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    Torrefaction of Pelletized Oil Palm Empty Fruit Bunches

    Ahmad, Arshad, Johari, Anwar, Oladokun, Olagoke
    arXiv.org, May 10, 2015
    © ProQuest LLC All rights reserved, Engineering Database, Publicly Available Content Database, ProQuest Engineering Collection, ProQuest Technology Collection, ProQuest SciTech Collection, Materials Science & Engineering Database, ProQuest Central (new), ProQuest Central Korea, SciTech Premium Collection, Technology Collection, ProQuest Central Essentials, ProQuest One Academic, Engineering Collection (ProQuest)
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    Title: Torrefaction of Pelletized Oil Palm Empty Fruit Bunches
    Author: Ahmad, Arshad; Johari, Anwar; Oladokun, Olagoke
    Contributor: Oladokun, Olagoke (pacrepositoryorg)
    Subject: Calorific Value ; Solid Fuels ; Briquets ; Pyrolysis ; Drying
    Description: The torrefaction of oil palm Empty Fruit Bunch (EFB) briquettes was examined in this study. The results indicate that temperature significantly influenced the mass yield, energy yield and heating value of oil palm empty fruit bunch (OPEFB) briquettes during torrefaction. The solid uniform compact nature of EFB briquettes ensured a slow rate of pyrolysis or devolatization which enhanced torrefaction. The mass yield decreased from 79.70 % to 43.03 %, energy yield from 89.44 % to 64.27 % during torrefaction from 250 {\deg}C to 300 {\deg}C. The heating value (HHV) of OPEFB briquettes improved significantly from 17.57 MJ/kg to 26.24 MJ/kg after torrefaction at 300 {\deg}C for 1 hour. Fundamentally, the study has highlighted the effects of pelletization and torrefaction on solid fuel properties of oil palm EFB briquettes and its potential as a solid fuel for future thermal applications.
    Is part of: arXiv.org, May 10, 2015
    Identifier: 2331-8422 (E-ISSN)

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    Kinetic Study on a Commercial Amorphous Hydrocracking Catalyst by Weighted Lumping Strategy

    Sadighi, Sepehr, Ahmad, Arshad, Irandoukht, Akbar
    International Journal of Chemical Reactor Engineering, 2010, Vol.8(1) [Peer Reviewed Journal]
    Walter de Gruyter GmbH
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    Title: Kinetic Study on a Commercial Amorphous Hydrocracking Catalyst by Weighted Lumping Strategy
    Author: Sadighi, Sepehr; Ahmad, Arshad; Irandoukht, Akbar
    Publisher: De Gruyter
    Subject: Hydrocracking ; Vacuum Gas Oil ; Lump Kinetic Model ; Amorphous
    Description: Hydrocracking is an important upgrading process in the petroleum refinery, and it is generally used to process feedstocks ranging from vacuum gas oil (VGO) to vacuum residue. In this work, hydrocracking of VGO using a dual functional amorphous catalyst was carried out at a pilot scale unit under the following reaction conditions: liquid hourly space velocity (LHSV) from 1 to 1.5 hr-1 and reaction temperatures of 360-440°C at the constant pressure and hydrogen to oil, 156 bar and 1780 Nm3/m3, respectively. The effluent of the reactor was characterized to dry gas, naphtha, kerosene, diesel and unconverted VGO or residue. The pilot tests demonstrated that performing experiments beyond the temperature, recommended by catalyst vendor, lead the process to unstable hydrocracking. To describe the yield of hydrocracking products a five-lump discrete lumping approach with ten reactions was proposed. At first, the kinetic model contained twenty kinetic constants which were estimated by using the conventional objective function. The estimated parameters showed that the tendency of the catalyst to convert VGO to gas and naphtha was negligible whilst rate constants for hydrocracking of VGO to middle distillates were considerably high which was compatible with the nature of amorphous hydrocracking catalysts. After evaluating the magnitude of reaction rates and eliminating the ignorable constants, the network was reduced to six reactions in which only nine parameters were needed. The predictions indicated that the latter network could fit the yield of products more acceptable as if the average absolute deviation between experimental and calculated yields was descended from 16.25% to 12.6%. Then, to have a better prediction, a weighted objective function was used in which weight factors were calculated by a proposed weighted least square expression. The results confirmed that this approach could reduce average absolute deviation of model to 10.75%, and it created a fairly even distribution of deviation between hydrocracking products.
    Is part of: International Journal of Chemical Reactor Engineering, 2010, Vol.8(1)
    Identifier: 1542-6580 (E-ISSN); 10.2202/1542-6580.2193 (DOI)

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    Comparison of Lumping Approaches to Predict the Product Yield in a Dual Bed VGO Hydrocracker

