500m for dry distillation on the ground, in which oil shale with buried depth less than 100m is suitable for open-pit mining and oil shale with buried depth of 100 ~ 500 m is suitable for underground mining. In China, shallow oil shale resources with a buried depth of 500m account for 65%, and oil shale resources with a buried depth of 500 ~ 1000 m account for 35%. There are more than 20 oil shale mines suitable for open-pit mining, including Maoming, Dianbai and Gaozhou in Guangdong, Fushun and Lingyuan in Liaoning, Danzhou in Hainan, Luozigou in Jilin, Arun Banner and Linkou in Heilongjiang, Bamaode and Aohan Banner in Inner Mongolia, Tongchuan and Binxian in Shaanxi, and the northern foot of Bogda Mountain, Devil Mountain, Lucaogou and Xinjiang.
Oil shale resources are abundant, which is beneficial to centralized development and utilization. Due to the thin thickness and low oil content of oil shale in China, the abundance of oil shale resources in China is generally low. The ore-bearing areas with resource abundance ≥6000× 104t/km2 mainly include Fushun in Liaoning, Danzhou in Hainan, the northern foot of Bogda Mountain in Junggar Basin, Devil Mountain in Jilin, Luozigou and Naiman Banner in Inner Mongolia. The ore-bearing areas with resource abundance of (6000 ~ 2000) × 104t/km2 mainly include Maoming in Guangdong, Dianbai, Gaozhou, Huadian in Jilin, Yaojie in Gansu, Tanshanling in Shaanxi, Tongchuan in Shandong, Wutu in Changle in Shandong and Sichakou and Dage in Fengning in Hebei.
Oil shale with complex and simple geology is beneficial to exploitation. The geological complexity of oil shale mines in China is medium to simple. Understanding the geological complexity of oil shale mines depends on the degree of geological exploration.
4. The geographical environment is diverse.
Generally speaking, oil shale mines in plains, hills and loess tablelands have convenient transportation, dense population and good market conditions, which are conducive to development and utilization; Oil shale mines in plateau, mountain, Gobi and desert environments have inconvenient transportation, sparse population and poor market conditions, which are not conducive to development and utilization.
The geographical environment of oil shale deposits in China is complex and diverse (Figure 5- 1). In the distribution of oil shale resources in China, plain environment accounts for 44.0%, hilly environment accounts for 7.5%, loess plateau environment accounts for 2 1.2%, plateau environment accounts for 16.4%, mountain environment accounts for 7.9% and Gobi environment accounts for 3.0%. The oil shale resources in plains, hills and loess tablelands account for 72.7%, which is generally beneficial to the exploration and development of oil shale resources in China. However, half of the top ten oil shale resources in China are located in plateau, mountainous and Gobi environments, such as Lunpola Basin and Biluocuo in Tibet in plateau environment, the northern foot of Bogda Mountain in Xinjiang in mountainous environment, You Xiang in Qinghai and Bagmaode in Inner Mongolia in Gobi environment, which are not conducive to the development and utilization of oil shale resources in these areas.
Figure 5- 1 Distribution of Oil Shale Resources in Different Geographical Environments in China
(B) Economic constraints on the development and utilization of oil shale
The price of crude oil plays a decisive role in the development and utilization of oil shale. If the international crude oil price is too low, the production cost of shale oil cannot compete with crude oil, and the oil shale refining industry cannot survive. For example, in the early 1990s, the international crude oil price dropped to about 10 USD/barrel, and Maoming shale refinery with nearly 30 years of production history had to stop production at 1992 due to serious losses.
At present, it is generally believed that oil shale refining can be profitable when the crude oil price is higher than 40 ~ 50 USD/barrel (Dammer, 2007). The Research Report on the Planning and Development of Unconventional Energy in the United States published by the U.S. Department of Energy in September 2007 holds that when the oil price in the United States reaches $35/barrel, it is profitable to produce shale oil by underground retorting. When the oil price reaches $54/barrel, it is beneficial to produce shale oil by dry distillation on the ground.
In recent years, the international crude oil price has soared, reaching as high as 147 USD/barrel in July 2008 (Zhang Kang, 2009), which has promoted the development of shale oil industry in the world and China. After that, the oil price dropped to $65,438+$34 per barrel in February 2008, but rebounded from June 2009, fluctuating to around $80 per barrel.
