Noor Shawal Nasri

Preparation and Characterization of Green Porous Palm Shell Based Activated Carbon by Two Step Chemical Activation Using KOH

The large quantity of agricultural waste materials that poses disposal challenge to our environment could be converted into useful products such as activated carbon (AC). Palm oil shell based porous AC was prepared by two step process using KOH as the chemical activant. Palm oil shell was carbonized at 800°C for 2 hours and activated using CO2 at same temperature for 1 hour which yield 23.27% fixed carbon. The AC was characterized by Langmuir surface area, BET surface area and pore volume of 410.7 m2/g, 350 m2/g and 0.2 cm3/g respectively, the FTIR analysis identified the presence of alkanes, carbonyls and hydroxyls as the main functional groups in the AC. Scanning electron microscopy images illustrates the gradual formation of pores from the precursor to the produced AC due to elimination of volatiles and contaminants in the material. However, the AC produced showed basic properties suitable for the removal of hydrophobic organic contaminants in water and wastewater.

Comparison on the characteristics of bio-based porous carbons by physical and novel chemical activation

There is significantly abundant portion of waste agricultural materials in the world serving as environmental challenge, however, they could be converted into useful value added products like activated carbon. Coconut shell based carbons were synthesized using physical activation by CO2 and chemical activation with potassium hydroxide and potassium acetate. The BET surface areas and pore volumes are 361m2/g and 0.19cm3/g for physical activation, 1353m2/g and 0.61cm3/g for activation with KOH and 622m2/g and 0.31cm3/g for potassium acetate activated carbon. From the Fourier Transform Infrared Spectroscopy analysis, hydroxyls, alkenes and carbonyl functional groups were identified with more prominence on the chemically activated porous carbons. Thermogravimetric analysis (TGA) results showed occurrence of moisture pyrolysis at 105°C, the pyrolysis of hemicellulose and cellulose occurred at 160–390°C and lignin at (390-650°C). Carbonization at 700°C and 2hrs had highest yield of 32%. Physical activation yielded lower surface area with approximately 88% micropores. On the other hand, chemically activation yielded higher surface area with elevated mesopores. The porous carbons can be applied to salvage pollution challenges.

Optimization of preparation of microwave irradiated bio-based materials as porous carbons for VOCs removal using response surface methodology

Effluents from various industries release volatile organic compounds (VOCs) into the environment which causes serious environmental problems. Coconut shell based porous carbons (CSPC) were synthesized with potassium hydroxide as activating agent for adsorption of Benzene and Toluene. Central composite design (CCD) method under the response surface methodology (RSM) of the Design expert software version 7.1.6. was employed in the optimization of the preparation conditions of the porous carbons. The effects of three preparation variables (i.e. microwave power, irradiation time and KOH impregnation ratio) on Benzene and Toluene adsorption were studied. Based on the CCD, quadratic models were developed to correlate the preparation variables to the responses (Benzene and Toluene adsorption). The influence of process parameters on the properties of CSPC was examined using analysis of variance (ANOVA) to identify the significant parameters. The optimum condition was obtained at microwave power of 500W; irradiation time 4mins; and 1.5 KOH impregnation ratio, which resulted in 84% of Benzene and 85% of Toluene respectively at 95% yield.

CO2 adsorption equilibria on a hybrid palm shell-PEEK porous carbons

CO2 emission is attributed to be the major contributing factor for global warming. In this work, hybrid porous carbons were prepared by K2CO3 microwave assisted activation of palm shell with polyetheretherketone (PEEK). The Porous carbons (M4P2 and M5P2) were investigated as potential sorbents for CO2 capture at various temperatures. The ideal CO2 adsorption capacities of porous carbons were determined using volumetric method at temperatures of 303.15 and 243.15, 378.15 and 443.15 K and pressures (1-4 bar). CO2 uptake of 2.97 and 2.55 mmol CO2 adsorbed/g adsorbent was achieved by M4P2 and M5P2 sorbents at 30 °C and 1 bar. The experimental data of the CO2 adsorption on the porous carbons were correlated by the Freundlich, Langmuir, Toths and Sips isotherm models. Sips adsorption isotherm model fits the data better with higher correlation coefficient and low root mean square deviation (RSMD) at all temperatures. CO2 adsorption was faster initially and then subsequently decreased with time. The findings revealed the potential of palm shell-PEEK as sorbents for CO2 adsorption applications.

