Displaying publications 81 - 100 of 371 in total

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  1. Fulltext Optimization and blends study of heterogeneous acid catalyst-assisted esterification of palm oil industry by-product for biodiesel production
    Akinfalabi SI, Rashid U, Arbi Nehdi I, Yaw Choong TS, Sbihi HM, Gewik MM
    R Soc Open Sci, 2020 Jan;7(1):191592.
    PMID: 32218977 DOI: 10.1098/rsos.191592
    The optimum conditions to produce palm fatty acid distillate (PFAD)-derived-methyl esters via esterification have been demonstrated with the aid of the response surface methodology (RSM) with central composite rotatable design in the presence of heterogeneous acid catalyst. The effect of four reaction variables, reaction time (30-110 min), reaction temperature (30-70°C), catalyst concentration (1-3 wt.%) and methanol : PFAD molar ratio (3 : 1-11 : 1), were investigated. The reaction time had the most influence on the yield response, while the interaction between the reaction time and the catalyst concentration, with an F-value of 95.61, contributed the most to the esterification reaction. The model had an R2-value of 0.9855, suggesting a fit model, which gave a maximum yield of 95%. The fuel properties of produced PFAD methyl ester were appraised based on the acid value, iodine value, cloud and pour points, flash point, kinematic viscosity, density, ash and water contents and were compared with biodiesel EN 14214 and ASTM D-6751 standard limits. The PFAD methyl ester was further blended with petro-diesel from B0, B3, B5, B10, B20 and B100, on a volumetric basis. The blends were characterized by TGA, DTG and FTIR. With an acid value of 0.42 (mg KOH g-1), iodine value of 63 (g.I2/100 g), kinematic viscosity of 4.31 (mm2 s-1), the PFAD methyl ester has shown good fuel potential, as all of its fuel properties were within the permissible international standards for biodiesel.
    Matched MeSH terms: Biofuels
  2. Heterotrophic cultivation of microalgae for production of biodiesel
    Mohamed MS, Wei LZ, Ariff AB
    Recent Pat Biotechnol, 2011 Aug;5(2):95-107.
    PMID: 21707527
    High cell density cultivation of microalgae via heterotrophic growth mechanism could effectively address the issues of low productivity and operational constraints presently affecting the solar driven biodiesel production. This paper reviews the progress made so far in the development of commercial-scale heterotrophic microalgae cultivation processes. The review also discusses on patentable concepts and innovations disclosed in the past four years with regards to new approaches to microalgal cultivation technique, improvisation on the process flow designs to economically produced biodiesel and genetic manipulation to confer desirable traits leading to much valued high lipid-bearing microalgae strains.
    Matched MeSH terms: Biofuels*
  3. Biodiesel Production from Citrillus colocynthis Oil Using Enzymatic Based Catalytic Reaction and Characterization Studies
    Nehdi IA, Sbihi HM, Blidi LE, Rashid U, Tan CP, Al-Resayes SI
    Protein Pept Lett, 2018;25(2):164-170.
    PMID: 28240158 DOI: 10.2174/0929866524666170223150839
    BACKGROUND: Biodiesel is a green fuel consisting of long chain fatty acid monoalkyl esters, which can be blended with diesel or used alone which is usually produced from vegetable oils/fats by either lipasecatalyzed transesterification. In this investigation, an enzyme (Novozym 435) catalyzed process was optimized to prepare methyl esters from crude Citrullus colocynthis oil (CCO) by transesterification of CCO with methanol. However, as per our knowledge, lipase-catalyzed transesterification have not been used for biodiesel production from Citrullus colocynthis.

    OBJECTIVE: The purpose of this work was to transesterify the CCO in the presence of Candida antarctica lipase as catalyst and methanol. Additionally, the physicochemical parameters/fuel properties of the Citrullus colocynthis methyl ester (CCME) were assessed and compared.

    METHODS: Lipase-catalyzed reactions were carried out in three necked flask (50 mL) attached with reflux condenser and thermometer, immersed in oil bath at constant stirring speed (400 rpm). The reaction mixture was consisted of CCO and varying the calculated amount of methanol, tert-butyl alcohol, and Novozym 435. The experimental parameters reaction time, methanol/oil molar ratio, reaction temperature, tert-butanol content, Novozym 435 content and water content were optimized for the transesterification reaction. The CCME yield was measured using gas chromatograph. The fuel properties of the produced CCME were determined as per American Society for Testing and Materials (ASTM) and European (EN) biodiesel standard methods.

