ازالة الكبريت ودراسة الحركية لوقود الديزل بعملية الامتزاز ذو الوجبة باستخدام الكاربون المنشط == Desulfurization And Kinetic Study of Diesel Fuel By Batch Adsorption On Activated Carbon
Author name:
سمر خالد الجنابي
Supervisor name:
نيران خليل ابراهيم
General topic:
Chemical Engineering
Specific topic:
Oil Refining and Gas Technology
Degree:
Master
University:
University of Technology - Department Of Chemical Engineering - Chemical Engineering and Oil Refining Branch
Language:
English
University location:
Baghdad
First pages:
38T312 - p.pdf
Abstract:
منتجات التقطير في المصافي , وخاصة قطفة زيت الغاز تحتوي على كميات كبيرة من مركبات الالكيل - بنزوثيوفين والتي هي الاكثر تمردا لازالة الكبريت عن طريق السلفرة الهيدروجينية التقليدية. وتستمر لوائح الوقود في جميع انحاء العالم في التشديد استجابة للحاجة الملحة | Refinery distillates, especially gas oil fractions contain considerable amounts of alkylated benzo - thiophene which are the most recalcitrant to desulfurization via conventional hydrodesulfurization. Fuel regulations continue to tighten worldwide in response to the need to cleaner air and refiners meet these regulations at a very significant cost. The need to cut the operational and capital costs has necessitated a renewed look to the non - hydrogen, low temperature and pressure processes for producing ultra low sulfur fuels.Non - conventional approaches for ultra low - sulfur fuels belong either to oxidative or a selective adsorption routes. The present research focuses on a batch adsorption desulfurization process for diesel fuel containing 580ppm sulfur, based on physical adsorption of refractory sulfur compounds on activated carbon (AC). The effects of time (0 - 3.5 hr), temperature (30 - 70 °C), diesel to AC ratio (2 - 10 ml/gm), AC particle size (0.2 - 1.44 mm), mixing velocity(100 - 1000 rpm), and initial sulfur concentration (280 - 580ppm) in commercial diesel fuel on the desulfurization efficiency were studied. The residual sulfur concentration in diesel fuel was decreased from 580 to 247 ppm, corresponding to a desulfurization efficiency of 57 %, at best conditions of 2.5 hr contact time, 50 ?, 2ml diesel/gm AC, 0.8 mm AC particle size, and 1000rpm mixing rate. The sulfur adsorption dependency on contact time and initial sulfur concentration in commercial diesel fuel (280 - 580ppm) were studied. Different kinetic models : Pseudo - first order (PFO), pseudo - second order (PSO) and intraparticle diffusion models were applied to fit the experimental data. The results of the kinetic analysis showed that the pseudo - first order model underestimates the equilibrium sorption capacity by about 33%. However the pseudo - second order model has succeeded in predicting the equilibrium sorption capacity with correlation coefficient, R2 = 0.995. The experimental adsorption isotherms were correlated by Langmuir and Freundlich models. The results indicated that Freundlich isotherm exhibits the best fits for the adsorptive desulfurization of diesel fuel with correlation coefficient (R2) of 0.989 as compared with the Langmuir model ( ). The adsorption intensity as estimated from the Freundlich isotherm is larger than one which is indicative of physical adsorption.
