Know "oil shale"

Oil shale is an unconventional oil and gas resource. It is listed as a very important replacement energy source in the 21st century due to its rich resources and feasibility of development and utilization. It is a non-renewable fossil energy source like oil, natural gas, and coal. In the past 200 years, In its development and utilization, it has accumulated a lot of experience in its resource status, main properties, mining technologies, and applied research.

definition

Oil shale, like coal, oil and natural gas, belongs to fossil fuels and is a non-renewable resource and primary energy source.

Oil shale (also known as kerogen shale) is a high-ash sedimentary rock containing combustible organic matter. The main difference between coal shale and ash is more than 40%, and the main difference with carbonaceous shale is that the oil content is more than 3.5%. Shale oil can be obtained by low-temperature dry distillation of oil shale. Shale oil is similar to crude oil and can be made into gasoline, diesel oil or fuel oil. In addition to separate reservoirs, oil shale often forms associated mineral deposits with coal and is mined together.

At present, most of the world's oil shale distribution areas are low in geological exploration, and it is difficult to correctly predict the global oil shale resources. Only some countries have carried out detailed exploration and evaluation of their oil shale deposits. As far as the current exploration situation is concerned, the United States is the country with the most abundant oil shale resources in the world. It has ascertained that the geological resources amounted to 334 billion tons, equivalent to 303.6 billion tons of shale oil.

From 2004 to 2006, China made the first evaluation of oil shale resources in China and found that the geological resources amounted to 719.9 million tons, and the converted shale oil was 47.6 billion tons. The amount of oil shale produced in the coal mining process in China reaches nearly 10 million tons, and the annual discharge of the oil shale alone in the Fushun West Open-pit Mine amounts to 8 million tons, which means that the large amount of arable land is discarded, which seriously affects the ecological environment around the mining area.

Resources

Oil shale oil production rate of less than 6% is a poor mine, higher than 10% of the rich mine. The proven oil shale reserves of more than 4% in the world, equivalent to approximately 470 Gt of shale oil, exceed the proven oil reserves. The U.S. Green River Basin in the western part of the country has the largest oil shale deposit in the world; China’s oil shale resources are also relatively abundant, second only to the United States, Brazil, and Russia. The most prestigious one is Fushun’s mining area, which is symbiotic with coal. Proven oil shale reserves of 3.6 Gt, the average oil production rate of about 5.5%; Maoming oil shale mines, recoverable reserves of 4Gt, the average oil production rate of 6.0%.

Method of manufacture

Large chunks of oil shale are crushed, screened, and sent to a huge furnace; heated in an air-free condition, the organic matter decomposes to produce oil and gas; the oil and gas enter a cooling unit and is cooled and condensed into an oily liquid. Shale oil.

Development

In fact, it is very troublesome to extract oil shale from the ground and refinish it. Scientists have come up with a good idea: drill some holes in the ground to the ground, insert perforated steel pipes into the oil shale, and then launch a high-frequency electromagnetic wave on it, relying on the heat generated by high-frequency electricity, The oil shale is decomposed into shale oil and gas, allowing it to run along the production drilling to the ground to serve humanity.

Raw biomass

Oil shale is mainly produced by corrosive and coalification by lower plankton such as algae. Some tiny animals, higher aquatic or terrestrial plant debris, such as spores, pollen, keratin and other plant tissue debris, are also involved in the formation of oil shale.

nature

Shale oil is very much like petroleum. Apart from liquid carbon and hydrogen substances, it also contains small amounts of oxygen, nitrogen, and chemicals. After shale oil is further processed and refined, it can produce liquid fuels such as gasoline, kerosene, and diesel oil, and has the same function as oil.

The main purpose of oil shale

There are many by-products in oil shale refining: ammonium sulfate can be used as fertilizer; phenols and pyridine can be used as chemical raw materials for the production of synthetic fibers, plastics, dyes, and medicines; the exhaust gas, like gas, It can be used as gas fuel; shale ash residue can be used to make cement clinker, ceramic fiber, ceramics and other construction materials. In summary, various fuel oils can be extracted, and various synthetic fuel gases and chemical raw materials can also be refined. By-products can also be used for building materials such as bricks and cement. Oil shale can be described as "the whole body is a treasure." To sum up, oil shale has three main uses:

1. Dry distillation for shale oil and related products

Shale oil can be obtained if the oil shale is broken up and heated to about 500°C. China often calls shale oil artificial oil. In general, 1 ton of oil shale can extract 38 to 378 liters (equivalent to 0.3 to 3.2 barrels) of shale oil. After shale oil hydrocracking refining, it can obtain a variety of chemical products such as gasoline, kerosene, diesel, paraffin, stone tar and so on.

2, as fuel for power generation, heating and transportation

The first is to generate electricity. There are two forms of power generation using oil shale. One is to directly use oil shale as boiler fuel to generate steam to generate electricity; the other is to low-distill oil shale to generate gaseous fuel, which is then sent to the internal combustion engine for combustion and power generation. The former form is currently widely used. Second, oil shale combustion heating can be used. In 2001/2002, the benefits that Estonia used to generate electricity from oil shale and heat to residents and industries accounted for 76% and 14% of national tax revenue, respectively, which is of great significance to its national economy. Once again, oil shale combustion can be used to drive the engine for long-distance transportation.

3, production of building materials, cement and fertilizer

As an addendum, shale retorting and burning shale ash are mainly used for the production of cement, brick and other building materials. In Germany, 300,000 tons of oil shale is used every year for the production of cement. In China, semi-coke ash residue after oil shale retorting and combustion is used to make building materials such as block, brick, cement, and ceramics.

In addition, oil shale can also be directly used for the production of organic fertilizers. For example, there is a company in Shaanxi Province that plans to invest 10 million yuan to use the existing oil shale resources in the Indochina area to carry out technological transformation on the basis of the original 50,000 tons of phosphate fertilizer production line and build a production line that can produce 50,000 tons of oil shale organic compound fertilizer annually.

Different countries have different uses of oil shale. In Estonia, oil shale is mainly used to generate and refine shale oil; in Brazil, oil shale is mainly used for transportation fuel; in Germany, oil shale is mainly used for the manufacture of cement and building materials; in China and Australia, oil pages The rock is mainly used to extract shale oil and used as fuel; in Russia and Israel, oil shale is mainly used for power generation.