Showing papers on "Raffinate published in 1996"

Atmospheric mineral leaching process

Abstract: The present invention relates to a method of processing a sulphide mineral composition which at least partly comprises an iron containing mineral, the method comprising the steps of: (a) milling said composition to a particle size P80 of 20 microns or less; (b) leaching said composition with a solution comprising sulphuric acid and ferric ions at ambient pressure whilst sparging with an oxygen containing gas in an open tank reactor at a temperature of up to about the boiling point of the solution, whereby at least some of the acid and at least some of the ferric ions are obtained from dissolution of the iron containing mineral, and ferrous ions generated by the leaching reaction are substantially re-oxidised to ferric ions in the leaching solution; (c) precipitating excess iron and separating said iron together with any solid materials from the leaching solution; (d) extracting desired metal ions from the leaching solution by solvent extraction with an organic solvent, such that the raffinate comprises sulphuric acid and ferric ions; (e) returning the raffinate to the leaching tank and blending with further milled composition; (f) separating the metals from the organic phase obtained in step (c) by stripping with electrolyte and electrowinning.

Production of ethanol by continuous fermentation and liquid-liquid extraction

Abstract: A continuous pilot plant was constructed for fermentation production of ethanol, using liquid-liquid extraction to remove the product and with recycle of the fermented broth raffinate. The plant was operated for up to 18 days with feed glucose concentrations in the range 10.0-45.8% (w/w). The solvent was n-dodecanol and immobilised yeast was used to overcome the problem of emulsification. The concentration of by-products in the fermented broth had no adverse effect on the rate of ethanol production. A mathematical model to predict the time required for achievement of 99% of the steady-state by-products concentrations was shown to be in good agreement with the experimentally determined concentration of the main by-product, glycerol. At a feed glucose concentration of 45.8% (w/w), the aqueous purge was equivalent to 2.8 m 3 of effluent per m 3 of ethanol produced and represented a 78% reduction in the volume of the aqueous purge compared with using a feed containing 10% (w/w) glucose.

Method for recovering nickel from high magnesium-containing ni-fe-mg lateritic ore

Abstract: A method is provided for recovering nickel from high magnesium-containing lateritic ores which also contain iron. The ores which are referred to as saprolitic ores are subjected to leaching (2) with a mineral acid from the group consisting of HC1, H2SO4 and HNO3, HC1 being preferred. Following leaching with HC1, for example, the pregnant solution obtained is separated from undissolved solids and the nickel preferably recovered by contacting the solution with a resin (4) selective to nickel absorption. The raffinate remaining which contains iron and magnesium chlorides may be subjected to pyro-hydrolysis (10A) to produce their respective oxides and free HC1 for recycle into the leaching system. The nickel is extracted from the resin using a stripping solution of the acid, and the nickel thereafter extracted from the nickel-loaded stripping solution.

The effect of butadiene and reaction conditions on the dimerization of 1-butene over NiY zeolite

Abstract: Oligomerization could effectively upgrade the n-butenes in Raffinate II to more valuable octenes. In order to use this feedstock, however, one must consider the effects of butadiene and isobutylene on the catalyst. Experiments were conducted with industrially supplied Raffinate II, and with pure 1-butene, to study the influence of these compounds and reaction conditions on the activity of NiY zeolite catalyst. Results show that isobutylene increases the activity of the catalyst, but that butadiene strongly deactivates the catalyst even at low levels. Evidence suggests that deactivation is caused by butadiene irreversibly complexing with active nickel sites, and by pore blockage. We propose that the oligomers blocking the zeolitic pores are formed via the Diels-Alder reaction. Catalyst deactivation is so severe that Raffinate II cannot be used with Ni catalysts unless steps are taken to remove all traces of butadiene from the feed.

Raffinate hydroconversion process (JHT-9601)

Abstract: A process for producing a high VI/low volatility lubricating oil basestock. The process comprises subjecting the raffinate from a solvent extraction step to a two step, single stage hydroconversion process wherein the first step involves severe hydroconversion of the raffinate followed by a cold hydrofinishing step.

