bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of combustion and nitrogen gas atmospheres on the torrefaction performance of oil palm frond leaves and stems
Authors: Premchand  , Komiyama Masaharu , Aqsha Aqsha , Uemura Yoshimitsu 
Published: March 2020

Abstract
Torréfaction is a well-known method to thermally treats biomass at lower temperature range (200 to 300 °C) under inert atmosphere. However, the continuous supply of pure inert gas on large scale resist the commercialisation of this process. To investigate the effect of combustion gas (flue gas) on torrefaction performance of oil palm fronds leaves (OPFL) and stems (OPFS), both samples were torrefied at 200 °C for 30 min in a vertical tubular reactor under the atmosphere of combustion gas produced from wood pellets and nitrogen (inert) gas. The major components of combustion gas were nitrogen and carbon dioxide (total 76 vol% to 83 vol%) and the rest of the mixture contained oxygen, carbon monoxide and hydrogen. The effects of combustion gas atmosphere on the torrefaction performance of OPFL and OPFS including solid yield, calorific value, energy yield, proximate and ultimate compositions were investigated and compared with those of nitrogen atmosphere torrefaction. The combustion gas torrefaction resulted in lower solid yield and energy yield but with higher energy density (calorific value, carbon content) as compared to nitrogen torrefaction. Under combustion gas atmosphere, torrefaction of OPF stems gave higher solid yield (84.66 wt%) than OPF leaves (80.85 wt%) while solid yield of both samples under nitrogen atmosphere was almost same (88.02 wt% and 88.54 wt%). The increase in solid conversion under combustion atmosphere was caused by the partial oxidation took place in the presence of oxygen. Non-condensable gases at the outlet of the torrefaction reactor contained carbon dioxide and carbon monoxide.
A Review on Hybrid Processes for Palm Oil Mill Effluent: Possible Approaches
Authors: Al-Amshawee S K , Yunus M Y , Azoddein A A 
Published: March 2020

Abstract
The aim of this review paper is to explore and examine hybrid processes and systems for polishing palm oil mill effluent (POME). Nitrification process, and nutrients removal are highly significant to process highly contaminated POME. Besides, quality of POME process is extremely important to solve fresh water shortage that has blocked millions of people from accessing a clean water. Hence, attentions have been made on water pollution to raise a global demand to improve POME processing and discharge unharmful effluent to the waterways. For decades, using a stand-alone technology to treat POME has faced fouling, and disability to deliver the promising quality. A new approach is termed as hybrid or combined system has the ability to deliver higher performance and more effective contamination removal than stand-alone technologies. Hybrid system is a novel technique can be used to achieve higher efficacy that single physical, chemical, or biological technology can’t accomplish. This review reports various hybrid systems and united technologies to treat POME including their advantages, disadvantages, and limitations.
Optimization of sweet potato pectin extraction using hydrochloric acid
Authors: Abang Zaidel D N , Ismail N H , Mohd Jusoh Y M , Hashim Z , Wan Azelee N I 
Published: March 2020

Abstract
Pectin has been used widely as thickener, stabilizer and gelling agent. However, the sources of pectin industrially are still limited. This study aims to optimize the extraction of pectin from sweet potato residue using hydrochloric acid. In this study, proximate analysis of the sweet potato residues were performed and the extraction of pectin from sweet potato residues using hydrochloric acid was optimized to maximize its yield using response surface methodology (RSM). Three parameters were manipulated and optimized which were temperature (°C), pH and extraction time (min). The extracted pectin was further analyzed for its degree of esterification (DE) using Fourier Transform Infrared Spectroscopy (FTIR). The sweet potato residue sample obtained moisture content of 79.7±1.7%, ash content of 1.08±0.09% and carbohydrate content of 34.3±2.7%. The optimum condition to extract pectin from sweet potato residues using hydrochloric acid was at extraction temperature 60 °C, pH 1 and extraction time 60 min with 23.48 % pectin yield. The pectin has 57.48% of DE which indicates high methoxyl pectin. The results show that hydrochloric acid can be used as one of the solvents to extract pectin from sweet potato.
Integrated production of prebiotic xylooligosaccharides and high value cellulose from oil palm biomass
Authors: Noorshamsiana A W , Nor Faizah J , Kamarudin H , Nur Eliyanti A O , Fatiha I , Astimar A A 
Published: March 2020

