Husna Mohd Zain

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.

Adsorption isotherm breakthrough time of acidic and alkaline gases on treated porous synthesized KOH-FeCl3.6H2O sustainable agro-based material

Poisoning gases are very harmful when smelled and even low concentrations of the gases are can be lethal. The gases are widely used in various industries. Activated carbon (AC) can be useful to filter the gases. AC derived from local agricultural by-product materials can be used as adsorbent instead of using commercial activated carbon (CAC) for application in safety respiratory devices like gas masks. The study was carried out to produce AC derived from palm kernel shell (PKS) and to determine the breakthrough and saturation time adsorption isotherm of SO2, NH3 and O2 on the AC produced. The preparation of AC involved two main steps which are carbonization and activation process. After carbonization process, the resulted char (PKS-char) was then impregnated with Potassium Hydroxide(KOH) and Ferric chloride hexahydrate (FeCI3.6H2O) followed by activation process using microwave heating. The prepared AC (PKAC-KOH-FECI3) was characterized by Thermo-gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Nitrogen adsorption isotherm. Breakthrough adsorption study was conducted in a stainless-steel reactor which loaded with 3.6 g of activated carbon for each run. The saturation time results were determined from the Yoon equation. From the adsorption breakthrough results, the PKAC-KOH-FeCI3 produced 51 s, 100 s, and 6.33 s breakthrough time for SO2, NH3, and O2 adsorption. The saturation time of PKAC-KOH-FeCI3 for SO2, NH3, and O2 adsorption were 16,947 s, 33,461 s, and 2,094 s. The results revealed that AC prepared from PKS treated with KOH-FeCI3 can be further developed as potential adsorbent for the gas phase applications.

CO2 adsorption isotherms on KOH, H3PO4 and FeCl3.6H2O Impregnated palm shell kernel activated carbon

Commercial sorbents available are expensive as a result of using high cost and non-renewable materials as precursors. It is imperative to select cheap, viable and sustainable carbon source for production of adsorbents for subsequent use in adsorption applications. Palm kernel shell char was obtained by carbonisation process at 730 °C ± 20 °C for 2 h with 10 °C/min heating rate under inert gas flow. The bio-char obtained was further grinded and sieved to 0.5 to 0.85 mm, then treated and synthesised separately each sample by KOH, H3PO4 and FeCl3.6H2O solution with ratio 1 : 1 weight ratio and followed by microwave treatment technique. Samples treated with chemicals used were named as PKS-POT (Palm Kernel Shell with Potassium Hydroxide ), PKS- PAP (Palm Kernel Shell with Phosphoric acid) and PKS-FER(Palm Kernel Shell with Ferric chloride hexahydrate). CO2 gas was used during the adsorption and desorption study. Samples were characterised by Brunauer–Emmett–Teller (BET), scanning electron microscope (SEM) and Fourier transform infraredspectroscopy (FTIR). PKS-POT showed highest BET surface area (208.7037 m2/g) and pore volume (0.06580 cm3/g). PKS-POT’s SEM result also confirms large surface area, pores and more compact of the shell structure which related to high adsorption capacity compared to PKS-PAP and PKS-FER. CO2 PKS-POT, PKS-PAP and PKS-FER adsorption capacities were 2.19, 0.62 and 1.25 mmol/g and no CO2 gas left for the end desorption phase. From the study concluded that sustainable palm kernel shell material was successfully achieved to obtain the high surface area, high porosity and high adsorption sorbent capacity.

Sustainable Recycle Solid Waste to Synthetic Renewable Solid Energy

Renewable energy is a source of energy that can be recovered and recycled. The recyclable material is removed first before energy is recovered from the residual waste. In this study, the effect of pyrolysis temperature on the calorific value of sustainable materials and gas emission quality were carried out. Pyrolysis and non-pyrolysis processes were initially conducted before calorific value determination. Calorific values of the samples were measured by bomb calorimeter. The sample that contains the highest calorific value was chosen and compared with coal. Testing of the prepared samples was accomplished using combustion process. The characterizations of the samples were determined by TGA analysis, SEM, FTIR and elemental analysis. From the results obtained, it is observed that the calorific value of sustainable material depends on the number of hydrogen, carbon and thermal energy.

Enhancing Sustainable Recycle Solid Waste to Porous Activated Carbon for Methane Uptake

Potential agro wastes (i.e palm kernel shell and coconut shell) for producing low cost activated carbon (AC) was investigated. In this study, the activated carbon was produced by carbonization, chemical impregnation with KOH and microwave irradiation. The pyrolysis was carried out at 700 °C in an inert environment for 2 h. Microwave activation was carried out at 400W for 6 minutes. Characteristics of the material were investigated using Fourier transform infrared spectroscopy (FT-IR) analysis and scanning electrode microscopy (SEM). Methane adsorption equilibrium data on the activated carbons produced were obtained using static volumetric method. Microwave palm shell activated carbon (MPAC) and microwave coconut shell activated carbon (MCAC) recorded highest methane uptake of 2.489 and 1.929 mmol/g at 3 bar, 30°C. The adsorption data were correlated with Langmuir and Freundlich isotherms. The results shows that microwave activated carbon from palm shell and coconut shell have good methane adsorption characteristics.