    RESULTS: In this study, an enzymatic catalyst was employed to synthesize the CCME from CCO via transesterification. Several variables affecting the CCME yield were optimized as lipase quantity (4%), water content (0.5%), methanol/oil molar ratio (5:1), reaction temperature (43 °C), reaction medium composition (80% tertbutanol/ oil), and reaction time (3.7 h). A CCME yield of 97.8% was achieved using enzyme catalyzed transesterification of CCO under optimal conditions. The significant biodiesel fuel properties of CCME, i.e. cloud point (0.70 °C); cetane number (49.07); kinematic viscosity (2.27 mm2/s); flash point (143 °C); sulfur content (2 ppm) density (880 kg/m3) and acid value (0.076 mg KOH/g) were appraised. CCME also exhibited long-term storage stability (4.80 h) and all the biodiesel fuel properties were within the range of standards (ASTM D6751 and EN 14214).

    CONCLUSION: The lipase-catalyzed transesterification produced better conversion than the base-catalyzed reaction. The fuel properties of CCME were within the limits of the ASTM D6751 and EN14214 standards. Furthermore, CCME showed good oxidative stability and a long shelf life due its high natural antioxidant content. CCME showed better fuel properties and long-term storage stability due to which it can be used as a potential alternative fuel.

    Matched MeSH terms: Biofuels
  4. Evaluating the Potential of Oleaginous Yeasts as Feedstock for Biodiesel Production
    Mukhtar H, Suliman SM, Shabbir A, Mumtaz MW, Rashid U, Rahimuddin SA
    Protein Pept Lett, 2018;25(2):195-201.
    PMID: 29359654 DOI: 10.2174/0929866525666180122112805
    BACKGROUND: Lipid-producing microorganisms, said to be oleaginous have been recognized since several years. We had investigated the effects of medium components and culturing situations on cell growth and lipid accumulation of oleaginous yeasts which were analytically examined so as to enhance lipid yield for biodiesel production.

    OBJECTIVE: The main objective of this study was to explore oleaginous yeast, Yarrowia lipolytica isolated from soil and optimization of culture conditions and medium components to obtained better quality microbial oil for biodiesel production.

    METHODS: Fifty yeast strains were isolated from soil from different regions of Lahore and eleven of them were selected for oil production. The isolated yeast colonies were screened to further check their lipid producing capabilities by the qualitative analysis. Five yeast strains were designated as oleaginous because they produced more than 16% of oil based on their biomass. To estimate the total lipid content of yeast cells, the extraction of lipids was done by performing the procedure proposed by Bligh and Dyer. The transesterification of yeast oils was performed by using different methods. There were three different strategies customized to transesterifying microbial oil using base catalyzed transesterification, acid catalyzed transesterification and enzyme-based transesterification. After completion of transesterification, sample was used for fatty acid methyl esters (FAMEs) were analyzed by gas-chromatograph with ionization detector type MS.

    RESULTS: The isolate IIB-10 identified as Yarrowia lipolytica produced maximum amount of lipids i.e. 22.8%. More amount of biomass was obtained when cane molasses was utilized as carbon source where it produced 29.4 g/L of biomass while sucrose and lactose were not utilized by IIB-10 and no biomass was obtained. Similarly, meat extracts showed best results when it was used as nitrogen source because it resulted in 35.8 g/L biomass of Yarrowia lipolytica IIB-10. The culturing conditions like size of inoculum, effect of pH and time of incubation were also studied. The 10% of inoculum size produced 25.4 g/L biomass at 120 h incubation time, while the pH 7 was the optimum pH at which 24.8 g/L biomass was produced by Yarrowia lipolytica IIB-10. GC-MS analysis showed that biodiesel produced by transesterification contained similar fatty acids as found in vegetable oil for this reason it is widely accepted feedstock for biodiesel production.

    CONCLUSION: The analysis of fatty acids methyl esters showed the similar composition of microbial oil as in vegetable oils and high amount of methyl esters were obtained after transesterification. Therefore, potentially oleaginous yeast could be used to generate a large amount of lipids for biodiesel production that will be the better substitute of petroleum-based diesel and will also control the environmental pollution.

    Matched MeSH terms: Biofuels
  5. Fulltext Remotely sensed evidence of tropical peatland conversion to oil palm
    Koh LP, Miettinen J, Liew SC, Ghazoul J
    Proc Natl Acad Sci U S A, 2011 Mar 22;108(12):5127-32.
