CN104342207A

CN104342207A - Technology for producing naphtha or motor gasoline through flexible hydrogenation of Fischer-Tropsch synthesis oil

Info

Publication number: CN104342207A
Application number: CN201310342538.6A
Authority: CN
Inventors: 王生友
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-08-08
Filing date: 2013-08-08
Publication date: 2015-02-11

Abstract

A technology for producing motor diesel oil and steam cracking naphtha through hydrofining/cracking of Fischer-Tropsch synthesis oil is ripe and industrialized. According to a technology disclosed by the invention, oil-washing naphtha coming from a Fischer-Tropsch synthesis oil apparatus is singly subjected to mild hydrogenation, a complete hydrogenation refining and cracking technology for heavy distillate oil and wax is reserved, when high-quality diesel oil is produced, easily-blendable vehicle gasoline is produced, on-site sale is facilitated, and various difficulties when naphtha is transported and sold to steam cracking apparatuses are avoided. By adjusting the mild hydrogenation operation conditions, complete hydrogenation on naphtha can be realized, thereby satisfying material requirements for steam cracking.

Description

The flexible hydrogenation of Fischer-Tropsch synthesis oil produces the technique of petroleum naphtha or motor spirit

Art

The present invention is the one of oil hydrogenation technique, specifically, is based on the different fractions of Fischer-Tropsch synthesis oil by different hydrogenation depth, at the automobile-used fine-quality diesel oil of production simultaneously, only by map function condition, need produce the method for steam cracking petroleum naphtha or motor spirit.

Background technology

Current coal liquifaction technique mainly contains two kinds: direct liquefaction and indirect liquefaction.From aspects such as technology maturity, investment, energy consumption, energy conversion efficiency and quality producies, indirect liquefaction has stronger competitive power than direct liquefaction.

ICL for Indirect Coal Liquefaction general technology is, fine coal (or coal water slurry) is pressurized high-temperature gasification under water vapour and pure oxygen condition, generates crude synthesis gas (i.e. CO+H ₂), then mountain refining plant is transformed into desirable H ₂the synthetic gas of/CO ratio, removes CO through low-temperature rectisol ₂+ H ₂after S etc., enter paste state bed reactor, under the effect of Fe-series catalyst, Fischer-Tropsch synthesis occurs, generate light ends oil, heavy distillate, pyroparaffine, water and contain a series of products such as sour oxygenatedchemicals.Before Fischer-Tropsch synthesis oil goes out device, often through stripping tower, go out wax, heavy distillate, light ends oil and synthesis tail gas with initial gross separation; Because containing a large amount of liquefied gas component in synthesis tail gas, often by the light ends oil such as F-T synthesis device compressor lime set, stripping over-head naphtha and synthesis tail gas through Vapor recovery unit process, cutting for gas, liquefied gas, synthesizing stable petroleum naphtha, industrial by the latter also referred to as low temperature oil wash petroleum naphtha.

Because containing a considerable amount of alkene, diolefine in Fischer-Tropsch synthetic, containing sour oxygenatedchemicals etc., also needing carry out hydrotreatment and be separated the requirement that could meet vehicle fuel.

Hydrogenation of Fischer-Tropsch synthesis oil flow process general is at present, oil product (comprising wax, heavy distillate, low temperature oil wash petroleum naphtha) is through the supercharging of reaction feed pump, mix with circulating hydrogen, through interchanger and/or the laggard hydrofining reactor of process furnace temperature raising, reactor bed occurs olefin saturated, containing laggard fractionating systems of reaction such as sour oxygenatedchemicals hydrogenation deoxidations.In separation column, often the component (unconverted oil) heavier than diesel oil distillate is delivered to hydrocracking reactor, to obtain more intermediate oils (diesel oil, petroleum naphtha etc.).Consider that oil from Fischer-Tropsch synthesis is mainly based on normal paraffin, cause the condensation point of diesel oil distillate quite high, limit its northerly use in winter, be therefore born some novel procesies, and the heavy gas oil that separation column is extracted out is produced low freezing point diesel fuel by hydrodewaxing.

Fischer-Tropsch synthesis oil after hydrogenation, the diesel cetane-number of fractionation gained reaches 70-80, not sulfur-bearing, nitrogen and aromatic hydrocarbons, is ideal derv fuel oil component.Gained petroleum naphtha normal paraffin content is very high, and saturation ratio is high, is the raw material of desirable steam cracking alkene.

