bluuebunny/crossref_metadata_2025 huggingface dataset:
Process simulation of the pilot scale bioethanol production from rice straw by Aspen Hysys
Authors: Le Phung K , Le Tin D T , Nguyen Quan D , Tran Viet T , Mai Phong T
Published: May 2020

This work is to implement a working model of an integrated process for bioethanol in the process simulation based on rigorous model using the Aspen HYSYS simulation software. As a case study, the simulation is applied to design a pilot plant that converts rice straw into ethanol. The model is based on the process for biochemical conversion of lignocellulosic biomass (rice straw) to ethanol, proposed by the pilot plant of producing bio-ethanol with capacity of 152 kg rice straw/batch. The plant for manufacturing bio-ethanol with rice straw as raw materials comprises basically three units: Pretreatment of rice straw by alkaline treatment; Simultaneous saccharification fermentation (SSF) of rice straw to produce bio-ethanol and the unit for separation and purification of bio-ethanol mixture from simultaneous and fermentation unit. Modeling of rice straw feedstock as a solid material in Aspen HYSYS, including the creation of necessary hypothetical components. Investigate and analyze the final ethanol yield of the simulation project in comparison with actual process. The model proposed was for easily evaluate and analyze various factors which affect to the final ethanol yield by changing operating conditions and being possible to find the optimal conditions for different input flow rate and many independent factors. The simulation model obtained in this study can be applied to any SSF processes with different biomass feedstock.
Production and characterization of biodiesel from Annona muricata seed oil
Authors: Avendaño J R , Canlas S , Falalimpa M , Dimaano M N
Published: May 2020

Due to the depletion of available energy resources, the usage of fossil fuel has increased steadily. Additionally, the gas emissions of fossil fuel proved to be harmful to the environment. Therefore, researches now focus on utilizing second-generation biodiesel that do not compete with edible seed oils but still can be of great use as an alternative to commercially-produced diesel. The purpose of this research is to extract the oil from Annona muricata (Guyabano) seeds and convert it to biodiesel by esterification using hydrochloric acid and transesterification using potassium hydroxide. The average oil yield was 18.92% while the average crude biodiesel yield was 94.76%. The characterization results of the biodiesel composed of 5% guyabano methyl ester in commercial diesel (B5) were all within the limits set by the Philippine National Standards (PNS). However, the water content for the pure biodiesel (B100) was not within the standard range. The kinematic viscosity of B100 is at the maximum limit of PNS. Nevertheless, it suggests that pure Guyabano biodiesel has the potential to be utilized in diesel engines.
Thermogravimetric analyses (TGA) of three oil palm biomass pyrolysis: Kinetics and reaction mechanisms
Authors: Soh Megan , Jing Chew Jiuan , Sunarso Jaka
Published: May 2020

Oil palm biomass generated from the plantation site (i.e., oil palm trunk (OPT) and oil palm frond (OPF)) are an attractive source for pyrolysis given their abundant availability. Despite this potential, there is no comprehensive study on the pyrolysis of OPT and OPF. In this work, the pyrolysis of OPT, OPF, and PKS are compared and analysed by thermogravimetric analysis (TGA). The kinetics and reaction mechanisms of these biomass during pyrolysis were determined using Kissinger-Akahira-Sunose (KAS) model-free method and Šesták-Berggren function. Pyrolysis of the three oil palm biomass is complex and exhibits different thermal behaviours and strong overlapping reaction between the pseudo-components, which can be attributed to their different constituents. The apparent activation energy of OPT, OPF, and PKS are 17.83-116.58, -45.36-225.60, and 56.50-90.42 kJ mol-1. The variation in the apparent activation energy indicates that pyrolysis of the three oil palm biomass involves multiple reaction mechanisms. Thermal decomposition of the pseudo-hemicellulose and pseudo-cellulose in the three oil palm biomass are co-controlled by two reaction mechanisms, i.e., phase boundary reaction and nucleation, with phase boundary reaction as the dominant mechanism.
Sequential Thermal and Power Integration for Locally Integrated Energy Sector
Authors: Lee P Y , Liew P Y , Walmsley T G
Published: May 2020

Energy Efficiency is aligned with the United Nation Sustainable Development Goal for ensuring access to affordable, reliable, sustainable and modern energy for all. Locally Integrated Energy Sector (LIES) concept is introduced for energy conservation between industrial, service and residential sectors. The LIES concept extended the Process Integration technique for energy recovery between multiple process plants through the utility system, known as Total Site Heat Integration (TSHI). However, the development of LIES techniques is divided into two main directions, which are heat and power energy integration. This paper introduces a sequential approach for integrating the heat and electricity system in a LIES. The optimization is done based on time frame, which Time Slices (TSLs) are identified based on drastic changes in heat and electricity supply and demand. The heat system is first analysed by TSHI techniques, which the heat excess and demand are determined. The excess and demand is then used for cogeneration opportunities estimation, which the backpressure and condensing turbine are used. The potential power generation estimated then included to analyse the electricity system using Power Pinch Analysis tools. The use of heat and power storage system are also included in the study, for assessing its impact on the LIES’s energy efficiency. The study considered on- and off-grid power supply system to satisfy the power demand of the system. This proposed heat and power optimisation framework aims to select a system configuration with minimal energy cost.
Effect of DMPA Content on Colloidal Stability of Jatropha Oil-based waterborne Polyurethane Dispersion
Authors: Nurdin N S , Saalah S , Lim A T , Francis A Y , Abdullah L , SaifulAzry S
Published: May 2020