AbstractOil palm empty fruit bunch (OPEFB) fibre, which is the byproduct of fruits being stripped from the fresh fruit bunch in palm oil mill, was evaluated in terms of the production of xylooligosaccharides (XOs) and the solid residue was treated for cellulose recovery. Chemoenzymatic hydrolysis that consists of chemical fractionation of OPEFB fibre to isolate xylan with further enzymatic hydrolysis to XOs in a packed bed column reactor (PBCR) was performed. An immobilised xylanase ofThermomyces lanuginosusat the concentration of 8.25 fungal xylanase unit wheat/mililitre (FXUW mL−1) was employed on a PBCR to hydrolyse the xylan at 55 °C and pH 5.5. The yields of XOs are composed of xylopentaose, xylotetraose, xylotriose and xylobiose, successfully produced from the OPEFB-xylan, shown in HPLC analysis with the total production of 8,776 mg/L and the immobilised xylanase can be recycled up to six enzymatic treatment cycles. The solid residue generated from the xylan extraction was further treated with mild concentration of bleaching agents of 20% (v/v) formic acid and 5% (v/v) hydrogen peroxide at 85 °C. The Fourier transform infrared spectroscopy (FTIR) analysis showed that the products obtained have the standard cellulose structure and functional group. Further analyses on the properties of the extracted cellulose in terms of crystallinity, thermal stability and morphology were conducted. The integrated process to produce XOs from OPEFB and recover cellulose from its byproduct is sustainable to extract fine chemicals from OPEFB.
Total phenol content of Clinacanthus nutans Lindau (C.nutans) medicinal plant extracted using vacuum solvent-free microwave extraction (SFME)
Authors: Othman Siti N S , Mustapa Ana N , Hamid Ku Halim Ku 
Published: March 2020

Abstract

Clinacanthus nutans Lindau (C.nutans) is a popular medicinal herb plant in Asia regions such as Malaysia, Indonesia, Thailand and China for its high polyphenols content. Various conventional extraction techniques have been use to extract bioactive compounds in C.nutans, however, the methods have limitations such as usage of organic solvent, time- consuming and low extraction yield. In this study, polyphenols content from C.nutans leaves extracted by solvent-free microwave extraction (SFME) with addition of water, to enhance absorption of energy from microwaves. Energy density or irradiation power per unit of sample volume is used instead of applied microwave power to determine actual energy absorbed by the microwave extraction. It is determined from energy absorbed by microwave power of 200, 300 and 400 W. The effect of process parameter on the polyphenol contents: energy density of 0.073, 0.078 and 0.108 W/ml in 5, 10 and 15 min with 6 ml/g of solvent-to-feed (S/F) ratio was studied. The highest total phenol content (TPC) was obtained at 0.073 W/ml, 6 ml/g of S/F ratio and 5 min of extraction time with TPC of 24.08 ± 0.51 mg GAE/g DW at temperature of 79 °C Results demonstrated that the TPC of C.nutans was higher when extracted under vacuum pressure compared to TPC at ambient pressure. The results suggest that SFME method using water under vacuum state appears as the most efficient and green technique for the extraction of polyphenols from C.nutans extract in shorter time with no use any of organic solvent to produce reasonably high TPC.
Optimization of lovastatin in solid-state fermentation using oil palm frond
Authors: Daud N F S , Said F M , Ho J M 
Published: March 2020

AbstractLovastatin plays a role in lowering the cholesterol level in the human blood, especially the bad cholesterol or low density lipoproteins (LDL). Concurrently, lovastatin increase the good cholesterol or high density lipoproteins (HDL), to prevent the formation of plaque inside the blood vessels. The objective of this research was to experimentally optimize the lovastatin compound produced byMonascus purpureusFTC5357 under solid state fermentation (SSF) using oil palm frond (OPF). In order to identify the optimal condition to produce lovastatin, four parameters which were pH, initial moisture content, peptone and potassium, were optimized using Box-Behnken design. Based on the ANOVA analysis performed, initial moisture content, potassium and peptone contributed significantly to the lovastatin production. Meanwhile, pH had the least impact to the lovastatin production.. Peptone pronounced to be the most contributed factor, as the lovastatin production increased with the increasing of peptone in the substrate. Under optimized condition (pH 5.50, moisture content at 60%, 3.40 g of potassium, and 3.30 g of peptone) maximum lovastatin yield was 45.84 μg/g. The lovastatin produced through SSF using OPF as a substrate byMonascus purpureusFTC 5357 has a great potential to be utilized as a source of lovastatin in future.
Nanoporous carbon based palm kernel shell and its characteristics of methane and carbon dioxide adsorption
Authors: Ariyanto T , Prasetyo I , Mukti N F , Cahyono R B , Prasetya A 
Published: March 2020

