Applied Petrochemical Research最新文献

A one-dimensional adiabatic mathematical model was developed for the riser reactor of an industrial residue fluid catalytic cracking unit (RFCCU). A seven-lump kinetic model was presented for the catalytic cracking of vacuum residue, taking cognisance of diffusion resistance, which is a departure from the general norm in the literature. Also, heat transfer resistance between the fluid and solid phases was incorporated into the energy balances for instantaneous and one-dimensional vaporization of feedstock. The developed model was a set of twelve coupled, highly non-linear and stiff ordinary differential equations, ODEs, which was numerically solved with an implicit MATLAB built-in solver, ode23t, designed deliberately for handling stiff differential equations to circumvent the problem of instability associated with explicit methods. An excellent agreement was achieved between the industrial RFCCU plant data and the simulated results of this study, with average absolute deviation being?<?±?5% for instantaneous vaporization of feedstock in all cases investigated. Moreover, the simulated results revealed that half of the reactor was relatively redundant as this accounted for only 3% of the conversion. Hence, the findings of this study could be useful to the production practice for the Khartoum Refinery Company.

There are four major existing refineries as follows:

Thus, the total installed capacity is 445,000?bpsd. These plants in the last 15–20?years had a poor operating record with average capacity utilization hovering between 15 and 25% per annum. As a result, 70–80% of the national petroleum products demand is met through import. As at 2017, the aggregate demand of petroleum products in Nigeria was equivalent to 750,000?bpsd. Hence, there is ample scope for investment in new plants and revamp of the existing ones to make them more efficient. This paper traces the history of refining in Nigeria, highlights the current poor record of capacity utilization, proffers solutions for improving their viability, and presents prospects for growth of the industry in Nigeria.

Kinetics and mechanism of heterogeneous transesterification reaction of African pear seed oil (APO) catalyzed by phosphoric acid-activated kaolin clay to produce biodiesel were investigated. Heterogeneous catalyst synthesized by activating clay with phosphoric acid was used to examine the effect of time, temperature, methanol/oil molar ratio, catalyst concentration and agitation speed on the production of biodiesel. The kinetics was studied using two elementary reaction mechanisms: Eley–Rideal (ER) and Langmuir–Hinshelwood–Hougen–Watson (LHHW). The results obtained showed that the clay belongs to kaolinite group and acid-activated clay catalyst, AAC was able to convert APO to standard biodiesel with the variation of catalyst concentration, temperature methanol, speed and reaction time having significant effect in the production. About 78–80% biodiesel production was obtained with 10:1 methanol/oil molar ratio, 3?wt% AAC catalyst concentration, time 3?h, speed 300?rpm and at 60?°C temperature. The kinetics result revealed that the LHHW is the most reliable representation of the experimental data using acid-activated clay catalyst with surface reaction between adsorbed triglyceride and adsorbed methanol as rate determining step (RDS). The activation energy for the forward reaction was determined to be 10.08?kJ/mol. Hence, the production of biodiesel from non edible oil APO with cheap and available heterogeneous catalyst (AAC) is achievable.

The aim of this study is to convert polypropylene waste into usable liquid fuel via pyrolysis technique using kaolin as a low-cost catalyst. Waste polypropylene was thermally and catalytically degraded in a chemical vapour deposition (CVD) horizontal glass reactor at a temperature of 450?°C, residence time of 30?min, and heating rate of 30?°C/min. The kaolin clay was characterized by XRF analysis while the ultimate and proximate analysis of the polypropylene feed carried out gave combustible materials content of 93.77?wt%, fixed carbon of 1.62?wt%, calorific value of 45.20?MJ/kg and elemental composition with carbon (83.65%), hydrogen (14.27%), oxygen (0.15%), sulphur (0.1%), chlorine (1.16%), and nitrogen (0.67%). Thermal cracking was carried out in the absence of catalyst and the process gave a yield of liquid, gaseous, and solid products of 67.48, 8.85, and 23.67?wt%, respectively. Furthermore, kaolin clay was employed as a catalyst in catalytic pyrolysis of the same feedstock for catalyst-to-plastic ratio of 1:1, 1:2, 1:3, and 1:4 at the same operating parameters as in thermal cracking. Optimum yield was obtained at a catalyst-to-plastic ratio of 1:3 with a yield of 79.85, 1.48, and 18.67?wt% for liquid, gaseous, and solid products, respectively. The liquid products obtained for both thermal and catalytic cracking at optimum conditions were characterized for their suitability as fuel. The properties determined were density, viscosity, flash point, fire point, pour point, and calorific value. The results suggest that catalytic pyrolysis produced liquid products, whose properties are comparable to conventional fuels (gasoline and diesel oil) than that produced through thermal pyrolysis. FTIR analysis of the liquid product from catalytic pyrolysis also shows that it contains hydrocarbons with different functional groups such as aromatics, olefins, carbonyl, amines, sulphides, and hydroxyl.