Driven by the increase of oil price in the market as well as environmental concerns by the society, a renewable raw material such as vegetable oil becomes the alternative to produce bio-based polyol to replace non-renewable polyols in polyurethane production. The recent development of aqueous polyurethane dispersion proves that environmentally waterborne PUD offers an efficient alternative to the solvent-borne PUD for the application in ink, adhesives, and coatings. In this study, the jatropha oil has been successfully functionalized to polyol (JOL) by epoxidation and oxirane ring opening steps. Jatropha oil-based waterborne polyurethane (JPU) dispersions were produced by polymerizing the JOL with isophorone diisocyanate (IPDI) and dimethylolpropionic acid (DMPA). The colloidal stability of JPU dispersions was studied in terms of particle size and zeta potential. Varying DMPA content from 5.0-7.0 wt.% resulted in small average particle size of dispersion from 39.40 nm to 133.2 nm. High zeta potential obtained in a range of -52 mV to -65 mV indicates the particles in the dispersion are sufficiently separated and therefore stable. Eventually, the study provides an overview of vegetable oil-based waterborne polyurethane dispersion with good stability for surface coating application.
Study of glycerolysis of lactic acid
Authors: Rahayu Suprihastuti S , Putra D M , Hasna A
Published: May 2020

Increasing production of a biodiesel industry, will also increase the by-product of the industry, glycerol. Further processes were investigated to get an added value of the byproduct. Glycerol esters of lactic acid and in particulars glycerol monolactate is one of the more value of derivative material from glycerol, which is known as safe, nontoxic and biodegradable emulsifier in food, cosmetics, and pharmaceutical industries. This research aims to study the effect of temperature and reactant ratio to the rate of catalyst free glycerolysis reaction of lactic acid. Experiments were conducted in a three-necked flask equipped with a thermometer, a stirrer and a reflux condenser. The reactions were conducted for 4 hours at 100°C – 140°C while the mole ratios of glycerol to lactate acid were varied 1:1 to 5:1. The conversion of lactic acid to ester increased by increasing the reaction temperature. The results also showed that more glycerol ratio to lactate acid, the higher conversion of the acid was obtained. As of the variables studied, maximum conversion was 86.28% at mole ratio of reactants was 5:1, 140°C within 4 hours. Irreversible homogeneous second order reaction model was suitable with the experimental data.
Black Liquor Droplet Swelling Model during Pyrolysis
Authors: Wintoko J , Purwono S , Fahrurrozi M , Soehendro B
Published: May 2020

Black liquor is a spent pulping liquor from kraft pulping process. The concentrated black liquor is combusted or gasified to recover the chemical energy and to recycle the pulping chemicals. It undergoes several processes, i.e. drying, pyrolysis, and combustion and/or gasification. The droplet swells slightly during drying. Conversely, it swells heavily during pyrolysis. It can swell up to 20-30 time its original volume. The swelling stops when the pyrolysis reaction ends and/or when the solid loses its viscoelastic properties. Swelling phenomena also happens in other system, e.g. polymer foam moulding and coal pyrolysis. Two key phenomena for swelling behaviour are: gas production inside a material that forms gas bubbles and the material viscoelastic properties. The bubbles grow and whole droplet then swells accordingly. For black liquor droplet swelling, some empirical models has been developed but none of them are based on the theoretical bubble growth process. In this paper, the black liquor droplet swelling modelling based on the bubble growth process is developed. The model generally in agreement with the black liquor droplet swelling experimental data from a single droplet Thermogravimetry Analyser (TGA).
Study of Barium Sulfate Scale Dissolution into Ethylenediaminetetraacetic acid (EDTA)
Authors: Sazali R.A , Awang Kechik N.I , Yahya E , Mat-Shayuti M.S
Published: May 2020

Barium sulfate (barite) scale deposition may cause the problem in surface and subsurface production equipment resulting in reduced production, decrease in pressure, and premature failure of down holes equipment. One of the barite scale management is by using dissolver. There are many chelating agents that can be used to dissolve this scale including ethylenediaminetetraacetic acid (EDTA). In this work, EDTA is used to dissolve the laboratory-reproduced barium sulfate scale. Barite scale was reproduced in the laboratory by mixing barium chloride (BaCl2) solution and sodium sulfate (Na2SO4) solution at 25°C. The sensitivity analysis was performed to determine the optimum parameters/conditions in which EDTA dissolution is optimum through Inductively Coupled Plasma Optical Emission Spectrometry (ICP-EOS) analysis and characterization study using Field Emission Scanning Electron Microscope (FESEM). This includes the effect of agitation, temperature, pH, catalyst used, and the presence of oxalate ion. These laboratory tests showed that the solubility of barite increased as it was agitated; at high pH of 11 to 13; and at elevated temperature of 95°C. Potassium chloride (KCl) at high elevated temperature was used as synergy/activator to improve the dissolution of barium sulfate with EDTA. As a conclusion, this project sets a framework to identify the best EDTA formulation and estimate its dissolution profile to ensure a more informed treatment design for barite scale removal.
An Investigation on The Effect of Silica Nanoparticle Concentration on Oil-based Mud Rheology and Fluid Loss Control Characteristic
Authors: Zairani Wan Bakar Wan , Mohd Saaid Ismail , Hayati Jarni Husna , Aqsa Nadeea Mat Isa Noor , Sauki Arina , Shafiq Mat Shayuti Muhammad
Published: May 2020

