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Study on kinetic model of microwave thermocatalytic treatment of biomass tar model compound

Anis S, Zainal ZA

Bioresour Technol, 2014 Jan;151:183-90.
PMID: 24231266 DOI: 10.1016/j.biortech.2013.10.065

Kinetic model parameters for toluene conversion under microwave thermocatalytic treatment were evaluated. The kinetic rate constants were determined using integral method based on experimental data and coupled with Arrhenius equation for obtaining the activation energies and pre-exponential factors. The model provides a good agreement with the experimental data. The kinetic model was also validated with standard error of 3% on average. The extrapolation of the model showed a reasonable trend to predict toluene conversion and product yield both in thermal and catalytic treatments. Under microwave irradiation, activation energy of toluene conversion was lower in the range of 3-27 kJ mol(-1) compared to those of conventional heating reported in the literatures. The overall reaction rate was six times higher compared to conventional heating. As a whole, the kinetic model works better for tar model removal in the absence of gas reforming within a level of reliability demonstrated in this study.
Upgrading producer gas quality from rubber wood gasification in a radio frequency tar thermocatalytic treatment reactor

Anis S, Zainal ZA

Bioresour Technol, 2013 Dec;150:328-37.
PMID: 24185417 DOI: 10.1016/j.biortech.2013.10.010

This study focused on improving the producer gas quality using radio frequency (RF) tar thermocatalytic treatment reactor. The producer gas containing tar, particles and water was directly passed at a particular flow rate into the RF reactor at various temperatures for catalytic and thermal treatments. Thermal treatment generates higher heating value of 5.76 MJ Nm(-3) at 1200°C. Catalytic treatments using both dolomite and Y-zeolite provide high tar and particles conversion efficiencies of about 97% on average. The result also showed that light poly-aromatic hydrocarbons especially naphthalene and aromatic compounds particularly benzene and toluene were still found even at higher reaction temperatures. Low energy intensive RF tar thermocatalytic treatment was found to be effective for upgrading the producer gas quality to meet the end user requirements and increasing its energy content.
Gasification of palm empty fruit bunch in a bubbling fluidized bed: a performance and agglomeration study

Lahijani P, Zainal ZA

Bioresour Technol, 2011 Jan;102(2):2068-76.
PMID: 20980143 DOI: 10.1016/j.biortech.2010.09.101

Gasification of palm empty fruit bunch (EFB) was investigated in a pilot-scale air-blown fluidized bed. The effect of bed temperature (650-1050 °C) on gasification performance was studied. To explore the potential of EFB, the gasification results were compared to that of sawdust. Results showed that maximum heating values (HHV) of 5.37 and 5.88 (MJ/Nm3), dry gas yield of 2.04 and 2.0 (Nm3/kg), carbon conversion of 93% and 85 % and cold gas efficiency of 72% and 71 % were obtained for EFB and sawdust at the temperature of 1050 °C and ER of 0.25. However, it was realized that agglomeration was the major issue in EFB gasification at high temperatures. To prevent the bed agglomeration, EFB gasification was performed at temperature of 770±20 °C while the ER was varied from 0.17 to 0.32. Maximum HHV of 4.53 was obtained at ER of 0.21 where no agglomeration was observed.
Thermocatalytic treatment of biomass tar model compounds via radio frequency

Anis S, Zainal ZA, Bakar MZ

Bioresour Technol, 2013 May;136:117-25.
PMID: 23567671 DOI: 10.1016/j.biortech.2013.02.049

A new effective RF tar thermocatalytic treatment process with low energy intensive has been proposed to remove tar from biomass gasification. Toluene and naphthalene as biomass tar model compounds were removed via both thermal and catalytic treatment over a wide temperature range from 850 °C to 1200 °C and 450 °C to 900 °C, respectively at residence time of 0-0.7 s. Thermal characteristics of the new technique are also described in this paper. This study clearly clarified that toluene was much easier to be removed than naphthalene. Soot was found as the final product of thermal treatment of the tar model and completely removed during catalytic treatment. Radical reactions generated by RF non-thermal effect improve the tar removal. The study showed that Y-zeolite has better catalytic activity compared to dolomite on toluene and naphthalene removal due to its acidic nature and large surface area, even at lower reaction temperature of about 550 °C.
Microwave-enhanced CO2 gasification of oil palm shell char

