Catalysts processing

Slurry (Suspension) Polymerization. This polymerization technology is the oldest used for HDPE production and is widely employed because of process engineering refinement and flexibHity. In a slurry process, catalyst and polymer particles are suspended in an inert solvent, ie, a light or a... 

In this process, catalysts, such as boric acid, molybdenum oxide, zirconium, and titanium tetrachloride or ammonium molybdate, are used to accelerate the reaction. The synthesis is either carried out in a solvent (aUphatic hydrocarbon, trichlorobenzene, quinoline, pyridine, glycols, or alcohols) at approximately 200°C or without a solvent at 300°C (51,52). 

In some liquid-phase processes, catalyst components are slowly leached from the catalyst bed and eventually the catalyst must be replaced. The feasibility of this type of process involves economics, ie, the costs of catalyst maintenance and keeping a unit out of service for catalyst replacement, and product quality and safety, ie, the effects of having catalyst components in the product and their ease of removal. 

The 0X0 process for higher alcohols CO -1- H9 -1- C3H6 /1-butanal further processing. Catalyst is rhodium triphenylphos-phine coordination compound, 100°C (212°F), 30 atm (441 psi). 

In many cases, two identical reaction systems (e.g., a pilot plant scale and a full-scale commercial plant) exhibit different performances. This difference in performance may result from different flow patterns in the reactors, kinetics of the process, catalyst performance, and other extraneous factors. 

Advances in catalysis will result in the development of high yield, low waste manufacturing processes. Catalysts frequently allow the use of less reactive raw materials and intermediates, and less severe processing conditions. High yields and improved... 

Normally, crude oils are not used directly as fuels or as feedstocks for the production of chemicals. This is due to the complex nature of the crude oil mixture and the presence of some impurities that are corrosive or poisonous to processing catalysts. 

Oxygen compounds in crude oils are more complex than the sulfur types. However, their presence in petroleum streams is not poisonous to processing catalysts. Many of the oxygen compounds found in crude oils are weakly acidic. They are carboxylic acids, cresylic acid, phenol, and naphthenic acid. Naphthenic acids are mainly cyclopentane and cyclohexane derivatives having a carboxyalkyl side chain. 

Reduce harmful impurities in petroleum fractions and residues to control pollution and to avoid poisoning certain processing catalysts. For example, hydrotreatment of naphtha feeds to catalytic reformers is essential because sulfur and nitrogen impurities poison the catalyst. 

Antioxidant additive in the polyethylene resin. While such an additive can prevent oxidation, and thus odor, it also can contribute directly to the odor. If an antioxidant is needed, it must be FRA approved, should have a high melting point, and should be used at a minimum level consistent with the extrusion process. Catalyst residues and antioxidants present in polyethylene sometimes interact to form odorous products. 

Oxidative dehydrogenation processes Catalyst development Pt group Cu, Sn, and Cl 86... 

Process Catalyst Pressure/atm Temperature/°C Density of product/g cm" ... 

Microelectronic circuits for communications. Controlled permeability films for drug delivery systems. Protein-specific sensors for the monitoring of biochemical processes. Catalysts for the production of fuels and chemicals. Optical coatings for window glass. Electrodes for batteries and fuel cells. Corrosion-resistant coatings for the protection of metals and ceramics. Surface active agents, or surfactants, for use in tertiary oil recovery and the production of polymers, paper, textiles, agricultural chemicals, and cement. 

Cobalt catalysts such as HCo(CO)4 are widely used for hydroformyla-tion of higher alkenes, despite the higher temperatures and pressures required. The main reason for this is that these catalysts are also efficient alkene isomerization catalysts, allowing a mix of internal and terminal alkenes to be used in the process. Catalyst recovery is more of a problem here, involving production of some waste and adding significantly to the complexity of the process. A common recovery method involves treating the catalyst with aqueous base to make it water soluble, followed by separation and subsequent treatment with acid to recover active catalyst (4.3). 

Catalysts are the workhorses of chemical transformations in the industry. Approximately 85-90 % of the products of chemical industry are made in catalytic processes. Catalysts are indispensable in... 

Continuous processes are designed to operate 24 hours a day, 7 days a week, throughout the year. Some down time will be allowed for maintenance and, for some processes, catalyst regeneration. The plant attainment that is, the percentage of the available hours in a year that the plant operates, will usually be 90 to 95%. 

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