Oil based mud (OBM) is well known in drilling operation for its good properties. However, under HPHT conditions, OBM might encounter thermal degradation, which will affect the performance of the mud leading to fluid loss and unstable rheology. Previous studies showed that implementation of nanoparticle as drilling mud additive can control the fluid loss into the formation thus preventing formation damage. In this research we evaluate the potential of using nanoparticle from silica as the fluid loss preventing agent. The OBM was used in this study and its performance at low and high temperature was evaluated after addition of nanosilica powder. The experiment was conducted at 275°F and 350°F with varying nanosilica concentration per amount of a commercial fluid loss control additive (gilsonite) between 30 to 70 %, by total mud weight between 0 to 2 wt. %. Result of the study shows that the application of nanosilica in OBM results in better mud rheology and can effectively reduce fluid loss up to 50% concentration especially at HPHT conditions. The silica nanoparticles have the potential to enhance drilling fluid properties, which contributes to more efficient drilling operations with less formation damage. This finding would be economically beneficial to the industry as silica is an abundant earth element.
Effect of temperature and concentration of industrial waste graphene on rheological properties of water based mud
Authors: Humairah Monashofian Putra Putri , Mohamed Jan Badrul , Fazly Abdul Patah Mohamad , Usman Mohd Junaidi Mohd
Published: May 2020

It is no secret that nano technology has been widely applied in various industries. In the upstream oil and gas industry, nanoparticle technology has received widespread attention due to its ability to enhance drilling fluid properties; thus improves drilling efficiency and reduces the overall operation cost. The objective of the study is to investigate the effects of temperature and concentration of graphene retrieved from unwanted industrial waste on rheological and filtration properties of the water based drilling mud (WBM). It is known that graphene is very expensive. At the same time, the availability and abundance of industrial carbon based waste presents an opportunity to extract graphene from unwanted, inexpensive waste and utilise it to improve the drilling fluid properties. Three types of drilling fluids are formulated (basic WBM, WBM plus commercial graphene and WBM plus waste graphene) and tested based on the recommended API 13B-1 practice. Both commercial and waste graphene concentration was varied at 0.05, 0.1 and 0.2 ppb. For each concentration, the mud rheological and filtration properties were measured before and after aging for 16 hours at different temperature of 200°F, 225°F and 250°F while the pressure was fixed at 500 psi. Results showed that the addition of small concentration of graphene nanoparticles increases the plastic viscosity (PV), yield point (YP), and improved the API and HPHT filtrate loss volume. However further increment in concentration caused the filtration property to deteriorate hence 0.05 ppb was taken as the optimum amount. It reduced the filtration loss by 8.43% at API condition and 18.57%, 13.82% and 14.06% at 200°F, 225°F and 250°F respectively.
Rheological Study of Oil Palm Trunk Waste as Viscosifier Agent for Water-Based Mud
Authors: Jarni H H , Sariman M F , Sauki A , Bakar W Z W , Mohd T A T
Published: May 2020

The cellulose obtained from Oil Palm Trunk (OPT) is used to determine its potential as a viscosifier agent for the Water-Based Mud (WBM). The cellulose was extracted by using two methods which are Method 1 (Chlorination-Bleaching Process and Mercerization Method) and Method 2 (Dewaxed-Alkaline-Delignification Method). The characterization of OPT cellulose is defined by FTIR while the content of the cellulose product is determined by the Weighting Method. The mud samples were formulated by the presence of different weight of cellulose applied. The rheological properties analysis was conducted on the viscosity (PV), gel strength, yield point (YP) and, filtrate volume. FTIR Spectrometry results showed that Method 2 mimicked the behavior of HEC cellulose (commercial product). Method 2 produced cellulose which has a similar functional group that appears at the same spectral peaks with HEC cellulose. On the yield percentage, Method 2 yields more cellulose by 43.05% while Method 1 only yields 37.63% of cellulose. While the results from the rheological analysis summarized that cellulose obtained from Method 2 portrays a good range of results as it met the standard range of PV for the WBM by API Recommended Practice 13B-1. In conclusion, the cellulose extracted from Method 2 has the potential to be commercialized as a viscosifier agent for WBM.
Experimental study of batch electrocoagulation treatment of peat water in Sarawak with aluminium electrodes
Authors: Abdul Rahman N , Albania Linus A , Gilan U J , Jihed E E , Kumar N K M F , Yassin A , Philip A
Published: May 2020