Synthesis and Characterization of Low-Cost Porous Carbon from Palm Oil Shell via K2CO3 Chemical Activation Process

The abundant fraction of agricultural waste materials in the environment that poses disposal challenge could be converted into useful value added products such as activated carbon. Palm oil shell based carbon was prepared by two step process using K2CO3 as the chemical activant. The Langmuir surface area, BET surface area and pore volume were 817 m2/g, 707m2/g and 0.31cm3/g. From the FTIR analysis, carbonyls, alkenes and hydroxyls were identified. The SEM image shows gradual formation of pores due to elimination of volatiles and contaminants. Carbonization at 800°C for 2 hours and activation at same temperature for 1h has the highest yield of 23.27%. The proximate and ultimate analysis shows high percentage of carbon and low percentage of ash which is an indication of a good material for production of porous carbon. The activated carbon produced showed basic properties suitable for removal of organic contaminants in aqueous solutions. However, the aim of this study is to produce a green and porous carbon with controlled pores and surface properties for organic contaminants removal from water and wastewater.

Anticorrosion Performance of Zinc Ferrite Pigmented Lignin/Phenol Epoxy Novolac Resin Based Coating

Corrosion in most processing equipment has always been a key research area. It is an important threat that needs to be prevented and controlled. Application of epoxy-based coatings on the surfaces of metallic parts is among the preventive measures but it is toxic and expensive. In this work, the anticorrosion performance of zinc ferrite pigmented bio-based epoxy-novolac coatings was studied. Initially, bio-based novolac resins were prepared by condensation from the reaction between phenol, bio-oil phenolic fractions and formaldehyde in an acidic medium. The prepared novolac was later transformed to epoxide with epichlorohydrine and 30 percent sodium hydroxide solution. The final coating formulation was obtained by mixing the prepared epoxy with zinc ferrite (a nontoxic anticorrosion pigment) and solvent. Anticorrosion tests using the formulated coatings and two other conventional coatings for comparison were conducted by simulating actual field conditions in a closed autoclave loop system that used 3 percent sodium chloride and water medium. The results showed that the zinc ferrite pigmented bio-based formulated coatings are very efficient in protecting the substrates since they exhibit similar protection ability with the conventional ones. The prepared epoxy can be said to be an eco-friendly and cheap source of resin for coating formulation that will reduce production cost and negative environmental effects as compared to conventional materials

Methane adsorption on KOH microwave treated porous carbon from sustainable coconut solid waste material

The shorter driving range is the challenge of compressed natural gas (CNG) as a vehicular fuel. In this study, adsorbent is prepared from coconut shells using KOH microwave activation to overcome the challenge of CNG storage system. The CNG storage system has some disadvantages which include high-pressure operation with less safety guard, and heavy storage cylinders. The adsorbent is used as a potential Sorbent for methane (CH4) storage at different pressures. The coconut shell was carbonized from ambient temperature to 700 ± 20 oC at 10oC min-1 heating rate with 1 L min-1 N2 flow rate. The carbonization temperature of the precursor was determined using thermo-gravimetric and derivative thermogravimetric (TG/DTG) analysis. The activation was achieved with well modified microwave equipment operated at 500W and 5 minutes. The CH4 adsorption characteristics were conducted using volumetric adsorption equipment at an ambient temperature and pressures of 4, 5 and 7 bar. The CH4 uptake achieved at 4, 5 and 7 bar are 2.9707, 3.0559 and 3.6685 mmol g-1. The experimental data simulated using two common adsorption models: Langmuir and Freundlich. The experimental data was also evaluated using the common adsorption kinetic namely pseudo-first order, pseudo- second, order kinetics and Elovich. For the three initial pressures of 4, 5 and 7 bar, CH4 adsorption show more fits to pseudo-second order with R2> 0.967, R2 > 0.967 and R2> 0.960. The results reveal that coconut shell is a viable and sustainable material for synthesizing of the adsorbents for methane adsorption.

