This page has only limited features, please log in for full access.

Dr. Khaled Y. Benyounis
Dublin city university

Basic Info

Basic Info is private.

Research Keywords & Expertise

0 Industrial Engineering
0 Optimization
0 Welding
0 Laser Materials Processing
0 design of experiment (DOE)

Fingerprints

Optimization
Welding
design of experiment (DOE)

Honors and Awards

The user has no records in this section


Career Timeline

The user has no records in this section.


Short Biography

The user biography is not available.
Following
Followers
Co Authors
The list of users this user is following is empty.
Following: 0 users

Feed

Journal article
Published: 09 August 2021 in Energies
Reads 0
Downloads 0

Dates are an important food source in many countries that produce different types of dates. Dates have a significant amount of waste, either from planting or eating them. A large amount of seeds are produced from eating it. This study is considered to explore the quantity and the quality of biogas produced from the Sagai date seeds through the anaerobic digestion process (AD) before and after oil extraction and exploitation of oil in biodiesel production. In addition, the study aims to tests the resulted digestate from the AD process. This test was performed to ensure that the digestate contains the three basics elements (N, P and K) to be used in agriculture. In its preparation, the date seeds were ground after washing via a grinding machine without exposure to any other treatment process. Design of Experiments (DOE) was applied in determining the effect of temperature, volatile solid and sludge quantity on the resulted biogas. The energy balance at the optimum results was calculated. The highest biogas volumes from the AD of date seed before and after oil extraction were 4140 cc and 3534 cc, respectively, at 37 °C, 4.2 g-VS and 50% sludge quantity. While the highest methane/g-VS were 1143.8 cc/g-VS and 949.6 cc/g-VS, respectively, at 37 °C, 1.1 g-VS and 50% sludge quantity. The oil obtained using the Soxhlet method at 70 °C, 1:4 ratio of date seeds to n-hexane solvent and 5 h reaction time was 16% of the date seed mass (79% biodiesel and 9% glycerine). Therefore, the resultant effect from the main findings indicated that the study supports the investigation of the possibility of exploiting date seeds in the production of biogas, biodiesel and bio-fertiliser.

ACS Style

Alla Alrefai; Raid Alrefai; Khaled Benyounis; Joseph Stokes. Biogas Produced by Anaerobic Digestion Process and Biodiesel from Date Seeds. Energies 2021, 14, 4851 .

AMA Style

Alla Alrefai, Raid Alrefai, Khaled Benyounis, Joseph Stokes. Biogas Produced by Anaerobic Digestion Process and Biodiesel from Date Seeds. Energies. 2021; 14 (16):4851.

Chicago/Turabian Style

Alla Alrefai; Raid Alrefai; Khaled Benyounis; Joseph Stokes. 2021. "Biogas Produced by Anaerobic Digestion Process and Biodiesel from Date Seeds." Energies 14, no. 16: 4851.

Journal article
Published: 17 December 2020 in Energies
Reads 0
Downloads 0

A significant expansion of anaerobic digestion (AD) processes would certainly result in a reduction in the current dependence on fossil fuels. The operational costs, the large amounts of digestate generated and the expenses of dealing with it and the volatility of the fuel indexes represent major environmental and economical challenges to the diffusion of AD. Increasing the bio-products of AD could possibly help in increasing its profitability and limit these challenges. This study investigates the influence of mango starch and seed coats on the biogas produced from mango waste. To overcome the environmental challenges, the digestate was tested and its bio-fertiliser potential proven. The study reached the conclusion that the effect of the starch on the AD biogas of mango waste is low while the effect of the seed coats is quite high. This finding supports further investigations to evaluate the effect of the production of mango starch and seed coat-based products on the profitability of AD. The highest energy balance achieved was 65% at 32 °C, 3.93 g-VS organic concentration and 37% sludge concentration, which yielded a maximum CH4 yield of 62.5%. This finding encourages the application of gate fees for accepting bio-waste, which may help in overcoming its economic challenges.

ACS Style

R. Alrefai; A.M. Alrefai; K.Y. Benyounis; J. Stokes. Enhancing the Economic Viability of Anaerobic Digestion by Exploiting the Whole Biomass of Mango Waste and Its Residues after Digestion. Energies 2020, 13, 6683 .

AMA Style

R. Alrefai, A.M. Alrefai, K.Y. Benyounis, J. Stokes. Enhancing the Economic Viability of Anaerobic Digestion by Exploiting the Whole Biomass of Mango Waste and Its Residues after Digestion. Energies. 2020; 13 (24):6683.

Chicago/Turabian Style

R. Alrefai; A.M. Alrefai; K.Y. Benyounis; J. Stokes. 2020. "Enhancing the Economic Viability of Anaerobic Digestion by Exploiting the Whole Biomass of Mango Waste and Its Residues after Digestion." Energies 13, no. 24: 6683.