Peat water is commonly found in the coastal areas of Southern and Central Sarawak. About 39% of the rural communities in Sarawak are yet to receive clean water supply. As such the rural communities depend excessively rainwater and peat water for domestic usage. However, the usage of untreated peat water for domestic usage may cause harm to human health and well-being as it contains natural organic matters such as humic substances. Electrocoagulation is an environmentally friendly and simple process of water treatment. This research aims to develop a batch electrocoagulation process for treatment of peat water in Sarawak using Aluminium electrodes. The research includes the study on electrocoagulation for peat water treatment, design, and fabrication of batch electrocoagulation process using Aluminium, experimental study for optimum performances of the electrocoagulation, and economic analysis of the electrocoagulation system. Several parameters that affect the performances of the electrocoagulation system are studied such as the inter-electrode distance, number of electrodes, current density and treatment time. The performance of the system is evaluated based on the removal efficiency on turbidity, colour, Chemical Oxygen Demand (COD), Total Organic Content (TOC) and Total Suspended Solid (TSS). The system successfully removes 100% of colour, 93.35% of turbidity, 89.80% of COD, 88.22% of TOC, and 87.50% of TSS by using a current density of 25 A/m2in 80 minutes and 8 Aluminium electrodes with inter electrode spacing of 2 cm. The final quality of treated peat water is determined to be suitable for domestic usage which falls under Class 1 water of the National Water Quality based on the parameters analyzed. The operating cost of 25 A/m2current density for 80 minutes of treatment time by using 8 electrode plates is RM 4.32 per m3of peat water.
The permit to work in relation with occupational accident at Petrochemical Plant
Authors: Jusoh Nizar , Wijayanuddin Ali Mohamad , Amran Tuan Abdullah Tuan , Husain Alias
Published: May 2020

Permit To Work is an official documents used as a means of communication, control and managing of work activities to prevent accident at the Petrochemical Plant. But in many cases the Permit To Work has failed in its roles to control work activities which causes the occupational accident in the plant. Because of that this study was conducted to assess the Permit To Work in occupational accident occurred in the Petrochemical Plant This study was conducted by distributing 260 survey questionnaire to Work-leader of various contractor company that work in the Plant. The data was analysed using the Exploratory Factor Analysis (EFA), Confirmatory Factor Analysis (CFA) to confirm the five Permit To Work elements construct. The Structural Equation Model was performed to identify most significant element related to failure of Permit To Work, and it was found that the hazardous activity and worksite inspection are the main element contributed to occupational accident in the Petrochemical Plant.The result of all the study has indicated that the Permit To Work and their element play important roles and it must be fully comply in every Permit To Work Process for work that need to be done in the Petrochemical Plant to ensure no accident occurred at Petrochemical Plant.

This is Part 1 of two paper, focusing on PTW Assessment. Part 2 deal with PTW Accident Model, PTW in Bow Tie, Predictive Modelling and Case Study.
Combined natural and chemical coagulants to remove fluoride from wastewater
Authors: Chee V L , Chong C H , Choo C M , Choong Thomas S Y
Published: May 2020

The combined chemical and natural coagulant showed greater fluoride ion removal in synthetic hydrofluoric acid wastewater when compared to natural coagulant or chemical coagulant treatment alone. The impact of applying fibrous thin film on the coagulation activity was assessed in this study. In this study, a new chemical coagulant called Ecogent F-Loc was introduced. It can increase 40% of fluoride removal when combined with sodium aluminate. Combined chemical and natural coagulants gave the highest fluoride reduction using theMoringa Oleiferaseed and eggshell with dosage of 100 ppm were 57% and 73%, respectively. When the chemical coagulant added withMoringa Oleiferaseed, the fluoride removal efficiency increased from 50% to 77%. This showed that the combined chemical and natural coagulant showed similar coagulation effect as conventional chemical coagulant. In term of fibrous thin film, there is no significant effect on the coagulation activity of coagulant, but it helped to reduce the turbidity and coagulant residue in the synthetic wastewater and used to produce ionic solution for fluoride removal. In addition, the direct contact between particles and the impeller of Jar Test equipment can destroy the surface morphology of coagulant particles. With the support of the fibrous thin film, this challenge can be solved. In conclusion, the combined natural and chemical coagulant solutions can be used to substitute existing chemical treatment in fluoride wastewater treatment.
Chromium removal from chrome-tannery effluent after alkaline precipitation by adsorption using municipal solid waste-derived activated biochar
Authors: Parañaque Julienne Eris L. , Concepcion Maguyon-Detras Monet , Migo Veronica P. , Alfafara Catalino G.
Published: May 2020

Municipal solid wastes (MSW) accumulation and generation of toxic wastewater are common issues especially in highly industrialized and urban communities. To address these concerns, municipal solid wastes was converted to activated biochar (MSWAB), which can be used to treat alkaline-precipitated tannery wastewater by adsorption to meet the environmental limit of 0.5 ppm Crtotal concentration. Alkali precipitated tannery wastewater has an initial Crtotal concentration of about 3364.37. MSW pyrolysis at 500°C for 30 mins produced about 50.42 % w/w biochar, which was activated using KOH to improve its adsorption capacity. Equilibrium time for Cr adsorption using MSWAB was established after 1 hour of adsorption. The effect of pH and adsorbent dosage on the Crtotal removal were then tested from pH 6.5 to 12 and from 0.2 to 10 mg MSWAB/mL wastewater, respectively, using 2k factorial design. Statistical results show that both factors were significant on the percent removal of Crtotal. Maximum Crtotal removal obtained was about 98.97% using MSWAB as adsorbent at pH 12 with 10 mg/mL dosage. Freundlich isotherm best described the adsorption of Cr onto MSWAB (R2 = 0.8231) as compared to the Langmuir isotherm (R2 = 0.5079). Commercial activated carbon (CAC) with a removal of 57.39 % was still observed to have higher removal efficiency compared to the 55 % removal using MSWAB at pH 8.5. However, considering the low cost of feedstock used, environmental benefits, and its adsorption performance, MSWAB can be a possible alternative for CAC.
Nutrient Recovery from Slaughterhouse Wastewater
Authors: Sreyvich S , Petrus H T B M , Purnomo C W
Published: May 2020

