Razi Ahmad
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Preferred name
Razi Ahmad
Official Name
Razi, Ahmad
Alternative Name
Ahmad, Razi
Ahmad, R. B.
Ahmad, R.
Ahmad, R. Badlishah
Main Affiliation
Scopus Author ID
54419444500
Researcher ID
B-9254-2012

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Adsorption of carbon dioxide (CO2) by activated carbon derived from waste coffee grounds

2021-05-24 , Lim H.K. , Umi Fazara Md Ali , Razi Ahmad , Aroua M.K.

Currently, three are several agricultural bio-based materials have been successfully utilized as gas adsorbents. In this study, waste coffee grounds (WCGs) have been selected as a potential precursor of Carbon Dioxide (CO2) adsorbents. The preparation parameters for activated carbon derived from WCGs were optimized using Response Surface Methodology (RSM). The optimized preparation parameters were found to be 1:3.67 impregnation ratio of acid, 533oC of carbonization temperature and 1.13 hours of activation time, which resulted in 23.6 wt% of yield. The physical and chemical characteristics of WCGAC in terms of surface morphology, carbon content, ash content and yield were also investigated. The CO2 breakthrough time using WCGAC were carried out at the temperatures of 30, 40, and 60°C. It was found that WCGAC shows a longer CO2 breakthrough times (5 mins) and a higher adsorption capacity (4.33 mg CO2/g adsorbent) at 30oC.

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Torrefaction of palm kernel shell using conventional and microwave irradiation pretreatment

2020 , Razi Ahmad , M A M Ishak , N N Kasim , K Ismail

This study describes the properties of torrefied palm kernel shell (PKS) by conventional and microwave irradiation (MI) pretreatment. In conventional pretreatment, the untreated PKS was torrefied using fixed bed reactor at temperature of 210, 230, 250, 270 and 290 °C for 60 min of holding time. In MI pretreatment, the untreated PKS was irradiated with microwave power of 200, 300, 450 and 600 W for 8 min of holding time. The torrefied samples were analysed for mass and energy yield, energy density, calorific value and proximate and ultimate analysis. The results showed that, the properties of torrefied samples were improved with increasing torrefaction temperature and microwave power. The mass and energy yield, moisture, volatile matter and oxygen content of torrefied PKS decreased, whereas, the calorific value, energy density and carbon content increased with increasing torrefaction temperature and microwave power. The torrefaction temperature of 270 °C and microwave power of 450 W were appropriate to upgrade the PKS properties. Therefore, the change in properties of torrefied PKS revealed the potential of applying pretreatment prior to further thermal conversion such as pyrolysis and gasification.

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Malayan tapir roadkill: assessment towards road user and mitigation strategies

2025 , Nur Hafizah Mohd Shabuddin , Norhafezah Kasmuri , Aishah Sabrina Abdul Jalal , Satoto Endar Nayono , Razi Ahmad

Biodiversity conservation has become one of the key components in the Sustainable Development Goals (SDGs) agenda. In line with Goal 11 towards sustainable cities and communities and Goal 15 for life on land, the conflict between animals and humans must be reduced. Persisting the development of infrastructure and urbanization, animals, particularly the Malayan Tapir, have been on the brink of extinction as their numbers have been depleted due to roadkill. These animals need to migrate in search of food and shelter. However, deforestation and land conversion into highways and buildings make it challenging for them to survive. This study investigated the road user awareness and perception of Malayan tapir roadkill and strategies for mitigation among villagers in Felda Bersia, Perak. From the results, deforestation and illegal logging are the leading causes of roadkill, with a mean value of 4.36. Later, road user attitudes and awareness are the most significant factors, as 95.3% of respondents need more understanding of preserving the Malayan Tapir from roadkill, by which the preservation methods scored an overall mean value of 4.19. Therefore, it evaluated the effectiveness of the management approaches in reducing roadkill, focusing on road users' viewpoints and preferences. Mitigation options included identifying roadkill hotspots and maintaining more fences. These findings will aid in guiding the conservation efforts and upgrading the development of targeted strategies to protect the Malayan tapir population. Moreover, by engaging with local communities and incorporating road user perspectives, this outcome would later promote a collaborative approach to safeguarding this endangered species from becoming extinct.

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Investigation on effect of gas concentration in distinguishing conventional plastic and bioplastic for plastic recycling

2022-12 , Ragunathan Al Santiagoo , Allan Melvin Andrew , Wan Amiza Amneera Wan Ahmad , Razi Ahmad , Syakirah Afiza Mohammed , Abdul Ghapar Ahmad , Vikneswaran Vijean , Mustaffa Zainal

Distinguishing type of plastic was important for the recycling process. In this project, the effect on gas concentration released from composite was studied to distinguish between conventional plastic and bioplastic. This project involved the fabrication of a composite from polypropylene (PP), empty fruit bunches (EFB), and recycle acrylonitrile butadiene rubber (NBRr), with PP used as a conventional plastic and PP/NBRr/EFB used as a bioplastic. Trans-polyctylene (TOR) was used as a compatibilizer to evaluate the effect on the PP/NBRr/EFB. Tensile testing and SEM were conducted to study the mechanical properties and morphological properties on the PP/NBRr/EFB and the PP/NBRr/EFB/TOR composite. The gas sensor (MQ135) was used in this study to detect the presence of NH3 and CO2 released from heating conventional plastic and bioplastic. From the overall result, composite with TOR as compatibilizer has shown better performance than composite without TOR in mechanical, morphological and gas sensor testing. By using MATLAB software, it shows that from gas sensor testing, it can be verified to distinguish between conventional plastic and bioplastics for plastic recycling. The average classification obtained from the Probabilistic Neural Network (PNN) was 99.29 % accurate.