    PMID: 21383161 DOI: 10.1073/pnas.1018776108
    Rising global demands for food and biofuels are driving forest clearance in the tropics. Oil-palm expansion contributes to biodiversity declines and carbon emissions in Southeast Asia. However, the magnitudes of these impacts remain largely unquantified until now. We produce a 250-m spatial resolution map of closed canopy oil-palm plantations in the lowlands of Peninsular Malaysia (2 million ha), Borneo (2.4 million ha), and Sumatra (3.9 million ha). We demonstrate that 6% (or ≈880,000 ha) of tropical peatlands in the region had been converted to oil-palm plantations by the early 2000s. Conversion of peatswamp forests to oil palm led to biodiversity declines of 1% in Borneo (equivalent to four species of forest-dwelling birds), 3.4% in Sumatra (16 species), and 12.1% in Peninsular Malaysia (46 species). This land-use change also contributed to the loss of ≈140 million Mg of aboveground biomass carbon, and annual emissions of ≈4.6 million Mg of belowground carbon from peat oxidation. Additionally, the loss of peatswamp forests implies the loss of carbon sequestration service through peat accumulation, which amounts to ≈660,000 Mg of carbon annually. By 2010, 2.3 million ha of peatswamp forests were clear-felled, and currently occur as degraded lands. Reforestation of these clearings could enhance biodiversity by up to ≈20%, whereas oil-palm establishment would exacerbate species losses by up to ≈12%. To safeguard the region's biodiversity and carbon stocks, conservation and reforestation efforts should target Central Kalimantan, Riau, and West Kalimantan, which retain three-quarters (3.9 million ha) of the remaining peatswamp forests in Southeast Asia.
    Matched MeSH terms: Biofuels*
  6. Evaluation of recycled paper mill effluent digestion in a modified anaerobic hybrid baffled (MAHB) reactor: reactor performance & kinetic studies
    Hassan SR, Zaman NQ, Dahlan I
    Prep Biochem Biotechnol, 2020;50(3):234-239.
    PMID: 31762367 DOI: 10.1080/10826068.2019.1692214
    Recycled paper mill effluent (RPME) consists of various organic and inorganic compounds. In this study, modified anaerobic hybrid baffled (MAHB) bioreactor has been successfully used to anaerobically digest RPME. The anaerobic digestion was investigated in relation to methane production rate, lignin removal, and chemical oxygen demand (COD) removal, with respect to organic loading rate (OLR) and hydraulic retention time (HRT). The analysis using kinetic study was carried out under mesophilic conditions (37 ± 2 °C) and influent COD concentrations (1000-4000 mg L-1), to prove its practicability towards RPME treatment. First-order kinetic model was used to clarify the behavior of RPME anaerobic digestion under different OLRs (0.14-4.00 g COD L-1 d-1) and HRT (1-7 d). The result shows that the highest COD removal efficiency and methane production rate were recorded to be 98.07% and 2.2223 L CH4 d-1, respectively. This result was further validated by evaluating the biokinetic coefficients (reaction rate constant (k) and maximum biogas production (ym)), which gave values of k = 0.57 d-1 and ym = 0.331 L d-1. This kinetic data concludes that MAHB presented satisfactory performance towards COD removal with relatively high methane production, which can be further utilized as on-site energy supply.
    Matched MeSH terms: Biofuels*
  7. A review on pretreatment methods for lipid extraction from microalgae biomass
    Mat Husin MA, Mohd Yasin NH, Takriff MS, Jamar NH
    Prep Biochem Biotechnol, 2024 Feb;54(2):159-174.
    PMID: 37220018 DOI: 10.1080/10826068.2023.2214923
    Microalgal lipids are promising and sustainable sources for the production of third-generation biofuels, foods, and medicines. A high lipid yield during the extraction process in microalgae could be influenced by the suitable pretreatment and lipid extraction methods. The extraction method itself could be attributed to the economic and environmental impacts on the industry. This review summarizes the pretreatment methods including mechanical and non-mechanical techniques for cell lysis strategy before lipid extraction in microalgae biomass. The multiple strategies to achieve high lipid yields via cell disruption techniques are discussed. These strategies include mechanical (shear forces, pulse electric forces, waves, and temperature shock) and non-mechanical (chemicals, osmotic pressure, and biological) methods. At present, two techniques of the pretreatment method can be combined to increase lipid extraction from microalgae. Therefore, the extraction strategy for a large-scale application could be further strengthened to optimize lipid recovery by microalgae.
    Matched MeSH terms: Biofuels
  8. Fulltext Improved Nylon 6,6 Nanofiber Membrane in A Tilted Panel Filtration System for Fouling Control in Microalgae Harvesting
    Mat Nawi NI, Abd Halim NS, Lee LC, Wirzal MDH, Bilad MR, Nordin NAH, et al.
    Polymers (Basel), 2020 Jan 21;12(2).