Poultry slaughterhouse wastewater commonly contains high concentration of NH4+ and PO43-. These nutrients can cause eutrophication and unpleasant odor problem if untreated properly. By adding some minerals, the nutrients can be recovered in the form of immiscible powder called struvite. Struvite precipitation process for nutrients recovery from waste sources is beneficial not only providing slow-releasing and high-quality fertilizer but also reducing soil and water pollution from rich-nutrients wastewater. Three parameters in struvite precipitation will be observed in this study which are pH, temperature, and PO43-/Mg2+ molar ratio. The optimum conditions obtained based on the highest removal efficiency of phosphate (99.3%) and ammonium (98.1%) are PO43-/Mg2+ ratio of 1:3; pH of 9.0; and temperature at 30°C. Meanwhile for kinetic study, the temperature increase will reduce the rate constant (k) value, while increasing pH tend to increase k values. The obtained powder of struvite has been confirmed by X-Ray diffraction (XRD) with expected impurity of MgCl2 due to the excess usage during struvite precipitation process. This study is applicable for wastewater treatment plant which not only treating wastewater but also producing eco-friendly fertilizers.
Exergy analysis and energy utilization in the transportation sector of the Philippines
Authors: Buenafe R J Q , Lomeda R A P , Rivera R R C , Tagalog C L , Soriano A N
Published: May 2020

This paper analysed the energy and exergy utilization of the four transportation sectors (road, rail, water, and air) in the Philippines during the years 1990 to 2016. The consumption per fuel was also considered in the analysis because each sector utilizes one or more type of fuel. The collected data showed that road transportation has the highest fuel utilization, and energy and exergy efficiency amongst the four followed by the aviation and marine subsectors which are both less significant than the results from the road transportation sector. Also, it was observed that diesel and gasoline are the ones commonly used in the road, rail, and marine subsectors compared to LPG, ethanol, biodiesel, and electricity. Comparing the overall energy and exergy efficiencies from 20 years ago, it was observed that the efficiencies are gradually increasing annually in small increments. The data presented in this research will be beneficial to the Philippine transportation sector to effectively reduce cost and improve the quality of transport in the country. It is also helpful to base future transportation designs on the energy and exergy efficiencies to better improve transportation and reduce the environmental impact which can both be practical for the economy and the ecosystem.
Sustainability assessment of levulinic acid and succinic acid production from empty fruit bunch
Authors: Hafyan R H , Bhullar L , Putra Z A , Bilad M R , Wirzal M D H , Nordin N A H M
Published: May 2020

Empty fruit bunch (EFB) generated as waste in plantation mill activities in Malaysia is a potential biomass feedstock of biorefinery for fuels and chemicals production. Levulinic acid and succinic acid, two out of 12 chemical building blocks identified by Department of Energy (DOE) to be used in synthesis of high-value materials, can be produced from biochemical conversion of the EFB. This paper evaluates sustainability assessment of EFB to levulinic acid and succinic acid. The assessments include net present value (NPV), global warming potential (GWP), and Hazard identification and ranking (HIRA) to cater for economic, environment, and safety performances, respectively. The results show that the levulinic acid production is more economically attractive than succinic acid production. The environmental impact quantification reveals that the levulinic acid has lower GWP score of 6.3 kgCO2-eq/kg levulinic acid than succinic acid with 11.2 kgCO2-eq/kg succinic acid. Meanwhile, the succinic acid production is inherently safer than levulinic acid production due to its less severe operating conditions.
Cogeneration system for energy saving and CO2 emission reduction: A case study of textile factory
Authors: Sommani P , Krittametaporn T , Lothongkum A W
Published: May 2020

Thailand has many textile factories of which the complete value chain consists of upstream, midstream and downstream sectors. It is well-known that textile manufacturing consumes considerable amount of energy. The textile factory in this case study is located at Bang Poo Industrial Estate in Samut Prakarn province, Thailand. It is categorized as a midstream sector and has been consuming final energy in terms of 87% thermal energy (steam) and 13% electrical energy. The factory had 6 fire-tube steam boilers having capacity of 40 tons steam per hour. The age of the existing boilers was longer than 20 years. Therefore, it was decided to install a cogeneration system to replace the existing boilers for energy saving, safety integrity and CO2 emission reduction. The gas turbine topping cycle cogeneration system with waste heat recovery was selected due to several advantages such as low energy consumption, high boiler efficiency and high energy efficiency. Considering the energy and environmental issues, the results showed 92% overall efficiency, 19.5% primary energy or natural gas savings, and 38.6% reduction of CO2 emission when compared to the separated heat and power system. In summary, the cogeneration system shows positive energy and environmental impacts.
Safety culture level among workers in the selected manufacturing plant
Authors: Zakaria Junaidah , Rosmani Che Hassan Che , Diana Hamid Mahar , Hani Sukadarin Ezrin , Razak Zakaria
Published: May 2020

