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The energy demand in Malaysia has shown a dramatic increase over the last few years: with natural gas and coal being the primary contributors. Nevertheless, due to declining in fossil fuel reserves coupled with negative environmental impacts, shifting to sustainable renewable energy for meeting the future energy demand is recommended. Since Malaysia is rich with natural resources, utilization of biomass energy (bioenergy/biofuel) as the alternative energy is promising to be further explored. Therefore, this review paper intents to discuss the current scenario of different types of biomass energy in Malaysia along with the up-to-date local biomass energy–related environmental policy (from 2016 onwards). In addition, challenges and barriers for large-scale implementation of the biomass energy in Malaysia are to be discussed. Overall, this review paper is interesting as it can assist in promoting the biomass utilization as energy source, and to ensure the future growth of biomass energy market in the country along with its effective implementation while alleviating poor disposal problem and to create job employment opportunities. Furthermore, a collective effort to expand potential biomass feedstocks, apart from oil palm, should be emphasized to encourage the renewable energy production diversification in the nation. [ABSTRACT FROM AUTHOR]

The increase in carbon dioxide (CO 2 ) concentration in atmosphere brings in major concern nowadays. Accordingly, a study on the volumetric CO 2 adsorption by using the palm kernel shell-based activated carbon synthesized via direct activation at 850 °C for 1 h has been investigated. The adsorbents are characterized using various analytical techniques to analyze the elemental, surface, and textural characteristics. Referring to the physiochemical analysis, it verifies that the proposed activation method effectively converts the palm kernel shell to value-added activated carbon material. The synthesized palm kernel shell-based activated carbon shows comparable CO 2 adsorption capacity and CO 2 /nitrogen selectivity with the commercial grade activated carbon. The regeneration study that has been carried out via pressure swing indicates easy regenerability and good stability after the multiple adsorption-desorption cycles. The experimental CO 2 adsorption isotherm data is examined by using several isotherm models – Langmuir, Freundlich, and Sips, by using non-linear regression method. The findings reveal that the Sips model mathematically represents the CO 2 adsorption, irrespective of adsorption temperature. Besides, heterogeneity characteristics of gas-solid adsorption is further confirmed through the isosteric heat of adsorption (Q st ) value that decreases with increasing surface loading. [ABSTRACT FROM AUTHOR]

The activated carbon is acknowledged as a promising adsorbent to be applied in various applications due to its low cost, well-developed pore structures, and high adsorption capacity. At present, the increasing abundance of oil palm wastes has resulted in various environmental problems. Accordingly, these agro wastes can be employed as potential low-cost precursors for the activated carbon production. This review paper presents a comprehensive overview on the recent advancement in the utilisation of oil palm wastes as the origin of the activated carbon production, specifically from the year 2011 to the present. Throughout this review paper, a strong emphasis is put on the recent activation methodology towards the oil palm residues. This includes the types of thermal heating mode: conventional furnace-heating and microwave-heating. The experimental designs applied in fabricating the activated carbons from the oil palm wastes are discussed. Overall, this review paper assists researchers to move forward in exploring a simple and economically-viable technique to produce oil palm wastes-based activated carbon with outstanding physiochemical properties and excellent adsorption capacity. [ABSTRACT FROM AUTHOR]

Abstract: CO2 (Carbon dioxide) emissions are one of the greenhouse gases that cause global warming. The power generation industry is one of the main emitters of CO2, and the emissions are expected to increase in the coming years as there seems to be no abatement in the consumption of fossil fuels for the production of electricity. Thus, there is a need for CO2 adsorption technologies to mitigate the emissions. However, there are several disadvantages associated with the current adsorption technologies. One of the issues is corrosion and the need for specialized equipment. Therefore, alternative and more sustainable materials are sought after to improve the viability of the adsorption technology. In this study, several types of agricultural wastes were used as activated carbon precursors for CO2 adsorption process in a TGA (thermogravimetric analyser). The adsorption was also modelled through a pseudo-first order and second order model, Elovich's kinetic model, and an intra-particle diffusion model. From the correlation coefficient, it was found that pseudo-second order model was well-fitted with the kinetic data. In addition, activation energy below than 42 kJ/mol confirmed that the physisorption process occurred. [Copyright &y& Elsevier]

