JPS582385A - Manufacture of pitch from petroleum fraction and pitch thereby - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Summary of the Invention A pitch manufacturing method involves subjecting a residue obtained by thermally decomposing a petroleum fraction to one continuous thermal aging treatment, and the first thermal aging treatment is performed in a first reactor. While maintaining the temperature difference between the hot lower part and the cold upper part, the first thermal aging treatment is carried out in the first reactor at a pressure higher than atmospheric pressure but lower than 1JKy/plow2. The process is carried out in the second reactor at a pressure below atmospheric pressure while injecting steam into the first reactor, and the amount of steam is adjusted to 0.3 to 3 volumes of water per pitch produced/tanikura.

The pitch produced by this method is suitable for use in the production of carbon fibers.

The present invention relates to a pitch manufacturing method and a pitch manufactured by this method.

The pitch obtained by the method of the invention is suitable for use in the production of carbon fibers.

French Patent No. 1, 3, 1 describes a method for producing carbon or graphite fibers from petroleum pitch, in which the starting material for producing the fibers is subjected to λ discontinuous steps, namely distillation. Then, p is obtained by thermal ripening.

The present invention relates to a method for continuously producing petroleum hitch suitable for producing carbon fibers.

Therefore, according to the present invention, the method for producing pitch is such that the residue obtained by thermally decomposing the petroleum fraction is subjected to a kind of continuous thermal aging treatment, and the thermal aging treatment of the pitch is carried out by heating the first reactor. The first thermal aging treatment is carried out in the m1 reactor at a pressure higher than atmospheric pressure but lower than /jKP/C1n2 while maintaining the temperature difference between the lower part and the cold upper part. The process is carried out in a second reactor at a pressure below atmospheric pressure while injecting steam into the reactor, and the amount of steam produced is 0.
It is characterized by having 3 to 3 containers of water.

Hydrocarbons obtained by thermal cracking of petroleum fractions are heavy hydrocarbon substances, and steam cracking and thermal cracking of petroleum fractions are produced as by-products in catalytic cracking. These are, for example, light distillate fractions (33~
(0°C).

Residues from steam cracking of light or heavy gas oils, and residues from hot cracking of atmospheric or vacuum distillation residues.

Or it can be a residue from catalytic cranking of the vacuum distillate. The residue obtained by pyrolysis of petroleum fractions can be used separately by the method of water extraction or mixed with other residues of cracked petroleum fractions or the residues obtained from such residues. It can also be used in combination with Products obtained from the distillation of steam cracking residues in packed or grate columns are also suitable as starting materials for the invention.

Although the pressure in the first reactor is higher than atmospheric pressure / ! 9
Lower than 1011k2. 'Of 'l L < U /
31sy/(p lower than wrb2.

Preferably, the first thermal aging treatment is performed at 1 tao-ti, 2°C,
It is preferably carried out at a temperature of 300°C to 10°C.

The lower part of the reactor (hereinafter referred to as the ripening zone) has a temperature that is considerably higher than the temperature in the upper part of the reactor (hereinafter referred to as the reactor top). Maintaining this temperature difference between the reaction top and the ripening zone ensures a partial reflux of the light fractions into the ripening zone.

Thus, some of the reactive molecules of the t&gt; stock are reintroduced into the ripening zone, improving pitch yield. .

The temperature difference between the reactor top and the ripening zone in the first reactor is preferably Il'i, 200 to . 200°C, more preferably jO-100°C.

The temperature difference between the top of the reactor and the ripening zone can be determined in accordance with known methods, for example km or by adjusting the flow rate of the cooling liquid through the cooling coils of 1 part of the reactor 1ii, for example French Patent No. 1, 37t, 2o2- It can be maintained by adjusting as described in the q specification or by using cold condensate from a straddle reflux device.

The treatment duration in each reactor, i.e. the residence time t, can be defined according to the following formula: In the seventh reactor, the residence time Ufd is preferably between 70 minutes and 2 hours, preferably Leave for 13 minutes to 3 hours.

The λth thermal aging treatment can be carried out at a temperature of 20°C, more preferably 300°C.

The residence time in the second reactor is between 5 minutes and 2 hours, more preferably between 10 minutes and 1 hour.

The pressure is 10 tmHf1 to 1 atm, preferably 100 tmHf to 1 atm.

