Plant performance, analysis laboratory

Confidence The accuracy of the conclusions drawn from any unit test depends upon the accuracy of the laboratory analyses. Plant-performance analysts must have confidence in these analyses including understanding the methodology and the limitations. This confidence is established through discussion, analyses of known mixtures, and analysis of past laboratory results. This confidence is established during the preparation stage. 

The economic treatment discussed so far is hmited to analytical laboratories where samples are received from an outside source it will not apply to laboratories attached to processing plants performing quahty-control analyses. The cost of the automatic equipment, in these cases, wiU be small in relation to the plant cost, and it wiU be the improved precision of analysis and speed of response that wiU have the greatest economic significance. Automatic analysers in production hnes are ideal for quality control, and there is ample scope for additional automation. However, this is an area where the... 

The basic principles of sulfuric and hydrofluoric acid catalyzed alkylation reactions have been described in many different articles and books, some of which are tabulated in the bibliography (13-23). The complexity of the reaction is such that many details could not be isolated until the advent of sophisticated analytical equipment and techniques. The fact that commercial refinery allqrlation units almost always receive feeds of varying rate and/or composition makes the analysis of such plants performance very difficult. Even with a constant feed, the number of olefinic compounds usually present in the feed promotes different reactions and side-reactions, the products of which generally end up in the alkylate product. Laboratory studies of alkylation of isobutane with individual pure olefins have provided significant data on reaction rates and yields as influenced by the common reaction variables (24). 

Laboratory Instrumentation Successful operation of a modern coal preparation plant requires the availability of a well equipped and well staffed coal analysis laboratory This laboratory must be capable of performing tests to characterize... 

Preparatory work for the steps in the scaling up of the membrane reactors has been presented in the previous sections. Now, to maintain the similarity of the membrane reactors between the laboratory and pilot plant, dimensional analysis with a number of dimensionless numbers is introduced in the scaling-up process. Traditionally, the scaling-up of hydrodynamic systems is performed with the aid of dimensionless parameters, which must be kept equal at all scales to be hydrodynamically similar. Dimensional analysis allows one to reduce the number of variables that have to be taken into accoimt for mass transfer determination. For mass transfer under forced convection, there are at least three dimensionless groups the Sherwood number, Sh, which contains the mass transfer coefficient the Reynolds number. Re, which contains the flow velocity and defines the flow condition (laminar/turbulent) and the Schmidt number, Sc, which characterizes the diffusive and viscous properties of the respective fluid and describes the relative extension of the fluid-dynamic and concentration boundary layer. The dependence of Sh on Re, Sc, the characteristic length, Dq/L, and D /L can be described in the form of the power series as shown in Eqn (14.38), in which Dc/a is the gap between cathode and anode Dw/C is gap between reactor wall and cathode, and L is the length of the electrode (Pak. Chung, Ju, 2001) ... 

Design procedures included laboratory tests on polymer rheology, relative permeability, shear degradation, screen factor, stability, and salinity effects. Computer simulations were performed to predict recoveries and to examine optimum polymer concentration. Field injectivity tests were conducted to examine injectivity behavior with time and to gain experience in surface handling of the polymer. Pressure-falloff tests were conducted in conjunction wiA the injectivity tests. Finally, the prqiamtion involved design of the polymer-injection plant and analysis of costs. 

The environmental impact of a new product needs to be assessed before it can be released for general use. Chemicals released into the environment can enter the food chain and be concentrated in plants and animals. Aquatic ecosystems are particularly sensitive, in this respect, since chemicals, when applied to agricultural land, can be transported in the ground water to rivers and then to the lakes, where they can accumulate in fish and plant life. The ecokinetic model presented here is based on a simple compartmental analysis and is based on laboratory ecosystem studies (Blau et ah, 1975). The model is useful in simulating the results of events, such as the accidental spillage of an agrochemical into a pond, where it is not ethical to perform actual experimental studies. 

Indications from both microscopic analyses of metallic particles from corrosion tests and evidence from the Oklo natural reactors indicate that performance assessment calculations should not assume 99Tc is easily mobilized. It is entirely inappropriate to use "Tc release as a marker for fuel corrosion because Tc is not located in the fuel matrix. The TEM examinations of corroded e-particles have shown that Mo is preferentially leached from these phases, a behaviour that is similar to the one observed at Oklo. It is interesting to note that laboratory dissolution of billion-year old 4d-metallic particles for a chemical analysis required a corrosive mix of peroxide and acid (Hidaka Holliger 1998) similar to the experience at SNF reprocessing plants. It is doubtful that the oxidation potential at the surface of an aged fuel will be sufficient to move Tc(0) from the e-metal particles. 

Biological Samples. There were three types of biological samples obtained from workers at the plant urine, whole blood, and feces. All urine and blood samples were internally "spiked" at the factory with 1 yg/mL of a nitrosopiperidine (NPiP) standard. NPiP was used for spiking because it has a similar stability and recovery characteristic to nitrosomorpholine, and to provide a means of gauging the accuracy of the analytical methods. Due to the inability to perform homogeneous mixing on-site, the feces samples were not spiked until they were thawed upon return to the laboratory. Ethyl acetate extracts of urine samples were examined for the presence of N-nitrosodiethanolamine (NDEIA), a metabolite of NMOR, by HPLC-TEA. All samples were immediately frozen at the plant (-80°C) and kept at this temperature until analysis. 

The adaptation of supercritical fluid extraction (SFE) in routine residue and metabolism analysis as well as other extraction/separation laboratories and applications has been slow. This is despite the demonstrated feasibility of using SFE for the removal of sulfonylureas, phenylmethylureas and their metabolites from soil and plant materials (1-2), as well as widespread demonstrated use of supercritical fluid extraction for other applications (3-6). The reason for this is simple. Although automated, SFE extraction apparatus typically only analyzes a single sample at a time. The technique could not compete effectively with the productivity of an experienced technician performing many sample extractions simultaneously. In essence, with a one vessel automated supercritical fluid extractor, operator attendance is high and throughput is about the same or even less than current conventional liquid-liquid and solid-liquid extraction techniques. 

Washability analysis procedure used in a laboratory before preparation plant design to determine the cleaning processes to be employed and used during normal operation to evaluate the performance of the cleaning equipment and the amenability of the raw coal feed to the cleaning processes chosen (ASTM D-4371). 

One additional factor not directly covered in this paper is the issue of performance stability and the associated costs for refurbishment, repair or replacement of components with lifetimes shorter than the overall plant. None of the laboratory experiments to date for S-I, HyS or HTSE has run long enough and provided data that can be used to quantify degradation factors or lifetimes. Performance variation with time and limited lifetimes of components can be factored into the analysis, particularly as operating cost and replacement capital inputs. 

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