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Acrylonitrile route

Acrylonitrile Route. This process, based on the hydrolysis of acrylonitrile (79), is also a propylene route since acrylonitrile (qv) is produced by the catalytic vapor-phase ammoxidation of propylene. [Pg.155]

The yield of acrylonitrile based on propylene is generally lower than the yield of acryhc acid based on the dkect oxidation of propylene. Hence, for the large volume manufacture of acrylates, the acrylonitrile route is not attractive since additional processing steps are involved and the ultimate yield of acrylate based on propylene is much lower. Hydrolysis of acrylonitrile can be controUed to provide acrylamide rather than acryhc acid, but acryhc acid is a by-product in such a process (80). [Pg.155]

In terms of sustainability, the process starting from propene would be preferable, since it avoids the risks connected with the use of HCN in the butadiene route, even if produced on demand. However, the butadiene route to produce adiponitrile (ADN) is more cost-effective, owing to the need to use an electrochemical reaction for acrylonitrile dimerization. The problem of cost, however, is highly dependent on several factors, including sensitivity to natural gas prices (which influences butadiene cost), the market for acrylonitrile, and soon. The acrylonitrile route is used by Solutia, BASF and Asahi Kasei. New plants to make caprolactam, using ADN as intermediate, are under construction in Asia. [Pg.140]

The acrylonitrile route is basically a propylene route because acrylonitrile is produced from propylene by ammooxidation [456,457]. [Pg.289]

Adiponitrile is made commercially by several different processes utilizing different feedstocks. The original process, utilizing adipic acid (qv) as a feedstock, was first commercialized by DuPont in the late 1930s and was the basis for a number of adiponitrile plants. However, the adipic acid process was abandoned by DuPont in favor of two processes based on butadiene (qv). During the 1960s, Monsanto and Asahi developed routes to adiponitrile by the electrodimerization of acrylonitrile (qv). [Pg.220]

The current routes to acrylamide are based on the hydration of inexpensive and readily available acrylonitrile [107-13-1] (C3H3N, 2-propenenittile, vinyl cyanide, VCN, or cyanoethene) (see Acrylonitrile). For many years the principal process for making acrylamide was a reaction of acrylonitrile with H2SO4 H2O followed by separation of the product from its sulfate salt using a base neutralization or an ion exclusion column (68). [Pg.134]

Even ia 1960 a catalytic route was considered the answer to the pollution problem and the by-product sulfate, but nearly ten years elapsed before a process was developed that could be used commercially. Some of the eadier attempts iacluded hydrolysis of acrylonitrile on a sulfonic acid ion-exchange resia (69). Manganese dioxide showed some catalytic activity (70), and copper ions present ia two different valence states were described as catalyticaHy active (71), but copper metal by itself was not active. A variety of catalysts, such as Umshibara or I Jllmann copper and nickel, were used for the hydrolysis of aromatic nitriles, but aUphatic nitriles did not react usiag these catalysts (72). Beginning ia 1971 a series of patents were issued to The Dow Chemical Company (73) describiag the use of copper metal catalysis. Full-scale production was achieved the same year. A solution of acrylonitrile ia water was passed over a fixed bed of copper catalyst at 85°C, which produced a solution of acrylamide ia water with very high conversions and selectivities to acrylamide. [Pg.135]

Other routes to acrylonitrile, none of which achieved large-scale commercial appHcation, are acetaldehyde and HCN (56), propionittile dehydrogenation (57,58), and propylene and nitric oxide (59,60) ... [Pg.184]

Addition of Hydrogen Cyanide. At one time the predominant commercial route to acrylonitrile was the addition of hydrogen cyanide to acetylene. The reaction can be conducted in the Hquid (CuCl catalyst) or gas phase (basic catalyst at 400 to 600°C). This route has been completely replaced by the ammoxidation of propylene (SOHIO process) (see Acrylonitrile). [Pg.374]