Superheated steam is injected below the reactor interface of the lPJλ reactor. The rate of water vapor injection into the second reactor is still QO03~3 volumes of water in the final pitch/result obtained. This process allows for the stripping of some of the lighter products and also induces a vacuum in the second reactor. I can do it. Therefore, there is no need to create a temperature difference between the top and bottom of the reactor, and the temperature of the second reactor is equal to the temperature of the first reactor depending on the desired result. , can be equal or lower.

The Fi of the present invention also includes the hit obtained by the method of the present invention. The pitch according to the invention has the following properties: Fremmer's Softening Point ("c) 1so-,z
z.

β Resin Gold - (Tflt%) <3S α Resin Gold* (xi%) <o, z The pinch produced according to the invention is suitable for use in the production of carbon or graphite fibers. For example, a β-resin content of less than 31 ply and a Kremer@Sarnaud softening point of 160-2.70°C were applied at the time of the present application and/or at the time of the application.
The carbon or graphite fibers described in the British Patent Application No. I//7tJ1, filed May 2nd, 2003, have priority, and can be used in the process for producing graphite fibers.

A specific example of an apparatus for manufacturing pitch according to the method of the present invention will be described below with reference to the accompanying drawings.

The residue obtained by pyrolysis of petroleum fractions, as described above, is first pumped from a source (not shown) into a second reactor via a path. Before entering the reactor, the feed is heated to the ripening temperature by two heat exchangers 3 and 3 and a tube furnace designed to gradually heat it while avoiding local overheating of this feed. preheated to.

The liquid feed in path λ is expanded by valve t to the pressure of the first reactor.

Since the feed and removal rates of vapor and sludge are relatively constant, the residence time of the material in the reactor is equal to path/4'
is determined by the rate of withdrawal from the bottom of the reactor through the reactor. Conveniently, the residence time can be adjusted by controlling the liquid level of the material in the reactor by actuation of a valve in the line/g.

The light steam and dregs produced during the thermal aging process are
It is withdrawn from the reactor via path io. The steam and gas are cooled in condenser// and fed into reflux drum/2. Gas and condensation! The i-liquid is separated in a reflux drum/2 and the residue is removed via path λ. Condensate is route, 2
3, can be removed via JLTK drum/2
The liquid level therein can be regulated by actuation of valve 7 in line 23.

Some of the condensate from the reflux drum/λ can be used to maintain a temperature difference between the upper part of the reactor (i.e. the top) and the lower part of the reactor (i.e. the ripening zone). Seven parts of the cold condensate is returned to the top of the reactor, thereby reducing the temperature at the top of the reactor. The temperature difference is maintained by adjusting to 1' of the condensate returned to the reactor by actuation of valve 13. Condensate that is not refluxed to the reactor is removed and stored (as shown) or further processed.

Alternatively, the temperature difference is 7 ns patent @, 237t20
As described in the specification, it is also possible to adjust and maintain the flow rate of the cooling liquid flowing through the cooling coil in the upper part of the reactor. However, the use of recycled condensate improves the yield by reintroducing 7 parts of the light hydrocarbons removed during the ripening step.

The liquid material exiting from the bottom of the reactor l via the channel is expanded by the valve to the pressure of the Iμ reactor Oj.

The pitch can be preheated to the ripening temperature of the second reactor/3 by means of a heat exchanger, 27, as desired.

The residence time of the substance in the second reactor/3 is adjusted in the same way as in the first reactor/, i.e. the level of liquid substance/6 in reactor lj is adjusted by actuation of valve/7 in path 2g. Determined by removing liquid product from the bottom of the vessel. - The product pitch withdrawn from the bottom of the second reactor is cooled by a heat exchanger and then removed and stored (not shown) or further processed.

Superheated steam is the route! Injected by valve 2J at j. This steam can be used to supply heat to the second reactor, thus heater 27 may not be required.

The temperature difference in reactor /j can be adjusted in the same way as in all reactors /j. The light distillate gas produced during the thermal aging process in the second reactor /3 is withdrawn via path 2/.

These are cooled by passing through a heat exchanger 3.

The scum and condensate are separated in a reflux drum/r.

Water generated from steam is collected in a reservoir, 2g, and extracted through a valve λ. The liquid level in the reflux drum is determined by the valve λO! The cap of the condensate regulated and refluxed into one reactor lj is closed by a valve /P. The unrefluxed #condensate is combined with the 1M condensate from reactor 1 and removed and stored (not shown) or further processed. The condensate is separated by an extraction or distillation process and
For example, naphthalene, styrene or/and cometernaphthalene can be obtained or incorporated into gasoline or fuel after distillation. λ
It may be preferable to treat the i-liquid by-products of two reactors separately and mix them. Whereas the condensate from the first reactor/can be used as is in Kanlin,
The condensate from the first reactor /j needs to be distilled before it can be incorporated into the gasoline.

