BASF-process

The BASF process [39] has some resemblance to the Fuji process it is also a two-step process, and a PVC content lower than 5% is required in the feedstocks. The waste plastics are melted at 250-380°C and volume reduction and better uniformity are achieved. In this process, relatively cheap alkaline solid snbstances snch as calcium oxide, sodium carbonate or other alkalis in solution are used to remove HCl by absorption. Depending on the different plastics processed, oil product yields ranging from 20 to 70% can be achieved. This process is suitable for the treatment of mixed plastics containing heteroatom contaminants. 

After scrubbing with oil and the removal of polymers and naphthalene, the gaseous effluent is compressed. It is then sent to the extraction section employing N methylpyr-rolidone as solvent. 

The burner employed in BASF s first plant by iG Farben at Oppau (West Germany) during the Second World War was of the Sachsse type. Simultaneously, Union Carbide developed a similar facility, which was commissioned in 1950. Subsequently, SB A Socitte 

Beige de VAzote) developed another burner, identical in its principle, but different in design. In Italy, Montecatini tested an identical system to that of B.45F, but operating under pressure. 

Nitric oxide is catalytically hydrogenated in an ammonium hydrogen sulfate solution  

The catalyst is platinum on carbon that is suspended in a dilute sulfuric acid solution. 

Cyclohexanone oxime is formed by reacting cyclohexanone with ammonium hydroxylammonium sulfate  

Oximation takes place in a special column by means of countercurrent flow of cyclohexanone and hydroxylamine solution with 97 to 98% conversion. Temperature is kept above the melting point of cyclohexanone oxime264. 

The above steps make 1.5 to 1.55 pounds of ammonium sulfate per pound of caprolactam produced. The entire process make 2.3 to 2.35 pounds of ammonium sulfate per pound of caprolactam. The yield of caprolactam is -70%, which results in 0.94 pounds of caprolactam per pound of cyclohexane consumed266. 

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Reppe s work also resulted in the high pressure route which was estabUshed by BASF at Ludwigshafen in 1956. In this process, acetylene, carbon monoxide, water, and a nickel catalyst react at about 200°C and 13.9 MPa (2016 psi) to give acryUc acid. Safety problems caused by handling of acetylene are alleviated by the use of tetrahydrofuran as an inert solvent. In this process, the catalyst is a mixture of nickel bromide with a cupric bromide promotor. The hquid reactor effluent is degassed and extracted. The acryUc acid is obtained by distillation of the extract and subsequendy esterified to the desked acryhc ester. The BASF process gives acryhc acid, whereas the Rohm and Haas process provides the esters dkecdy. 

Table 9. BASF Process Consumptions and By-Product Yields and Cracked Gas Composition, ...

The BASF process uses /V-methy1pyrro1idinone as the solvent to purify acetylene in the cracked gas effluent. Alow pressure prescmbbing is used to remove naphthalenes and higher acetylenes. The cracked gas is then compressed to 1 MPa (10 atm) and fed to the main absorption tower for acetylene removal. Light gases are removed from the top of this tower. 

More recent process research aimed at anionic PS is that of BASF AG. Unlike the Dow Process, the BASF process utilizes continuous linear-flow reactors (LFR) with no back-mixing to make narrow polydispersity resins. This process consists of a series alternating reactors and heat exchangers (Fig. 22). Inside the reactors, the polymerization exotherm carries the temperature from 30°C at the inlet to 90°C at the outlet. The heat exchangers then take the temperature back down to 30°C. This process, which requires no solvent, results in the formation of narrow polydispersity PS. 

The first CO route to make adipic acid is a BASF process employing CO and methanol in a two-step process producing dimethyl adipate [627-93-0] which is then hydroly2ed to the acid (43—46). Cobalt carbonyl catalysts such as Co2(CO)g are used. Palladium catalysts can be used to effect the same reactions at lower pressures (47—49). 

The BASF Process. Styrene is blended with a low boiling hydrocarbon and then polymerised. The product is chipped. The chips are then converted into expanded polymer as in method (4) described in detail below. 

BASF Patents. A BASF process for HIPS as described by the patent to Bronstert et al (3 ) is related closely to the patent of Ruffing ( ) discussed above. 

The BASF process requires pretreatment. Plastics are separated from non-plastics, ground and agglomerated. The agglomerate is fed into the process. 

As for processing costs, the BASF process would require a gate fee of 160 per tonne for a... 

The Texaco, Polymer Cracking, VEBA and BASF processes all produce mainly liquid organics or gases that replace primary oil- or gas-based resources. However, it has to be acknowledged that both BASF and VEBA have been closed down or will be closed down shortly, and that the other two processes have not yet been realised on a large scale. 

The oxidation of an undisclosed methanol derivative to the corresponding formaldehyde compound is a large-scale BASF process which was established in recent years, whereas the similar methanol-to-formaldehyde process, performed on a much larger scale, has been practised at BASF for more than 100 years [1,49-51, 108]. The exact nature of the substituent(s) was not disclosed by BASF for reasons of confidentiality, although many publications on that topic appeared. The nature of the substituent makes the derivative, as the results of the investigations show, more labile to temperature. 

Figure 5.1. The generations of oxo processes [3] (symbolized by full points).A, First generation Ruhrchemie process 1943 (diaden process [4]) B, second generation Ruhrchemie process C, second generation BASF process D, second generation Kuhlmann process E, third generation Shell process F, third generation LPO (UCC) process G, third generation BASF process H, third generation Exxon (Kuhlmann) process I, fourth generation Ruhrchemie/Rhone-Poulenc process...