    PMID: 31973178 DOI: 10.3390/polym12020252
    The competitiveness of algae as biofuel feedstock leads to the growth of membrane filtration as one of promising technologies for algae harvesting. Nanofiber membrane (NFM) was found to be efficient for microalgae harvesting via membrane filtration, but it is highly limited by its weak mechanical strength. The main objective of this study is to enhance the applicability of nylon 6,6 NFM for microalgae filtration by optimizing the operational parameters and applying solvent vapor treatment to improve its mechanical strength. The relaxation period and filtration cycle could be optimized to improve the hydraulic performance. For a cycle of 5 min., relaxation period of ≤2 min shows the highest steady-state permeability of 365 ± 14.14 L m-2 h-1 bar-1, while for 10 min cycle, 3 min. of relaxation period was found optimum that yields permeability of 402 ± 34.47 L m-2 h-1 bar-1. The treated nylon 6,6 NFM was also used to study the effect of aeration rate. It is confirmed that the aeration rate enhances the steady-state performance for both intermittent and continuous mode of aeration. Remarkably, intermittent aeration shows 7% better permeability than the full aeration for all tested condition, which is beneficial for reducing the total energy consumption.
    Matched MeSH terms: Biofuels
  9. Fulltext Removal of hydrogen sulfide from a biogas mimic by using impregnated activated carbon adsorbent
    Zulkefli NN, Masdar MS, Wan Isahak WNR, Md Jahim J, Md Rejab SA, Chien Lye C
    PLoS One, 2019;14(2):e0211713.
    PMID: 30753209 DOI: 10.1371/journal.pone.0211713
    Adsorption technology has led to the development of promising techniques to purify biogas, i.e., biomethane or biohydrogen. Such techniques mainly depend on the adsorbent ability and operating parameters. This research focused on adsorption technology for upgrading biogas technique by developing a novel adsorbent. The commercial coconut shell activated carbon (CAC) and two types of gases (H2S/N2 and H2S/N2/CO2) were used. CAC was modified by copper sulfate (CuSO4), zinc acetate (ZnAc2), potassium hydroxide (KOH), potassium iodide (KI), and sodium carbonate (Na2CO3) on their surface to increase the selectivity of H2S removal. Commercial H2S adsorbents were soaked in 7 wt.% of impregnated solution for 30 min before drying at 120°C for 24 h. The synthesized adsorbent's physical and chemical properties, including surface morphology, porosity, and structures, were characterized by SEM-EDX, FTIR, XRD, TGA, and BET analyses. For real applications, the modified adsorbents were used in a real-time 0.85 L single-column adsorber unit. The operating parameters for the H2S adsorption in the adsorber unit varied in L/D ratio (0.5-2.5) and feed flow rate (1.5-5.5 L/min) where, also equivalent with a gas hourly space velocity, GHSV (212.4-780.0 hour-1) used. The performances of H2S adsorption were then compared with those of the best adsorbent that can be used for further investigation. Characterization results revealed that the impregnated solution homogeneously covered the adsorbent surface, morphology, and properties (i.e., crystallinity and surface area). BET analysis further shows that the modified adsorbents surface area decreased by up to 96%. Hence, ZnAc2-CAC clarify as the best adsorption capacity ranging within 1.3-1.7 mg H2S/g, whereby the studied extended to adsorption-desorption cycle.
    Matched MeSH terms: Biofuels
  10. Fulltext The new abnormal: Identifying and ranking anomalies in the land trade market
    Interdonato R, Bourgoin J, Grislain Q, Tagarelli A
    PLoS One, 2022;17(12):e0277608.
    PMID: 36454792 DOI: 10.1371/journal.pone.0277608
    Large-scale national and transnational commercial land transactions, or Large-Scale Land Acquisitions (LSLAs), have been gaining a lot of academic attention since the late 2000s and since the reported rush for land, resulting in turn from an increase in demand for arable land. If many data exist to characterize land deals, the analysis of investment networks remain limited and predominantly portrays power asymmetries between countries from the Global North investing in the Global South. The aim of this work is to perform a deeper investigation on the land trade market, specifically focusing on cases that do not follow such narratives. For instance, almost 25% of the countries included in the transnational land trade network do not follow a strict investor/target dichotomy, thus being characterized by a double role, i.e., they both acquire and cede land in the transnational context. In order to globally acknowledge for what was currently considered as abnormal cases, we model open access data about LSLAs extracted from the Land Matrix Initiative (LMI) open-access database into a network graph, and adapt an eigenvector based centrality method originally conceived for online social networks, namely LurkerRank, to identify and rank anomalous profiles in the land trade market. We take into account three different network snapshots: a multi-sector network (including all the transnational deals in the LMI database), and three networks referring to specific investment sectors (agriculture,mines and biofuels). Experimental results show that emerging economies (e.g., China and Malaysia) play a central role in the land trade market, by creating alternative dynamics that escape the classic North/South one. Our analyses also show how African countries that are often seen as targets of land trade transactions in a specific sector, may often acquire foreign land in the context of investments in the same sector (i.e., Zimbabwe for biofuels and the Democratic Republic of Congo for the mining sector).
