توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Maximization Of Propylene In FCC Process By Adding ZSM–5 Additive to FCC Catalyst
نویسنده(ها): ، ، ،
اطلاعات انتشار: ششمین کنگره بین المللی مهندسی شیمی، سال
تعداد صفحات: ۹
FCC units are present in most refineries for production of gasoline, LPG and middle distillates, representing a conversion capacity above 14 MMBPD. FCC also plays an increasing role in residue conversion with now more than 4 MMBPD of RFCC capacity in the world and accounts for more and more of the propylene market(with more than 25% of propylene world production coming from FCC gas plants)[5].The effects of operating parameters such as reaction temperature, and ZSM–5 as FCC catalyst additive, on the distribution of the product and the yield of propylene were investigated on a bench scale fluidized bed reactor. It is the aim of this work to perform an overall analysis of the yields and selectivity of hydrocarbons obtained in the vacuum gas oil conversion over FCC and ZSM–5 catalysts .The effectiveness of ZSM–5 additive adding in FCC process was investigated. The experimented data of off gas analysis showed that, VGO cracking at high reaction temperatures of 450–550°C increases the yield of propylene. Similar behavior is observed with the addition of 10–25 wt.% ZSM–5 additive. The combination of th two effects (high temperature and ZSM–5 addition) makes the FCC unit an excellent source of light olefins for downstream petrochemical units. Higher FCC reactor temperatures (600– 650°C) would not have positive effect for increasing propylene yield.<\div>

۲Decreased out of plane shape of unsymmetrical laminates using carbon nanotubes
نویسنده(ها): ،
اطلاعات انتشار: کنفرانس دو سالانه بین المللی مکانیک جامدات تجربی، سال
تعداد صفحات: ۶
In this paper, a method was proposed to decrease the out of plane deformation of unsymmetrical laminated composites by addition of carbon nanotubes (CNTs). Due to the negative thermal expansion and high modulus of CNTs, addition of CNTs result in a great reduction in the transverse coefficient of thermal expansion (CTE) of a lamina as well as, ultimately, on the out of plane deformation of unsymmetrical laminates. The results from the thermo–mechanical analysis (TMA) confirm that considerable reductions in the CTE of a lamina can be achieved by a suitable addition of CNTs through the polymeric matrix. By addition of 1 wt.% CNTs, the difference between the longitudinal andtransverse CTE of a carbon\epoxy lamina decreased up to %21. In the next step, three phase CNT\Carbon fiber\Epoxy [902\02]T unsymmetrical laminate were fabricated using the hand–lay–up method in different CNTs weight loadings. The specimens then was allowed to cool to room temperature naturally and after that the curvature of laminated was measured accurately. A considerable decrease was observed in out of plane deformation of laminates by increasing in CNT contents. These findings confirm that CNTs possess excellent potential to be used as a thermal expansion compensator for the modification of the out of plane deformation of the unsymmetrical fiber\epoxy laminated composites.<\div>

۳The Effect of Post–Cure Process on The Thermo–Mechanical Behavior ofHybrid Carbon\Glass\Epoxy Laminated Composites
نویسنده(ها): ، ،
اطلاعات انتشار: کنفرانس دو سالانه بین المللی مکانیک جامدات تجربی، سال
تعداد صفحات: ۵
This paper examined the influence of post–cure process on the mechanical and physical properties of a hybrid carbon\glass\epoxy laminated composite. Post–cure process is currently a very popular restorative technique for the purposes of increasing material cure, and thus enhancing properties of composite materials. To this end, hand fabricated composites cured in room temperature and then subjected to immediate post–cure process (100oC for 4 hours). The specimen then was allowed to cool to the room temperature naturally. Finally, tensile tests and thermo–mechanical analysis were carried out to measuring the thermo–mechanical properties of specimens. Compared with the prior composites,the results showed that post–curing process increase the young’s modulus and strength of composites. It is also found that post–curing process slightly increase glass transition temperature and has a negligible effects on coefficients of thermal expansion of composites. Therefore, the post–cure temperature and duration is an effective way of increasing in mechanical properties and reducing the destructive effectsof residual stresses in laminated composites.<\div>
نمایش نتایج ۱ تا ۳ از میان ۳ نتیجه