Workers in the manufacturing industry face many safety risks due to the nature of the job. The state of safety and health performance determine by examining the safety climate factors which reflects workers’ perception of the psychological aspect in safety culture domain. This study aimed to assess the safety culture level and its contributing factor to the safety culture in a selected chemical manufacturing plant. Survey data was collected from 309 employees in a factory located in Kuantan Pahang. They were randomly selected and represent two groups, namely executive and technician. A standardized climate questionnaire was used and answered by the respondents within 20 to 30 minutes. Sixty-five percent of the total respondents agree that the safety culture level at their workplace is high, and another 35% revealed that it is moderate. Perceived safety climate and personal attitude among two groups employee were compared using an Independent Sample t-test. Results revealed a significant difference between groups (t=7.428, P=0.007) for management commitment, (t=6.133, P=0.014) for safety rules and procedures, (t=15.823, P=0.001) for supportive environment, (t=10.949, P=0.001) and lastly for physical work environment, (t=6.067, P=0.014). A Pearson correlation coefficient was computed to assess the relationship between safety culture factors and demographic information of the respondents. There was a positive correlation between safety rules and procedures and level of education, r = 0.135, p = 0.018, and Involvement and years of working experience, r = 0.165, p = 0.004. Increases in the level of education were found correlated with increases in perceived safety rules and procedures while increases of years of working experience was directly correlated with increases in involvement to safety in the organization.
Adsorption of 4-Nitrophenol from wastewater using Sea Mango (Cerbera odollam) based Activated Carbon
Authors: Zufarhana Zulkurnai Nurul , Wahidatul Azura Zainon Najib Nor , Fazara Md Ali Umi , Ru Shien Tan
Published: May 2020

The presence of phenols and phenolic compounds in water and wastewater has gained great public attention and it is one of the most frequent pollutants in wastewater. In this study, the adsorption of 4-Nitrophenol from wastewater using activated carbon prepared from the non-edible Sea Mango (Cerbera odollam) fruit was investigated. The Sea Mango Activated Carbon (SMAC) was prepared through a physicochemical activation which consists of H3PO4 impregnation and followed by CO2 gasification. The influences of process variables represented by solution pH value, contact time, initial concentration and adsorbent dosage on removal efficiency of 4-NP onto Sea Mango Raw Material (SMRM) and Sea Mango Activated Carbon (SMAC) were studied. Result showed that the optimum pH for 4-NP removal was at pH 3. The dosage usage required to complete 100 ml of 4-NP on SMRM and SMAC was 1.0 g. Batch studies were performed to evaluate the adsorption process, and it was found that the Freundlich isotherm effectively fits the experimental data for the adsorbates better than the Langmuir model with the highest adsorption capacity 158.730 mg/g of 4-nitrophenol on SMAC. It was found that 70.49% and 97.98% of 4-NP was adsorbed onto SMRM and SMAC, respectively, at an initial concentration of 20 mg/L.
Mass transfer evaluation of substrate, intermediate products and inhibitors in membrane bioreactor on biogas production
Authors: Hidayat M , Kurniawan I G , Prakosa M A , Dökümcü S , Millati R , Cahyanto M N
Published: May 2020

Problem of fruit wastes can be minimized by fermenting them to produce biogas. Biogas production using membrane bioreactor (MBR) is an effort to prevent microbial washout especially with the presence of some inhibitors such as D-limonene and xanthone that are naturally originated from the fruits. In the membrane system, nutritional compounds such as glucose (substrate) and acetic acid (intermediate product) in fruit waste are expected to pass through, but the inhibitors are retained as membrane is hydrophilic and the inhibitors are hydrophobic.

Two membranes poly vinylidine difluoride (PVDF) and poly ether sulfone (PES) were used. In this study, permeability of inhibitors and nutritional compounds across the membranes were evaluated. In the separated experiments, D-limonene or xanthone solution as inhibitors and glucose or acetic acid as nutritional compounds at various concentrations were pumped through the membrane placed in a module. Flux of compounds through membrane was determined by collecting each milliliter of permeate at a certain time. The concentration of compounds in the feed and permeate were analyzed using gas chromatography or high performance liquid chromatography. Permeability of compounds were calculated the obtained concentration and flux.

The results showed that both membranes are able to retain the inhibitors while the substrate (glucose) and intermediate product (acetic acid) are let go across the membranes. The result showed that PES had better performance than PVDF in term of flux, while the selectivity is fairly the same for both membranes. Thus, it can be concluded that PES is more suitable for fermentation using membrane bioreactors.
Extraction of Silica from Rice Straw Using Alkaline Hydrolysis Pretreatment
Authors: Haslija Abu Bakar Ayu , Jia Ni Carey Chong
Published: May 2020