In recent years, China mainly produces shale oil in Fushun, Liaoning, Huadian, Jilin and Luozigou. The oil shale used in Fushun is a by-product of coal, and the mining cost is not included in the shale oil cost. The production cost per ton is about 1 1,000 RMB (equivalent to 2 1 USD/barrel). Huadian oil shale mine adopts underground mining, and the production cost per ton of shale oil is less than 2,500 yuan (equivalent to 52.5 US dollars/barrel); Luozigou oil shale mine adopts open-pit mining, and the production cost per ton of shale oil is about 1800 RMB (equivalent to $38/barrel). In 2007, the average price of shale oil in China was 3,000 yuan/ton (US$ 63/barrel), and in 2008 it reached 5,000 yuan/ton (US$ 0/05/barrel). Since June 2009, the price of shale oil is about 4,500 yuan/ton (equivalent to 95 dollars/barrel). This shows that shale oil production in China is favorable at present.
However, under the impact of the financial crisis, the international crude oil price fell below $40/barrel around the end of 2008, and the domestic shale oil price "dived" to 2000 yuan/ton (equivalent to $42/barrel). Many enterprises lose money or even lose money, and the shale oil market is not smooth. Some enterprises have just built and put into operation shale refining units, and their products have no market and are in a dilemma. Due to the abundant shale oil stocks, several private shale oil refineries in Jilin had to suspend production temporarily or semi-stop production. Fushun shale refinery has oil storage tanks and has not stopped production. This shows that the low crude oil price has a great influence on the shale refining industry in China.
The above shows that the price of shale oil plays a key role in the development of shale oil industry. Economic factors, especially the price of crude oil, are the decisive factors for the development of shale oil industry. In China, shale oil is usually sold as fuel oil, and the price of fuel oil is closely related to the world crude oil price. Experience shows that under the current conditions in China, generally speaking, the oil content of oil shale that can be mined in the open pit is limited to more than 5%, and for oil shale that can be mined underground, it is worth developing and utilizing if the oil content is limited to more than 8%.
It is generally estimated by international industry experts that after the recovery of the world economy, the international crude oil price will rise to above $80/barrel again by the end of 20 10 (Hu, Xue, 2009). This is very beneficial to the development of shale oil industry.
If there are other high-value associated mineral resources in oil shale mines, it will be beneficial to the comprehensive utilization of mineral resources and reduce costs.
In addition, financing difficulties also restrict the development of oil shale industry. Oil shale industry has huge investment. The oil shale refining project with the production scale exceeding 10× 104t needs to invest more than 200-300 million yuan. Small enterprises do not have such economic ability, and it is difficult for banks to borrow money. The comprehensive utilization project of oil shale cannot be guaranteed in construction funds.
(3) Technical constraints on development and utilization
Oil shale is mainly used for dry distillation and oil refining, and can also be used for direct combustion to generate steam and electricity, as well as shale ash to produce cement and other building materials.
Oil shale distillation refining can be divided into underground distillation and above-ground distillation.
Underground dry distillation means that oil shale is directly heated underground without exploitation, so that shale is decomposed into shale oil and gas and exported to the ground. The underground dry distillation process is suitable for oil shale deposits with deep burial (below 500 meters and below 600 meters underground) and oil shale layer thickness of tens of meters. A considerable number of green river oil shale deposits in the United States are suitable for this process; China's oil shale mines are generally thin, and there are basically no oil shale mining areas suitable for underground dry distillation process. Although the oil content of oil shale in some areas such as Bogda Mountain in Xinjiang is high, and the thickness of coal seam is 160m, the occurrence of strata is steep, which is not suitable for underground dry distillation process. Moreover, the underground dry distillation process is not mature, and it is also in the pilot stage in the United States, and it has not started testing in China.
Dry distillation above ground means that oil shale is mined in the open air or underground, then crushed and screened to the required particle size, and then heated to about 500℃ in a suitable dry distillation furnace for dry distillation and oil refining.
At present, Fushun massive shale retort furnace in China is a mature furnace type, but its capacity is small. The oil yield of 100t oil shale is also low, which is only 65% of that of laboratory aluminum dry distillation. Moreover, the small-particle shale left after crushing and screening accounts for about 15% ~ 20%, which cannot be used for Fushun furnace processing and is discarded. There are also gas-fired massive shale square furnaces in China, each furnace can process 300 tons of oil shale every day, and the oil yield is higher than that of Fushun furnace, but the semi-coke heat generated by shale is not fully utilized, which is also a disadvantage. Furthermore, these two types of furnaces are poor in environmental protection and have a lot of three wastes, which need to be treated seriously.
Foreign retort furnaces, such as Petrosix lump shale retort furnace in Brazil, process 6000 tons of oil shale every day, 60 times larger than Fushun furnace, and the oil yield can reach 90% of the laboratory aluminum retort oil output. It is also a mature furnace type, but the disadvantage is that the semi-coke produced is polluted and needs landfill and vegetation treatment.