Lahijani P, Zainal ZA, Mohamed AR, Mohammadi M

Bioresour Technol, 2014 Apr;158:193-200.
PMID: 24607454 DOI: 10.1016/j.biortech.2014.02.015

CO2 gasification of oil palm shell (OPS) char to produce CO through the Boudouard reaction (C + CO2 ↔ 2CO) was investigated under microwave irradiation. A microwave heating system was developed to carry out the CO2 gasification in a packed bed of OPS char. The influence of char particle size, temperature and gas flow rate on CO2 conversion and CO evolution was considered. It was attempted to improve the reactivity of OPS char in gasification reaction through incorporation of Fe catalyst into the char skeleton. Very promising results were achieved in our experiments, where a CO2 conversion of 99% could be maintained during 60 min microwave-induced gasification of iron-catalyzed char. When similar gasification experiments were performed in conventional electric furnace, the superior performance of microwave over thermal driven reaction was elucidated. The activation energies of 36.0, 74.2 and 247.2 kJ/mol were obtained for catalytic and non-catalytic microwave and thermal heating, respectively.
CO2 gasification reactivity of biomass char: catalytic influence of alkali, alkaline earth and transition metal salts

Lahijani P, Zainal ZA, Mohamed AR, Mohammadi M

Bioresour Technol, 2013 Sep;144:288-95.
PMID: 23880130 DOI: 10.1016/j.biortech.2013.06.059

This study investigates the influence of alkali (Na, K), alkaline earth (Ca, Mg) and transition (Fe) metal nitrates on CO2 gasification reactivity of pistachio nut shell (PNS) char. The preliminary gasification experiments were performed in thermogravimetric analyzer (TGA) and the results showed considerable improvement in carbon conversion; Na-char>Ca-char>Fe-char>K-char>Mg-char>raw char. Based on TGA studies, NaNO3 (with loadings of 3-7 wt%) was selected as the superior catalyst for further gasification studies in bench-scale reactor; the highest reactivity was devoted to 5 wt% Na loaded char. The data acquired for gasification rate of catalyzed char were fitted with several kinetic models, among which, random pore model was adopted as the best model. Based on obtained gasification rate constant and using the Arrhenius plot, activation energy of 5 wt% Na loaded char was calculated as 151.46 kJ/mol which was 53 kJ/mol lower than that of un-catalyzed char.
Co-gasification of tire and biomass for enhancement of tire-char reactivity in CO2 gasification process

Lahijani P, Zainal ZA, Mohamed AR, Mohammadi M

Bioresour Technol, 2013 Jun;138:124-30.
PMID: 23612170 DOI: 10.1016/j.biortech.2013.03.179

In this investigation, palm empty fruit bunch (EFB) and almond shell (AS) were implemented as two natural catalysts rich in alkali metals, especially potassium, to enhance the reactivity of tire-char through co-gasification process. Co-gasification experiments were conducted at several blending ratios using isothermal Thermogravimetric analysis (TGA) under CO2. The pronounced effect of inherent alkali content of biomass-chars on promoting the reactivity of tire-char was proven when acid-treated biomass-chars did not exert any catalytic effect on improving the reactivity of tire-char in co-gasification experiments. In kinetic studies of the co-gasified samples in chemically-controlled regime, modified random pore model (M-RPM) was adopted to describe the reactive behavior of the tire-char/biomass-char blends. By virtue of the catalytic effect of biomass, the activation energy for tire-char gasification was lowered from 250 kJ/mol in pure form 203 to 187 kJ/mol for AS-char and EFB-char co-gasified samples, respectively.
Ash of palm empty fruit bunch as a natural catalyst for promoting the CO₂ gasification reactivity of biomass char