    Matched MeSH terms: Biofuels*
  11. First Report of Lasiodiplodia theobromae Causing Stem Canker of Jatropha curcas in Malaysia
    Sulaiman R, Thanarajoo SS, Kadir J, Vadamalai G
    Plant Dis, 2012 May;96(5):767.
    PMID: 30727556 DOI: 10.1094/PDIS-06-11-0482-PDN
    Physic nut (Jatropha curcas L.) is an important biofuel crop worldwide. Although it has been reported to be resistant to pests and diseases (1), stem cankers have been observed on this plant at several locations in Peninsular Malaysia since early February 2008. Necrotic lesions on branches appear as scars with vascular discoloration in the tissue below the lesion. The affected area is brownish and sunken in appearance. Disease incidence of these symptomatic nonwoody plants can reach up to 80% in a plantation. Forty-eight samples of symptomatic branches collected from six locations (University Farm, Setiu, Gemenceh, Pulau Carey, Port Dickson, and Kuala Selangor) were surface sterilized in 10% bleach, rinsed twice with sterile distilled water, air dried on filter paper, and plated on water agar. After 4 days, fungal colonies on the agar were transferred to potato dextrose agar (PDA) and incubated at 25°C. Twenty-seven single-spore fungal cultures obtained from all locations produced white, aerial mycelium that became dull gray after a week in culture. Pycnidia from 30-day-old pure cultures produced dark brown, oval conidia that were two celled, thin walled, and oval shape with longitudinal striations. The average size of the conidia was 23.63 × 12.72 μm with a length/width ratio of 1.86. On the basis of conidial morphology, these cultures were identified as Lasiodiplodia theobromae. To confirm the identity of the isolates, the internal transcribed spacer (ITS) region was amplified with ITS1/ITS4 primers and sequenced. The sequences were deposited in GenBank (Accession Nos. HM466951, HM466953, HM466957, GU228527, HM466959, and GU219983). Sequences from the 27 isolates were 99 to 100% identical to two L. theobromae accessions in GenBank (Nos. HM008598 and HM999905). Hence, both morphological and molecular characteristics confirmed the isolates as L. theobromae. Pathogenicity tests were performed in the glasshouse with 2-month-old J. curcas seedlings. Each plant was wound inoculated by removing the bark on a branch to a depth of 2 mm with a 10-mm cork borer. Inoculation was conducted by inserting a 10-mm-diameter PDA plug of mycelium into the wound and wrapping the inoculation site with wetted, cotton wool and Parafilm. Control plants were treated with plugs of sterile PDA. Each isolate had four replicates and two controls. After 6 days of incubation, all inoculated plants produced sunken, necrotic lesions with vascular discoloration. Leaves were wilted and yellow above the point of inoculation on branches. The control plants remained symptomless. The pathogen was successfully reisolated from lesions on inoculated branches. L. theobromae has been reported to cause cankers and dieback in a wide range of hosts and is common in tropical and subtropical regions of the world (2,3). To our knowledge, this is the first report of stem canker associated with L. theobromae on J. curcas in Malaysia. References: (1) S. Chitra and S. K. Dhyani. Curr. Sci. 91:162, 2006. (2) S. Mohali et al. For. Pathol. 35:385, 2005. (3) E. Punithalingam. Page 519 in: CMI Descriptions of Pathogenic Fungi and Bacteria. Commonwealth Mycological Institute, Kew, Surrey, UK. 1976.
    Matched MeSH terms: Biofuels
  12. Indole-3-acetic acid (IAA) induced changes in oil content, fatty acid profiles and expression of four fatty acid biosynthetic genes in Chlorella vulgaris at early stationary growth phase
    Jusoh M, Loh SH, Chuah TS, Aziz A, Cha TS
    Phytochemistry, 2015 Mar;111:65-71.
    PMID: 25583439 DOI: 10.1016/j.phytochem.2014.12.022
    Microalgae lipids and oils are potential candidates for renewable biodiesel. Many microalgae species accumulate a substantial amount of lipids and oils under environmental stresses. However, low growth rate under these adverse conditions account for the decrease in overall biomass productivity which directly influence the oil yield. This study was undertaken to investigate the effect of exogenously added auxin (indole-3-acetic acid; IAA) on the oil content, fatty acid compositions, and the expression of fatty acid biosynthetic genes in Chlorella vulgaris (UMT-M1). Auxin has been shown to regulate growth and metabolite production of several microalgae. Results showed that oil accumulation was highest on days after treatment (DAT)-2 with enriched levels of palmitic (C16:0) and stearic (C18:0) acids, while the linoleic (C18:2) and α-linolenic (C18:3n3) acids levels were markedly reduced by IAA. The elevated levels of saturated fatty acids (C16:0 and C18:0) were consistent with high expression of the β-ketoacyl ACP synthase I (KAS I) gene, while low expression of omega-6 fatty acid desaturase (ω-6 FAD) gene was consistent with low production of C18:2. However, the increment of stearoyl-ACP desaturase (SAD) gene expression upon IAA induction did not coincide with oleic acid (C18:1) production. The expression of omega-3 fatty acid desaturase (ω-3 FAD) gene showed a positive correlation with the synthesis of PUFA and C18:3n3.