Fluid separator apparatus

Abstract: An apparatus for separating contaminated waste water into a substantially uncontaminated homogeneous extract water portion and into a heterogeneous raffinate fluid portion. Upon being subjected to sufficient circular flow, in an environment emulating the action of a centrifuge, the heavier liquid and solid components are caused to gravitate out of the waste water. This apparatus is constructed with an elongated housing means which is preferably disposed between a water storage tank and fluid contaminant discharge device. Contained longitudinally within the elongated housing is a separator chamber having a portion of a frustoconically shaped centrifugation surface which directs the incoming waste water into a turbulent and circular pattern. As the waste water gains momentum during this centrifuge-like flow pattern, it abruptly strikes a substantially vertical impact plate which precipitates the forced separation of the impurities and contaminants from the waste water. The heavier extract component gravitates to a sump region located in the bottom of the housing, while the lighter raffinate fluid portion component rises into a raffinate separation region located in the top of the housing. A combination of baffle plates both promote the separation of the extract from the raffinate fluid portion and prevent the re-mixing thereof, once separation occurs. The accumulated extract portion is discharged through a drain at the bottom of the housing and raffinate fluid portion is discharged to the contaminant discharge device through an outlet located in the top portion of the housing.

A study on separation of molybdenum from tungsten by an adsorption process using activated carbon

Abstract: In this paper a new process for separation of molybdenum from tungsten is described. When sodium tungstate solution containing molybdenum is treated with alkali sulfide in the proper condition, the molybdenum is transformed into the thiomolybdate and the tungsten is present as tungstate. When the solution is brought into contact with activated carbon, the molybdenum contained in the solution can be adsorbed quantitatively and the tungsten remaining in the raffinate can be recovered. The new process has advantages such as good results in removing molybdenum, little loss of tungsten and easy operation.

Process for the recovery of caprolactam from waste containing nylon

Abstract: A process for depolymerizing nylon 6 and recovering caprolactam from the depolymerized products by extraction with alkyl phenolic compounds. Process steps include (a) treating a first mixture comprising nylon 6 with water at a temperature between about 200° C. and about 400° C. to yield a second mixture comprising depolymerized nylon 6 components, wherein the second mixture contains caprolactam at a concentration between about 5 wt. % and about 35 wt. %; (b) optionally, separating insoluble material from the second mixture; (c) extracting the second mixture with an extraction agent to yield an aqueous raffinate third mixture and an organic phase fourth mixture comprising caprolactam and the extraction agent, wherein the extraction agent is an alkyl phenol having a boiling point higher than that of the caprolactam; (d) recovering caprolactam from the organic phase fourth mixture by distillation; (e) recycling the aqueous raffinate third mixture to step (a).

Etherification-hydrogenation process

Abstract: A process for removing dienes from etherification uses a hydrogenation zone (24) in the reactor distillation column (20) above the etherification zone (22). MTBE is produced and the unreacted C4 stream is also subjected to selected hydrogenation of the butadiene contained in the C4 feed stream. The C4 stream is introduced via line (101) and methanol is introduced via line (102) which is combined in flow line (104) and subsequently enters the distillation column (20) via line (103) wherein the C4 stream is contacted with methanol in the etherification zone (22) where the MTBE is distilled downward. The unreacted C4's then are subjected to selective hydrogenation in the hydrogenation zone (24) wherein butadiene in the overhead raffinate (108) is reduced by over 90 %. The hydrotreated C4's are thus suitable for cold acid alkylation or other use wherein butadiene is harmful.