Lahijani P, Zainal ZA, Mohamed AR, Mohammadi M

Bioresour Technol, 2013 Mar;132:351-5.
PMID: 23195653 DOI: 10.1016/j.biortech.2012.10.092

Palm empty fruit bunch ash (EFB-ash) was used as a natural catalyst, rich in potassium to enhance the CO2 gasification reactivity of palm shell char (PS-char). Various EFB-ash loadings (ranging from 0 to 12.5wt.%) were implemented to improve the reactivity of PS-char during CO2 gasification studies using thermogravimetric analysis. The achieved results explored that the highest gasification reactivity was devoted to 10% EFB-ash loaded char. The SEM-EDS and XRD analyses further confirmed the successful loading of EFB-ash on PS-char which contributed to promoting the gasification reactivity of char. Random pore model was applied to determine the kinetic parameters in catalytic gasification of char at various temperatures of 800-900°C. The dependence of char reaction rate on gasification temperature resulted in a straight line in Arrhenius-type plot, from which the activation energy of 158.75kJ/mol was obtained for the catalytic char gasification.
Upgrading agricultural wastes using three different carbonization methods: Thermal, hydrothermal and vapothermal

Yeoh KH, Shafie SA, Al-Attab KA, Zainal ZA

Bioresour Technol, 2018 Oct;265:365-371.
PMID: 29925052 DOI: 10.1016/j.biortech.2018.06.024

In this study, three different methods for high quality solid fuel production were tested and compared experimentally. Oil palm empty fruit bunches, mesocarp fibers, palm kernel shells and rubber seeds shells were treated using thermal (TC), hydrothermal (HTC) and vapothermal (VTC) carbonization. All thermochemical methods were accomplished by using a custom made batch-type reactor. Utilization of novel single reactor equipped with suspended internal container provided efficient operation since both steam generator and raw materials were placed inside the same reactor. Highest energy densification was achieved by VTC process followed by TC and HTC processes. The heating value enhancement in VTC and TC was achieved by the increase in fixed carbon content and reduction in volatile matter. The formation of the spherical components in HTC hydrochar which gave a sharp peak at 340 °C in the DTG curves was suggested as the reason that led to the increment in energy content.
Glucose-6-phosphate dehydrogenase (G6PD) variants in Malaysian Chinese

Ainoon O, Joyce J, Boo NY, Cheong SK, Zainal ZA, Hamidah NH

Hum Mutat, 1999 Oct;14(4):352.
PMID: 10502785 DOI: 10.1002/(SICI)1098-1004(199910)14:4<352::AID-HUMU1

We screened 38 G6PD-deficient male Chinese neonates for known G6PD mutations using established PCR-based techniques. We found 50.0% (19 of 38) were mutation 1376G>T, 34.2% (13 of 38) were mutation 1388G>A, 5.2% (2 of 38 ) were mutation 95A>G and 2.2% (1 of 38) was mutation 1024C>T. In 7% (3 of 38) of the cases the mutations remained uncharacterised. Sixty three percent (24 of 38) of the G6PD deficient neonates had neonatal jaundice with 28.9 % (11 of 38) developing moderate to severe hyperbilirubinemia. The group of neonates with 1388 mutation showed the highest incidence of moderate to severe hyperbilirubinemia requiring phototherapy and/or exchange transfusion respectively. Majority (70%) of the G6PD deficient neonates showed severe enzyme deficiency. However, there was no meaningful association between the level of enzyme activity and the severity of neonatal jaundice. In summary, four mutations account for more than 90% of the G6PD deficiency cases among the Chinese in Malaysia and the pattern of distribution of the molecular variants is similar to those found among the Chinese in Taiwan and southern mainland China. Our findings also suggest the possible association of nt 1388 mutation with severe neonatal jaundice.
A systematic review of behaviour change techniques in pharmacist-delivered self-management interventions towards patients with chronic obstructive pulmonary disease