Abstract: Calcination of CaCO3 is a process of producing CaO – a widely used substance in high temperature applications. However, the efficiency of the process depends on the variable involved and the assumption made. Therefore, this paper aims to illustrate the effects of few variables on calcination and carbonation reaction of CaCO3 via thermo-gravimetric analyzer (TGA) in order to optimize the process. In the present work, cockle shells were used as CaCO3 sources. The experimental variables i.e. particle size, heating rate, calcination and carbonation temperature were employed. A minimum of two runs of experiments for each variable were conducted and the standard deviation for all of the runs are found to be less than 1. Analysis of XRD, XRF and EDX indicates the conversion of CaCO3 in cockle shells to CaO after calcination. The optimum adsorptive capacity of synthesized CaO for CO2 at the optimum conditions is 0.72 kg CO2/kg CaO. [Copyright &y& Elsevier]

• K 2 CO 3 -activated carbon is obtained from mixtures of petroleum coke and palm shell. • Facile activation route through mechano-chemical K 2 CO 3 activation has been applied. • Box-Behnken design is used for optimization of yield and CO 2 adsorption capacity. • Optimized activated carbon shows a well-developed porosity and surface morphology. • Porous carbon from blend precursors has superior yield and CO 2 adsorption capacity. In this study, a binary mixture of petroleum coke and palm kernel shell had been investigated as potential starting materials for activated carbon production. Single-stage potassium carbonate (K 2 CO 3) activation under nitrogen (N 2) atmosphere was adopted in this research study. Effect of several operating parameters that included the impregnation ratio (1−3 wt./wt.), activation temperature (600−800 °C), and dwell time (1−2 hrs) were analyzed by using the Box-Behnken experimental design. Influence of these parameters towards activated carbon yield (Y 1) and carbon dioxide (CO 2) adsorption capacity at an atmospheric condition (Y 2) were investigated. The optimum conditions for the activated carbon production were attained at impregnation ratio of 1.75:1, activation temperature of 680 °C, and dwell time of 1 h, with its corresponding Y 1 and Y 2 is 56.2 wt.% and 2.3991 mmol/g, respectively. Physicochemical properties of the pristine materials and synthesized activated carbon at the optimum conditions were analyzed in terms of their decomposition behavior, surface morphology, elemental composition, and textural characteristics. The study revealed that the blend of petroleum coke and palm kernel shell can be effectively used as the activated carbon precursors, and the experimental findings demonstrated comparable CO 2 adsorption performance with commercial activated carbon as well as that in literatures. [ABSTRACT FROM AUTHOR]

• Electrocatalysis is a promising approach for carbon dioxide mitigation. • Utilization of Graphene Oxide-Copper coated Nickel mesh in electrocatalysis process. • Electrocatalysis depends on types of catalyst/electrolyte and catalyst loading. • Ethanol is the main product of heterogeneous electrocatalyst process. The bifunctional Graphene Oxide-Copper (GO-Cu) coated nickel mesh that was fabricated through layer-by-layer approach was used as a working electrode in carbon dioxide (CO 2) electro-reduction process for ethanol production. The findings confirmed smooth and well-dispersed deposition of Cu-nanoparticles onto GO, and less corrosion behavior in 0.1 M potassium carbonate (K 2 CO 3) solution. Besides, linear sweep voltammetry and chronoamperometry analysis was performed to determine the electro-reduction activity of the fabricated electrode. Novelty of this study covers a working electrode production that possesses high durability and stability while maintaining good current and proton conductivity, as well as high efficiency and selectivity towards desirable product. [ABSTRACT FROM AUTHOR]