The high catalyst loading typical of sol gel entrapped catalysts ensures a desirably high substrate/catalyst (S/C) ratio as the major part of the heterogeneous catalyst weight originates from the silicate matrix. For example, in a preparative-scale reaction of the alcohol raol-(2-naphthyl)-ethanol only 250 mg of sol-gel CaLB immobilizate could be used per 10 g of substrate. For comparison, all this makes the process based on sol-gel immobilized lipase very competitive with the commercial BASF process using lipase immobilized on Amberlite to produce the amine at a scale of 1000 tons per year. 

Union Carbide (34) and in particular Dow adopted the continuous mass polymerization process. Credit goes to Dow (35) for improving the old BASF process in such a way that good quality impact-resistant polystyrenes became accessible. The result was that impact-resistant polystyrene outstripped unmodified crystal polystyrene. Today, some 60% of polystyrene is of the impact-resistant type. The technical improvement involved numerous details it was necessary to learn how to handle highly viscous polymer melts, how to construct reactors for optimum removal of the reaction heat, how to remove residual monomer and solvents, and how to convey and meter melts and mix them with auxiliaries (antioxidants, antistatics, mold-release agents and colorants). All this was necessary to obtain not only an efficiently operating process but also uniform quality products differentiated to meet the requirements of various fields of application. In the meantime this process has attained technical maturity over the years it has been modified a number of times (Shell in 1966 (36), BASF in 1968 (37), Granada Plastics in 1970 (38) and Monsanto in 1975 (39)) but the basic concept has been retained. 

Let us recall that by the sol-gel method one can obtain very efficiently very well-defined systems such as Ti silicalite, which can be considered as a single site system where titanium is tetracoordinated in a zeolitic matrix and undergoes epoxidation of propylene or hydroxylahon of benzene to phenol. Bear in mind that it took industry more than 20 years to realize such an industrial processes (Dow-BASF process) [1]). 

Scheme 6.6 BASF process for enzymatic resolution of amines.

Scheme 7.10 The resolution of chiral amines examples of the substrate range used by the BASF process demonstrated on a multi-ton scale.

The industrial catalytic Reppe process is usually applied in the production of acrylic acid. The catalyst is NiBr2 promoted by copper halides used under forcing conditions. The BASF process, for example, is operated at 225°C and 100 atm in tetrahydrofuran solvent.188 Careful control of reaction conditions is required to avoid the formation of propionic acid, the main byproduct, which is difficult to separate. Small amounts of acetaldehyde are also formed. Acrylates can be produced by the stoichiometric process [Eq. (7.20)], which is run under milder conditions (30-50°C, 1-7 atm). The byproduct NiCl2 is recycled ... 

In contrast, high-molecular-weight (up to 500,000) elastomeric materials are formed by lowering the polymerization temperature. Two important continuous slurry processes are used the Exxon (Vistanex) process with A1C13 catalyst and the BASF process (Oppanol), which polymerizes isobutylene dissolved in ethylene (in a ratio about 1 2) in the presence of BF3. Ethylene serves as the internal cooler. 

There is litde recent information on the Exxon and BASF processes (85—87). The CRF, Exxon, and BASF processes use sulfuric acid as the extraction medium. The BASF process is the dominant process in Europe. It uses the dilutest acid of any commercial process. This permits selective reaction even in the presence of butadiene. The BASF process uses vapor—liquid extraction unlike the Exxon and CRF processes which are of the liquid—liquid type. 

Figure 15.1. Processes for making adsorbents, (a) Flowsketch of a process for making molecular sieve adsorbents, (b) Process for reactivation of bone char, (c) Silica gel by the BASF process. The gel is formed and solidifies in air from sodium silicate and sulfuric acid, then is washed.free of sodium sulfate with water (Ullmann, Encyclopedia of Chemical Technology, Verlag Cliemie, Weinheim, Germany).

In the classical oxo process the catalyst cohalt carbonyl is formed in situ by introducing divalent cobalt into the reactor. High temperature is required for this catalyst formation that gives a mixture of aldehydes and alcohols containing only 60-70% of linear product. A new BASF process using cobalt carbonyl hydride shows improved selectivity and efficient catalyst recovery. The catalyst is prepared by passing an aqueous solution of cobalt salt over a promoter and extracting the catalyst from the water phase with olefin. 

The first-generation catalyst, a cobalt carbonyl ligand, was employed in the BASF process. In the next generation, phosphine species were added to milden the reaction conditions and to optimize the linear to branched ratio. In the third... 

Among the various reactions catalyzed by bases, we have selected (i) the polymerization of ethylene oxide catalyzed by MgO (260), (ii) the closely related reaction of ethylene oxide with alcohols on basic hydrotalcites to give polyoxyethylene polymer (the Henkel process), (iii) the phenol alkylation with methanol on MgO (General Electric and BASF processes) (261), and (iv) phenol animation to give aniline on MgO (the USS process) (262). 

The BASF process differs from the conventional process principally in the method used to prepare the hydroxylamine sulfate that is needed for the oximation step. The BASF process differs from the conventional process principally in the method used to prepare the hydroxylamine sulfate that is needed for the oximation step. The steps in the BASF process are listed below and shown in Figure 21.246,264,266 ... 

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