Background technology
World economy sustainable development, in current global range, the main source of Chemicals is fossil energy, wherein most importantly oil and coal.These two kinds of fossil energies all belong to Nonrenewable energy resources, not only resource is day by day exhausted, and heaviness and in poor quality aggravation, difficulty of processing and tooling cost increase gradually, new oil substitutes is found except carrying out existing oil Refining Technologies improving, produce satisfactory product with minimum cost, especially the development and utilization of renewable resources obtains paying attention to more and more widely.
Bio-oil is as renewable resources, and main composition is carbon, hydrogen and oxygen, very similar to the composition of alkane, alcohol, ether etc., and each research unit and enterprise are all making great efforts to carry out its research as clean energy.The method production biofuel (being generally fatty acid methyl ester) utilizing transesterify has been proven technique, but because fatty acid methyl ester oxygen level is high, although many countries and regions have put into effect the standard of biofuel successively, and are not suitable for all oil engines.Bio-oil produces automotive fuel by the method for hydrogenation, and all remove by oxygen or partly remove the product produced and meet automotive fuel standard, this method directly can meet the requirement of existing market.
Existing animal-plant oil hydrogenation method produces the processing technology of automotive fuel, US20060186020, EP1693432, CN101321847A, CN200710012090.6, CN200680045053.9, CN200710065393.4, CN200780035038.0, CN200710012208.5, CN200780028314.0 and CN101029245A etc. disclose vegetables oil hydroconversion process, adopt coker naphtha, diesel oil distillate (straight-run diesel oil, LCO and coker gas oil), the petroleum hydrocarbon cuts such as wax oil cut and bio-oil are mixed into hydrogenation catalyst bed, produce diesel product or preparing ethylene by steam cracking raw material etc.US5705722 discloses the diesel oil blending component producing diesel oil distillate scope containing the vegetables oil such as unsaturated fatty acids, fat and animal oil mixing back end hydrogenation.EP1741767 and EP1741768 discloses a kind of method of producing low freezing point diesel fuel cut with animal-plant oil.
Comprise in the bio-oil hydrogenation process of aforesaid method, one of subject matter run into is that bed carbon distribution causes shorten running period, needs more catalyst changeout of often stopping work, and the main purpose product of these technology is automotive fuel.
Solvent oil is important petroleum products, and its added value is higher than fuel product, and particularly the added value of high-grade low aromatic solvent naphtha is higher.The low aromatic solvent naphtha raw materials for production of current top grade are limited (is generally only limitted to gasoline fraction or the kerosene(oil)fraction of paraffinic crude, or reforming raffinate oil etc.), owing to requiring aromaticity content lower (some solvent oil index request aromaticity content is lower than 0.1%), therefore need to adopt complicated processing route, condition is harsh, production cost is high, limits the production of high-grade low aromatic solvent naphtha.
In prior art, bio-oil usually passes through separately or produces the method for automotive fuel with the method for other petroleum products mixing back end hydrogenations.The present invention is by optimizing the grating technology and operational condition that use reduction-state hydrogenation catalyst, and first paragraph hydrotreatment (hydrogenation catalyst of grating), second segment hydrocracking can be directly raw material production low aromatic solvent naphtha with bio-oil.The present invention extends the raw material sources of high added value low aromatic solvent naphtha, and production cost is low, can improve added value of product further.
Summary of the invention
For the deficiencies in the prior art, the invention provides the two-stage method method of hydrotreating that a kind of bio-oil produces aromatic solvent naphtha, first paragraph uses reduction-state hydrogenation catalyst, second segment uses sulphided state non-precious metal catalyst, can be separately stock oil with animal-plant oil, the method of direct production low aromatic solvent naphtha under the condition of hydrogenation, has hydrogenation process and stablizes, the features such as running period is long.
The two-stage method method of hydrotreating that bio-oil of the present invention produces low aromatic solvent naphtha comprises following content:
A one or more in () bio-oil are stock oil;
B () is under Hydroprocessing conditions, stock oil and hydrogen pass through the first paragraph reaction zone of at least two hydrogenators, hydrogenation catalyst is loaded in hydrogenator, stock oil and hydrogen are first by the hydrogenator of cold operation, then by the hydrogenator of high-temperature operation, under response behaviour, the active ingredient of hydrogenation catalyst is one or more in W, Mo, Ni and Co of reduction-state;
C () first paragraph reaction zone hydrogenation effluent is separated into gas phase and liquid phase, recycle in first paragraph reaction zone after gas-phase dehydration process, the second segment reaction zone using hydrocracking catalyst is entered after liquid phase mixes with circulation gas, under response behaviour, the active metal component of hydrocracking catalyst is one or more in W, Mo, Ni and Co of sulphided state;
D gas phase that the reaction effluent gas-liquid separation of () second segment reaction zone obtains recycles in second segment reaction zone, and liquid phase fractionation in separation column that the reaction effluent gas-liquid separation of second segment reaction zone obtains obtains low aromatic solvent naphtha.
E () supplements S-contained substance in second segment reaction mass, to maintain hydrogen sulfide content in the circulation gas of second segment reaction zone.
In the inventive method step (a), the bio-oil used can comprise vegetables oil or animal grease, vegetables oil comprises one or more in soybean oil, peanut oil, Viscotrol C, rapeseed oil, Semen Maydis oil, sweet oil, plam oil, Oleum Cocois, tung oil, oleum lini, sesame oil, Oleum Gossypii semen, sunflower seed oil and rice bran wet goods, and animal grease comprises one or more in butter, lard, sheep oil and fish oil etc.