This study aims to develop an inexpensive, environmentally-friendly adsorbent for capturing CO 2 using coconut shells, widely abundant in Asian agricultural waste. The raw coconut shell adsorbent (CS) has undergone dual functionalization utilizing Chlorella microalgae and magnesium oxide (MgO) to enhance its physicochemical properties. Through dual functionalization, minimizing the loss of surface area and reducing the temperature sensitivity often occurring during CO 2 adsorption is possible. The surface morphology, functional groups, and thermochemical properties of CS-hydrochar were characterized and evaluated. The characterization demonstrates the successful development of the ternary composite (HCS-A-Mg), with a specific surface area of 1045 m2/g and containing nitrogen and metal oxide functional groups. XRD analysis of HCS-A-Mg reveals crystalline peaks at 36.8°, 42.9°, and 63°, confirming the successful impregnation of MgO. The adsorption result showed that HCS-A-Mg exhibits a higher CO 2 adsorption capacity of 2.63 mmol/g, 50% higher than pristine hydrochar (HCS). The adsorption study revealed that the CO 2 adsorption capacity of HCS-A-Mg can be maximized to 3.23 mmol/g at 101 °C and 4.6 bar. Adsorption isotherms shows that the non-linear Sips model best describes the adsorption process, indicating a multilayer adsorption mechanism with profound surface heterogeneity of n = 2.3 for HCS-A-Mg, signifying higher accessibility of gas molecules deep into pores, enabling a variety of adsorption sites for CO 2 binding. Selectivity and reusability studies were conducted to validate the adsorbent applicability for industrial applications. HCS-A-Mg has higher CO 2 /N 2 selectivity by 41–57% and 0.05% loss of adsorption capacity after the 10th cyclic operation, suggesting their suitability for industrial applications. This finding underscores the potential of microalgae and magnesium oxide in advancing carbon capture technology and addressing environmental challenges. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper investigates the integrated catalytic adsorption (ICA) steam gasification of palm kernel shell for hydrogen rich gas production using pilot scale fluidized bed gasifier under atmospheric condition. The effect of temperature (600–750 °C) and steam to biomass ratio (1.5–2.5 wt/wt) on hydrogen (H2) yield, product gas composition, gas yield, char yield, gasification and carbon conversion efficiency, and lower heating values are studied. The results show that H2 hydrogen composition of 82.11 vol% is achieved at temperature of 675 °C, and negligible carbon dioxide (CO2) composition is observed at 600 °C and 675 °C at a constant steam to biomass ratio of 2.0 wt/wt. In addition, maximum H2 yield of 150 g/kg biomass is observed at 750 °C and at steam to biomass ratio of 2.0 wt/wt. A good heating value of product gas which is 14.37 MJ/Nm3 is obtained at 600 °C and steam to biomass ratio of 2.0 wt/wt. Temperature and steam to biomass ratio both enhanced H2 yield but temperature is the most influential factor. Utilization of adsorbent and catalyst produced higher H2 composition, yield and gas heating values as demonstrated by biomass catalytic steam gasification and steam gasification with in situ CO2 adsorbent. [ABSTRACT FROM AUTHOR]

The present study investigates the optimization of hydrogen (H2) production with in-situ catalytic adsorption (ICA) steam gasification by using a pilot-scale fluidized bed gasifier. Two important response variables i.e. H2 composition (in percent volume fraction, %) and H2 yield (in g kg−1 of biomass) are optimized with respect to five process variables such as temperature (600 °C–750 °C), steam to biomass mass ratio (1.5–2.5), adsorbent to biomass mass ratio (0.5–1.5), superficial velocity (0.15 m s−1–0.26 m s−1) and biomass particle size (350 μm–2 mm). The optimization study is carried out based on Response Surface Methodology (RSM) using Central Composite Rotatable Design (CCRD) approach. The adsorbent to biomass mass ratio is found to be the most significant process variables that influenced the H2 composition, whereas temperature and biomass particle size are found to be marginally significant. For H2 yield, temperature is the most significant process variables followed by steam to biomass mass ratio, adsorbent to biomass mass ratio and biomass particle size. The optimum process conditions are found to be at 675 °C, steam to biomass mass ratio of 2.0, adsorbent to biomass mass ratio of 1.0, superficial velocity of 0.21 m s−1 that is equivalent to 4 times the minimum fluidization velocity, and 1.0 mm–2.0 mm of biomass particle size. The theoretical response variables predicted by the developed model fit well with the experimental results. [ABSTRACT FROM AUTHOR]