The present invention will be explained below with reference to Examples, but the scope of the present invention is not limited thereby.

Examples 7-3 Petroleum residues obtained from steam cranking of naphtha fractions were subjected to continuous thermal aging treatment according to the present invention.

The residue had the following properties: Density (λs°C) l, oz/A 11Δ
-Viscosity (20℃), 2J+c,s
t Content of hexane insolubles 79.2 wt% Conradson carbon content i g, z Tachi AFNOR
Flammable PJ'C sulfur
(, l/weight ASTM Distilled IP 1.2°C YO%, 20°C IO%, 2.23°C 30%, 2J3°C YOCH, 222°C 70% 327°C Table 1 shows the results of charcoal fibers The conditions and results of the thermal aging treatment carried out on the above residue to obtain a pitch suitable for production are summarized.

The resins listed in the table have the following properties: alpha resins are resins that are insoluble in quinoline.

Beta resin is soluble in quinoline but insoluble in toluene.

The age of the month used in the table is as follows: south = 1 Temperature of ripening zone (°C) is the temperature measured as °C in the paper section of the reactor.

"Pressure (bar)" is the nominal pressure in bar within the reactor. The pressure in the reactor is given as /bar per example, ie less than 7 atmospheres. However, the injection line of steam into the fourth reactor will have the effect of reducing the pressure slightly below atmospheric pressure.

“Residence time (m1n)” is the processing duration in the reactor (
min, ) is calculated using the formula shown above.

"Distillate" is the weight of light distillate removed from the reactor during the thermal aging process.

"Steam Injection" indicates the ratio of the volume of water injected to the volume of hitch product.

"Yield (%)" is the weight of pitch product.

"KS Softening Point (°C)" is the Flemer-Sarnaud softening point at 1°C.

[α + β resin content i (%)” is the weight % of α resin and β resin in the produced pitch.

[(α resin content < O, 1%) J indicates that the α resin content of the produced pitch is less than O, S weight % for each example.

wJl table

[Brief explanation of the drawing]

The drawing is a flow diagram illustrating the proper operation of the apparatus for use in the present invention.

Claims (1)

[Claims] (1) The residue obtained by thermally decomposing a petroleum fraction is subjected to two consecutive thermal aging treatments, and the first thermal aging treatment is carried out in the hot lower part and the cold upper part of the first reactor. Is p higher than atmospheric pressure while maintaining the temperature difference between /! The first thermal aging treatment is carried out in the first reactor at a pressure lower than that of KP/ax2, and the first reaction is carried out at a pressure below atmospheric pressure while injecting steam into the second reactor below the gas-liquid interface. A method for producing pitch, characterized in that the process is carried out in a vessel, and the steam is made into a volume of water of 90.3 to 3 volumes per 7 volumes of pitch produced. (2) The method according to claim 1, wherein the temperature at which the first degree thermal aging treatment is performed is 0-1720°C. (3) The temperature at which the first thermal aging treatment is performed is 3oo-titi.
. The method according to claim 1, wherein the temperature is .degree. (4) m/residence time in reactor/θ minutes -/-
The method according to any one of claims 1 to 3, wherein -^^ to is time. (5) The method according to claim V, wherein the residence time in the first reactor is 75 minutes to 3 hours. (6) The temperature at which the second thermal aging treatment is performed is 1 ta O-≠, 20
The method according to any one of claims 7 to 5, wherein the temperature is .degree. (7) The temperature at which the first heat aging treatment is performed is 300-'7
The method according to claim @1, wherein the temperature is 10°C. (8) The method according to any one of claims 1 to 2, wherein the residence time in the second reactor is 5 minutes to 2 hours. (9) The method according to claim g*, wherein the residence time in the second reactor is 70 minutes to 1 hour. (11 The pressure in the second reactor is 'IOmmHg to l
The method according to any one of claims 7 to 2, wherein the pressure is atmospheric pressure. The process according to claim 1O, wherein the pressure in the αυ WJ2 reactor is between 100 txHll and 2-1 atm. The following properties of the pitch are: Frema Ichiban Renault softening point /jO~260°C β resin-containing lid <3jMW Chi α resin metal lid ((11,j3 [ii% How to get a pinch.