Jamil N, Zainal ZA, Alias SH, Chong LY, Hashim R

Res Social Adm Pharm, 2023 Aug;19(8):1131-1145.
PMID: 37202279 DOI: 10.1016/j.sapharm.2023.05.006

BACKGROUND: Self-management interventions often employ behaviour change techniques in order to produce desired target behaviours that are necessary for day-to-day living with a chronic disease. Despite the large number of self-management interventions for patients with chronic obstructive pulmonary disease (COPD), previously reported interventions have been typically delivered by healthcare providers other than the pharmacist.
OBJECTIVE: This systematic review examined the components of pharmacists-delivered COPD self-management interventions according to an established taxonomy of behaviour change techniques (BCTs).
METHODS: A systematic search was conducted on PubMed, ScienceDirect, OVID, and Google Scholar from January 2011 to December 2021 for studies of pharmacist-delivered self-management interventions in COPD patients.
RESULTS: A total of seventeen studies of intervention were eligible for inclusion in the narrative review. Interventions were educational and were delivered individually and face-to-face for the first session. Across studies, pharmacists spent an average of 35 min on the first meeting and had an average of 6 follow-up sessions. Recurrent BCTs in pharmacist interventions were "Information on the health consequence", "Feedback on behaviour", "Instruction on how to perform a behaviour", "Demonstration of the behaviour" and "Behavioural practice/rehearsal".
CONCLUSIONS: Pharmacists have provided interventions towards improving health behaviours, especially on adherence and usage of inhaler devices for patients with COPD. Future self-management interventions should be designed using the identified BCTs for the improvement of COPD self-management and disease outcomes.
Fulltext The Use of Medicines with Anti-cholinergic Properties and Their Health Impacts among Hospitalised Malaysian Geriatric Patients

Wahab IA, Akbar B, Zainal ZA, Che Pa MF, Naina B

Malays J Med Sci, 2019 Mar;26(2):77-87.
PMID: 31447611 MyJurnal DOI: 10.21315/mjms2019.26.2.9

Background: Studies have shown that the use of medicines with anti-cholinergic (Ach) properties can increase elderly patients' risk of experiencing falls, confusion, and longer hospital stays (LOS). These adverse effects are preventable with appropriate intervention. Little is known about the use of medicines with Ach properties and their impact on Malaysian elderly patients. This study aimed to investigate the use of medicines with Ach properties and their impact on fall risk, confusion, and longer LOS among hospitalised elderly patients.
Methods: This study utilised a cross-sectional design and was conducted at a single centre where convenience sampling was employed to collect data from elderly patients (> 60 years) admitted to geriatric and medical wards at Hospital Tuanku Ja'afar during a 2-month period (July 2017-August 2017). Patients were excluded from this study if their hospital admission was planned for an elective procedure or if neurocognitive and hepatic impairment were diagnosed prior to the hospital admission. Medicines with Ach properties were identified and classified according to the anti-cholinergic drug scale (ADS). Univariate and multiple logistic regression statistical analyses were performed to assess its impacts on falls, confusion, and LOS.
Results: A total of 145 elderly patients with a mean age of 71.59 years old (SD = 8.02) were included in the study. Fifty-two percent of the participants were female, and the average hospital stay was 6 days (SD = 2.09). Medicines with Ach properties were administered in 62% (n = 90) of the cases. The most commonly prescribed medicine with Ach properties was furosemide (n = 59), followed by ranitidine (n = 44), warfarin (n = 23), and methylprednisolone (n = 22). Compared to patients who did not receive medicines with Ach properties, patients who received them had a significantly higher risk of falls [odds ratios (OR) = 2.61; 95%CI: 1.18, 5.78; P = 0.018], confusion (OR = 3.60; 95%CI: 1.55, 8.36; P = 0.003), and LOS (OR = 4.83; 95%CI: 2.13, 10.94; P < 0.001). Multiple comorbidities also showed a significantly increased risk of falls (OR = 3.03; 95%CI: 1.29, 7.07; P = 0.010).
Conclusion: Medicines with Ach properties had a significant impact on elderly patients' health. Strategies for rationally prescribing medicines with Ach properties to Malaysian elderly patients need to be improved and be recognised as an important public health priority.
Fulltext Targeted Primary and Secondary Preventive Strategies for Depression among Malaysian Pharmacy Students

A Wahab I, Goh KW, Zainal ZA, Mohamed Yusof NS, Huri HZ, Jacob SA, et al.