From the indirect liquefaction project distribution of China's coal and the distribution of cracking of ethylene project, ethylene project comes from refinery because of raw material, therefore most integrated with Refinery Projects or close southeastern coast, Coal Chemical Engineering Project then mainly concentrates on the area that motherland is western and northern coal resource is abundant, distance is very far away mostly for the two, and petroleum naphtha transport is a bottlenecks.The more important thing is, existing ethylene project has lighter hydrocarbons, the raw material sources such as refinery's distillation product petroleum naphtha, hydrogenation tail oil etc. in fixing oil field substantially, and extra raw material may be restricted.

Economically set out, be compared with alkene with coal through methanol conversion, with coal through petroleum naphtha alkene, coal → synthetic gas → oil product → hydrofining → petroleum naphtha → steam cracking → alkene of having passed by, the very long of industrial chain sacrifices its market competitiveness.

Current China motor spirit is mainly from the catalytic cracking unit of refinery, and its octane value height mainly has benefited from its higher olefin(e) centent (more than 50%) and isoparaffin content.Mountain makes gasoline be easy to oxidation by air in the too high alkene that enlivens, and generates colloid, and reduce gasoline quality, refinery is had to gasoline hydrogenation to reduce olefin(e) centent.Alkene is as motor spirit octane value significant contributor, and after hydrogenation, gasoline octane rating significantly declines, and the method needing the Aromatic raffinate with reformer, alkylate oil, MTBE etc. to be in harmonious proportion makes up loss of octane number.

Following three tables, are boiling range and the analyses that certain F-T synthesis device delivers to oil hydrogenation device three kinds of materials, can visually see whereby, the oil property that F-T synthesis device comes, thus determine processing scheme:

Oil wash petroleum naphtha oiliness analytical table

Stock oil title	Oil wash petroleum naphtha	Analytical procedure
			Boiling range/DEG C		GB/T6536-1997
Fore-running/10%	3.4/87
			30％/50％	105.6/106
70％/90％	207.9/141.5
			95%/do	150.7/160
Bromine valency: gBr/100mL	12-45	SH/T0236-92
			Maleic value: g/100g	＞17.76	FRIPP-02
Acidity: mgKOH/100mL	633.6	GB/T258-77

Heavy distillate oiliness analytical table

Stock oil title	Heavy distillate	Analytical procedure
			Boiling range/DEG C		GB/T6536-1997
Fore-running/10%	166.5/195.5
			30％/50％	234.4/248.4
70％/90％	281.4/330.9
			95%/do	350.1/369.2

Bromine valency: gBr/100mL	/	SH/T0236-92
			Acid number: mgKOH/100g	140	GB/T258-77

Pyroparaffine analytical table

Stock oil title	Pyroparaffine	Analytical procedure
			Boiling range/DEG C		GB/T6536-1997
Fore-running/10%	338.4/400
			30％/50％	490/560
70％/90％	620/700
			95%/do	720/750
Acid number mgKOH/100g	11	GB/T264-83(83)
			Carbon residue, %	0.06	GB/T268-87
C，％	84.74	SH/T0656-1998(2004)
			H，％	14.54	SH/T06561998(2004)

More than mountain visible in table, oil wash petroleum naphtha boiling range meets the requirement of national gasoline boiling range, diolefine contained by it and acid number are all the highest in three kinds of oil products.

Summary of the invention

For retaining the alkene that in oil wash petroleum naphtha, octane value is very high, can reduce and remove again and wherein oxidizablely enliven alkene, diolefine and acidic oxide etc., technique described in the invention, retain original wax and heavy distillate complete hydrogenation flow process, to the oil wash petroleum naphtha mild hydrogenation of F-T synthesis, obtain derv fuel oil respectively and be easily in harmonious proportion motor spirit.

Based on the above, the present invention is intended to the oil product utilizing the initial gross separation sent here from Fischer-Tropsch synthesizer, utilizes flexible hydrogenation technique, while production fine-quality diesel oil, produces the motor spirit or steam cracking petroleum naphtha that are easy to be in harmonious proportion.

Main technique of the present invention is: retain heavy distillate and wax hydrofining in current High Temperature High Pressure system, fractionation and process; Allow the selective hydrogenation under mild hydrogenation condition of oil wash petroleum naphtha, directly go out motor spirit mixed oil.