Journal article
Published: 28 May 2020 in Energies
Reads 0
Downloads 0

Cassava is a form of food that is rich in starch abundant in many countries. Several bio-products can be extracted from its starch and used as an alternative for oil-based products. This study primarily aims to investigate the influence of the starch isolated from cassava peel on the quantity and quality of the biogas produced via anaerobic digestion. Beating pre-treatment was applied for the first time to isolate the starch and mechanically pre-treat the substrate. The influence of temperature, volatile solid and sludge quantity investigations were analysed with the aid of Design of Experiments (DOE). An optimisation process was applied in calculating the energy balance at the optimal results and this was needed in evaluating the impact of the starch on the biogas produced. The study revealed that the influence of the starch on the biogas quality is quite low and, as such, negligible. The largest biogas volume as obtained was 3830 cc at 37 °C, 4.2 g-VS and 50% sludge quantity, while at the same time the maximum CH4 g−1-VS was 850 cc g−1-VS at 37 °C, 1.1 g-VS and 50% sludge quantity. The optimal results show the energy gain could be achieved based on the set criteria.

ACS Style

Alla Mohammed Alrefai; Raid Alrefai; Khaled Younis Benyounis; Joseph Stokes. Impact of Starch from Cassava Peel on Biogas Produced through the Anaerobic Digestion Process. Energies 2020, 13, 2713 .

AMA Style

Alla Mohammed Alrefai, Raid Alrefai, Khaled Younis Benyounis, Joseph Stokes. Impact of Starch from Cassava Peel on Biogas Produced through the Anaerobic Digestion Process. Energies. 2020; 13 (11):2713.

Chicago/Turabian Style

Alla Mohammed Alrefai; Raid Alrefai; Khaled Younis Benyounis; Joseph Stokes. 2020. "Impact of Starch from Cassava Peel on Biogas Produced through the Anaerobic Digestion Process." Energies 13, no. 11: 2713.

Journal article
Published: 11 May 2020 in Energies
Reads 0
Downloads 0

Anaerobic digestion (AD) has undergone many developments since its first appearance. Despite that, there are still some environmental and economical obstacles that are limiting its sustainability. On the other hand, different types of starch have proven their effectiveness in some different applications. Food processing industries are considered one of the largest generators of waste in the environment. With an aid of the response surface methodology (RSM), the proposed study aimed to find an optimised way to overcome the obstacles by studying the impacts of the starch isolated from the potato peels on the biogas produced from the AD of potato peels before and after starch separation. The study found that potato peels represented approximately 12.5% of the potato total weight. The starch has only a slight influence on the quantity of the biogas produced and much lower influences on its quality. This finding suggests further investigation is required on the production of starch bio-based products simultaneously with the biogas and bio-slurry, which may mitigate environmental influences and economical obstacles of AD and make it more commercially attractive. The study showed also that the highest energy gain by the g-VS/0.2 L of potato peels was 62.9% at 35 °C, 1.62 g-VS/0.2 L organic concentration and 50% sludge concentration, which yielded a maximum CH4 of 72.4%.

ACS Style

R. Alrefai; A.M. Alrefai; K.Y. Benyounis; J. Stokes. An Evaluation of the Effects of the Potato Starch on the Biogas Produced from the Anaerobic Digestion of Potato Wastes. Energies 2020, 13, 2399 .

AMA Style

R. Alrefai, A.M. Alrefai, K.Y. Benyounis, J. Stokes. An Evaluation of the Effects of the Potato Starch on the Biogas Produced from the Anaerobic Digestion of Potato Wastes. Energies. 2020; 13 (9):2399.

Chicago/Turabian Style

R. Alrefai; A.M. Alrefai; K.Y. Benyounis; J. Stokes. 2020. "An Evaluation of the Effects of the Potato Starch on the Biogas Produced from the Anaerobic Digestion of Potato Wastes." Energies 13, no. 9: 2399.

Journal article
Published: 23 April 2020 in Processes
Reads 0
Downloads 0

Whiskey distillery waste streams consisting of pot ale (liquid residue) and spent grain (solid residue) are high strength organic wastes and suitable feedstock for anaerobic digestion (AD) from both economic and environmental stand points. Anaerobic digestion of pot ale and pot ale/spent grain mixtures (with mixing ratios of 1:1, 1:3, and 1:5 by wet weight) was performed after implementation of a novel hybrid pre-treatment (combined chemical and mechanical) in order to modify lignocellulosic structure and ultimately enhance digestion yield. Lignin, hemicellulose, and cellulose fractions were determined before and after chemical pre-treatment. Effects of different inoculum rates (10–30–50% on wet basis) and beating times (0–7.5–15 min) on anaerobic digestion of pot ale alone and of pot ale/spent grain mixtures were investigated in lab scale batch mode with a major focus of optimising biogas yield by using response surface methodology (RSM) in Design Expert Software. The highest biogas yields of 629 ± 8.5 mL/g vs. (51.3% CH4) and 360 ± 10 mL/g vs. (55.0 ± 0.4) with anaerobic digestion of pot ale alone and spent grain mix after 1M NaOH and 7.5 min beating pre-treatments with 50% inoculum ratio respectively. The optimum digestion conditions to maximise the biogas quality and quantity were predicted as 10 and 13 min beating times and 32 and 38 °C digestion temperatures for anaerobic digestion of pot ale alone and spent grain mix respectively.