    Matched MeSH terms: Biofuels/analysis
  13. Fulltext Repeated fed-batch cultivation of nitrogen-fixing bacterium, bacillus sphaericus UPMB10, using glycerol as the carbon source
    Ariff, A.B., Ooi, T.C., Shamsuddin, Z.H., Halimi, M.S.
    Pertanika Journal of Science & Technology, 2010;18(2):-.
    MyJurnal
    The exponential fed-batch cultivation of Bacillus sphaericus UPMB10 in 2 l stirred tank fermenter was performed by feeding the initial batch culture with 14 g l-1 of glycerol according to the algorithm aimed at controlling the specific growth rate (μ) of the bacterium. Very high viable cell count (1.14 x 1010 cfu ml-1), which was four times higher as compared to batch cultivation, was achieved in the fed-batch with a controlled μ at 0.4 h-1. In repeated exponential fed-batch cultivation, consisting of four cycles of harvesting and recharging, a final cell concentration of 1.9 x 1011 cfu ml-1 was obtained at the end of the fourth cycle (46 h). Meanwhile, acetylene reduction of cell samples collected from repeated fed-batch cultivation remained unchanged and was maintained at around 20 nmol C2H2 h-1 ml-1 after prolonged cultivation period, and was comparable to those obtained in batch and exponential fed-batch cultivation. Glycerol could be used as a carbon source for high performance cultivation of B. sphaericus, a nitrogen fixing bacterium, in repeated fed-batch cultivation with high cell yield and cell productivity. The productivity (0.68 g l-1 h-1) for repeated fed-batch cultivation increased about 6 times compared to that obtained in conventional batch cultivation (0.11 g l1 h-1). A innovative method in utilizing glycerol for efficient cultivation of nitrogen fixing bacterium could be beneficial to get more understanding and reference in manipulating the integrated plans for sustainable and profitable biodiesel industry.
    Matched MeSH terms: Biofuels
  14. Fulltext Synthesis of jatropha curcas-based methyl ester and ethyl ester as biodiesel feedstocks
    Azhari Muhammad Syam, Robiah Yunus, Tinia Idaty Mohd. Ghazi, Choong, Thomas Shean Yaw
    Pertanika Journal of Science & Technology, 2012;20(1):165-173.
    MyJurnal
    Research on the use of Jatropha curcas triglycerides as biodiesel feedstock has received worldwide attention due to its inherent characteristics. Unlike palm oil, J. curcas oil is not edible, and thus, it will not disturb the food supply. However, to the researchers' experiences with the synthesis of J. curcas, oil-based biodiesel has shown that the fuel characteristics depend largely on the type of alcohol used as the excess reactants. Transesterification reaction is chosen for this process with sodium methoxide as the catalyst. Comparison studies on the yield of esters using methanol and ethanol, as well as the impacts on the reaction rate are discussed. The effects of reaction time and molar ratio on the reaction conversion are also examined. The determination of reaction yield is based on the conversion of triglycerides into alkyl esters as the main product. The findings are described as follows: the highest percentage yield of product is attained at 96% for methanol as an excess reactant, and this is 90% when ethanol is used. The optimum conditions of parameters are achieved at 6:1 molar ratio of alcohol to triglycerides, 50 min of reaction time and reaction temperature of 65°C for methanol and 75°C for ethanol. The biodiesel properties of both ester fuels were determined according to the existing standards for biodiesel and compared to the characteristics of diesel fuel.
    Matched MeSH terms: Biofuels
  15. Fulltext Catalytic gasification of empty fruit bunch for enhanced production of hydrogen rich fuel gas
    Mohammed, M.A.A., Salmiaton, A., Wan Azlina, W.A.K.G., Mohamad Amran, M.S., Omar, R., Taufiq-Yap, Y.H., et al.
    Pertanika Journal of Science & Technology, 2012;20(1):139-149.
