PDF | Systematic approaches for the invention of conceptual chemical process text, Conceptual Design of Chemical Processes by Douglas (), was pub-. CONCEPTUAL DESIGN OF CHEMICAL PROCESSES James M. Douglas, Ph. D., is currently a professor of chemical engineering at the. University of. Conceptual design of chemical processes / James M. Douglas Publisher: Singapore: McGraw-Hill, ; Digital Description: application/pdf, xviii, p.: ill.
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CONCEPTUAL DESIGN OF CHEMICAL PROCESSES • James M. Douglas Un~ rsilY of Massodwsttts McGraw-Hili Rook Company New York 51 Louis San. Conceptual Design of Chemical Processes (by James M. Douglas) - Ebook download as PDF File .pdf) or view presentation slides online. Textbook for process. Design Of Chemical Processes By James M Douglas [PDF] [EPUB] Download with Facebook or download with email - Fri, 05 Apr GMT (PDF).
The full text of this article hosted at iucr. Use the link below to share a full-text version of this article with your friends and colleagues. Learn more. Volume 46 , Issue 3. Please check your email for instructions on resetting your password. If you do not receive an email within 10 minutes, your email address may not be registered, and you may need to create a new Wiley Online Library account. If the address matches an existing account you will receive an email with instructions to retrieve your username.
Mar 16, Sean rated it it was ok Someone suggested to me that the approach to "Process Design" elaborated in academia can be traced back to a seminal book- this one. As the title suggests, it attempts to design chemical processes, rather than process plants.
Its author understands that the expert designer proceeds by intuition and analogy, aided by back of the envelope calculations, but sees the need for a method which helps beginners to cope with all of the extra calculations they have to do whilst they are waiting to become e Someone suggested to me that the approach to "Process Design" elaborated in academia can be traced back to a seminal book- this one.
Its author understands that the expert designer proceeds by intuition and analogy, aided by back of the envelope calculations, but sees the need for a method which helps beginners to cope with all of the extra calculations they have to do whilst they are waiting to become experts. The arguments underlying the academic approach since built on it are helpfully set out explicitly.
It assumes that the purpose of conceptual design is to decide on process chemistry and parameters like reaction yield. Choices between technologies are not considered.
The radiation beam passes through this flame at its longest axis, and the flame gas flow-rates may be adjusted to produce the highest concentration of free atoms. The burner height may also be adjusted, so that the radiation beam passes through the zone of highest atom cloud density in the flame, resulting in the highest sensitivity.
The processes in a flame include the stages of desolvation drying in which the solvent is evaporated and the dry sample nano-particles remain, vaporization transfer to the gaseous phase in which the solid particles are converted into gaseous molecule, atomization in which the molecules are dissociated into free atoms, and ionization where depending on the ionization potential of the analyte atoms and the energy available in a particular flame atoms may be in part converted to gaseous ions.
Each of these stages includes the risk of interference in case the degree of phase transfer is different for the analyte in the calibration standard and in the sample. Ionization is generally undesirable, as it reduces the number of atoms that are available for measurement, i. In flame AAS a steady-state signal is generated during the time period when the sample is aspirated. This typically consists of stages, such as drying — the solvent is evaporated; pyrolysis — the majority of the matrix constituents are removed; atomization — the analyte element is released to the gaseous phase; and cleaning — eventual residues in the graphite tube are removed at high temperature.
Tubes may be heated transversely or longitudinally, where the former ones have the advantage of a more homogeneous temperature distribution over their length. In ET AAS a transient signal is generated, the area of which is directly proportional to the mass of analyte not its concentration introduced into the graphite tube.
This technique has the advantage that any kind of sample, solid, liquid or gaseous, can be analyzed directly. It shows a very high degree of freedom from interferences, so that ET AAS might be considered the most robust technique available nowadays for the determination of trace elements in complex matrices.
The glow discharge occurs in a low-pressure argon gas atmosphere between 1 and 10 torr. In this atmosphere lies a pair of electrodes applying a DC voltage of to V to break down the argon gas into positively charged ions and electrons.
These ions, under the influence of the electric field, are accelerated into the cathode surface containing the sample, bombarding the sample and causing neutral sample atom ejection through the process known as sputtering. The atomic vapor produced by this discharge is composed of ions, ground state atoms, and fraction of excited atoms.
When the excited atoms relax back into their ground state, a low-intensity glow is emitted, giving the technique its name. The requirement for samples of glow discharge atomizers is that they are electrical conductors. Consequently, atomizers are most commonly used in the analysis of metals and other conducting samples.
However, with proper modifications, it can be utilized to analyze liquid samples as well as nonconducting materials by mixing them with a conductor e.
Hydride atomization[ edit ] Hydride generation techniques are specialized in solutions of specific elements. The technique provides a means of introducing samples containing arsenic, antimony, selenium, bismuth, and lead into an atomizer in the gas phase. With these elements, hydride atomization enhances detection limits by a factor of 10 to compared to alternative methods.
The volatile hydride generated by the reaction that occurs is swept into the atomization chamber by an inert gas, where it undergoes decomposition.
This process forms an atomized form of the analyte, which can then be measured by absorption or emission spectrometry. Cold-vapor atomization[ edit ] The cold-vapor technique is an atomization method limited to only the determination of mercury, due to it being the only metallic element to have a large enough vapor pressure at ambient temperature. The mercury, is then swept into a long-pass absorption tube by bubbling a stream of inert gas through the reaction mixture.
The concentration is determined by measuring the absorbance of this gas at Detection limits for this technique are in the parts-per-billion range making it an excellent mercury detection atomization method. In classical LS AAS, as it has been proposed by Alan Walsh,  the high spectral resolution required for AAS measurements is provided by the radiation source itself that emits the spectrum of the analyte in the form of lines that are narrower than the absorption lines.
Continuum sources, such as deuterium lamps, are only used for background correction purposes. The advantage of this technique is that only a medium-resolution monochromator is necessary for measuring AAS; however, it has the disadvantage that usually a separate lamp is required for each element that has to be determined.
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