50 years of rare earth research in Malaysia: Past, future trend and what is missing? A bibliometric analysis

The bibliometric analysis was conducted using R Bibliometrix software on 4,876 articles related to rare earth published by author from Malaysia. All the articles are indexed in Scopus from 1971 to 2023. The multidimensional analytical approach provided holistic view of the scope of rare earth research in Malaysia and its progression, the major topics, institutes, trends and gaps. Based on the general descriptive data analysis, the results showed that rare earth research has gained influence in Malaysia since 2009. A clustering analysis of the retrieved keywords showed that fiber lasers and saturable absorber in rare earth was the most frequently discussed topic. The study also revealed a major gap in this area especially on the upstream and middle stream study of rare earth. The gaps should be filled in order to position Malaysia as one of the rare earth powerhouse

Grease Quality Issues on Middle Voltage Switchgear: Corrosivity, Resistivity, Safety and Ageing

Grease products recommended by OEM for conventional 11kV switchgears are generally trusted. Some disadvantages might however exist among them or their supply could be insufficient and lead to use of non-OEM-recommended grease. This paper reports analysis methods to evaluate both types of grease that were recently used in the switchgears at local electrical distribution stations owned by Tenaga Nasional Berhad. Hardened, greenish and severely irritating greases probably caused by incompatible compounding, electrochemical reaction, and hazardous components, respectively, were among common problems faced by workers. Eight physical tests and four chemical tests were conducted on 10 grease samples using thermogravimetry, switchgear rig, gas chromatography and infrared spectroscopy besides other equipment and standard methods. Grease stability, oil bleeding, flammability of grease droplet and dropping point were among the characteristics determined in the analyses. The results reveal copper corrosion, chemical change, instable and inconsistent grease, and toxics in grease, which surprisingly included the OEM-recommended one. ABSTRAK: Produk gris yang disyorkan oleh Pengeluar Peralatan Asal (OEM) bagi gear-suis konvensional 11 kV secara umumnya dipercayai ramai. Kemungkinan terdapat kekurangan pada produk-produk tersebut ataupun bekalan gris mereka yang tidak mencukupi telah mendorong kepada penggunaan gris yang tidak disyorkan oleh OEM. Kaedah analisis kajian ini melaporkan tentang kedua-dua jenis gris yang kebelakangan ini digunakan oleh Tenaga Nasional Berhad pada gear-suis di stesen pencawang elektrik. Gris mengeras, berlumut dan menjengkelkan mungkin disebabkan oleh sebatian bahan yang tidak sesuai, tindak balas elektrokimia dan komponen yang tidak selamat, masing-masing adalah antara masalah yang dihadapi oleh para pekerja. Lapan ujian fizikal dan empat ujian kimia telah dijalankan pada 10 sampel gris menggunakan termogravimetri, pemakai gear-suis, kromatografi gas dan spektroskopi inframerah selain alatan lain dan kaedah-kaedah piawai. Antara ciri-ciri yang dikaji dalam analisis ini adalah kestabilan gris, sifat lelehan minyak, sifat mudah terbakar titisan gris dan takat rendah gris. Hasil kajian mendapati gris ini menyebabkan tembaga terhakis, sifat kimia berubah, sifat gris yang tidak stabil dan mudah berubah, dan juga beracun memberi kejutan kerana pihak OEM tetap mengesyorkan gris jenis ini

Comprehensive assessment of biochar integration in agricultural soil conditioning: Advantages, drawbacks, and future prospects