Galoter granular shale retort in Estonia uses hot shale ash as solid heat carrier to heat shale for retorting and refining in rotary furnace. Each furnace processes 3000 tons of oil shale every day, which is 30 times larger than Fushun furnace, and the oil yield can reach 85% of that of laboratory aluminum retorting. Moreover, after being crushed and screened, the granular oil shale mined from mineral deposits can all be used for dry distillation in the furnace, with easy treatment of three wastes and less sewage, and can be directly sent to power stations. From the process point of view, choosing Galoter furnace is beneficial to expand production scale and improve production efficiency. However, if the Galoter device is selected, it needs to be negotiated with the production or design unit, and the introduction will cost a lot of foreign exchange.
At present, Fushun Mining Bureau has introduced Taciuk granular shale retort (ATP). Taciuk Zan was developed in Canada, enlarged in Australia and made in Germany. Australia's SPP/CPM has built a demonstration retort with a daily processing capacity of 6,000 tons of oil shale in Australia. After several years of trial operation, the operating rate reached 60%. After that, SPP sold the equipment to an American energy company, which decided that Taciuk process was not mature and stopped production. Taciuk furnace imported by Fushun Mining Bureau is also 6000 tons of oil shale per day, which can handle granular shale that Fushun furnace can't handle. The device will be put into trial operation before the end of 20 10. It is estimated that it will take some time to achieve normal operation.
In addition to introducing advanced dry distillation technology, China has independently developed new and more advanced dry distillation furnaces. PetroChina supports Daqing Oilfield to adopt the new dry distillation technology of granular shale developed by Dalian University of Technology, and plans to build a set of industrial test equipment for processing 2,000 tons of oil shale every day, with an annual output of 5× 104 tons. In addition, China Coal Group supports Heilongjiang Longhua Company to carry out pilot research (50t oil shale /d) based on the fluidized dry distillation process of silty shale developed by Shanghai Boshen Company, and plans to build an industrial test device with a daily processing capacity of 2000t oil shale, with an annual output of 5× 104t oil shale. These two projects are dry distillation refining projects independently developed by China. They are venture capital, but they are worth encouraging.
The above shows that the existing dry distillation process of oil shale in China is mature, but it is not suitable for developing large-scale shale oil industry; China's self-developed advanced dry distillation process is in the pilot stage, and it will take a long time to mature the technology. The advanced underground dry distillation technology of oil shale abroad is not mature and is not suitable for oil shale mines in China. The advanced foreign oil shale dry distillation process is mature and suitable for developing large-scale shale oil industry, but the process is complex, technology introduction requires a lot of foreign exchange, and the capital investment payback period is long, which is unbearable for small and medium-sized enterprises. In other words, the current technical level of oil shale retorting process does not support the large-scale development of shale oil industry, and the technical level of oil shale retorting process needs to be improved in the next few years to support the large-scale development of shale oil industry.
(4) Constraints of environmental protection
There are two kinds of oil shale mining methods: underground mining and open-pit mining. Whether underground mining or open-pit mining, it is necessary to lower the groundwater level below the oil shale layer, which will do harm to the cultivated land and forests near the mine. According to rough estimation, in order to obtain 1m3 oil shale, 25m3 groundwater is generally needed. The extracted groundwater can only be discharged into the river after the solid particles are precipitated. Foreign systematic monitoring shows that mining water greatly increases the sulfate content in the ground, groundwater and lakes. In Brazil, the groundwater level and quality have long been disturbed by oil shale mining.
In addition to the completely burning fluidized bed furnace (Germany and Israel have mastered this technology), there are some traditional ways of burning oil shale to generate electricity. Grinding combustion has the disadvantages of low utilization rate, great pollution and great health hazard, and there are fine and inhalable dust in the discharged gas. These dusts contain toxic substances, which not only endanger the environment near the power plant, but also affect areas far away from the power plant. In addition, the heat, waste water and semi-coke released during shale oil production may also cause environmental problems.
Environmental protection is the main condition for government environmental protection departments to restrain oil shale industry. The feasibility report of any new shale oil production project must be reviewed by the environmental protection department before it is approved by the development and reform commissions at all levels, and there are strict regulations on the pollutants contained in wastewater, waste and waste gas in shale oil production, as well as their treatment and discharge.