Abstract
Biogas is typically composed of 55% methane, 45% carbon dioxide, and small amount of impurities. For high quality of fuel, it is necessary to increase percentage of methane by removing carbon dioxide. This can be performed by molecular sieve utilizing different diffusivity of methane and carbon dioxide passing through pores. This work presents a study of adsorption properties (isotherm and kinetics) of carbon dioxide and methane on porous carbon from palm kernel shell. The biochar of palm kernel shell was activated at high temperature of 800 °C with steam. The carbon produced was then characterized by N2-sorption analysis, and ultimate analysis. The usability of material for CO2 and CH4 adsorption was tested using a static volumetric method. The results showed that steam-activated porous carbon features a higher surface area (650 m2 g−1) and more mesoporous structures with respect to the carbon produced without steam activation. In the adsorption study, the results showed that the carbon exhibited a higher adsorption to CO2 (2.0 mmol g−1) than CH4 (1.1 mmol g−1) at 1 atm and 30 °C. In the adsorption kinetics test, results displayed that the adsorption of CO2 on carbon is slower than methane, which is good for separation purposes.
Effect of extraction solvent on total polyphenol content, total flavonoid content, and antioxidant activity of soursop seeds (Annona muricata L.)
Authors: Nguyen V T , Nguyen M T , Tran Q T , Thinh P V , Bui L M , Le T H N , Le V M , Linh H T K 
Published: March 2020

Abstract
Soursop (Annona muricata L.), a plant native to South America, is widely distributed in tropical and subtropical regions of the world. In this study, extract of A. Muricata was obtained using various solvents including distilled water, ethanol, ethyl acetate, and chloroform. Total polyphenol content, total flavonoid content and the antioxidant activity of A. muricata seed extracts were investigated using various in vitro assays. The highest extraction yield (23.60%) was obtained by using chloroform. The extract obtained by ethanol showed the highest total polyphenol content (282.71 ± 8.64 mg GAE/100g DW) and the highest flavonoid content (86.57 ± 3.20 mg QE/100g DW). The same extract also exhibited the highest DPPH (341.57 ± 6.90 AAE/100g DW), ABTS (382.20 ± 9.71 mg AAE/100g DW) radical scavenging activity and FRAP (369.84 ± 7.96 mg AAE/100g DW). These results indicate that A. muricata can be used in dietary applications with the potential to reduce oxidative stress.
Comparative study on removal of Monodyes by using Ni-Al layered double hydroxides
Authors: Dao T T U , Nguyen T H T , Phan T T Q , Do T S , Vo D V N , Tien N A 
Published: March 2020

Abstract
The toxic and carcinogenic effluents discharged from the textile and garment industry represent a major concern to the environment and public health. Treatment technologies for these effluents to reduce toxicity and dye concentration are therefore crucial. The objective of this study was to focus on eliminating four monoazo dyes including Congo (CR), Methyl orange (MO), Methylene blue (MB) and Crystal violet (CV) using adsorbents, Ni/Al LDHs. The results proved that Ni/Al LDHs exhibit excellent adsorption capacity on anionic dyes (CR, MO) instead of cationic dyes (CV, MB). The maximum adsorption capacity of Methyl Orange on Ni/Al LDHs was found to be 93.517 mg/g and Congo red at 87.975 mg/g. In addition, the study of leaching test of adsorbents show stable synthetic materials in aqueous media. The analyses mentioned above indicates that Ni/Al LDHs may be a promising adsorbent to remove anion dyes from aqueous media.
Cellulose hydrolysis in an enzymatic membrane reactor: fouling mechanism
Authors: Lim S Y , Ghazali N F 
Published: March 2020