    Sadighi, Sepehr, Ahmad, Arshad, Shirvani, Mansoor
    International Journal of Chemical Reactor Engineering, 2012, Vol.9(1) [Peer Reviewed Journal]
    Walter de Gruyter GmbH
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    Title: Comparison of Lumping Approaches to Predict the Product Yield in a Dual Bed VGO Hydrocracker
    Author: Sadighi, Sepehr; Ahmad, Arshad; Shirvani, Mansoor
    Publisher: De Gruyter
    Subject: Hydrotreating ; Hydrocracking ; Lump Kinetic Model ; Hydrogen Consumption ; Dual Bed Hydrocracking Reactor
    Description: In this research, to predict the product yields of a pilot scale VGO hydrocracking reactor charged with mono functional hydrotreating and hydrocracking catalysts, two different four-lump models are developed. The first one, called combined bed model, is a simplex in which there is no boundary between hydrotreating and hydrocracking reactions through the reactor. The second one, called dual bed model, is a rigorous model in which hydrogen consumption and hydrotreating reactions are included. In this way, the reactor is subdivided into two different layers, so the effect of hydrotreating reactions on the hydrocracking section can be considered. Results show that the absolute average deviation (AAD%) of the yield prediction for the combined bed and the dual bed models are 8.23 percent and 5.87 percent, respectively. The main reason for the lower average deviation of the dual bed model is its higher accuracy to predict the yield of gas which is also the major advantage of this approach. However, the simplicity of the combined bed model can make it more applicable and attractive, especially when hydrogen consumption as well as sulfur, nitrogen and aromatic specifications of the feed and products are not accessible.
    Is part of: International Journal of Chemical Reactor Engineering, 2012, Vol.9(1)
    Identifier: 1542-6580 (E-ISSN); 10.1515/1542-6580.2519 (DOI)

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    Resistance to Change of Academics towards Accreditation

    Kadzrina Abdul Kadir, Darwina Ahmad Arshad, Johanim Johari
    Journal of Business and Social Review in Emerging Economies, 01 December 2016, Vol.2(2), pp.127-134 [Peer Reviewed Journal]
    Directory of Open Access Journals (DOAJ)
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    Title: Resistance to Change of Academics towards Accreditation
    Author: Kadzrina Abdul Kadir; Darwina Ahmad Arshad; Johanim Johari
    Description: When universities makes the decision to go for accreditation to improve performance standards, there has been an impact on academics who are involved in the process. The literature suggests that for accreditation such as business programs such as AACSB, both positive and negative impact could occur for academics. This paper gives an overview on three areas of literature that is pertinent to this topic: resistance to change, accreditation impact on the university, and accreditation impact on business academics with balanced scorecard to measure accreditation impact.
    Is part of: Journal of Business and Social Review in Emerging Economies, 01 December 2016, Vol.2(2), pp.127-134
    Identifier: 2519-089X (ISSN); 2519-0326 (E-ISSN); 10.26710/jbsee.v2i2.29 (DOI)

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    The 3M National Teaching Fellowship: Findings from a National Questionnaire on the Impact of the Program

    Ahmad, Arshad, Stockley, Denise, Smith, Ron, Hastings-Truelove, Amber
    Collected essays on learning and teaching, 2017, Vol.10, p.15 [Peer Reviewed Journal]
    ERIC (U.S. Dept. of Education)
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    Title: The 3M National Teaching Fellowship: Findings from a National Questionnaire on the Impact of the Program
    Author: Ahmad, Arshad; Stockley, Denise; Smith, Ron; Hastings-Truelove, Amber
    Subject: Questionnaires ; Fellowships ; Program Effectiveness ; Program Evaluation ; Administrator Attitudes ; Teacher Attitudes ; Student Attitudes ; National Surveys ; Selection Criteria ; Influences ; Institutional Characteristics ; Higher Education ; Teaching (Occupation) ; Foreign Countries ; Education
    Description: In 2016 the 3M National Teaching Fellowship reached a milestone in celebrating the 30th anniversary of the first fellowship in 1986. The fellowship is the premier award of the Society for Teaching and Learning in Higher Education and each year up to 10 fellows are announced. Thus far, there has not been a systematic review or evaluation of the fellowship program. This study is a starting point to engage the various stakeholders and gather their perspectives regarding the fellowship program. This paper highlights the findings of a national questionnaire that targeted 3M National Teaching Fellows, administrators, educational developers, faculty, and students. The findings provide a snapshot of the awareness of the fellowship, the impact of fellows on their institutions and beyond, and recommendations for the future of the program.
    Is part of: Collected essays on learning and teaching, 2017, Vol.10, p.15
    Identifier: 2368-4526 (ISSN); 2368-4526 (E-ISSN)