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Oil palm waste-derived reduced graphene oxide (rGO) for dynamic adsorption of dye in a fixed-bed system

2024-01-01 , Mohd Ali Jinnah S.N.H. , Umi Fazara Md Ali , Subash Chandra Bose Gopinath , Naimah Ibrahim , Razi Ahmad , Mohamed Zuki F.

This study focuses on investigating the dynamic adsorption of Rhodamine B (RhB) from reduced graphene oxide (rGO) derived from oil palm waste. The synthesis of rGO from palm kernel shell (PKS) was achieved through double oxidation and carbonization method, resulting in a yield of 73.5 wt%. The reduction of oxygen-containing functionalities process using PKS was confirmed by FTIR spectroscopy, microscopic evaluation, and X-ray diffraction analyses. Laboratory-scale fixed-bed experiments were conducted with various process parameters. Both PKS and rGO were used as adsorbents, and a comparison was made based on breakthrough curve analysis, adsorption capacity and percentage removal of dye. The adsorption kinetics of RhB on PKS and rGO were best described by the non-linear Yoon-Nelson model, with a high adsorption capacity of 88.32 mg/g and 195.24 mg/g respectively. Using both PKS and rGO, the maximum adsorption capacity was observed when using 10 cm bed depth column, inlet dye concentration of 5 mg/L, flow rate of 12 mL/min and pH of 7. PKS exhibited good dye removal with an efficiency of 66.54%. Meanwhile, the exothermic behavior highlighted the potential of utilizing rGO for maximum dye removal, achieving an efficiency of 90.35%. This study justifies rGO as a cost-effective superior dye removal adsorbent, providing new prospect for large-scale dye removal.

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A review on enhancement of oil palm solid waste through torrefaction

2023-09 , Nur Rahimah Ibrahim , Razi Ahmad , Mohd Azlan Mohd Ishak

Biomass is one of the renewable energy sources and is easily obtained in Malaysia. Due to the substantial amount of biomass waste generated by agricultural activities, Malaysia actually has great potential for biomass power generation. The oil palm industry is the largest contributor to biomass waste in Malaysia, particularly oil palm solid waste. The raw oil palm solid waste produced low-quality products during thermochemical conversion. Thus, the torrefaction process is one of the approaches to improve the characteristics of raw oil palm solid waste. Therefore, the objectives of this study are to review the production and characteristics of solid biofuel from oil palm solid waste via the torrefaction process. Torrefaction is a thermal conversion method of biomass in the low-temperature range of 200–300 °C. Different reaction conditions such as temperature and reaction time lead to several characteristics of biofuel products. The solid fuel of pretreated oil palm solid waste has enhanced overall quality and its characteristics after torrefaction.

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The direct and catalytic pyrolysis of rice straw

2010 , Razi Ahmad

A study of the catalytic pyrolysis on rice straw was carried out in a fixed-bed reactor. The work objectives were to determine the influences of pyrolysis parameters i.e pyrolysis temperature, heating rate and holding time on distribution of product yield. The optimization process was analyzed by employing central composite rotatable design (CCRD) in response surface methodology (RSM). The catalysts used in this research were zeolite ZSM-5 and dolomite. The catalytic pyrolysis was carried out based on optimized condition of bio-oil yield. The characterization of pyrolysis product between non-catalytic and catalytic pyrolysis were investigated, by elemental, spectroscopic and chromatographic techniques. The char yield produced from pyrolysis process was high at low heating rates, while the gas yield produced was high at higher temperature and longer holding time. The experimental value of the optimum bio-oil yield was 27.62% as compared to the predicted value which bio-oil yield was 27.87% at pyrolysis temperature of 450 oC, heating rate of 77.63 oC/min and holding time of 2.61 min by using optimization process in the Design Expert (DOE) software. The chemical characterization studies of uncatalysed bio-oil derived from pyrolysis of rice straw contained considerable amounts of carbonyl and oxygenated compound, resulting in higher oxygen content in elemental composition and low pH value. Used of zeolites ZSM-5 and dolomite caused an increase in gas yields and a decrease in bio-oil yields. The product yields and the quality of the produced bio-oil were affected by the used of catalyst. The major improvement in the quality of liquid product with the use of catalyst was the increase of phenol concentration (useful chemicals) and the reduction of some corrosive acids which are undesirable compound in bio-oil. Dolomite catalyst having the most impacts than zeolite ZSM-5 in removing some of aldehyde and ketone compounds which are responsible for the thermal or storage stability. The influence of the zeolite ZSM-5 and dolomite catalyst used in this study caused only enhancement of liquid production in terms of quality but not the bio-oil produced.

