Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
  • C10B55/00—Coking mineral oils, bitumen, tar, and the like or mixtures thereof with solid carbonaceous material

Definitions

• the invention relates to a method for the continuous coking of pitches, in particular hard coal tar pitches, and the use of the coke obtained by this method.
• the process according to a) is high-temperature coking and, apart from a few special features, corresponds to the known coal coking process.
• a hard coal tar pitch with a coking residue according to Brockmann-Muck of more than 50% is used as the input product.
• the coke obtained is very hard and generally does not need to be calcined because of the high coking temperature of at least 1000 ° C.
• the process is very labor-intensive. Because of the different physical and chemical properties of the hard pitch, the plants, in particular the brick lining, are much more susceptible to repair than those of coal than those of coal coking.
• the process itself is discontinuous, so that a large number of chambers are necessary in order to enable quasi-continuous operation.
• the process according to b) is a smoldering process at around 500 ° C.
• hard coal tar soft pitches are also used.
• the delayed coker was originally operated as a thermal cracker. However, it was soon recognized that it is an excellent device for producing highly anisotropic special cokes.
• the smoldering coke obtained must be dried and calcined for further use. The plant costs are high, so that profitability is only given in the production of particularly high-quality coke or valuable oils. This is usually not the case with untreated coal tar pitch.
• the method itself can be carried out quasi-continuously with at least two coker drums.
• the process according to c) is also a smoldering process, but is carried out continuously.
• the fluid coker is a thermal cracker for mineral oil residues.
• the coke generated as a waste product is used as fuel. This process is less suitable for coal tar pitches because of the low oil and gas yield.
• the object of the invention is therefore to develop a simple, inexpensive process for the coking of hard coal tar pitches and comparable products and to find suitable fields of application for the coke thus produced.
• the object is achieved in that the hard pitch is coked in a rotary tube furnace provided with a broaching tool and heated from the outside at temperatures of the inner wall between 500 and 800 ° C. and a residence time of 0.5 to 1.5 hours, the resulting gases and Vapors are passed in countercurrent to the coking pitch, and the smoldering coke obtained is then calcined in the usual manner, preferably without prior cooling.
• Aromatic residues with a softening point (EP) according to Kraemer-Sarnow (K.-S.) of at least 130 ° C and a coking residue according to Brockmann-Muck (B.-M.) of at least 45% by weight are referred to as hard pitch.
• E softening point
• K.-S. Kraemer-Sarnow
• B.-M. coking residue
• the rotary kiln should advantageously be divided into several sections that can be heated differently. The segments facing the feed side are heated to an outside temperature of approximately 850 ° C. by external heating. The outside temperature of the following sections can then drop to around 600 ° C.
• the gases and vapors are conducted in countercurrent to the coking pitch.
• the vapors are condensed after leaving the rotary kiln and can be used as a soot oil component or can be used for hard pitch production.
• the feeding of an inert gas on the discharge side of the rotary kiln has proven to be helpful. This shortens the dwell time of the vapors in the coking zone and prevents soot formation and deposits in the subsequent vapor lines.
• a screw that is conical towards the feed side and weighted with granular material has proven itself, which is at least about 1/3, preferably 1/2 times as long as the rotary tube and its inclination is greater than that of the rotary tube.
• the broaching tool is preferably self-centering and is moved non-positively by the drum.
• the pitch can be introduced in pieces, for example via a rotary valve, or in liquid form in the rotary kiln.
• the smoked coke is discharged in pieces via another rotary valve and can be fed directly to the calciner. Since there is no need to cool the coke with water in the coking processes a) and b), considerably less time and energy is required for the calcination.
