Since process design starts with the reactor, the first decisions are those which lead to the choice of reactor. These decisions are among the most important in the whole design. Good reactor performance is of paramount importance in determining the economic viability of the overall design and fundamentally important to the environmental impact of the process. In addition to the desired products, reactors produce unwanted byproducts. These unwanted byproducts create environmental problems. As we shall discuss later in Chap. 10, the best solution to environmental problems is not elaborate treatment methods but not to produce waste in the first place.  [c.15]

Chemical process design starts with the selection of a series of processing steps and their interconnection into a flowsheet to transform raw materials into desired products. Whereas a great emphasis in chemical engineering traditionally has heen placed on the analysis or simulation of flowsheets, the creation or synthesis of flowsheets has received, hy comparison, little attention. Yet the decisions made during the synthesis of the flowsheet are of paramount importance in determining the economic viability, safety, and environmental impact of the flnal design. This text will concentrate on developing an understanding of the concepts required at each stage of the synthesis of process flowsheets.  [c.473]

It has been used as a bird repellant and is the parent compound of the anthraquinone vat dyes in which the dyeing is carried out by immersion in the reduced vat solution followed by air oxidation to the original insoluble compound.  [c.37]

It may be regarded as the parent of a number of important classes of compounds derived from the y-pyrone skeleton (e.g. flavone, xan-thone) and the important chroman derivatives called the tocopherols (vitamin E).  [c.97]

Used in reprographic processes, particularly the ozalid blue-print paper processes.  [c.133]

C. It can be prepared from uric acid, but is not obtained naturally, and is not physiologically important, although many of its derivatives are. It is the parent compound of a group of compounds of animal and vegetable origin, collectively called purines. The group includes adenine and guanine, which are constituents of the nucleic acid portion of nucleo-proteins, their breakdown products, hypo-xanthine, xanthine and uric acid, and the drugs caffeine, theobromine and theophylline.  [c.333]

It is the parent substance of a group of compounds which includes cytosine, thymine and uracil, which are constituents of nucleic acids and barbituric acid and its derivatives, which are important medicinally.  [c.335]

SchifT s bases A -Arylimides, Ar-N = CR2, prepared by reaction of aromatic amines with aliphatic or aromatic aldehydes and ketones. They are crystalline, weakly basic compounds which give hydrochlorides in non-aqueous solvents. With dilute aqueous acids the parent amine and carbonyl compounds are regenerated. Reduction with sodium and alcohol gives  [c.353]

Slags are also produced in metal refining processes where oxidation is used to separate the impurities, e.g. steelmaking, copper and lead refining. The aim in refining is to control the slag composition to elTect the removal of impurities and this process invariably means that some of the parent metal is oxidized and passes into the slag. In steelmaking the aim is to remove C, S and P and this requires a slag high in CaO, i.e. a basic slag.  [c.361]

Sydnones are neutral, highly crystalline, stable compounds, soluble in most organic solvents. N-Arylsydnones typically are obtained by treating N-nitroso-N-aryl-glycines with etha-noic anhydride. The parent glycine is regenerated when the sydnone is heated with dilute alkali.  [c.382]

Colourless crystals m.p. 174 C. It is obtained by the action of heat on phenyl salicylate. It may be reduced to xanthene. It is the parent substance of the xanthone group of dyestuffs.  [c.428]

The relations which permit us to express equilibria utilize the Gibbs free energy, to which we will give the symbol G and which will be called simply free energy for the rest of this chapter. This thermodynamic quantity is expressed as a function of enthalpy and entropy. This is not to be confused with the Helmholtz free energy which we will note sF (L" j (j, > )  [c.148]

Procurement is a matter of getting the right materials together at the right time and within a specified budget. For items which can be obtained from a number of sources a tendering process may appropriate, possibly from a list of company approved suppliers. Very exotic items, or items which are particularly critical, may be acquired through a single source contract where reliability is paramount. Made up items such as turbines will often be accompanied by test certification which has to be checked for compliance with performance and safety standards. Equipment must be inspected when the company takes delivery, to ensure that goods have not been damaged in shipment. The procurement team may also be responsible for ensuring that the supply of spare parts is secure. Spending at this stage can range anywhere from 10% to 40% of the total project cost.  [c.293]

The generic term azulene was first applied to the blue oils obtained by distillation, oxidation, or acid-treatment of many essential oils. These blue colours are usually due to the presence of either guaiazulene or velivazulene. The parent hydrocarbon is synthesized by dehydrogenation of a cyclopentanocycloheptanol or the condensation of cyclopentadiene with glutacondialdehyde anil.  [c.49]

The parent acid is unstable and always reverts to the lactone form shown. It is reconverted to acetoacetic ester by boiling alcoholic potassium hydroxide. Reduced by hydrogen iodide to dimethylpyrone.  [c.127]

M.p. 296 C. Accepts an electron from suitable donors forming a radical anion. Used for colorimetric determination of free radical precursors, replacement of Mn02 in aluminium solid electrolytic capacitors, construction of heat-sensitive resistors and ion-specific electrodes and for inducing radical polymerizations. The charge transfer complexes it forms with certain donors behave electrically like metals with anisotropic conductivity. Like tetracyanoethylene it belongs to a class of compounds called rr-acids. tetracyclines An important group of antibiotics isolated from Streptomyces spp., having structures based on a naphthacene skeleton. Tetracycline, the parent compound, has the structure  [c.389]

Si,Al) 02n frameworks with a negative charge which is balanced by cations present in the cavities. The cations are easily exchanged and water and gases can be selectively absorbed into the cavities. Various types of zeolites are known including analcite, chabaz-ite, faujasile, the synthetic zeolite A, natrolite and thomsite. Sodium-containing zeolites are used to soften water, replacing Ca " by Na, the zeolite (permutit) is regenerated with concentrated NaCI solution. Zeolites are used to remove molecules of specific sizes by absorption into the pores of the zeolite (molecular sieves) for drying solvents and absorbing gases.  [c.432]

The recording of the acoustic emission values is realized with a conventional PC with a 120MHz Pentium processor, 64 Mbyte RAM and an integrated eight channel analog/digital converter card. Onechannel measurings permit a maximum sample rate of 700 kHz which is equal to a recording time about 46 s. For low frequency investigations up to 50 MHz analysing frequency, conventional piezoelectric acceleration trancducers were used.  [c.15]

The AEBBL SW ains on the PC. The software uses a menu structure, easy to use by a non expert operator. AEBIL has been designed to operate in DOS environjnent in order to enhance its real-time operation capabilities. The user-interface has been developed so as to permit a window-driven operation.  [c.70]

See pages that mention the term Pairmeter : [c.221]    [c.231]    [c.238]    [c.240]    [c.256]    [c.348]    [c.350]    [c.77]    [c.62]    [c.69]    [c.77]    [c.106]    [c.123]    [c.183]    [c.188]    [c.188]    [c.191]    [c.211]    [c.219]    [c.222]    [c.249]    [c.252]    [c.265]    [c.281]    [c.281]    [c.294]    [c.309]    [c.345]    [c.407]    [c.297]    [c.386]   
Standard Handbook of Petroleum and Natural Gas Engineering Volume 1 (1996) -- [ c.1312 ]