AbstractEnzymatic Membrane Reactor (EMR) was applied to overcome drawback from batch cellulose hydrolysis such as inability of reusing the enzyme and product inhibition which leads to low product yield. However, the major problem of EMR is membrane fouling. Therefore, the membrane fouling mechanisms in EMR was investigated using Hermia’s pore blocking model. In this study, fed batch cellulose hydrolysis in EMR was carried out for 72 hours. The hydrolysate was filtered using polyethersulfone (PES) membrane at 24 hours interval and the flux of permeate was recorded. The cellulose hydrolysis has successfully converted more than 80% of the substrate into reducing sugar in EMR, which is approximately 20% more in batch hydrolysis. The product inhibition was minimized when there was glucose removal in EMR. The flux was analysed and the result showed that the membrane fouling was controlled by cake filtration mechanism. The larger size of substrate and enzyme than the membrane pore size blocked the membrane pore and eventually cause the development of cake layer.
Quaternary Ammonium based Eutectic Ionic Liquids (EILs) as absorbent for Sulfur Dioxide (SO2)
Authors: Chandran K , Chong F K , Zaid H F M 
Published: March 2020

Abstract
Sulfur dioxide (SO2) is a corrosive acid gas which pose severe threat to the environment and human health. Therefore, its removal from air is necessary to protect human health and environmental quality. Existing SO2 removal technologies involves using lime or limestone in wet scrubbers. Recently, the application of eutectic ionic liquids (EILs) were extensively employed to capture SO2 gases. The main objective of this study is to determine the SO2 absorption capacities of quaternary ammonium based EILs. Quaternary ammonium- based EIL, choline chloride which is known to display many advantages in absorbing acidic gas, were selected as the hydrogen bond acceptor (HBA) and three different types of hydrogen bond donor (HBD) were investigated; glycerol, ethylene glycol, and urea. The absorption experiments were conducted in a laboratory scale reactor. SO2 gas stream was passed continuously through the reactor to get contact with the EIL surface and be absorbed, and the absorption was monitored using sodium hydroxide (NaOH) solution with pH 10. The results show that SO2 was absorbed by choline chloride (ChCl) based EILs within 120 min of contact time. The absorption capacity of ChCl with glycerol was 0.54 mg/g, 0.54 mg/g and 0.53 mg/g for 1:2, 1:3 and 1:4, respectively. The results also show that the SO2 absorption capacity increases as the ChCl:Gly molar ratio increases. The extent of absorption was also greatly affected by the composition of the EILs. ChCl with ethylene glycol gave the highest absorption capacity of 0.57 mg/g of the SO2 was absorbed compared to ChCl with glycerol as well as with urea. The use of EILs as an absorbent are a promising method for SO2 capture.
Chemical constituents of the stem of Coccinia grandis
Authors: Trinh Pham Thi Nhat , Nguyen Thanh Quang , Hau Nguyen Van , Hung Quach Tong , Du Cao Van , Tuan Nguyen Trong , Thuy Nguyen Thi Le , Dung Le Tien 
Published: March 2020

Abstract

Coccinia grandis extact showed various bioactivities such as water and ethyl acetate extract of stem showed anti-inflammatory, antibacterial activities and lowered plasma glucose level. From the ethyl acetate extract of the stem of Coccinia grandis collected in Tiengiang province, Vietnam, six phytocompounds including 4-hydroxy benzaldehyde (1); 3,4’-O- dimethylcedrusin 9’-O-glucopyranoside (2); (+)-medioresinol (3); syringaldehyde (4); vanillic acid (5) and (+)-syringaresinol (6) were separated and characterised. Their chemical structures were determined by spectroscopic methods (1D NMR, 2D NMR and MS) and comparison with published data. All isolated compound are reported from the Coccinia grandis for the first time.
Screening of significant factors affecting pravastatin production by Penicillium sp. ESF21P
Authors: Zainol Norazwina , Seydametova Emine , Salihon Jailani , Convey Peter 
Published: March 2020

Abstract
Pravastatin is a clinically useful cholesterol-lowering agent. The development of a one-step fermentation process using pravastatin-producing microfungi may be an attractive approach from an economic point of view. To facilitate this, previously 54 fungal cultures were isolated from soil samples. Among them, Penicillium sp. ESF21P was the most active pravastatin producer (196.83 mg/L). The objective of the present study is to determine significant factors affecting pravastatin production by Penicillium sp. ESF21P. The method of the 27-3 fractional factorial design with seven variables was performed using Design-Expert 6.0.8 software package. The seven factors studied were slant age, spore concentration, inoculum volume, fermentation time, temperature, initial pH of the medium, and agitation rate. The results obtained confirmed that the factorial model was significant. Amongst the tested factors, only four were important: agitation rate, slant age, initial pH of the medium, and fermentation time with a percentage contribution of 25.66%, 11.56%, 9.72%, and 7.69%, respectively. These significant factors will be optimized further using response surface methodology.
Experimental and Theoretical Study on Sm/Eu-Gd Extraction by P204 and [A336][P204]
Authors: Ismail N A , Abdul Aziz M A , Hisyam A 
Published: March 2020