Int J Environ Res Public Health, 2022 Aug 05;19(15).
PMID: 35954990 DOI: 10.3390/ijerph19159629

The global depression burden has remained a challenge throughout the pre- and post-pandemic era. The pandemic effect has led to the spiraling of mental disorders among young people who will be the next generation of leaders. This study aims to identify university students’ sociodemographic, psychosocial and academic backgrounds and performance associated with depression symptoms for the development of primary and secondary preventive strategies for mental health. A cross-sectional study was conducted using an online questionnaire distributed to 19 institutions in Malaysia offering a Bachelor of Pharmacy degree program. The self-rated Depression Anxiety Stress Scale (DASS-42) was used to assess depression symptoms. Pearson’s chi-square test and Fisher’s exact test were used to assess the investigated variables with depression symptoms. Independent T-test and one-way ANOVA were used to compare means of depression score across variables. Binary logistic regression was employed to examine the relationship between the investigated variables and depression symptoms. A total of 610 pharmacy students participated, of which 47% (n = 289/610) were having depression symptoms. Students who smoke nicotine and those who have separated parents, family history of mental illness, and poor academic performance were associated with depression symptoms (p < 0.05). Differences in geographical areas, race and religion also showed significant associations with depression symptoms. Parental marital status, poor academic performance, history of mental illness and comorbidities were statistically predicting depression symptoms (p < 0.05). Primary preventive strategies allowing students to harness healthy coping skills for stress, nicotine-free campaigns and a holistic curriculum are warranted. Secondary measures on mindfulness and compassion skills activities to benefit students who experienced early life crises are highly recommended. Enforcing these targeted strategies in collaboration with health and social sectors should be the primary agenda of universities to ensure their uptake.
Fulltext Classification of Raw Stingless Bee Honeys by Bee Species Origins Using the NMR- and LC-MS-Based Metabolomics Approach

Razali MTA, Zainal ZA, Maulidiani M, Shaari K, Zamri Z, Mohd Idrus MZ, et al.

Molecules, 2018 Aug 28;23(9).
PMID: 30154302 DOI: 10.3390/molecules23092160

The official standard for quality control of honey is currently based on physicochemical properties. However, this method is time-consuming, cost intensive, and does not lead to information on the originality of honey. This study aims to classify raw stingless bee honeys by bee species origins as a potential classifier using the NMR-LCMS-based metabolomics approach. Raw stingless bee honeys were analysed and classified by bee species origins using proton nuclear magnetic resonance (¹H-NMR) spectroscopy and an ultra-high performance liquid chromatography-quadrupole time of flight mass spectrometry (UHPLC-QTOF MS) in combination with chemometrics tools. The honey samples were able to be classified into three different groups based on the bee species origins of Heterotrigona itama, Geniotrigona thoracica, and Tetrigona apicalis. d-Fructofuranose (H. itama honey), β-d-Glucose, d-Xylose, α-d-Glucose (G. thoracica honey), and l-Lactic acid, Acetic acid, l-Alanine (T. apicalis honey) ident d-Fructofuranose identified via ¹H-NMR data and the diagnostic ions of UHPLC-QTOF MS were characterized as the discriminant metabolites or putative chemical markers. It could be suggested that the quality of honey in terms of originality and purity can be rapidly determined using the classification technique by bee species origins via the ¹H-NMR- and UHPLC-QTOF MS-based metabolomics approach.

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