Rice straw is an abundant resource in Asian countries, for instance, Malaysia and India. Rice straw is a major agricultural waste product, which caused disposal issue in areas. Residue burning crops was adopted for the farmers to dispose of rice straw after harvest in order to prepare seedbed preparation for next season. An alarming air pollution report impacted by open burning of rice straw contributes to global warming. Commercialization of silica is an alternative method to dispose of agro-waste residues. The main objective of this research is to extract silica from rice straw. The amorphous silica was derived by first digesting rice straw with Soda AQ solution by varying NaOH concentration from 5 wt% - 25 wt% and 0.1 wt% anthraquinone (AQ) to dissolve silica content and acid precipitation at pH 7 to obtain silica gel. Other parameters such as the effect of digestion temperature (60 °C to 90 °C), digestion time (1 hour to 3 hours), and Soda AQ to rice straw impregnation phase ratio (150:5 to 500:5). The optimum effects of parameter had yielded 74.11 % of silica and it was demonstrated by Soda AQ with NaOH concentration 20 wt% and 0.1 wt% AQ, temperature of 75 °C, digestion time of 3 hours and the ratio 200:5 of Soda AQ to rice straw. Characterization of rice straw was performed by using Fourier Transforms Infrared Spectroscopy (FTIR). The commercialization of silica had the potential to be utilized as construction materials and silica gel that aids to absorb moisture.
Comparative study of Heat Pump Assisted Distillation Column and Its Application for Pressure Swing Distillation Process
Authors: Retno Sawitri Dyah , Budiman Arief
Published: May 2020

Two of the well-known heat pumps assisted distillation column scheme are direct vapor recompression and bottom flashing. The comparison between the two schemes was systematically studied for binary mixture of non-azeotropic benzene-toluene system. Simulation was carried out using Aspen Plus software. The best scheme was selected based on economic evaluation (utility cost and TAC reduction). The application of both schemes was also studied for pressure swing distillation process. Pressure swing distillation is one of the most common methods for separating pressure-sensitive azeotropic system. Direct vapor recompression scheme and bottom flashing scheme can be applied to enhance the energy savings. The minimum-boiling homogeneous azeotropic mixture of methyl acetate-methanol was chosen as representative in process simulation.
Effect of surface-etched modification on halloysite nanotubes (HNTs) for polysulfone mixed matrix membrane in CO2/CH4 separation
Authors: Jafa J , Anissuzaman S. M. , Chiam C K , Bolong N , Razali A R , Ismail A F , Ismail N M
Published: May 2020

Mixed matrix membranes (MMMs) were fabricated from a 25 wt% of polysulfone (PSf) with halloysite nanotubes (HNTs) selected as the inorganic filler. The incorporation of 1 wt% to 5 wt% of HNTs in the membrane is promising in improving the performance of the membrane for gas separation due to its barrier properties. HNTs was modified by surface-etched method before it is embedded into the membrane in order to reduce the interfacial defects as well as the agglomeration in the membrane. This study further investigated the improvement of the polymer-clay interface interaction, characterize the functional groups, structure and surface area of the newly modified clay and also mechanical properties of the membrane. From the FTIR spectra, it can be seen that the functional group of surface-etched HNTs reduced in intensities compared to the unmodified HNTs. There are no distinct changes in XRD pattern for both unmodified and modified HNTs and tensile strength shows an increment in MMMs embedded with modified clay compared to unmodified clays. The incorporation of surface-etched HNTs was able to improve the membrane properties to a desired membrane that can be applied in the CO2 and CH4 separation.
Microwave assisted extraction of lipid from Nannochloropsis gaditana microalgae using [EMIM]Cl
Authors: Rezaei Motlagh S , Harun R , Biak D R A , Hussain S A
Published: May 2020

Ionic liquids (ILs) have been recognized as superior solvent due to their exclusive properties, green and varied applications in chemical industries. ILs can be apply as solvent in extracting lipid from algal biomass. This study examined the application of microwave-assisted extraction (MAE) with ILs to extract total lipids from microalgae for biodiesel production. 1-ethyl-3-methyl imidazolium chloride ([EMIM]Cl) IL was utilized as the solvent and microwave irradiation applied for the pretreatment method. The experimental findings were compared with those from conventional method using Soxhlet extraction. For [EMIM]Cl plus microwave irradiation assisted extraction, it was reveald that the highest lipid yield was achieved 13.9% in the optimum condition at 3.3 w/v of solid loading, process duration of 5 min, temperature of 80 °C and microwave power of 800 W. Also, microwave irradiation with IL had improved the lipid extraction up to 3.1 times compared to the Soxhlet result. The findings from this study displays that the MAE with IL has the potential to be applied in extracting compounds from biomass.
Simulation of the Drying Process of Polysaccharide Extract Solution in a Spray Dryer
Authors: Nurtono Tantular , Widiyastuti Widiyastuti , Mufyda Rahmatika Annie , Machmudah Siti , Winardi Sugeng
Published: May 2020