Process for the production of an internal combustion engine fuel base by hydrotreatment and extraction, and the product therefrom

Abstract: The invention concerns a petroleum product and a process for the production of a petroleum product which can form part of a blend for an internal combustion engine fuel, the process comprising a) hydrotreating a hydrocarbon feedstock at a partial pressure of hydrogen at the reactor outlet of about 05 MPa to about 6 MPa, b) separating a product (P) from step a) into a product (P1) with a final boiling point of about 300° C and a product (P2) with an initial boiling point greater than the final boiling point of product (P1), c) performing a liquid-liquid extraction with a solvent (S1), to produce an extract (E1) and a raffinate (R1) from product (P2), d) recovering solvent (S1) from raffinate (R1) to produce a product (Q1), depleted in solvent (S1), which has improved qualities and contains less than 500 ppm by weight of sulphur

Single‐stage fractionation of poly(ethylene‐co‐vinyl acetate) in supercritical ethylene with saft

Abstract: Using the discrete thermodynamics approach, the single-stage fractionation of a polydisperse poly(ethylene-co-vinyl acetate) in supercritical ethylene and ethylene-vinyl acetate mixtures is modeled with an EOS rooted in statistical associating fluid theory (SAFT). The simulation results are compared to new high-pressure coexistence data and size-exclusion chromatography data obtained on a few selected extracts. The polymer molecular-weight distribution is optimally represented by ten nearly-monodisperse pseudocomponents, determined by a nonuniform lumping method. SAFT quantitatively captures the effect of pressure, temperature and solvent composition on the solvent capacity and the extract yield over a broad range of conditions. The ethylene capacity monotonically increases with increasing pressure between 200 bar and the cloud point pressure, with increasing VA concentration in the solvent mixture, and with increasing temperature above ∼ 480 bar. At intermediate pressure (200–480 bar), SAFT predicts that the ethylene capacity behaves nonmonotonically with temperature. The extract and raffinate molecular weight and polydispersity are predicted also from SAFT as a function of pressure and solvent composition for a typical bubble- and dew-point-type fractionation, thereby illustrating the underlying differences between those two phase disengagement mechanisms.

Method for solvent extraction using a dual-skinned asymmetric microporous membrane

Abstract: The instant invention is directed to a method of solvent extraction. The steps of the method include: providing a dual-skinned asymmetric membrane; providing a feed containing a solute; and providing a solvent. The feed and the solvent are contacted across the membrane. The solute of the feed is extracted, and forming thereby a raffinate and an extract.

Multi-stage extraction process

Abstract: A process for multi-phase extraction is carried out in an extraction apparatus comprising a multiplicity of stages connected in series, wherein each stage comprises an extraction and a reextraction chamber. In the extraction chamber, a raffinate phase is brought into contract with an extractant, which is reextracted in contact with an extract phase in a reextraction chamber. In the course of the process, the extractant is conveyed in cross-flow to the extract and raffinate phases within the same stage in each case, while the raffinated and extract phases are conveyed through some or all of the stages in counter-current flow. The extractant is a continuous phase and the raffinate and extract are dispersed phases. The circulating flow of the extractant is maintained between the extraction and reextraction chambers solely due to the density differences of the dispersed phases in relation to the continuous phase.

Process for the recovery of caprolactam from waste containing nylon by extraction with alkyl phenols

Abstract: A process for depolymerizing nylon (6) and recovering caprolactam from the depolymerized products by extraction with alkyl phenolic compounds. Process steps include (a) treating a first mixture comprising nylon (6) with water at a temperature between about 200 °C and about 400 °C to yield a second mixture comprising depolymerized nylon (6) components, wherein the second mixture contains caprolactam at a concentration between about 5 wt.% and about 35 wt.%; (b) optionally, separating insoluble material from the second mixture; (c) extracting the second mixture with an extraction agent to yield an aqueous raffinate third mixture and an organic phase fourth mixture comprising caprolactam and the extraction agent, wherein the extraction agent is an alkyl phenol having a boiling point higher than that of the caprolactam; (d) recovering caprolactam from the organic phase fourth mixture by distillation; (e) recycling the aqueous raffinate third mixture to step (a).