• Rotary kilns are known to be used for the coking or calcination of solid fuels such as smoked coke and lignite or for the pyrolysis of predominantly solid waste
• solid fuels such as smoked coke and lignite
• pyrolysis of predominantly solid waste
• a rotary kiln with an inner diameter of 0.8 m and a heated length of 7.2 m with a 4 m long conical screw in the front part, 75 kg / h of a hard coal tar pitch with an EP (K.-S.) of 150 ° C and a coking residue (B.-M.) of 50%.
• the oven is divided into 6 sections, which are heated indirectly with gas.
• the temperature of the outer wall in the area of the inlet is 850 ° C and drops to 700 ° C towards the outlet.
• the pipe wall outside temperature is approximately 800 ° C on average over the individual heating zones.
• the rotary tube is driven at 2 rpm.
• the average residence time of the coking pitch in the rotary kiln is about 1.5 hours.
• the oven shows no caking and the green coke is produced in pieces (74% by weight greater than 5 mm, 99% by weight greater than 1 mm).
• the coke has a high density and strength. It is fed into a calcining drum without cooling or intermediate storage and calcined there at 1300 ° C in the usual way.
• Example 1 is repeated with a throughput of 300 kg / h of pitch at a speed of 6 rpm.
• the dwell time of the coking pitch in the rotary kiln is reduced to about 0.5 h. 71% by weight of green coke with 3.5% by weight of volatile and a bulk density of 0.5 g / cm 3, 11% by weight of heavy oil, 14% by weight of light oil and 4% by weight of gas and losses are produced .
• the rotary kiln is flushed with 30 m 3 / h nitrogen in counterflow to the pitch. Gases and vapors leave the furnace on the pitch feed side and are condensed in two stages.
• the green coke is immediately transferred to a conventional calcining drum and calcined there at 1300 ° C. 89% by weight of calcined coke with a residual hydrogen content of 0.1% by weight and a true density of 2.028 g / cm 3 are obtained.
• the analyzes of the oils and the gas are contained in Tables I and II.
• Table 111 the calcined coke (1) obtained according to the invention is compared in its properties with normal petro-coke (2) and with pitch coke from the horizontal chamber furnace (3). As usual, the examinations were carried out on shaped bodies.
• the coke according to the invention is characterized by low CO 2 burnup and high electrical conductivity. Despite the higher conductivity compared to the usual pitch coke, its structure is finer and more uniformly mosaic-like, as the cross-sectional images show.
• the advantages of the coking process according to the invention lie in the short coking time of 1.5 to 0.5 hours, the low capital expenditure and the easy operation. It is also possible to return the fine portion of the coke and coke it together with the bad luck.
• the rods are graphitized at 2700 ° C and their physical properties compared to those of a reactor graphite made from Gilsonite coke:
• the coke according to the invention is outstandingly suitable for the production of reactor graphite. It has an exceptionally low expansion coefficient and a low anisotropy coefficient for pitch coke made from normal, uncleaned hard pitch. Another advantage is its small pore volume.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Coke Industry (AREA)
• Working-Up Tar And Pitch (AREA)
• Inorganic Fibers (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

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• 1986
  • 1986-03-20 DE DE19863609348 patent/DE3609348A1/de not_active Withdrawn
• 1987
  • 1987-01-12 ES ES87100270T patent/ES2000091B3/es not_active Expired
  • 1987-01-12 AT AT87100270T patent/ATE45587T1/de active
  • 1987-01-12 DE DE8787100270T patent/DE3760453D1/de not_active Expired
  • 1987-01-12 EP EP87100270A patent/EP0237702B1/de not_active Expired
  • 1987-01-29 ZA ZA870673A patent/ZA87673B/xx unknown
  • 1987-02-02 CA CA000528742A patent/CA1268438A/en not_active Expired - Fee Related
  • 1987-03-06 US US07/023,052 patent/US4764318A/en not_active Expired - Fee Related
  • 1987-03-17 JP JP62060246A patent/JPS62227991A/ja active Pending
  • 1987-03-19 PL PL1987264723A patent/PL151853B1/pl unknown
  • 1987-03-19 CS CS186187A patent/CS274289B2/cs unknown
  • 1987-03-20 AU AU70434/87A patent/AU585436B2/en not_active Ceased

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