Agriculture nowadays faces numerous issues because of the fast growth in food demand and environmental considerations. Due to the rapid depletion of agricultural areas and soil quality caused by a continuously growing population and the excessive addition of chemical fertilizers, rehabilitated consideration is required for sustaining viable crop production methods. Biochar (BC) use in agricultural soils has garnered considerable interest. BCs offer significant agricultural and environmental advantages, including improved soil health, enhanced crop growth and production, carbon sequestration, reduced greenhouse gas (GHG) emissions, and nutrient dynamics regulation. BC application in agricultural systems is influenced by various parameters, including pyrolysis temperature, feedstock composition, dosage and procedure, nature of the soil, crop varieties, and biotic interactions that substantially impact the efficacy of BC under varying environmental conditions. BC improved nitrogen mineralization and plant absorption by modifying the rhizosphere's abiotic and microbiological activities. Thus, BC increased the plant's resistance to pathogens, decreased the availability of heavy metals (HMs), and promoted the plant's tolerance to environmental challenges. Nonetheless, BC application is hazardous in certain circumstances. This review discusses the advantages, drawbacks, and future developments of applying BC to agricultural soils. By providing an extensive assessment of the advantages and limitations of BC integration in agriculture soil conditioning, this review is highly informative regarding the development of soil and crop-specific BC with the appropriate properties. It could help increase agriculture yield, ensure food security, and enhance environmental management. In addition, this review highlights knowledge deficits and proposes future perspectives for commercializing large-scale BC applications

Aspen Plus Simulation of Bio-Char Production from a Biomass-Based Slow Pyrolysis Process

Biomass-based pyrolysis is a thermo-chemical conversion of biomass feedstock with low oxygen supplied level to produce bio-char, bio-oil and bio-syngas products via slow, intermediate and fast pyrolysis, respectively. The specific yields from pyrolysis process depend on operating conditions to maximize outputs. Bio-char can be used as soil improvement, animal feed supplements, filter material, carbon storage, and energy source. This study has focused on the development a simulation model for slow pyrolysis process utilizing biomass from oil palm empty fruit bunches (EFB) in Aspen Plus software. The facts that EFBs are abundant in Malaysia and have huge feedstock potentials could be realized, among them, through process design dan analysis in the Aspen Plus. Simulation model was developed based on EFB proximate and ultimate analyses and aimed for optimal product fraction yields and for the elemental composition of the pyrolysis products, considering several factors or effects such as pyrolysis temparature, pressure and inert gas flowrate. Simulation results showed the optimal value of bio-char yield was 68.6 wt. % at 9 bars, 300 °C, and 0.1 kg/min of inert gas flow rate. Eventhough the developed simulation model was an equilibrium-based one, it is useful especially in determining the optimal values of the key effects for the slow pyrolysis process

Aspen plus simulation of bio-char production from a biomass-based slow pyrolysis process

Biomass-based pyrolysis is a thermo-chemical conversion of biomass feedstock with low oxygen supplied level to produce bio-char, bio-oil and bio-syngas products via slow, intermediate and fast pyrolysis, respectively. The specific yields from pyrolysis process depend on operating conditions to maximize outputs. Bio-char can be used as soil improvement, animal feed supplements, filter material, carbon storage, and energy source. This study has focused on the development a simulation model for slow pyrolysis process utilizing biomass from oil palm empty fruit bunches (EFB) in Aspen Plus software. The facts that EFBs are abundant in Malaysia and have huge feedstock potentials could be realized, among them, through process design dan analysis in the Aspen Plus. Simulation model was developed based on EFB proximate and ultimate analyses and aimed for optimal product fraction yields and for the elemental composition of the pyrolysis products, considering several factors or effects such as pyrolysis temparature, pressure and inert gas flowrate. Simulation results showed the optimal value of bio-char yield was 68.6 wt. % at 9 bars, 300 ℃, and 0.1 kg/min of inert gas flow rate. Eventhough the developed simulation model was an equilibrium-based one, it is useful especially in determining the optimal values of the key effects for the slow pyrolysis process

Grease quality issues on middle voltage switchgear: corrosivity resistivity safety and ageing.

