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

Research Output
Now showing 1 - 7 of 7
  • Publication
    Torrefaction of palm kernel shell using conventional and microwave irradiation pretreatment
    (IOP Publishing, 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.
  • Publication
    A review on enhancement of oil palm solid waste through torrefaction
    (Springer, 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.
  • Publication
    Optimization studies of coal organic sulfur removal using Potassium Carbonate and Ethylene Glycol as a deep eutectic solvent
    (Malaysian Institute of Chemistry (Institut Kimia Malaysia), 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.
  • Publication
    Malayan tapir roadkill: assessment towards road user and mitigation strategies
    (Romanian Inventors Forum, 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.
  • Publication
    Effect on product Yield and Tar composition through co-gasification of pretreated palm kernel shell and Mukah Balingian coal
    (IOP Publishing, 2020)
    Razi Ahmad
    ;
    Mohd Azlan Mohd Ishak
    ;
    Nur Nasulhah Kasim
    ;
    Khudzir Ismail
    In this study, co-gasification of palm kernel shell (PKS) and Mukah Balingian (MB) coal was carried out in a fixed bed reactor. The effect of sample pretreatment of both samples were explored via co-gasification towards product yields and tar composition. Results indicated that, pretreated blending samples produced higher gas yield with lower tar and char yield than the untreated blending samples. This was due to low moisture and oxygenated components of the pretreated samples prior to co-gasification. The tar composition of the pretreated blending samples showed increasing in the aromatic and aliphatic alkane, whereas, noticeable decreasing of phenol and carbonyl. Thus, pretreated of PKS and MB coal have prominence influence on the distribution of product yields and tar composition through co-gasification.
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  • Publication
    Desulfurization and optimization of high sulfur Jambi province coal by ultrasonic-assisted process using Peroxyacetic Acid (PAA) treatment
    (Semarak Ilmu Publishing, 2025-06)
    Razi Ahmad
    ;
    Nurul Fatihah Nazua
    ;
    Syarifah Nursyimi Azlina Syed Ismail
    ;
    Mohd Fauzi Abdullah
    ;
    Mohd Azlan Mohd Ishak
    ;
    Wan Izhan Nawawi Wan Ismail
    ;
    Khudzir Ismail
    ;
    Muslim Darbi Abdulrrahman
    The desulfurization process of high-sulfur coal from Jambi Province, Indonesia was investigated using peroxyacetic acid (PAA) as mild oxidising agent by ultrasonic wave. This study reports the utilization of a mixture of acetic acid and 6% hydrogen peroxide (CH3COOH: H2COOH) 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. The optimum concentration, temperature, and processing time for the coal desulfurization process were determined using the Central Composite Design-Response Surface Methodology (CCD-RSM) to overcome the traditional methods that make finding the optimal standard difficult and time-consuming. Sonicating coal at 30 ËšC for 30 minutes with 70:30 (CH3COOH: H2COOH) was found to be the ideal parameter. Results shows that all inorganic and some of the organic sulfur could be removed from the coal using mild conditions without severely affecting the coal microstructure as observed in the FESEM-EDX. Through the FTIR analysis, the organic sulfur structural parameters show the relative abundance of aliphatic sulfur (thiol, thiophene and sulfone) and organic matters in these coals decreased after the coal treated by PAA.To clarify its chemical effect, the production regularities of hydroxyl radical under ultrasonic field was determined using the iodine release method. Experimental results also showed that the production rule of hydroxyl radical was consistent with the desulfurization degree. These findings confirmed that the synergistic action of physical and chemical effects of the ultrasonic played an important role in this desulfurization process, which could serve as a reference for further optimizing the coal desulfurization process.
      1  1
  • Publication
    Influence of temperature and blending ratio on product yield for co-gasification of torrefied palm kernel shell and low-density polyethylene
    (IOP Publishing, 2024)
    Nur Rahimah Ibrahim
    ;
    Razi Ahmad
    ;
    Mohd Azlan Mohd Ishak
    This study investigates the product yields produced from the co-gasification of torrefied palm kernel shell (TPKS) and low-density polyethylene (LDPE). Prior co-gasification, PKS was undergo pre-treatment process at different temperature. The optimum parameter for torrefaction was found at 250 °C for 60 min reaction time with 4.89 wt. % moisture content and 10.48 wt.% fixed carbon. Thus, the result indicated that TPKS a suitable fuel feedstock for futher thermal conversion. Then, TPKS and LDPE were gasified at temperature of 600, 800 and 1000 °C and blending ratio of 10:90, 50:50, 90:10 (TPKS:LDPE) for 60 min reaction time. Based on the findings found that, temperature plays an important role in co-gasification. Higher gasification temperature increases the carbon conversion which improves gasification rate. By varying temperature from 600 to 1000 °C, the gas yield increased whilst tar yield decreased sharply. For the effect of blending ratio, through blending of TPKS and LDPE, the gas and char yield increase, while tar decrease with increase torrefied TPKS ratio. Furthermore, it was observed that the product yields obtained from the co-gasification of TPKS and LDPE at 50:50 blending ratios produce the highest gas yield with low char and tar yield than another blending ratio. Therefore, based on the effect of temperature and blending ratio on product yield shows that the optimum parameter to produce maximum gas yield with minimum tar and char yield are at 50:50 (TPKS:LDPE) blending ratio at 800 °C for 60 minutes reaction time.