AbstractExtraction of rare earth using ionic liquid as extractant become an alternative practice to replace the common volatile organic solvents in recent years. In general, the work to extract rare earth element, require a large number of extraction stage, and different extractant used resulted in different number of extraction needed. Therefore an analysis on the theoretical number of stages is necessary prior to laboratory work. This study was designed to compare between the number of extraction stages required by 2-ethylhexyl phosphoric acid mono 2-the ester (P204), a common rare earth extractant with a bifunctional ionic liquid, and [A336][P204] in a counter-current extraction process for the separation of Sm in Sm-Eu-Gd mixed solution. The value of the separation factor (β) of both extractants, was obtained from the experimental work, while other process parameters were calculated using the counter-current theory developed by Xu Guangxian. Extraction of Sm using [A336] [P204] was optimum in 3.0 M of nitric acid, with organic to aqueous (O/A) ratio of 4:1, while the optimum condition for P204 was when the medium was 2.0 M of hydrochloric acid and 7:3 of O/A ratio. Theβvalue for the optimized condition for P204 was lower compared to the condition for [A336][P204] atβ:1.93 andβ:2.81, respectively. To derive an optimum extraction condition to calculate the number of extraction stage, target purity and recovery ratio were set to 99.9% and 90%, respectively, for both extractants. As a result, [A336][P204] was able to reduce the number of extraction stage by 5 compared to P204. The result indicated that [A336][P204] is preferable over P204 from the viewpoint of economic efficiency.
Water flux prediction of UV-photografted nanofiltration membrane for forward osmosis application
Authors: Rahman A F H A , Aziz S N S A , Abu Seman M N 
Published: March 2020

Abstract
In the application of forward osmosis, commercial nanofiltration (NF) membrane was modified via ultraviolet(UV)-photografting technique at different grafting parameters; monomer concentration (acrylic acid) and grafting time. However, the performance of the modified membrane measured at the osmotic pressure of 1M NaCl as draw solution limits their applications. In this research, the mathematical modelling was applied to predict the water flux at different osmotic pressure. The mathematical modelling indicated that the generated water flux follows the osmotic pressure but strictly affected by the grafting parameters. The result shows that at grafting time of 3min, the monomer concentration of 15 g/L generates the highest water flux followed by the membrane modified at the monomer concentration of 30 g/L. High water flux was attributed to the presence of strongly hydrophilic groups at new carboxyl layers leading to improved membrane properties. The approach of theoretical modelling on the membrane that is reported in this work allows estimating the water flux at different grafting parameter.
Oxidation of sulfide removal from petroleum refinery wastewater by using hydrogen peroxide
Authors: Mamat M C , Bustary A B , Azoddein A A M 
Published: March 2020

Abstract
Petroleum refinery wastewater typically has high concentration of sulfide which is known as the most hazardous pollutants. It is released to the environment either as dissolved sulfide (S2- and HS−) in effluents or as H2S in waste gases. The objective in this study is to determine the effectiveness of hydrogen peroxide (H2O2) in sulfide removal. The best sulfide concentration, dosage and reaction time were determined. The removal of sulfide from petroleum refinery wastewater via oxidation method by using hydrogen peroxide (H2O2) is presented in this study. The treated wastewater was analyzed by spectrophotometer. Result shows that the best concentration of sulfide simulated wastewater (300 mg/L), H2O2 dosage (1.5 ml) and reaction time (30 min) able to reduce 97.67%, 98.22% and 98.89% of sulfide concentration from simulated wastewater. Thus, sulfide removal from the actual petroleum refinery wastewater which is spent caustic by using H2O2 was able to reduce 99.83% (0.5 mg/L) sulfide concentration. Besides that, Chemical Oxygen Demand (COD) concentration was reduced to 98.29% (70 mg/L) and pH 8.41 after treatment. Thus, it is concluded that oxidation method by using H2O2 is effective in sulfide removal as well as COD, and pH from spent caustic. It does meet requirement from Department of Environment (DOE) for sulfide, COD and pH which are 0.5 mg/L, 100 mg/L and 5.5 – 9.0, respectively. The information obtained from this study is useful for scale up purpose in the petroleum refining industry that choose H2O2 via oxidation method to remove sulfide from spent caustic wastewater.