Simulation of hydrogen production for mobile fuel cell applications via autothermal reforming of methane

This paper presents a simulation of catalytic autothermal reforming (ATR) of methane (CH4) for hydrogen (H2) production. ATR is essentially an oxidative steam reforming, which combines the exothermic partial oxidation (PO) with the endothermic steam reforming (SR) under thermally neutral conditions. A model is developed using HYSYS 2004.1 to simulate the conversion behavior of the reformer. The model covers all aspects of major chemical kinetics and heat and mass transfer phenomena in the reformer. The ATR and preferential oxidation (PrOx) processes is modeled using conversion reactor, while the water gas shift (WGS) process is modeled using equilibrium reactor within HYSYS environment. The conditions used for high CH4 conversion and high H2 yield are at air to fuel ratio of 2.5 and water to fuel ratio of 1.5. Under this condition, CH4 conversion of 100% and H2 yield of 44% on wet basis can be achieved and the system efficiency is about 87.7%

The application of integrated sustainability tool for production of cyclohexanone

The sustainability problem for reactor systems which is consists of simultaneous calculation of the three sustainability index (one-dimensional index, two-dimensional index, three-dimensional index) in one single analysis and is shown in Figure 1. 1D sustainability analysis is developed according to Shadiya and High (2012), in which a one by one index is calculated for all three indicators. The environmental indicator is divided into two different indexes, which are environmental metric and resource usage metric. Economic indicator is evaluated by using a set of metrics for the cost effectiveness. Whereas, the social indicator is measured by using total inherent safety index and also health risk. Then, for 2D sustainability analysis is developed by referring to Ulhman and Sailing (2010), in which a 2D sustainability indicator is introduced by simultaneous assessment of two criteria out of three. The categories involved are economicenvironmental, socioeconomic and socio-environmental which are expressed in term of mass, water and energy intensity index. Furthermore, 3D sustainability analysis is based on Martins et. al. (2007). Here, the indexes used are energy intensity, material intensity, potential chemical risk and potential environmental impact. In this case, those four indexes are located inside a 3D index that complies all aspects in sustainability

Problem-based learning in facilities planning: a pilot implementation

In Universiti Teknologi Malaysia, Problem Based Learning (PBL) is proposed as an alternative to lectures in moulding engineering graduates to acquire attributes that are required to excel in today’s k-economy. To investigate if PBL is viable for undergraduates in the Faculty of Mechanical Engineering, a pilot implementation of PBL in Facilities Planning, a subject required for final year Mechanical Engineering undergraduates with specialization in Industrial Engineering was executed. With 60 students in the class, the whole syllabus of the subject was covered using three main PBL problems. PBL was conducted with the help of industrial partners: a semiconductor company, and a furniture factory. The outcome of the implementation was highly encouraging. Students were able to illustrate good understanding of the content, while progressively exhibiting maturity in their generic skills, such as communication, team-working, self-directed learning and problem-solving. However, several aspects of the execution can be further improved

Prediction of Minimum Fluidisation Velocity Using a CFD-PBM Coupled Model in an Industrial Gas Phase Polymerisation Reactor

The objective of this paper is to develop computational fluid dynamic (CFD)- population balance model (PBM) coupled model to predict a minimum fluidisation velocity in industrial polydisperse gas phase linear low-density polyethylene (LLDPE) polymerisation reactor. The population balance model (PBM) by direct quadrature method of moment (DQMOM) implemented in CFD framework was used to predict the minimum fluidisation velocity. The simulation results were validated by the operational data in terms of bed height and pressure drop. This CFD-PBM coupled model can be extended to investigate the flow field and particle kinetic through the reactor

Pyrolysis of Empty Fruit Bunch by Thermogravimetric Analysis

AbstractThe purpose of this paper is to study the characteristics of as received and wet-treated empty fruit bunch (EFB) for bio-oil production via pyrolysis technology. The elemental properties of the feedstock were characterized by an elemental analyzer while thermal properties were investigated using thermogravimetric analyzer (TGA). The pyrolysis process was being carried out at room temperature up to 700°C in the presence of nitrogen gas flowing at 150ml/min. The investigated parameters are particle sizes and heating rate. The particle sizes varied in the range of dp1<0.25mm and 0.25≤ dp2<0.30mm. The heating rates used were 50°C/min and 80°C/min. From the results obtain, smaller particle size dp1 produces 10% less char yields, while higher heating rate of 80°C/min increases rate of decomposition by almost 1mg/s. Treatment process reduces char yields of dp2 by a total of 5%. This study can provide an important basis in determining suitable properties of EFB and pyrolysis parameter for bio-fuel production via pyrolysis