The first U.S. plant for acrylonitrile manufacture used an ethylene cyanohydrin feedstock. This was the primary route for acrylonitrile manufacture until the acetylene-based process began to replace it in 1953 (40). Maximum use of ethylene cyanohydrin to produce acrylonitrile occurred in 1963. Acrylonitrile (qv) has not been produced by this route since 1970. [Pg.415]

Other Derivatives. Ethylene carbonate, made from the reaction of ethylene oxide and carbon dioxide, is used as a solvent. Acrylonitrile (qv) can be made from ethylene oxide via ethylene cyanohydrin however, this route has been entirely supplanted by more economic processes. Urethane intermediates can be produced using both ethylene oxide and propylene oxide in their stmctures (281) (see Urethane polymers). [Pg.466]

Reaction of coke with calcium oxide gives calcium carbide, which on treatment with water produces acetylene. This was for many years an important starting point for the production of acrylonitrile, vinyl chloride, vinyl acetate and other vinyl monomers. Furthermore, during World War II, Reppe developed routes for many other monomers although these were not viable under normal economic conditions. [Pg.10]

Commercial routes from acrylonitrile and from caprolactam have also been developed. This diamine may also be prepared from furfural and from butadiene. [Pg.481]

The product from acrylonitrile will withstand a bunsen flame in the open air and is the basis of one type of carbon fibre. None of the polymers produced by this route have a high degree of perfection in their ladder structure. [Pg.850]

Adiponitrile is an important intermediate for producing nylon 66. There are other routes for its production, which are discussed in Chapter 9. The way to produce adiponitrile via propylene is the electrodimerization of acrylonitrile. The following is a representation of the electrochemistry involved ... [Pg.221]

This new lower price changed the comparative economic advantages of some of the newer plastics and led to a search for new uses of acrylonitrile and its polymers and copolymers. A new route to Dacron was developed by du Pont using this lower priced acrylonitrile and the use of acrylic fabrics grew rapidly. There was also an increase in uses of ABS and acrylonitrile production capacity. [Pg.579]

Until the 1960s, acrylonitrile was, like vinyl acetate, made from acetylene (by reaction with hydrogen cyanide), but research on catalysts in the 1950s led to the much less costly route shown above. [Pg.128]

Hexamethylenediamine is now made by three different routes the original from adipic acid, the electrodimerization of acrylonitrile, and the addition of hydrogen cyanide to butadiene. Thus, the starting material can be cyclohexane, propylene, or butadiene. Currently, the cyclohexane-based route from adipic acid is the most costly and this process is being phased out. The butadiene route is patented by DuPont and requires hydrogen cyanide facilities. Recent new hexamethylenediamine plants, outside DuPont, are based on acrylonitrile from propylene, a readily available commodity. [Pg.136]

Hexamethylenediamine (HMDA), a monomer for the synthesis of polyamide-6,6, is produced by catalytic hydrogenation of adiponitrile. Three processes, each based on a different reactant, produce the latter coimnercially. The original Du Pont process, still used in a few plants, starts with adipic acid made from cyclohexane adipic acid then reacts with ammonia to yield the dinitrile. This process has been replaced in many plants by the catalytic hydrocyanation of butadiene. A third route to adiponitrile is the electrolytic dimerization of acrylonitrile, the latter produced by the ammoxidation of propene. [Pg.357]

Jug and co-workers investigated the mechanism of cycloaddition reactions of indolizines to give substituted cycl[3,2,2]azines <1998JPO201>. Intermediates in this reaction are not isolated, giving evidence for a concerted [8+2] cycloaddition, which was consistent with results of previous theoretical calculations <1984CHEC(4)443>. Calculations were performed for a number of substituted ethenes <1998JPO201>. For methyl acrylate, acrylonitrile, and ethene, the concerted [8+2] mechanism seems favored. However, from both ab initio and semi-empirical calculations of transition states they concluded that reaction with nitroethene proceeded via a two-step intermolecular electrophilic addition/cyclization route, and dimethylaminoethene via an unprecedented two-step nucleophilic addition/cyclization mechanism (Equation 1). [Pg.713]