ACS Style

Burcu Gunes; Maxime Carrié; Khaled Benyounis; Joseph Stokes; Paul Davis; Cathal Connolly; Jenny Lawler. Optimisation and Modelling of Anaerobic Digestion of Whiskey Distillery/Brewery Wastes after Combined Chemical and Mechanical Pre-Treatment. Processes 2020, 8, 492 .

AMA Style

Burcu Gunes, Maxime Carrié, Khaled Benyounis, Joseph Stokes, Paul Davis, Cathal Connolly, Jenny Lawler. Optimisation and Modelling of Anaerobic Digestion of Whiskey Distillery/Brewery Wastes after Combined Chemical and Mechanical Pre-Treatment. Processes. 2020; 8 (4):492.

Chicago/Turabian Style

Burcu Gunes; Maxime Carrié; Khaled Benyounis; Joseph Stokes; Paul Davis; Cathal Connolly; Jenny Lawler. 2020. "Optimisation and Modelling of Anaerobic Digestion of Whiskey Distillery/Brewery Wastes after Combined Chemical and Mechanical Pre-Treatment." Processes 8, no. 4: 492.

Journal article
Published: 18 November 2015 in Energy Conversion and Management
Reads 0
Downloads 0

The objective of this study was to evaluate the effect of beating (BT), ball milling (BM) and microwave pretreatment (MW) on the conversion of the macroalgae Laminaria spp. into biogas by anaerobic digestion (AD). The AD was carried out in batch at 38 ± 1 °C, over an incubation time of 25 days. After 3 days of digestion the BT pretreated samples yielded the best result by achieving a methane increase of up to 37% with respect to the raw seaweed. At 25 days, both BM and MW pretreatment lowered the methane yield with respect to the raw seaweed. Since BT produced higher methane yields with respect to the untreated sample, it was considered for energy balance analysis. After 3 days of digestion, the BT resulted in an energy gain of 28%, while at the end of digestion the break-even point was reached.

ACS Style

M.E. Montingelli; K.Y. Benyounis; J. Stokes; Abdul Ghani Olabi. Pretreatment of macroalgal biomass for biogas production. Energy Conversion and Management 2015, 108, 202 -209.

AMA Style

M.E. Montingelli, K.Y. Benyounis, J. Stokes, Abdul Ghani Olabi. Pretreatment of macroalgal biomass for biogas production. Energy Conversion and Management. 2015; 108 ():202-209.

Chicago/Turabian Style

M.E. Montingelli; K.Y. Benyounis; J. Stokes; Abdul Ghani Olabi. 2015. "Pretreatment of macroalgal biomass for biogas production." Energy Conversion and Management 108, no. : 202-209.

Journal article
Published: 30 November 2011 in Advances in Engineering Software
Reads 0
Downloads 0

Bi-layered tubing which consists of two different metallic layers is recommended to use in complex working environments as it offers combined properties that single layer structure does not have. However, in this wok, producing of T-shape bi-layered components using the tube hydroforming process is investigated. In this regard, the bulge height and the wall thickness reduction of the bi-layered hydroformed parts (responses) are modelled as functions of the geometrical factors using the combination of the finite element modelling (FEM) and Response Surface Methodology (RSM) for design of experiments (DOE). The geometrical factors effects and their interactions on the responses were determined and discussed. Based on the resultant models, a multi-response optimization study was conducted. Furthermore, for the optimum solutions, a significant agreement was indicated between the predicted and numerical values.

ACS Style

Abed Alaswad; K.Y. Benyounis; Abdul Ghani Olabi. Employment of finite element analysis and Response Surface Methodology to investigate the geometrical factors in T-type bi-layered tube hydroforming. Advances in Engineering Software 2011, 42, 917 -926.

AMA Style

Abed Alaswad, K.Y. Benyounis, Abdul Ghani Olabi. Employment of finite element analysis and Response Surface Methodology to investigate the geometrical factors in T-type bi-layered tube hydroforming. Advances in Engineering Software. 2011; 42 (11):917-926.