The application of integrated sustainability tool for separation of benzene and toluene mixture

Sustainability can be divided into three different dimensions as shown in figure 1, which are one-dimension (1-d) [1-2], two-dimension (2-d) [3] and three-dimension (3-d) [4]. sustainability tool was developed to assess and improve the sustainability of a process. however, the current developed sustainability tools are only based on one dimension of sustainability index, which mostly are 1-d sustainability [1]

A review and survey of Problem-Based Learning application in Engineering Education

This paper gives a review of Problem-Based Learning (PBL) applied in engineering courses worldwide, and a survey of academic staff who have implemented PBL in engineering classes in Universiti Teknologi Malaysia. The review of PBL application illustrates the extent of acceptance and success of PBL in schools of engineering in the international arena. The survey, on the other hand, illustrates the acceptance of PBL among engineering lecturers and the possibility of applying PBL in Malaysia. The main purpose of the survey is to obtain feedback on PBL regarding the impressions, set-backs and constraints faced, as well as innovations and tips for successful implementation from the faculty members involved

Enhancing learning through cooperative learning: UTM experience

Lecture-based classes are the predominant teaching method in all levels of education. This teaching style, undoubtedly is able to deliver knowledge to students and produce graduates. However, this teaching technique is usually unable to invoke higher level of cognitive skills. With an ever-growing volume of knowledge that must be covered in engineering education, an alternative technique must be used to enhance learning. Co-operative learning is a proven teaching technique that is able to enhance students’ learning through active learning. This technique has been widely accepted in engineering education in the United States, Europe, United Kingdom and Australia. In UTM, lecturers from different faculties of engineering implement cooperative learning in their classes. The main aim is to induce better retention, in-depth understanding and mastery of knowledge among students. This paper shows how cooperative learning successfully enhance students' learning by looking at the performance of their grades in different engineering classes

Energy efficient distillation columns analysis for aromatic separation process

Distillation operations became a major concern within energy savings challenge, which it becomes a primary target of energy saving efforts in industrially developed countries. However, there is still one problem, which is how do we improve the energy efficiency of the existing distillation columns systems by without having major modifications. Recently, a new energy efficient distillation columns methodology that will able to improve energy efficiency of the existing separation systems without having major modifications has been developed. Therefore, the objective of this paper is to present new improvement of existing methodology by designing an optimal sequence of energy efficient distillation columns using driving force method. Accordingly, the methodology is divided into four hierarchical sequential stages: i) existing sequence energy analysis, ii) optimal sequence determination, iii) optimal sequence energy analysis, and iv) energy comparison and economic analysis. In the first stage, a simple and reliable short-cut method is used to simulate a base (existing) sequence. The energy consumption of the base sequence is calculated and taken as a reference for the next stage. In the second stage, an optimal sequence is determined by using driving force method. All individual driving force curves is plotted and the optimal sequence is determined based on the plotted driving force curves. Then, by using a short-cut method, the new optimal sequence is simulated and the new energy consumption is calculated in the third stage. Lastly, in the fourth stage, the energy consumption for both sequences (base and optimal) is compared. The capability of this methodology is tested in designing an optimal synthesis of energy efficient distillation columns sequence of aromatics separation unit. The existing aromatics separation unit consists of six compounds (Methylcyclopentane (MCP), Benzene, Methylcyclohexane (MCH), Toluene, m-Xylene and o-Xylene) with five direct sequence distillation columns is simulated using a simple and reliable short-cut method and rigorous within Aspen HYSYS® simulation environment. The energy and economic analysis is performed and shows that the optimal sequence determined by the driving force method has better energy reduction with total of 6.78% energy savings and return of investment of 3.10 with payback period of 4 months. It can be concluded that, the sequence determined by the driving force method is not only capable in reducing energy consumption, but also has better economic cost for aromatic separation unit