A number of examples have been reported documenting the use of palladium phosphine complexes as catalysts. The dialkyl species [PtL2R2] (L2 = dmpe, dppe, (PMe3)2 R = Me, CH2SiMe3) catalyze the reaction of [PhNH3]+ with activated alkenes (acrylonitrile, methyl acrylate, acrolein).176 Unfunctionalized alkenes prove unreactive. The reaction mechanism is believed to proceed via protonation of Pt-R by the ammonium salt (generating PhNH2 in turn) and the subsequent release of alkane to afford a vacant coordination site on the metal. Coordination of alkene then allows access into route A of the mechanism shown in Scheme 34. Protonation is also... [Pg.294]

If you are exposed to a hazardous substance such as acrylonitrile, several factors will determine whether harmful health effects will occur and what the type and severity of those health effects will be. These factors include the dose (how much), the duration (how long), the route or pathway by which you are exposed (breathing, eating, drinking, or skin contact), the other chemicals to which you are exposed, and your individual characteristics such as age, sex, nutritional status, family traits, life style, and state of health. [Pg.10]

Results of studies in laboratory animals with 14C-acrylonitrile indicate acrylonitrile is rapidly and extensively absorbed by the oral route. Radiolabeled acrylonitrile is detected in blood within 30 minutes after administration of an oral dose and peak plasma concentrations are reached 6 hours after administration (Farooqui and Ahmed 1982). Extensive absorption is indicated by the fact that only 2 to 10% of administered radioactivity is recovered in the feces (Ahmed et al. 1982, 1983 Farooqui and Ahmed 1982 Young et al. 1977). [Pg.51]

Roberts et al. 1989). Studies indicate that the metabolism of acrylonitrile in animals proceeds by the same pathways whether exposure is by the oral (Ahmed et al. 1983 Langvardt et al. 1980 Pilon et al. 1988a) or the inhalation route (Gutetal. 1985 Muller et al. 1987 Tardif et al. 1987). No data were located regarding the metabolism of acrylonitrile following dermal exposure. [Pg.53]

In humans, metabolites of acrylonitrile have been identified in urine following occupational exposure (assumed to be by the inhalation route), and also in controlled exposure studies. Metabolites identified in humans were the same as those in animals (Jakubowski et al. 1987 Sakurai et al. [Pg.55]

The predominant route of excretion in rats is via urine (Gut et al. 1985 Tardif et al. 1987 Young et al. 1977). In rats exposed to 5 ppm of 1- C-acrylonitrile for 6 hours, 68% of the absorbed radioactivity was excreted in the urine within 220 hours, with 3.9% in the feces, 6.1% in expired air as CO2, and 18% of the radioactivity being retained in the body tissues. Following exposure to a higher concentration (100 ppm), a larger fraction of the dose was recovered in urine (82%) and a smaller fraction (2.6%) was retained in the body (Young et al. 1977), indicating that urinary excretion is dose-dependent. Percent fecal excretion was similar at both doses. [Pg.55]

Following oral exposure, the major route of excretion of acrylonitrile in rats is via the urine, either as thiocyanate or as other products of conjugation. Within the first 24 hours of a single oral dose, 40% to 60% was recovered in the urine (Ahmed et al. 1983). Farooqui and Ahmed (1982) reported that 10 days after the administration of a single dose, 61 % of the dose had been accounted for in the urine, 3% in feces and 13% in the expired air. Approximately 25% was retained in the body covalently bound to tissues (see Section 2.3.3). [Pg.55]


See other pages where Acrylonitrile route is mentioned: [Pg.195]    [Pg.195]    [Pg.182]    [Pg.186]    [Pg.282]    [Pg.361]    [Pg.261]    [Pg.89]    [Pg.126]    [Pg.94]    [Pg.626]    [Pg.334]    [Pg.296]    [Pg.298]    [Pg.27]    [Pg.35]    [Pg.46]    [Pg.52]    [Pg.56]    [Pg.57]    [Pg.57]   
See also in sourсe #XX -- [ Pg.11 ]




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