Process for the solvent extraction of nickel and cobalt values in the presence of magnesium ions from a solution

Abstract: A process for the extraction of nickel and/or cobalt values from a solution comprises the steps of effecting a cobalt solvent extraction in the presence of magnesium ions with a cobalt extractant to produce a cobalt extractant loaded with cobalt ions and a first raffinate containing nickel and magnesium ions in solution. The first raffinate is subjected to magnesium solvent extraction with a magnesium extractant to produce a magnesium extractant loaded with magnesium and cobalt ions and a second raffinate. The second raffinate is subjected to nickel solvent extraction with a nickel extractant to produce a nickel loaded extractant and a third raffinate.

Process for the recovery of an organic acid from the manufacture of a cellulose ester

Abstract: The present invention is directed to a process for the recovery of an organic acid. The organic acid is generated from the manufacture of a cellulose ester. The first step of the process is to remove the organic acid from the manufacture of cellulose ester. The acid is in the form of a weak acid stream comprising of the organic acid and water. The weak acid stream is resolved, via a solvent extraction, to form an extractor overhead stream and raffinate stream. The raffinate stream comprises solvent, water, and alcohol. The alcohol is produced in the recovery process by hydrolysis of the solvent after the solvent extraction. The raffinate stream is resolved into a overhead stream and a bottom stream. The overhead stream comprises water, alcohol, and solvent. Excess organic acid is added to the overhead stream to form a feed stream. The feed stream is catalyzed, via ion exchange resins, whereby a portion of the alcohol is esterified to the solvent. The solvent, thus produced, is recycled into the recovery process.

Process and apparatus for extracting aromatic compounds contained in a hydrocarbon feedstock

Abstract: An extraction process and an apparatus for separating aromatic compounds contained in a liquid hydrocarbon feedstock where the feedstock feed into the lower part of an extraction column is brought into intimate countercurrent contact therein with a third liquid and at least partially with at least one structured packing element (31) of the static mixer type contained in the upper part of the extraction column. Such third liquid (feed to the top of said column) is in the form of a solvent which is immiscible with the feedstock except for being capable of extracting the aromatic compounds. At least part of the extract phase rich in solvent and aromatic compounds is separated by liquid--liquid separation (26), preferably by gravity type decantation, into a phase rich in solvent and essentially depleted of raffinate, which is removed, and a phase rich in raffinate and impoverished in solvent, which is recycled to the extraction step. The extraction process is typically to be used to formulate lubricant oils.

Petroleum fuel base

Abstract: A fuel for internal combustion engines having an improved cetane index and lower sulfur content is obtained from a hydrocarbon charge, by a process comprising a step (a) for distillation (D1) in which a bottom product (Q1) is obtained via a line 3 and in which a top product (T1) is obtained via a line 2, a step (b) of liquid/liquid extraction (LE) using a solvent (S1) to obtain a raffinate (R1), (line 5) an extract from which product (Q1) is obtained (line 6), a step c) separating (D2) the raffinate (R1) enabling a product (Q2) to be obtained via line 7, which product has a low solvent (S1) content, and a step (d) of hydrotreatment (HDS) in which the mixture of the products (T1) and (Q2) are subjected to hydrotreatment with a hydrogen partial pressure of less than 10 megapascals, to obtain a product (P) (line 9) which has improved qualities and which contains less than 500 ppm by weight sulphur. According to one particular embodiment, the extract (E1) (line 6) is distilled in order to obtain, via line 11, a bottom product (Q3) which is then conveyed to a hydrotreatment zone in such a way that a product (P') is obtained via a line 12 which contains less than 0.3% by weight sulphur.