For the existing shale oil plants and oil shale power stations, the requirements for environmental protection are relatively loose. Fushun Mining Group has two shale oil plants. Although environmental protection has been improved in recent years and the factory area is greener, Fushun furnace has no intermediate hopper. When feeding regularly, the oil and gas in the furnace will leak out and pollute the atmosphere. In addition, the sewage generated in the production is added to the bottom basin, absorbed by shale ash and discharged out of the basin, thus preventing the sewage from being directly discharged into the water system. What the factory calls "zero discharge" of sewage is actually the transfer of sewage pollution, which makes the shale ash discharged into the shed contain more pollutants. Fushun Mining Group is taking measures to add a sewage treatment device to the shale oil plant in the open pit, and carry out sewage treatment according to the three processes of oil separation, flotation and biochemical treatment of ordinary refinery sewage, and add the purified sewage into the basin, so that the shale ash in the basin will not be polluted. The three wastes pollution of Wangqing shale refinery in Jilin Province is very serious and stinks, which is a typical example of poor environmental protection.
In recent years, the task of energy conservation and emission reduction in China is quite arduous, and the government's requirements for energy conservation and emission reduction are becoming more and more strict. Since 2009, the state has also actively studied and formulated strategic measures to deal with global climate change, taking the goal of controlling greenhouse gas emissions and adapting to climate change as an important basis for formulating medium-and long-term development strategies and plans, and incorporating them into national economic and social development plans. This is a great challenge to the development of oil shale industry.
In addition, oil shale resources in plain areas are mostly distributed in basic farmland or cultivated land. For example, the distribution areas of oil shale resources in Fuyu, Guo Qian, Nong 'an and Changchun Ridge in Jilin Province are mostly national ecological food bases, and the people's draught mainly depends on groundwater. The exploitation of oil shale may destroy the ecological environment of groundwater and grain base. Therefore, the Jilin Provincial Department of Land and Resources suggested that the oil shale resources in these areas should be reserved as strategic resources. Hainan province regards the construction of ecological environment and the development of tourism as its development strategy, and the development of Danzhou oil shale mine will be greatly challenged.
The above shows that with the development of oil shale industry, environmental protection is becoming more and more strict. The environmental protection of oil shale development and utilization will greatly restrict the development of oil shale industry in the future.
(v) Policy restrictions
For the development and utilization of oil shale, although the main influencing factor is oil price, appropriate policies are also very important for its development. The development of oil shale industry mainly involves fiscal and tax preferential policies, environmental protection policies and resource policies.
Reasonable fiscal and tax preferential policies can ensure the sustainable development of shale oil industry and ensure that shale oil production can make profits or reduce losses at low oil prices. In China, there has always been a preferential fiscal and taxation policy for the comprehensive utilization of oil shale, a by-product of coal mines. In 2004, the National Development and Reform Commission, the Ministry of Finance and State Taxation Administration of The People's Republic of China issued the Catalogue of Comprehensive Utilization of Resources (revised in 2003), which listed the associated oil shale of coal and shale oil produced as comprehensive utilization products and gave preferential tax policies. Over the years, preferential policies have included the implementation of tax incentives for value-added tax and corporate income tax. This has played a good role in making full use of its by-product oil shale resources and promoting the development of shale oil industry in China. However, in the Catalogue of Preferential Enterprise Income Tax for Comprehensive Utilization of Resources (2008 Edition), the oil shale associated with coal measures and its shale oil products are not clearly listed. Inquired by Fushun Mining Group, the relevant person of the National Development and Reform Commission said that it was omitted. Fushun Mining Group hopes to consider including shale oil in the comprehensive utilization product policy and give tax incentives as in 2004.
However, there is no preferential tax policy for the development and utilization of independent oil shale mines and main oil shale mines in China. Although the National Development and Reform Commission put forward the guidance catalogue of industrial structure adjustment in 2007, oil shale was listed as the first type of encouraged project ("2. Exploration and development of new energy sources such as oil shale. Oil and natural gas) should have encouraged and promoted the development of China's oil shale industry, but the effect is not as good as strong fiscal and tax preferential policies.
China has no environmental protection policy specifically for the oil shale industry. Formulating environmental protection norms and appropriate policies for oil shale development and utilization can not only promote the sustainable development of oil shale industry, but also avoid environmental damage caused by oil shale development and utilization.
China's current resource policy has no special provisions on oil shale resources, and it pays insufficient attention to oil shale resources management. Local protectionism exists in some areas and units, which affects the development and utilization of oil shale resources. For example, energy companies with strong economic and technological strength may not be able to obtain good oil shale mines; Places or units with oil shale resources may not have the economic and technical strength to develop oil shale, or are not prepared to develop and utilize it. Therefore, it is necessary to study the constraints of resource management policies on the development and utilization of oil shale.
To sum up, the rational formulation of future preferential policies, environmental protection policies and resource management policies will promote the healthy development of China's oil shale industry.