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    6-Lump Kinetic Model for a Commercial Vacuum Gas Oil Hydrocracker

    Sadighi, Sepehr, Ahmad, Arshad, Seif Mohaddecy, S. Reza
    International Journal of Chemical Reactor Engineering, 2010, Vol.8(1) [Peer Reviewed Journal]
    Walter de Gruyter GmbH
    Available
    More…
    Title: 6-Lump Kinetic Model for a Commercial Vacuum Gas Oil Hydrocracker
    Author: Sadighi, Sepehr; Ahmad, Arshad; Seif Mohaddecy, S. Reza
    Publisher: De Gruyter
    Subject: Vacuum Gas Oil ; Hydrocracking ; Lump Kinetic Model ; Catalyst Life ; Isomax
    Description: A 6-lump kinetic model, including a catalyst decay function for hydrocracking of vacuum gas oil in a commercial plant, is proposed. The model considers vacuum gas oil (VGO) and unconverted oil, having boiling point higher than 380-°C (380+°C) as one lump. Other lumps are diesel (260-380-°C), kerosene (150-260-°C), heavy naphtha (90-150-°C), light naphtha (40-90-°C) and gases (40-°C) as products. Initially, a kinetic network with thirty coefficients is considered, but following an evaluation using measured data and order of magnitude analysis, mainly the route passes of converting middle distillates to naphtha lumps are omitted; thus the number of kinetic coefficients is reduced to eighteen. This result is consistent with the reported characteristics of amorphous catalyst, which has the tendency to produce more distillates than naphtha. By using catalyst decay function in the kinetic model and replacing days on stream with a noble term, called accumulated feed, the prediction of the final approach during 1.5 years is in good agreement with the actual commercial data. The average absolute deviation (AAD%) of the model is less than 5% for all main products. If the residue or unconverted VGO is considered, the error only increases to 6.94% which is still acceptable for a commercial model. The results also confirm that the hydrocracking of VGO to upgraded products is represented better by a second order reaction.
    Is part of: International Journal of Chemical Reactor Engineering, 2010, Vol.8(1)
    Identifier: 1542-6580 (E-ISSN); 10.2202/1542-6580.2164 (DOI)

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    Torrefaction of Pelletized Oil Palm Empty Fruit Bunches

    Nyakuma, Bemgba Bevan, Ahmad, Arshad, Johari, Anwar, Abdullah, Tuan Amran Tuan, Oladokun, Olagoke
    Cornell University
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    Title: Torrefaction of Pelletized Oil Palm Empty Fruit Bunches
    Author: Nyakuma, Bemgba Bevan; Ahmad, Arshad; Johari, Anwar; Abdullah, Tuan Amran Tuan; Oladokun, Olagoke
    Subject: Physics - Physics And Society
    Description: The torrefaction of oil palm Empty Fruit Bunch (EFB) briquettes was examined in this study. The results indicate that temperature significantly influenced the mass yield, energy yield and heating value of oil palm empty fruit bunch (OPEFB) briquettes during torrefaction. The solid uniform compact nature of EFB briquettes ensured a slow rate of pyrolysis or devolatization which enhanced torrefaction. The mass yield decreased from 79.70 % to 43.03 %, energy yield from 89.44 % to 64.27 % during torrefaction from 250 {\deg}C to 300 {\deg}C. The heating value (HHV) of OPEFB briquettes improved significantly from 17.57 MJ/kg to 26.24 MJ/kg after torrefaction at 300 {\deg}C for 1 hour. Fundamentally, the study has highlighted the effects of pelletization and torrefaction on solid fuel properties of oil palm EFB briquettes and its potential as a solid fuel for future thermal applications. Comment: 5 pages, 2 Figures
    Identifier: 1505.05469 (ARXIV ID)

    • Several versions

    Making a Difference: Three Decades of Canada's Only National Teaching Award

    Stockley, Denise, Smith, Ronald, Ahmad, Arshad, Truelove, Amber Hastings
    The Canadian journal for the scholarship of teaching and learning, May 2019, Vol.10(1) [Peer Reviewed Journal]

    • Several versions

    Integration of fault tree and importance measure for toxic prevention barrier

    Nor Shadiah, H, Ahmad, Arshad, Khalil Mohamed, A
    E3S Web of Conferences, Vol.90 [Peer Reviewed Journal]

    • Several versions

    A comparison of CO2 adsorption behaviour of mono- and diamine-functionalised adsorbents

    Mohamad, Noor, Lotf, Ebrahim, Ahmad, Arshad, Abdullah, TAT
    E3S Web of Conferences, Vol.90 [Peer Reviewed Journal]