Separating method by chromatography in pseudo-moving phase wherein gap volume caused by deviation of period synchronization is corrected

Abstract: PURPOSE: To prevent the confusion of a compsn. of an extract and a raffinate brought about by gap vol. by controlling the correction time to the gap vol. in a loop circuit. CONSTITUTION: For example, in the continuity of the column one section (n) of the drain of an extract EA and a raffinate RB between two sections and the injection of a charged article A + B and an eluent S, a recirculating pump P and/or a measuring means are arranged on the just upstream side of the discharge of the extract EA or the raffinate RB stream. Whereupon, the gap vol. bringing about confusion in the compsn. of the extract and the compsn. of the raffinate is produced in a recirculating loop circuit. At each time when the gap vol. of the loop circuit is transferred to a just-after position having deteriorated separation characteristics, the connection time to the loop circuit is increased by a proper value and, if the gap vol. is neglected at the time of the transfer to the next position, a connection time is shortened so as to take back a value considered to be adapted.

Solvent extraction of cobalt and nickel values from a magnesium containing solution

Abstract: A process for the extraction of nickel and/or cobalt values from a solution comprises the steps of effecting a cobalt solvent extraction in the presence of magnesium ions with a cobalt extractant to produce a cobalt extractant loaded with cobalt ions and a first raffinate containing nickel and magnesium ions in solution. The first raffinate is subjected to magnesium solvent extraction with a magnesium extractant to produce a magnesium extractant loaded with magnesium and cobalt ions and a second raffinate. The second raffinate is subjected to nickel solvent extraction with a nickel extractant to produce a nickel loaded extractant and a third raffinate.

Solvent extraction method of separating ferric chloride from nickel chloride

Abstract: Ferric chloride is separated from nickel chloride in a spent etchant solution 10 using a solvent extractant system 12. An extractant solution 14 is mixed with an HCl solution 16 to form an aqueous layer 18 and an organic extractant 20. The organic extractant 20 is introduced into an extraction section 22 of the system 12 and mixed with a recycled, stripped organic solvent 32 and a first raffinate 34 to form a first mixture 36 which is separated into a first organic layer 38 and a Ni-containing aqueous layer 40. A feed solution 44 consisting of the spent etchant solution 10 and concentrated HCl is combined with the first organic layer 38 to form a second mixture 46 which is separated into the first raffinate 34 and an organic solution 47 having a high concentration of iron. The solution 47 is introduced into a stripping section 48 of the system 12 and mixed with a raffinate 58 to form a third mixture 60 which is separated into a partially stripped organic layer 62 and an aqueous ferric chloride solution 64. A second HCl solution 66 is combined with the organic layer 62 to form a fourth mixture 68 which is separated into the organic solvent 32 and the raffinate 58. The aqueous ferric chloride solution 64 is processed 70 to provide either a concentrated ferric chloride etchant solution 72 in a continuous system 13, or a dried ferric chloride salt 74, in a non-continuous system.

Zeolitic reforming with selective feed-species adjustment

Abstract: The feedstock to an aromatization process is processed by a selective adsorption step to remove hydrocarbon species, particularly indan, which have a severe adverse effect on aromatization catalyst stability. The feedstock preferably is a paraffinic raffinate from aromatics extraction. The intermediate from the adsorption step is particularly suitable for the selective conversion of paraffins to aromatics using a high-activity dehydrocyclization catalyst with high aromatics yields and long catalyst life.

Reforming catalyst system with differentiated acid properties

Abstract: A catalyst system comprising a physical mixture of particles of a non-acidic large-pore zeolite containing a platinum-group metal and particles comprising a refractory inorganic oxide which is metal-free is effective for the reforming of a hydrocarbon feedstock. Reforming of paraffinic feedstocks to effect aromatization, particularly of a raffinate from aromatics extraction, provides improved activity in producing gasoline-range products when using the catalyst system of the invention.

Extraction of metals by spherical vesicle-type liquid membranes in gravity column

Abstract: Spherical vesicle-type liquid membranes can be used for extraction of metals in a gravity column. The process involves a repeated cycle of spontaneous formation and destruction of vesicles with continuous removal of re-extract and raffinate. The consumption of extractant, diluent, and stabilizing surfactant is significantly reduced due to the small thickness of membranes and continuous application of the same volume of organic phase.