    MyJurnal
    Oil palm is widely grown in Malaysia. There has been interest in the utilization of oil palm biomass for production of environmental friendly biofuels. The gasification of empty fruit bunches (EFB), a waste of the palm oil industry, was investigated in this study to effectively and economically convert low value and highly distribution solid biomass to a uniform gaseous mixture mainly hydrogen (H2). The effects of temperature, equivalence ratio (ER) and catalyst adding on the yields and distribution of hydrogen rich gas products were also investigated. The main gas species generated, as identified by GC, were H2, CO, CO2, CH4 and trace amounts of C2H4 and C2H6. With temperature increasing from 700 to 1000 °C, the total gas yield was enhanced greatly and reached the maximum value (~ 90 wt. % ) at 1000°C with a big portion of H2 (38.02 vol. %) and CO (36.36 vol. %). Equivalence ratio (ER) showed a significant influence on the upgrading of hydrogen production and product distribution. The optimum ER (0.25) was found to attain a higher H2 yield (27.42 vol. %) at 850°C. The effect of adding catalysts (Malaysian dolomite1, P1), Malaysian dolomite2 (GML), NaOH, NaCl, CaO, ZnO, NiO) as a primary catalyst on gas product yield was investigated, and it was found that adding dolomite showed the greatest effect with the maximum H2 yield achieved (28.18 vol.%) at 850°C.
    Matched MeSH terms: Biofuels
  16. Fulltext Factors affecting the cold flow behaviour of biodiesel and methods for improvement - a review
    Edith, Odeigah, Janius, Rimfiel B., Robiah Yunus
    Pertanika Journal of Science & Technology, 2012;20(1):1-14.
    MyJurnal
    Biodiesel is an attractive renewable energy source, which is suitable as a substitute to the non-renewablepetroleum diesel. However, it is plagued by its relatively bad cold flow behaviour. In this review, the factorsaffecting the cold flow of biodiesel, vis-à-vis the contradicting requirement of good cold flow and good ignitionproperties, are discussed. Fuel filter plugging, and crystallization of biodiesel are considered, together with thecold flow properties such as Pour Point (PP), Cloud Point (CP), Cold Filter Plugging Point (CFPP) and LowTemperature Filterability Test (LTFT). In addition, various methods used to improve the cold flow of biodieselare also presented, with a special emphasis laid on the effects of these methods in reducing the Cloud Point.Strategies to improve cold flow, and yet maintaining the good ignition quality of biodiesel, are also proposed.As far as the cold flow of biodiesel is concerned, desirable attributes of its esters are short, unsaturated andbranched carbon chains. However, these desirable attributes present opposing properties in terms of ignitionquality and oxidation stability. This is because esters with short, unsaturated and branched carbon chainspossess very good cold flow but poor ignition quality and oxidation stability. The target is therefore to producebiodiesel with good cold flow, sufficient ignition quality, and good oxidation stability. This target proves tobe quite difficult and is a major problem in biodiesel research. New frontiers in this research might be thedesign of the new cold flow improvers that is similar to those used in the petroleum diesel but is tailored forbiodiesel. Genetic modifications of the existing feedstock are also desirable but the food uses of this particularfeedstock should always be taken into consideration.
    Matched MeSH terms: Biofuels
  17. Fulltext Biohydrogen production by local isolate of Clostridium Butyricum: initial nutrients optimization study
    Mohd. Sanusi Che Kadir, Jamaliah Md. Jahim, Nurina Anuar, Mohd. Sobri Takrif, Zahira Yaakub
    Pertanika Journal of Science & Technology, 2009;17(2):-.
    MyJurnal
    In this study, an anaerobic mesophilic bacterial strain, namely Clostridium butyricum KBH1, was isolated from a natural source. This strain grew well and produced biogas with an average hydrogen concentration of 60% (v/v) in the Reinforced Clostridial Media (RCM). To study the basic nutrient requirements, three main nutrients namely peptone (Pep), yeast extracts (Yes) and glucose (Glu) were chosen as factors, using an experimental design. The experiments were run according to 23 Full Factorial Design, followed by the Response Surface Method (RSM). The fermentation was performed in 30 ml serum bottles with 20 ml working volume in a sterile and anaerobic condition at 37°C with 5% inoculums. The results from the Analysis of Variance (ANOVA) for the factorial design showed that all the three factors had significantly affected the gas production by the C. butyricum. The response surface plot of the gas production by C. butyricum showed that the gas production could be enhanced by increasing peptone and yeast extract concentrations up to 15 g/l and 24 g/l respectively, without showing any substrate inhibition. Meanwhile, the glucose concentration showed an optimum at the middle point (8 g/l) with possible substrate inhibition at a high concentration (12 g/l). The total biogas production could be correlated to the three factors, using the quadratic equation: Gas =0.17 + 7.11Glu - 0.02Pep + 0.77Yes - 0.53Glu2 + 0.09Glu*Pep. The experimental results showed that the strain could grow well in substrate with high organic nitrogen content such as POME and might be not suitable for substrate with high sugar content due to substrate inhibition.