Chicago/Turabian Style

Abed Alaswad; K.Y. Benyounis; Abdul Ghani Olabi. 2011. "Employment of finite element analysis and Response Surface Methodology to investigate the geometrical factors in T-type bi-layered tube hydroforming." Advances in Engineering Software 42, no. 11: 917-926.

Journal article
Published: 22 May 2007 in Advances in Engineering Software
Reads 0
Downloads 0

Welding input parameters play a very significant role in determining the quality of a weld joint. The joint quality can be defined in terms of properties such as weld-bead geometry, mechanical properties, and distortion. Generally, all welding processes are used with the aim of obtaining a welded joint with the desired weld-bead parameters, excellent mechanical properties with minimum distortion. Nowadays, application of design of experiment (DoE), evolutionary algorithms and computational network are widely used to develop a mathematical relationship between the welding process input parameters and the output variables of the weld joint in order to determine the welding input parameters that lead to the desired weld quality. A comprehensive literature review of the application of these methods in the area of welding has been introduced herein. This review was classified according to the output features of the weld, i.e. bead geometry and mechanical properties of the welds.

ACS Style

K.Y. Benyounis; Abdul Ghani Olabi. Optimization of different welding processes using statistical and numerical approaches – A reference guide. Advances in Engineering Software 2007, 39, 483 -496.

AMA Style

K.Y. Benyounis, Abdul Ghani Olabi. Optimization of different welding processes using statistical and numerical approaches – A reference guide. Advances in Engineering Software. 2007; 39 (6):483-496.

Chicago/Turabian Style

K.Y. Benyounis; Abdul Ghani Olabi. 2007. "Optimization of different welding processes using statistical and numerical approaches – A reference guide." Advances in Engineering Software 39, no. 6: 483-496.

Journal article
Published: 15 May 2005 in Journal of Materials Processing Technology
Reads 0
Downloads 0

The optimization capabilities in design-expert software were used to optimize the keyhole parameters (i.e. maximize penetration (P), and minimize the heat input, width of welded zone (W) and width of heat-affected zone (WHAZ)) in CW CO2 laser butt-welding of medium carbon steel. The previous developed mathematical models to predict the keyhole parameters in terms of the process factors, namely laser power (LP), welding speed (S) and focused position (F) were used to optimize the welding process. The goal was to set the process factors at optimum values to reach the desirable weld bead quality and to increase the production rate. Numerical and graphical optimization techniques were used. In fact, two optimization criteria were taken into account. In this investigation, optimal solutions were found that would improve the weld quality, increase the productivity and minimize the total operation cost. In addition to that, superimposing the contours for the various response surfaces produced overlay plots.

ACS Style

K.Y. Benyounis; A.G. Olabi; M.S.J. Hashmi. Optimizing the laser-welded butt joints of medium carbon steel using RSM. Journal of Materials Processing Technology 2005, 164-165, 986 -989.

AMA Style

K.Y. Benyounis, A.G. Olabi, M.S.J. Hashmi. Optimizing the laser-welded butt joints of medium carbon steel using RSM. Journal of Materials Processing Technology. 2005; 164-165 ():986-989.

Chicago/Turabian Style

K.Y. Benyounis; A.G. Olabi; M.S.J. Hashmi. 2005. "Optimizing the laser-welded butt joints of medium carbon steel using RSM." Journal of Materials Processing Technology 164-165, no. : 986-989.

Journal article
Published: 15 May 2005 in Journal of Materials Processing Technology
Reads 0
Downloads 0

Laser butt-welding of medium carbon steel was investigated using CW 1.5 kW CO2 laser. The effect of laser power (1.2–1.43 kW), welding speed (30–70 cm/min) and focal point position (−2.5 to 0 mm) on the heat input and the weld-bead geometry (i.e. penetration (P), welded zone width (W) and heat affected zone width (WHAZ)) was investigated using response surface methodology (RSM). The experimental plan was based on Box–Behnken design. Linear and quadratic polynomial equations for predicting the heat input and the weld-bead geometry were developed. The results indicate that the proposed models predict the responses adequately within the limits of welding parameters being used. It is suggested that regression equations can be used to find optimum welding conditions for the desired criteria.

ACS Style

K.Y. Benyounis; Abdul Ghani Olabi; M.S.J. Hashmi. Effect of laser welding parameters on the heat input and weld-bead profile. Journal of Materials Processing Technology 2005, 164-165, 978 -985.

AMA Style

K.Y. Benyounis, Abdul Ghani Olabi, M.S.J. Hashmi. Effect of laser welding parameters on the heat input and weld-bead profile. Journal of Materials Processing Technology. 2005; 164-165 ():978-985.

Chicago/Turabian Style

K.Y. Benyounis; Abdul Ghani Olabi; M.S.J. Hashmi. 2005. "Effect of laser welding parameters on the heat input and weld-bead profile." Journal of Materials Processing Technology 164-165, no. : 978-985.