Comparative Study of Natural Gas Adsorption Isotherms on Koh and H3po4 Palm Kernel Shells Porous Activated Carbon

Sustainable energy of Natural Gas (NG) has been an increasingly valuable and advantageous fossil fuel as it produces a cleaner combustion, and efficient consumption. Compressed Natural Gas (CNG) storage method and its utilisation has caused several problems due to high cost of installation for extensive 25.86 MPa high- pressure bulky cylinder, internal cylinder corrosion, and the possibility of releasing an explosive compressed gas. Adsorb Natural Gas (ANG) storage as a new technology, where natural gas is adsorbed in a suitable adsorbent with high porosity to increase the volume of gas stored in the vessel at lower pressure 3.45 – 5.52 MPa is a promising alternative. The energy density stored in ANG storage system is greater than the CNG vessel at the same pressure. Solid sustainable material of Palm Kernel Shell (PKS) was treated chemically to obtain adsorbent media to determine its adsorption and desorption rate performance at certain pressure. The adsorbent obtained by treatment with KOH and H3PO4 labelled as PKS-ACB and PKS-ACA. Samples were characterised by SEM, BET, TGA and FTIR. The SEM, BET, TGA and FTIR results showed promising results. The adsorption rate of the first 20 minutes was 0.038 mmol/g.min for PKS-ACA and 0.034 mmol/g.min for PKS- ACB. The desorption rate of PKS-ACA and PKS-ACB was 643 mmol/g.min and 430 mmol/g.min. There was no gas residual left in the sorbent. Findings highlighted that sustainable solid waste materials of palm kernel shell are renewable; its surface property as natural gas adsorbent storage known as ANG.

Sulphur Dioxide and Oxygen Adsorption Isotherm Breakthrough Time on Surface Porous Palm Shell Activated Carbon

Sulphur dioxide (SO2) releases from various industries can affect the environment and human health. Activated carbon has been widely studied in gas and liquid adsorption due to its capability in filtration to remove organic materials and particulate matter. Palm kernel shell (PKS) is an agricultural by-product from palm-oil processing mills. PKS has been used as the based material for the production of activated carbon (AC). The research is aimed to produce AC derived from sustainable palm solid waste and to study the breakthrough time adsorption isotherm of SO2 and oxygen (O2) on the AC. In this study, palm kernel shell activated carbon (PKS-AC) was prepared via carbonisation, impregnation and activation. The dry PKS was carbonised at 700 °C for 2 h in a furnace and was then impregnated with ferric chloride hexahydrate (FECI3.6H2O) in 1 : 5 ratios (ferric chloride hexahydrate to PKS-char). The treated PKS-char was activated through microwave heating at 400 W power level and 6 min irradiation time. The prepared AC were characterised using Thermo-gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Nitrogen adsorption isotherm. Breakthrough adsorption of SO2 and O2 was investigated in a fixed-bed reactor. The results shows that the prepared AC produced 23 and 7.5 s breakthrough time for SO2 and O2 adsorption. In conclusion, AC that produced from agricultural waste via impregnation with ferric chloride and microwave induced can be a new promising method for the production of simple and good quality of AC.

Modelling of cadmium (II) uptake from aqueous solutions using treated rice husk: Fixed - Bed studies

Rice husk is an agricultural waste material obtained mainly from rice mills. Treated rice husk was evaluated as a sorbent for cadmium (II) ions removal from solutions by utilising fixed-bed adsorption mode. In this study, the influence of flow rate (3 and 9 mL/min), adsorbent heights of (0.9, 1.8 and 2.8 cm) and influent cadmium ions concentration of (5 and 20 mg/L) on the sorption capacity of the adsorbent in a fixed-bed column were explored. The highest uptake of 87 % was obtained using 20 mg/L initial Cd (II) solution was achieved at high flow rate of 9 mL/min and a bed height of 2.8 cm. The experimental results obtained from the column adsorption studies were correlated with the Thomas, Yoon–Nelson and Adams–Bohart models. The modelling results for the adsorption indicated that the Adams–Bohart model fitted well over the other models.