The drying process of droplets into particles on a spray dryer is influenced by several factors, including the temperature and the flow rate of inlet air as a carrier gas and a drying media. The effects of temperature of the inlet air in the spray dryer system was elucidated in this study. A solution containing 35 w% polysaccharide extract and water as the solvent was injected into a spray dryer. The inlet air temperatures were varied at 135, 170, and 200 °C with 3 L/min. The geometry of spray dryer consisted of the tubular-conical with a length of 48.8 cm and 15.2 cm diameter cylinder. The spray dryer unit was simulated using CFD code, Fluent Ansys R15.0 with the second phase of droplets/particles was modelled by the Lagrangian discrete phase model (DPM). The inlet air temperature also affected the size of the particles. The increase of the air temperature led to the increase of the average particle diameter leaving the chamber with the smaller standard deviation. The air flow rate affected the particle size. The higher the air flow rate, the smaller the size of the average diameter of the particles and smaller standard deviation would be. The evaporation rate increased with the increase of the flow rate and inlet air temperature. The resulting particles had an average size of 1.28∼1.9 μm diameter to drying with hot air that flowed continuously. The simulation result was validated by the experimental work with discrepancy less than 20%.
Effect of Stirring Rate and Freezing Time on the Percentage of Recovery of Residual Oil from Palm Oil Mill Effluent via a Stirred Freeze Crystallizer
Authors: Mohamed Anuar M. A. , Amran N. A. , Ruslan M. S. H.
Published: May 2020

In palm oil industries, treating palm oil mill effluent (POME) is still problematic due to both technologies sustainability and management will. In conjunction with the POME problem, increasing the oil extraction rate (OER) is also the most crucial task for these palm oil production community. The most promising method to address these two challenges is by direct recovering of lost oil in the POME. Among the popular separation processes for recovery of residual oil from POME are by using evaporation, adsorption and reverse osmosis as process media generated a good amount of percentage recovery of residual oil from the effluent. However, these methods require high amount of energy and the process itself are complex where it can affect the quality of the residual oil. The goal of this project is to extract and recover the residual oil in POME using an advanced approach called progressive freezing, in order to meet the standard quality discharged of effluent and improve oil extraction rate (OER). In this research, a cylindrical stirred freeze crystallizer was designed and fabricated, where the crystallizer was immersed in a refrigerated water bath for cooling purpose. The effect of stirring rate and freezing time on the percentage of recovery of residual oil was investigated. It was found that higher stirring rate resulted in a lower percentage oil recovery, which translated into low efficiency. On the other hand, higher percentage of oil recovery was monitored as the freezing time is prolong from 20 to 60 minutes. The highest percentage oil recovery of 76.5% was obtained at coolant temperature of 2°C, freezing time of 40 minutes and the stirring rate of 150rpm.
Preparation of Highly Hydrophobic PVDF-HFP Membrane with Anti-Wettability Characteristic
Authors: Toh M J , Oh P C , Mohd Shaufi M I S
Published: May 2020

Membrane gas-liquid separation technology has gained great interest in membrane desalination, distillation, and gas absorption attributed to its good operation flexibility, small footprint and high specific interfacial area. Membrane acts as the non-selective barrier between gas and liquid solvent by allowing the diffusion of gas molecules via pressure difference. Currently used membrane is susceptible to pore wetting at high operational pressure, transforming its non-wetted condition to partially wetted and wetted mode. Such condition introduces additional mass transfer resistance to gas molecules, leading to the poor removal flux. In order to alleviate the wetting tendency, membrane hydrophobicity needs to be enhanced. In this work, highly hydrophobic PVDF-HFP membrane of improved anti-wettability properties was synthesized via non-solvent induced phase separation. The effect of polymer concentration and coagulation medium on membrane wettability were studied. The results revealed that PVDF-HFP membrane of 10wt% polymer concentration presented high water contact angle of 100.4°. By changing water to ethanol as coagulation medium, membrane exhibited a symmetric nodular structure which enhanced water contact angle by 20.3% to 130.5º. To further improve membrane hydrophobicity, modified silica (MS) nanoparticles were used as surface modifier in coagulation bath. When the nanoparticles content increased from 0g to 2g, the water contact angle of the PVDF-HFP modified membrane increased significantly from 130.5° to 163.1°. As a result, the liquid entry pressure of the membranes increased gradually from 0.58bar to 3.38bar with MS incorporation. This disparity in membrane anti-wettability is due to the increase in surface roughness and reduction in surface energy. Additionally, the modified membrane at MS loading of 2g showed high porosity at 78%, which is adequate to provide increased mass transfer rate between gas and liquid solvent.
Preparation and properties of endothermic functional ceramics with iron tailings as raw materials
Authors: Meng Junping , Peng Jingxuan , Srinivasakannan C , Duan Xinhui , Liang Jinsheng
Published: May 2020

The present work attempts to utilize iron tailings as the main raw materials for preparation of functional ceramics as a means of resource utilization. A new type of endothermic functional ceramics, which can be used in the field of solar energy, was prepared via semi-dry pressing followed by pressureless sintering. The results show that the functional ceramics made of 68 wt% iron tailings, 26 wt% iron ore, 3 wt% alumina, 1 wt% potash feldspar and 2 wt% kaolin, sintered at 1185 °C exhibited the best overall performance. Visual observation reveals that there were no cracks on the surface of the samples even after 20 cycles of intense thermal shock. Other attributes could be summarized as follows: Infrared emissivity in mid-infrared region: 0.85; thermal conductivity at 500 °C: 2.066 W/(m·K); flexural strength: 119.03 MPa. XRD analysis indicates that the main crystalline phases in the samples are augite, magnetite and a small amount of hematite. An increase in the proportion of iron oxide contributed to lower melting temperature of the functional ceramics, deepen color, promote densification and increase infrared emissivity. In short, the introduction of iron tailings improves the thermal and physical properties to a certain extent.