Analyze according to oil wash petroleum naphtha, mild hydrogenation condition, should elect as: reaction pressure is generally at 2-4MPa, air speed 2-5h ^-1, temperature in 110-160 DEG C, oxygen oil ratio 100-600, the selective hydrogenation catalyst for gasoline of long-term industrial achievement selected by catalyzer.

Because hydrogenation reaction heat release, along feedstock direction, bed temperature raises gradually, hydrogenation is violent all the more, therefore needs reactor to arrange several bed, injects SAPMAC method hydrogen between bed, equal to control hydrogenator each bed bottom temp, to keep catalyzer to have identical deactivation rate, reduce catalyzer local coking, extension fixture on-stream time.Each bed bottom temp height, determines and enlivens alkene, diolefine and contain acid compound decreasing ratio and the monoolefin hydrogenation degree of depth.By carrying out assay to oil wash naphtha olefins content after hydrogenation, each bed bottom temp of adjustment mild hydrogenation further, after making hydrogenation, content of olefin in gasoline is no more than 35%, thus keeps the even inactivation of stable operation, steady quality and catalyzer.

The wax send here F-T synthesis device and heavy distillate refine the oxygenation cracking with unconverted oil through complete high-pressure hydrogenation, realize main production fine-quality diesel oil simultaneously, also produce isomery petroleum naphtha.Isomery petroleum naphtha and the oil wash petroleum naphtha containing part monoolefine are all stop bracket gasoline, are easy to reconcile into MTBE, alkylation wet goods the motor spirit needing label.On the other hand, oil wash petroleum naphtha belongs to light constituent, is easy to the feature of hydrogenation, also can improve mild hydrogenation temperature and pressure, the whole hydrotreated lube base oil of oil wash petroleum naphtha, to meet steam crack material demand.

The invention has the beneficial effects as follows:

(1) oil wash petroleum naphtha contains a large amount of diolefine, corrodes containing acid compound and its containing metal oil soluble salt brought, under complete hydrogenation condition, produce huge temperature rise and droop loss at refining reaction first bed, affect follow-up bed temperature and control and the first bed catalyst blocking inactivation.By with heavy oil (heavy distillate+wax) hydrogenation separate machined, the heavy oil complete hydrogenation device long-term operation that treatment capacity is maximum, difficulty of processing is the highest can be kept.The mild hydrogenation unit of oil wash petroleum naphtha, because treatment capacity is relatively few, and working pressure is low, and it is easy that agent is changed in maintenance.

(2) according to the oiliness analysis of oil wash petroleum naphtha, its acidity known is very high, and corrodibility is strong, corrodes and especially aggravate in the high temperature service such as process furnace of traditional technology.Because oil wash petroleum naphtha belongs to light constituent, hydrogenation reaction temperature is lower, and itself and mink cell focus are separated hydrogenation, is conducive to alleviating the corrosion of these acidic substance to hydrogenation system.

(3) oil wash petroleum naphtha mild hydrogenation, is stripped of oxidizable diolefine and containing acid compound, and when making it be used as gasoline, character is more stable, is not easy oxidation by air; Only need by improving mild hydrogenation temperature and pressure, allow oil wash petroleum naphtha complete hydrogenation, steam cracking petroleum naphtha can be produced, production decision flexible adjustment.

(4) oil wash petroleum naphtha mild hydrogenation, remains wherein stable monoolefine, namely remains suitable octane value, makes it be easier to reconcile into motor spirit than petroleum naphtha after complete hydrogenation;

(5) compared with the parallel feeding of original technique simultaneously hydrogenation, although this technique has looked many a set of hydrogenation system, the service temperature of this newly-increased mild hydrogenation system and pressure very low, its newly-increased investment and process cost are also little; On the other hand, the equipment High Temperature High Pressure of heavy distillate and wax hydrogenation requirements, because treatment capacity reduces, corresponding investment and process cost also reduce.The more important thing is, mainly concentrate in light constituent, high-temperature high-pressure apparatus time limit of service is extended because corrosive containing acid compound, in the long run, is also a kind of saving;

(6) in fractionating system, because of oil wash petroleum naphtha not with mink cell focus mixed hydrogenation, therefore also need not be separated with mink cell focus, greatly reduce fractionating system load, reduce reboiler furnace fuel consumption at the bottom of charging process furnace or tower.The preheating thermal source of oil wash petroleum naphtha, because its temperature is low, can utilize device preheating, energy-conservation useful to device.