Grease products recommended by OEM for conventional 11kV switchgears are generally trusted. Some disadvantages might however exist among them or their supply could be insufficient and lead to use of non-OEM-recommended grease. This paper reports analysis methods to evaluate both types of grease that were recently used in the switchgears at local electrical distribution stations owned by Tenaga Nasional Berhad. Hardened, greenish and severely irritating greases probably caused by incompatible compounding, electrochemical reaction, and hazardous components, respectively, were among common problems faced by workers. Eight physical tests and four chemical tests were conducted on 10 grease samples using thermogravimetry, switchgear rig, gas chromatography and infrared spectroscopy besides other equipment and standard methods. Grease stability, oil bleeding, flammability of grease droplet and dropping point were among the characteristics determined in the analyses. The results reveal copper corrosion, chemical change, instable and inconsistent grease, and toxics in grease, which surprisingly included the OEM-recommended one

Removal of chloride from rare earth wastewater industrial using bioremediation hybrid with electrocoagulation system

Chloride (Cl-) is a major anion found in all natural waters. It occurs naturally and is also a relatively minor contaminant. Currently, a larger amount chloride (Cl-) in wastewater was generated from rare earth industrial. Chloride is non-toxic to humans, however, it can bring harmful to some plants and aquatic. There is needed for treatment to remove chloride from wastewater before discharged to river or water bodies. Furthermore, chloride is also a very corrosive agent, and elevated levels pose a threat to infrastructure, such as road beds, bridges, and industrial pipes. The effect caused by these hazardous pollutants and growing concerns to environmental issues led to remove chloride concentration from rare earth wastewater by using bioremediation hybrid with electrocoagulation system. The application of yeast in the wastewater treatment has potential in the treatment and reuse of wastes containing solids and high concentrations of salt, fat and antibiotics. However, Electrocoagulation is a novel method in wastewater treatment especially in chloride removal and this emerging technology combines the functions and advantage of conventional methods such as coagulation, flotation, and electrochemistry in water and wastewater treatment. The treated rare earth wastewater was tested for its chloride (Cl-) concentration to determine the percentage of reduction by measured using spectrophotometer. Results shows S. cerivisiae cells grew and adapted well under condition 10 g/L NaCl in suitable nutrient medium. Yeast was able to growth in standard (10 hr), synthetic chloride (6 hr) and actual wastewater (6 hr) with OD increased from 0.8 to 2.4, 0.8 to 1.2 and 0.4 to 0.6 respectively. Besides that, the optimum yeast able to growth in standard pH 6 at first 9 hours with OD increased from 1.1 to 2.1. Thus, the samples directly treat by using electrocoagulation system. The result shows ferum plate able to remove chloride concentration which is 75.0 % removal at 5 minute and 2 Ampere. The information obtained from this study is useful for scale up purpose in the rare earth industry that choose bioremediation hybrid with electrocoagulation system method to remove chloride concentration from rare earth wastewater

Sodium grease formulation from waste engine oil

The present study was conducted to formulate sodium soap grease using waste engine oil (WEO). Greases were formulated by homogenizing sodium soap thickener in WEO for 2 hours at 150°C Different grease composition of oil-to-thickener ratio was designed which are 90/10, 80/20, 70/30 and 60/40. The formulated greases were analysed by conducting the consistency, oil bleeding, oil separation and FTIR characterization tests. The present study found that grease can be formulated using WEO and the thickener percentage have significant effect on formulated greases properties. Grease formulated with 70 – 80% of base oil and 20 – 30% of thickener was the best grease formulated as it shows desirable grease properties

Rheological and structural characterization of emulsified modification bitumen synthesized from industrial waste

The cooler surface temperature than surrounding air may result in condensation which will propagate the growth of mould and fungi. The operation theatre has to maintain the temperature lower than the ambient condition which may result in condensation and lead to fungi problems. The aim of this study is to eradicate the fungi problems through coating and insulation by formulating Emulsified Modified Bitumen (EMB) from industrial waste. The industrial grade bitumen (60/70) will be modified with recycle used oil and mix with three different types of emulsifier. Industrial waste such as recycle used oil was being used to reduce the usage of raw bitumen in the formulation of EMB and also to reduce the excessive environmental issue in Malaysia