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2 Zeszyty Naukowe. Chemia / Politechnika Śląska

2 2001

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Wpływ nierównomiernego przepływu gazu przez rury katalityczne na parametry pracy reformera

100%

Gołębiowski A. , Wróbel W.

2001

tom z. 142

29-33

Hydrocarbon steam reforming is one of the most important processes of heavy chemical synthesis. High volume velocities and heat loads are used in modern reformers and working parameters of catalytic tubes are very hard. Life time of tubes depends on maximal wall temperature which is influenced mainly by: the catalyst activity, the gas purity and a non-uniformities in the gas flow. The effect of a non-uniform gas flow through catalytic tubes on reformer performance are presented. Catalysts used nowadays have very good and stable mechanical properties. Nevertheless, gas flow resistance grows gradually during the operation of the reformer. Most often the catalyst is damaged during shut-down operation when it undergoes the influence of strong forces caused by tube dilatation. We have made statistical analysis of resistance changes in individual tubes assuming that they are random and a total resistance of the reformer is calculated as an equivalent resistance of a system the tubes connected parallely. We calculated wall temperature increase caused by reduced gas flow using an appropriately modified program for reformer simulations. An analysis of operational data and of results of the simulations indicates that the differences in gas flow can cause wall temperature increase by about 20 degrees centigrade. In extreme cases, it can shorten tube life-time by a half.

Analiza symulacyjno-porównawcza węzłów pozyskiwania gazu syntezowanego

80%

Dukowicz J. , Możeńska B. , Wróbel W.

2001

tom z. 142

15-19

Two basis types of synthesis gas obtainment units are found in the major part of domestic ammonia production plants. One of the systems includes primary reformer, secondary reformer and a heat recovery subsystem (ZAT, ZCh Police, ZAW, Puławy II). The other one consists of natural gas cracker and heat recovery subsytem (ZAK, Puławy I). The main controllable parameter at the inlet of the above mentioned units is C/H2O ratio. Entire cost of the synthesis gas obtainment is also influenced by prices of the raw materials (natural gas, steam, oxygen), as well as by the equipment design. Following computer implementation, mathematical models of the above mentioned equipment arising from our own investigations have been included to the "TAWAS" package [1], which enabled to analyse performance of the sections by computer simulation. The results obtained have provided both the guidelines to offers for modernization of the synthesis gas obtainment sections and the data to operate the existing.