Efficient design, operation, handling, and transportation of natural gas as liquefied natural gas (LNG) are controlled by its phase behavior. A phase, in a non-reacting system, is known to be stable when it is at its lowest Gibbs energy; an alternative criterion to the minimization of the Gibbs energy is presented for phase stability status determination of pure systems and mixtures. On this premise, the stability limit determination method by the Helmholtz stability criterion was employed for the determination of stability limits which were used to successfully generate stability limit profiles for LNG and its constituents. To further investigate the metastable region, a new and robust model was developed and successfully used to produce vapor and liquid spinodals as well as binodal curves for the LNG constituents. The model accurately predicted the critical points and was shown to be in very close agreement with the available predicted and experimental results.

The present work deals with isomerization of straight chain paraffin, n-hexane with an aim to make up loss in gasoline quantity as well as octane. This is due to its reduced benzene content warranted by its carcinogenic nature. Performance of impregnation of alkaline earth metals (Mg, Ca, Sr, and Ba) on Pt/desilicated (and dealuminated) zeolites Beta was studied and found that isomer selectivity as high as 99% with stable catalytic performance is achievable. Furthermore, replacing part of hydrogen (15%) with carbon dioxide in hydrogen as carrier gas improves hexane conversion. Hexane conversion increased as Mg–<?Ba–<?Ca–<?Sr–Pt/deSi Beta. Observed performance parameters have been explained on the basis of reported variation in acidity due to both alkaline earth metals and CO₂.

CO₂ has been found to be the main anthropogenic contributor to the greenhouse gas effect, thus, the development of carbon capture and storage (CCS) technology is extremely urgent. In this work, two kinds of Al₂O₃ pillared montmorillonite, one ZrO₂-pillared montmorillonite and one TiO₂?+?SiO₂ pillared montmorillonite were prepared and characterized by X-ray diffraction (XRD) for phase formation and N₂ adsorption–desorption isotherms for surface area and pore-size distribution. Equilibrium adsorption of CO₂ gas was measured at 273?K. CO₂ adsorption capacities of pillared clays increased with the increase of their pore volume. The uptakes of CO₂ by pillared clays were in the range of 0.53–1.18?mmol/g.

Currently, the manual method using hand-held infrared temperature measurement instruments for measuring temperatures on the external surfaces of ethylene cracking furnace tubes is highly subjective and is affected by a number of prominent issues, such as the high temperature working environments, which leads to low efficiency and poor measurement accuracy. Hence, an automatic temperature measurement system based on infrared light is designed and realized. In the system, a dual-phase drive synchronization method is proposed to rotate the thermodetector during horizontal movements, thus realizing automatic batch temperature measurements of the furnace tubes. Moreover, a temperature processing algorithm is developed to automatically identify furnace wall and tube surface temperatures, filter out abnormal temperatures and select only high-quality temperature measurements prior to calculating the final result. Real temperature measurement experiments demonstrated that the dual-phase drive temperature measurement system and temperature processing method are effective and efficient. Compared with the traditional manual way, temperatures obtained using the proposed system are more stable and accurate.