Ammonia Lab Report

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Abstract & Introduction PETRONAS Fertiliser Kedah Sdn. Bhd. is a company that deal with production of ammonia, methanol and urea. In this project, the primary reformer tube replacement and catalyst changeout was among many job that was done during the plant turn around. To understand about this project, we must familiarize first with the ammonia production in the ammonia plant and the function of the primary reformer in ammonia production. Ammonia Production Process Ammonia is produced from a gaseous mixture of hydrogen (H2) and nitrogen (N2) in the stochiometric ratio 3 to 1. The sources of hydrogen and nitrogen in the ammonia plant are natural gas and atmospheric air respectively. The preparation of this synthesis gas takes place in various…show more content…
Poisons are usually substances whose interaction with the active sites is very strong and irreversible. Sulphur is the most severe poison to the steam reforming catalyst. The poisoning of the catalyst is non-reactive as the catalyst surface sites are uniform to the poison, and accordingly the poison chemisorption occurs in a uniform manner. As a result, the net activity of the surface is a linear function of the amount of poison chemisorbed. The damage of sulphur poisoning to the catalyst are reversible if the poison is not too strongly adsorbed. Regeneration of the catalyst usually occurs simply by poison removal from the feed. Elimination of sulphur from the feed and reduction with hydrogen removes the poison to leave the catalyst surface as it was before. The catalyst will regain its normal activity during some hours of normal operation on pure gas. However, gross poisoning leads to bulk changes which are not readily reversed: in this case the poisoning is irreversible. Poisoned catalyst can hardly be regenerated, and therefore the best method to reduce poisoning is to decrease to acceptable levels the poison content of the feed. This is generally achieved by appropriate treatments of the feed by catalytic hydrodesulphurization followed by H2S…show more content…
Pressure drop measurement equipment Haldor Topsoe SpiraLoad unit 2 set. Results and Discussion Findings The tube replacement and catalyst change out resulted in several changes to the plant performance. The outer diameter of the tube remains at 152.0 mm but the inner diameter size change from 126.8 mm to 129.4 mm. The volume of catalyst loaded inside the tube increased by 20%. The new tubes have a thinner tube wall which resulted in higher heat transfer efficiency. This allowed for the reformer temperature to be brought down thus reducing the tube skin temperature and increase the tube life spent. The fuel consumption in the primary reformer is reduced and the fuel pressure to the burner is reduced. These reduced the risk of flame impingement to the tube and lower the chances of hotspot formation. The effect of increasing the volume of catalyst in improving the performance of the primary reformer can be seen in the volume of methane slippage. The slippage at the primary reformer has been reduced from ~11 vol. % to only ~7 vol. % methane. The pressure drop in the reformer tube also has been reduced from ~3bar to ~2bar. Data

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