Refinery gas analysis

FJMBMS at SERI and a Hewlett-Packard 5890 gas chromatograph/5970 Mass Selective Detector (GC/MSD) using a 1.5-m high-performance cross-linked methyl silicone capillary column. The noncondensible gases were analyzed with a Carle GC designed for refinery gas analysis, which used thermal conductivity detection (TCD) and was calibrated with a gravimetrically prepared reference mixture. Electronic grade methanol (99.9% pure) was used for comparison to the softwood feedstock. 

FIGURE 13.18 Typical chromatogram from a standard refinery gas analyzer with simultaneous TCDMD (a) refinery gas analysis, FID output (b) enlargement of C5 fraction of FID output (c) refinery gas analysis, TCD output. (Reprinted with permission from Reference 68, Wasson-ECE Instrumentation.)... 

The temperature profile inside the catalyst bed was monitored by three thermocouples and controlled by five-zone furnace. The performance activity tests were carried out for 48 hours after the steady state had been reached. The liquid product stream from the reactor was condensed at 10°C in a gas-liquid separator, and was immediately stripped of dissolved hydrogen sulfide by extraction with acidified cadmium chloride solution prior to analysis. The gaseous products were analyzed periodically by refinery gas analyzer. The experiments were designed to investigate the effects of temperature (220-350°C), space velocity (10 and 13 h ), hydrogen gas rate (67 and 80 NmVm ) with two feedstock types on the performance of the catalysts. 

Reaction products were analyzed using several chromatographs. Gas products were analyzed using a Flewlett-Packard Quad-Series Refinery Gas Analyzer Micro Gas Chromatograph (QRGA). The analysis of the aqueous phase collected beyond the reactor used a Hewlett-Packard 5790 GC with a thermal conductivity detector and a Porapak Q column. Oil and wax were combined and analyzed with a Hewlett-Packard 5890 GC with a flame ionization detector and a 60 m DB-5 column. The reactor wax was analyzed on a Hewlett-Packard 5890 High Temperature GC with an flame ionization detector and a 30 m alumina clad HT-5 column. 

The development of GC and the analysis of petroleum and petrochemicals have enjoyed a mutually beneficial relationship. Indeed, the first international symposium on vapor-phase (gas) chromatography was sponsored by the British Institute of Petroleum in 1956 (9). Papers describing the analysis of refinery gas, solvents, aromatics in coal-tar naphthas, and samples from the internal combustion engine were presented. Most of the work included in these presentations was done on homebuilt chromatographs. The first commercial gas chromatograph or vapor-phase fractometer was also described, along with the first ionization detector. 

Analysis of specific components or classes of components in refinery gases can be accomplished with single-column analyses. However, combinations of columns and valving are required for more complete analyses. The various aspects of hydrocarbon gas analysis have been discussed by Thompson (61). Applicable columns for these applications can also be found in column supplier catalogs and the reviews by Mindrup (62) and Leibrand (63). 

Smith, J. B., Predicting Future Failure Risk with Weibull Analysis, First International Conference on Improving Reliability in Petroleum Refineries and Chemical Plants and Natural Gas Plants, Organized by Gulf Publishing Co. and Hydrocarbon Processing, Houston, TX, November, 1992. 

Mahoney (1997) has analysed the 170 largest losses in refineries, petrochemical plants and gas processing plants from 1966 to 1996. Nearly all the losses in the analysis involved fires or explosions. Most common primary cause of losses was piping. Instone (1989) analysed some 2000 large loss claims of hydrocarbon industry at Cigna Insurance. Table 20 lists the ISBL equipment and Table 21 lists the data of the OSBL equipment by Mahoney (1992, 1997) and Instone (1989). 

GC-Computer System Nowadays, a large number of data-processing-computer-aided instruments for the automatic calculation of various peak parameters, for instance relative retention, composition, peak areas etc., can be conveniently coupled with GC-systems. A commercially available fairly sophisticated computer system of such type are available abundantly that may be capable of undertaking load upto 100 gas-chromatographs with ample data-storage facilities. In fact, the installation such as multi GC-systems in the routine analysis in oil-refineries and bulk pharmaceutical industries, and chemical based industries have tremendously cut-down their operating cost of analysis to a bare minimum. 

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