(7) this technique solves the difficulty that Coal Chemical Engineering Project is carried to petroleum naphtha user, can be while Coal Chemical Engineering Project location provides diesel oil, also provides easily to be in harmonious proportion motor spirit, achieves the energy conversion of country's " rich coal, oil-poor, weak breath ".

Accompanying drawing explanation

Below by Fig. 1, Fig. 2, this bright flexible hydrogenation technique is further illustrated.

Fig. 1 is the hydrogenation flow process of current general parallel feeding in same reactor;

Fig. 2 is flexible hydrogenation technique flow process described in the invention.

In figure, (1) is the parallel feeding from the next heavy distillate of Fischer-Tropsch synthesizer and wax, and (2) are low temperature oil wash petroleum naphthas.(3) be reaction feed/reaction effluent interchanger, (4) be process furnace, (5) hydrofining reactor, (6) be high pressure hot separator, (7) be cold high pressure separator, (8) be circulating hydrogen compressor, (9) be thermal low-pressure separators, (10) be cold low separator, (11) be separation column, (12) are supplementary new hydrogen, and (13) are mild hydrogenation reactors, (14) be gas-liquid separator, (15) are mild hydrogenation circulating hydrogen compressors.

Embodiment

In FIG, the heavy distillate come from F-T synthesis and wax (1), first mix with low temperature oil wash petroleum naphtha (2), afterwards with mix hydrogen and mix, through refined unit reaction feed/reaction effluent interchanger (3) preheating, be heated to hydrofining requirement temperature of reaction through process furnace (4) again and enter hydrofining reactor (5), reactor bed occurs the reaction such as olefins hydrogenation, oxycompound hydrogenation deoxidation, controls lower bed layer temperature in by hydrogen cold between bed.Reaction effluent is first through interchanger (3) the tentatively laggard refined unit high pressure hot separator (6) of cooling.High pressure hot separator (6) liquid phase enters thermal low-pressure separators (9), gas phase cools laggard cold high pressure separator (7) through air cooler, cold high pressure separator (7) liquid phase enters cold low separator (10), and gas phase uses through circulating hydrogen compressor (8) compression cycle.Thermal low-pressure separators (9) liquid phase directly enters separation column (11), and gas phase rises into separation column (11) with cold low separator (10) liquid phase after air cooler cooling.The gas phase of cold low separator (10) can enter PSA recover hydrogen through desulfurization.Fresh hydrogen is supplemented to hydrofining unit by pipeline (12).

In fig. 2, the heavy distillate come from F-T synthesis and wax (1) keep hydrogenation technique described in Fig. 1 no longer to repeat: the low temperature oil wash petroleum naphtha (2) come from F-T synthesis, first mix with circulating hydrogen, be heated to the laggard mild hydrogenation reactor (13) of initial reaction temperature through preheater.Diene hydrogenation is there is, containing reactions such as acid compound hydrogenation deoxidation, part monoolefin hydrogenations, controls lower bed layer temperature in by hydrogen cold between bed in oil wash petroleum naphtha and hydrogen in mild hydrogenation reactor bed.Mild hydrogenation unit process pressure general control is at 2-4MPa, air speed 2-5h ^-1, temperature in 120-160 DEG C, hydrogen-oil ratio 100-600.Mild hydrogenation reaction effluent is cooled to about 45 DEG C laggard gas-liquid separators (14) through air-cooler, and liquid phase delivers to tank field as blended gasoline, and gas phase uses through circulating hydrogen compressor (15) pressurized circulation.Fresh hydrogen is supplemented to mild hydrogenation unit and hydrofining unit by pipeline (12).

Claims

1. the flexible hydrogenation of Fischer-Tropsch synthesis oil produces the technique of petroleum naphtha or motor spirit, it is characterized in that: retain and refine and cracking main product diesel oil technique the complete high-temperature and high-pressure hydrogenation of F-T synthesis heavy distillate and wax at present; Under comparatively low hydrogen pressure and temperature of reaction, carry out mild hydrogenation separately to oil wash petroleum naphtha, remove active alkene, diolefine and containing acid compound, after controlling mild hydrogenation, in petroleum naphtha, olefin(e) centent is no more than 35%, reduces loss of octane number as far as possible.Recycling MTBE, alkylate oil, hydrocracked naphtha etc. are in harmonious proportion to mild hydrogenation petroleum naphtha component, meet the requirement of motor spirit label.Mild hydrogenation temperature and pressure can also be improved, make oil wash petroleum naphtha complete hydrogenation saturated, to produce steam cracking petroleum naphtha.