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Potential of pretreated palm kernel shell on pyrolysis

2023-01-01 , Razi Ahmad , Ragunathan Al Santiagoo , Abdul Ghapar Ahmad , Syakirah Afiza Mohammed , Wan Ahmad W.A.M. , Vikneswaran Vijean , Ibrahim N.R.

The impact of pretreatment on palm kernel shell (PKS) with torrefaction for the possibility of pyrolysis is discussed in this study. PKS samples were torrefied at different holding times of 30 and 60 minutes at temperatures of 200, 225, 250, 275, and 300 °C. In a fixed-bed reactor with a constant nitrogen flow rate of 500 ml/min, torrefaction pretreatment was carried out. The elemental composition, mass, and energy yield, as well as proximate analysis, were all performed on the pretreated PKS. The optimised pretreated PKS was pyrolyzed next at a temperature of 400 to 550 °C in a fixed-bed reactor. The outcomes demonstrated that the pretreated PKS had a significant mass and energy yield at a temperature of 250 °C and a holding time of 30 min. PKS's calorific value and carbon content both rose after pretreatment. However, the oxygen and moisture content decreased for pretreated PKS. The maximum bio-oil production of 58% was achieved during the pyrolysis of pretreated PKS at a temperature of 500 °C. At higher temperature of 550 ℃, the bio-oil decreased due to secondary cracking reaction. Consequently, the pretreated PKS has greater potential as effective feedstock for successive proses particularly pyrolysis for bio-oil production.

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Optimization studies of coal organic sulfur removal using Potassium Carbonate and Ethylene Glycol as a deep eutectic solvent

2023-06-29 , Syarifah Nursyimi Azlina Syed Ismail , Mohd Azlan Mohd Ishak , Khudzir Ismail , Wan Izhan Nawawi , Nur Nasulhah Kasim , Asnida Yanti Ani , Azil Bahari Alias , Razi Ahmad

Combustion of coal emits sulfur dioxide gas into the atmosphere. When reacting with water vapour, this gas produces sulfuric acid, also known as acid rain, causing environmental destruction, and endangering human health. One option to address these issues is to remove the sulfur from coal before combustion. Physical and chemical pre-treatments using oxidizing or reducing agents easily remove inorganic sulfur from coal, namely pyrite and sulfate sulfur. However, organic sulfur is hard to remove unless a particular reagent is applied to break the carbon-sulfur bonds to release the sulfur from the coal matrix. This study reports the utilization of a mixture of potassium carbonate and ethylene glycol (K2CO3:EG) under sonication to extract organic sulfur from coal. The ultrasonic shockwave separates sulfur from the coal's macromolecular structure by breaking the chemical connections that hold sulfur to coal. CCD-RSM experimental design was presented to overcome traditional methods that make finding the optimal standard difficult and time-consuming. The effects of molar ratio, temperature, and extraction time on the removal of organic sulfur in coal were investigated, and sonicating coal at 40 °C for 60 minutes with 1:16 K2CO3:EG was found to be the ideal parameter. The changes to the thiophene and organic sulfate FTIR peaks may serve as a preliminary measure of the effectiveness of K2CO3:EG in coal desulfurization. This research shows that solvent-pre-treated coal may be safe and environmentally advantageous, two goals of the 2030 Agenda for Sustainable Development.

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Compatibilizers Effect on Recycled Acrylonitrile Butadiene Rubber with Polypropylene and Sugarcane Bagasse Composite for Mechanical Properties

2023-10-16 , Zainal M. , Ragunathan Al Santiagoo , Razi Ahmad , Mohammed S.A. , Abdul Ghapar Ahmad , Vikneswaran Vijean , Wan Amiza Amneera Wan Ahmad , Allan Melvin Andrew

Compatibilizers effect on recycled acrylonitrile butadiene rubber (NBRr) with polypropylene (PP) and sugarcane bagasse (SCB) composite for mechanical properties is evaluated. Trans-Polyoctylene Rubber (TOR) and Bisphenol a Diglycidyl Ether (DGEBA) are used as compatibilizers in this study. Three (3) different composites (80/20/15, 60/40/15, and 40/60/15), with fixed filler (15 phr) and compatibilizers (10 phr) content, were carried out. These composites were arranged via melt mixing technique utilizing a heated two-roll mill at a temperature of 180 C for 9 minutes employing a 15-rpm rotor speed. Tensile and morphological properties were evaluated. The result shown average tensile strength dropped by 48.50% as the recycle NBR content rises 20 phr. Nevertheless, subsequent compatibilization reveals that the compositesâ tensile properties were all greater than control composites. The morphology discovered validates the tensile properties, indicating a stronger interaction between the PP/SCB and recycle NBR composites with the addition of compatibilizer DGEBA.

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