In the inventive method step (b), the Hydroprocessing conditions of the hydrotreating reactor of cold operation is generally reaction pressure 3.0MPa ~ 20.0MPa, and hydrogen to oil volume ratio is 200:1 ~ 3000:1, and volume space velocity is 0.3h-1~ 6.0h-1, average reaction temperature 120 DEG C ~ 280 DEG C; The operational condition of the hydrotreating reactor of high-temperature operation is reaction pressure 3.0MPa ~ 20.0MPa, hydrogen to oil volume ratio 200:1 ~ 3000:1, volume space velocity 0.3h-1~ 6.0h-1, average reaction temperature is higher than the hydrotreating reactor of cold operation 50 DEG C ~ 300 DEG C, preferably high 80 ~ 220 DEG C.Process furnace or interchanger are set between the hydrotreating reactor of cold operation and the hydrotreating reactor of high-temperature operation, to adjust the temperature of reaction of the hydrotreating reactor of high-temperature operation.First paragraph reaction zone can arrange 2 ~ 5 reactors.
Reaction mass first by the hydrogenator of cold operation, hydrogenation active component with the weight content of oxide basis for 3% ~ 10%.Multiple catalysts grating can be used in the hydrogenator of cold operation to use.In the hydrogenator of high-temperature operation, the active component content of catalyzer is in element quality, higher than the catalyzer in cold operation hydrogenator 3 ~ 25 percentage points.The carrier of hydrogenation catalyst is generally aluminum oxide, amorphous silicon aluminium, silicon oxide, titanium oxide etc., can contain other auxiliary agent, as P, Si, B, Ti, Zr etc. simultaneously.Can commercial catalyst be adopted, also can by the existing method preparation in this area.The business hydrogenation catalyst that first reaction zone uses mainly contains, as Fushun Petrochemical Research Institute (FRIPP) develop 3926, 3936, CH-20, FF-14, FF-18, FF-24, FF-26, FF-36, FH-98, FH-UDS, the hydrogenation catalysts such as FZC-41, the HR-416 of Inst Francais Du Petrole, the hydrogenation catalysts such as HR-448, the ICR174 of CLG company, ICR178, the hydrogenation catalysts such as ICR179, Uop Inc. is newly developed HC-P, HC-K UF-210/220, the TK-525 of Topsor company, TK-555, the hydrogenation catalysts such as TK-557, the KF-752 of AKZO company, KF-840, KF-848, KF-901, the hydrogenation catalysts such as KF-907.
In the inventive method step (b), catalyzer uses hydrogen 200 DEG C ~ 500 DEG C temperature before use, reduces under preferably 220 DEG C ~ 450 DEG C conditions.Whenever forbid in first paragraph system, inject sulfur-bearing, nitrogenous medium, avoid poisoning of catalyst.
In the inventive method step (c), the Hydroprocessing conditions of second segment reaction zone is generally reaction pressure 3.0MPa ~ 20.0MPa, and hydrogen to oil volume ratio is 200:1 ~ 3000:1, and volume space velocity is 0.3h-1~ 6.0h-1, average reaction temperature 180 DEG C ~ 465 DEG C; Preferred operational condition is reaction pressure 3.0MPa ~ 18.0MPa, hydrogen to oil volume ratio 300:1 ~ 2500:1, volume space velocity 0.4h-1~ 4.0h-1, average reaction temperature 200 DEG C ~ 445 DEG C.The working pressure of second segment reaction zone can be identical with first paragraph, also can be different.
In the inventive method step (c), the hydrocracking catalyst of second segment reaction zone has cracking function, as containing the component such as Y zeolite and/or ZSM-5 molecular sieve.The hydrogenation active metals component of hydrocracking catalyst is generally 5% ~ 40% with the weight content of oxide basis.The weight content of molecular sieve component in hydrocracking catalyst is generally 5% ~ 60%.Other refractory inorganic oxides can be contained in hydrocracking catalyst simultaneously.Second segment reaction zone use commercial catalysts mainly contain, as Fushun Petrochemical Research Institute (FRIPP) develop 3971,3976, FC-12, FC-18, FC-24, FC-26, FC-32, FC-46, FC-50, FDW-1 etc.
In the inventive method step (c), second segment reaction zone hydrogenation active component is the catalyzer of oxidation state, carries out conventional sulfidizing before the use, makes hydrogenation active component be converted into sulphided state, or use the catalyzer that ex situ presulfiding is good.
In the inventive method step (d), the low aromatic solvent naphtha obtained is mixed solvent oil distillate, can continue fractionation according to the actual requirements and obtain vegetable oil extraction solvent, No. 90 solvent oils, No. 120 solvent oils, No. 200 solvent oils, D30, D40 etc. trade mark low aromatic solvent naphthas.Specifically specifically can determine according to the boiling range of mixed solvent oil.If there is unconverted oil, unconverted oil can go out system, also capable of circulation time reactive system.
The sulfur-containing medium supplemented in reaction mass (optimum is dosed in stock oil) in the inventive method step (e) can be the compound of sulfur-bearing, as DMDS, CS2deng, also can be the oil light-end products of sulfur-bearing, as the boat coal, diesel oil etc. of sulfur-bearing.Supplementing by sulphur, can ensure that the hydrogen sulfide content in the circulation gas of second segment reaction zone is not less than 0.005v%, preferred 0.01v% ~ 2.0v%.