    Matched MeSH terms: Biofuels
  18. Fulltext Biodiesel from Pungam seed oil and Its effects on engine performance with a computerized engine test rig
    MohanRaj, T., Kumar, K. Murugu Mohan, Kumar, Perumal
    Pertanika Journal of Science & Technology, 2011;19(1):117-127.
    MyJurnal
    Vegetable oil has become more attractive recently because of its environmental benefits and better
    quality exhaust emission. A well-known transesterification process made biodiesel, pungam seed oil was selected for biodiesel production. Pungam seed oil is non-edible oil, thus, food versus fuel conflict will not arise if this is used for biodiesel production. A maximum of 75% biodiesel was produced with 20% methanol in the presence of 0.5% sodium hydroxide. The experimental investigations were carried out in an engine that is coupled with an eddy current dynamometer. The engine is a single cylinder water-cooled, direct injection diesel engine developing a power output of 3.7 kW at 1500 rev/min. The crank angle encoder measured the engine speed, whereas the piezo electric sensors measured the cylinder pressure and the fuel injection pressure. The experimental investigations were carried out for bio-diesel and diesel and the results were compared. From the experimental results, it is concluded that the use of bio-diesel as an alternative fuel leads to significant reduction in emissions and improved performance of diesel engines. This paper discusses the production process of biodiesel from Pungam seed oil and its performance in the compression ignition engine.
    Matched MeSH terms: Biofuels
  19. Fulltext Simulation and optimisation of Bioethanol purification using extractive distillation with additive solvent
    Anisuzzaman, S.M., Krishnaiah, D., Bono, A., Lahin, F.A., Suali, E., Zuyyin, I.A.Z.
    Pertanika Journal of Science & Technology, 2018;26(2):707-718.
    MyJurnal
    In this study, simulation and optimisation of the purification of bioethanol from an azeotropic mixture was done using the Aspen HYSYS and the Response Surface Methodology (RSM), respectively, to achieve an acceptable bioethanol content with minimal energy use. The objective of this study is to develop the simulation process of bioethanol production from a fermentation effluent. Additionally, the effects of parameters such as solvent temperature, number of entrainer feed stage, mass flow rate and third components of the process for production of bioethanol were studied. As bioethanol is a product of biofuel production, the main challenge facing bioethanol production is the separation of high purity ethanol. However, the separation of ethanol and water can be achieved with the addition of a suitable solvent such as 1,3-butylene glycol (13C4Diol), mixture 13C4Diol and ethylene glycol (EGlycol) and mixture 13C4Diol and glycol ethyl ether (DEG) in the extractive distillation process. For the 13C4Diol mixture, the temperature of entrainer is 90oC with 1500 kg/hr of entrainer rate, while the number of entrainer feed stage is one. The optimum conditions for mixture 13C4Diol and EGlycol require a temperature of entrainer of 90.77oC with an entrainer rate of 1500 kg/hr, while the number of entrainer feed stage is one. Lastly, for optimum conditions for the mixture 13C4Diol and DEG, the temperature of entrainer should be 90oC with an entrainer rate of 1564.04 kg/hr, while the number of entrainer feed stage is one. This study shows that process simulation and optimisation can enhance the removal of water from an azeotropic mixture.
    Matched MeSH terms: Biofuels
  20. Fulltext Modelling of pilot-scale anaerobic food wastes composting process with dry leaves or cow manure
    Lim, Wei Jie, Chin, Nyuk Ling, Yus AnizaYusof, Azmi Yahya, Tee, Tuan Poy
    Pertanika Journal of Science & Technology, 2019;27(1):421-442.
    MyJurnal
    Anaerobic composting is a promising method to fully transform food wastes into useful
    materials such as biofertilizer and biogas. In this study, the optimum proportions of food
    wastes containing vegetable, fruit and meat wastes with dry leaves or cow manure for
    composting were determined using the simplex centroid design and response optimizer.
    The effectiveness of the pilot-scale composting process was evaluated based on the targeted
    compost quality of C/N ratio at 21, pH value at 8 and electrical conductivity of 1 dS/m.
    Food wastes composting formulation with dry leaves suggested high percentage of dry
    leaves, 86.9% with low food wastes composition of 13.1% constituted by vegetable waste
    (1.1%), fruit waste (4.9%) and meat waste (7.1%). With cow manure formulation, only
    6% of cow manure was recommended with
    another 94.0% of food wastes contributed
    by a fair mix of vegetable waste (23.2%),
    fruit waste (34.3%) and meat waste (36.5%).
    The developed regression models were
    experimentally validated with predicted
    responses obtained in acceptable ranges for
    C/N ratio (21.2 - 21.8), pH (7.92 - 7.99) and
    electrical conductivity (0.97 - 1.03 dS/m).
    Matched MeSH terms: Biofuels
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