الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 92 |  |  |
| | | from | 92 | | |
Abstract
Petrochemicals are a necessary part of our lives, and we can’t imagine modern life without them. In fact, every part of our life today has its origins in the petroleum industry. Furthermore, in today’s world, petrochemical products, which are chemical products made from fossil fuels such as petroleum (crude oil), coal, and natural gas, are the origin of every modern industry.For these reasons a huge petrochemicals complex was established at the Middle East area which is used for the dehydrogenation of light hydrocarbons such as propane to propylene or butane to butylene. This project established for the first time using this technology for the commercial-scale production of propylene from propane. Our Company uses Propane as a feed stock where propane is transformed into Propylene through propane dehydrogenation (PDH) plant then Propylene is polymerized to produce polypropylene (PP) through PP plant. In this process propane is partly converted to propylene and hydrogen through the main dehydrogenation reaction and also CO2 is formed due to the hydrolysis reaction and Reconversion of coke lay down on the catalyst (caused by thermal cracking) with steam already during the operation cycle. Therefore CO2 is present in the process gas and must be removed to achieve purity specification of the propylene product. For this purpose, the MDEA process for sour gas removal is used. The process is an absorption process which uses MDEA, an amine solution which selectively absorbs CO2 contained in the product gas. However, the claimed conversion and selectivity were not achieved .in another aspect, reaction effluent changed in both composition and conditions from that stated by design. Consequently, the CO2 removal unit couldn’t handle this situation efficiently. It was found that the CO2 concentration out from reaction section unit increased more than expected which lead to series problems in sweetening unit (carryover, foaming, and MDEA degradation ….etc.).Therefore, modifications included changes in process configuration and some operating conditions, was proposed, in order to achieve purity specification of the Propylene product. A comparative process simulation by HYSYS was done for two cases; design basis process and the modified process. Simulation results showed that the modification can handle these huge amounts of CO2 out of the reaction section according to four modifications: 6- Using MDEA only without activator (piperazine). 7- Replace the old absorber with new one larger with three beds of structured packing instead of two beds of random packing. 8- Adding two pumps around with two stages of side air coolers.9- Adding reclaimer unit.10- Increasing MDEA circulation rate. The modified procedures were applied in an existing plant and the lab analysis showed good agreement with the simulation results.