Hamzah Fansuri

Mechanical Properties of MIRHA-Fly Ash Geopolymer Concrete

This paper provides a report about the results of an investigation carried out to understand the effect of Microwave Incinerated Rice Husk Ash (MIRHA) on the mechanical properties of fly ash geopolymer concrete to access the concrete performance development. Fly ash (350kg/m3) and MIRHA (0%, 3%, and 7%) were used as the source materials to replace cement, NaOH and Na2SiO3 solutions used as the alkaline liquids for the medium of polymeric reaction. In addition, sugar was used as retarder, as well as three different types of curing regime (ambient, external exposure or oven curing regime). The concrete mixing procedure was adjusted to obtain the proper homogeneity of dry materials and wet ones. In this project, a number of mechanical tests have been conducted including the pull-out test, compressive strength test, flexural strength test, and modulus of elasticity test. It was then observed that the performance of mechanical properties of MIRHA-fly ash geopolymer concrete improved with the use of oven curing as the curing regime for the concrete samples.

The modification of M41S materials: addition of metal clusters and nanoparticles

The incorporation of various molecular metal clusters, with well defined stoichiometry, into M41S materials has been investigated. The grafting of simple metal clusters, such as [Ru3(CO)12] and [PPN]2[Fe4(CO)13], and the larger, and in one instance, bimetallic, clusters [(dppe)2Cu][Cu6Fe4(CO)16] and [PPh4][Ru10(μ6-C)(μ-H)(CO)24] has been achieved. Nanoparticles containing iron and platinum were also anchored on silaceous supports. The proportion of iron to platinum in FePt nanoparticles was adjusted by altering the molar ratios of starting materials. Consequently, ratios of Fe : Pt of 20 : 80, 27 : 73, 40 : 60, 53 : 47 and 64 : 36 were examined. The materials produced in this manner were characterised by Powder X-ray Diffraction (XRD), BET surface areas and Transmission Electron Microscopy (TEM) and elemental analysis. The FePt materials were also investigated for their magnetic properties by SQUID magnetometry. A number of the metal containing materials were investigated for their potential to produce hydrocarbons in the Fischer–Tropsch synthesis.

The Relationship Between Structural and Catalytic Activity of α and γ-Bismuth-Molybdate Catalysts for Partial Oxidation of Propylene to Acrolein

Bismuth-molybdate catalysts are known to be effective for catalytic partial oxidation of propylene to acrolein. Their properties and the kinetics and reaction mechanisms for acrolein production have been extensively studied, especially in their basic forms, such as α, β, and γ-bismuth-molybdate. Although the reaction mechanisms have been reported widely in the literature, a general agreement has not been reached, especially from a catalyst-structure point of view. The present contribution reports an effort to understand the structural changes of α and γ-bismuth-molybdate catalysts at varying temperatures as examined using high temperature XRD and to relate the catalyst performance (activity and selectivity) for propylene partial oxidation to acrolein. The XRD analysis was performed at temperature between 250 and 450°C in ambient atmosphere and the Rietveld refinement method was used to extract unit cell parameters. The results showed a distinct similarity between the shapes of the thermal expansion of the catalysts and their activity and selectivity curves, indicating a significant role that the catalyst interatomic structure plays in the overall reaction mechanism.

The Effect of Pb2+ and Cd2+ Addition to Mechanical Properties of Fly Ash Geopolymer Paste

Immobilization of heavy metal ions using geopolymer paste is a promising way to solve the problem with heavy metal waste from industries. This research focused on the immobilization of Pb2+ and Cd2+ which are common heavy metal waste with distinctive cation size. The cations were immobilized by geopolymerization process to form geopolymer paste. The paste was prepared by using fly ash from a power plant in Cilacap, Indonesia, with SiO2/Al2O3 ratio = 3 and S/L = 1.6. According to XRF analysis, the ash is type C fly ash and additional Al(OH)3 was needed to achieve the SiO2/Al2O3 ratio. A solution of Cd2+ or Pb2+ from their respective nitrate salts was added to the geopolymer mixture to make an immobilized Cd2+ or Pb2+ in a fly ash geopolymer matrix. Compressive strength tests showed that the maximum strength was achieved when 3855 ppm of Cd2+ or 765 ppm of Pb2+ was added to the geopolymer mixture. The change of strength is explained to be caused by the filling of geopolymer cavities that were formed during the geopolymerization process. Due to the smaller size of Cd2+ than Pb2+, the strongest geopolymer paste was achieved at higher Cd2+ concentration than Pb2+. X-ray diffraction analyses results show that the addition of Cd2+ or Pb2+ shift the position on hump to larger 2θ.

Preparation of La 0.7 Sr 0.3 Co 0.2 Fe 0.8 O 3-δ (LSCF 7328) by Combination of Mechanochemical and Solid State Reaction

Structure evolution and morphology of La0.7Sr0.3Co0.8Fe0.2O3-δ (LSCF 7328) were investigated during two different preparation methods namely mechanochemical and combination of mechanochemical-solid state. The result shows that no characteristic peak of perovskite oxide was found on the diffractogram of the product of sole mechanochemical method at 600 rpm and up to 12 h of high energy milling process. On the other hand, the manual grinding method that was followed by solid state calcination produces irregular particle size. Due to the result, the combination of both methods was proposed to obtain the fine structure formation and particle size distribution. Rietveld refinement was used to investigate the lattice distortion. It was found that unit cell remains unchanged at increasing milling time. Moreover, the combination method produces regular particle size at milling time of 0.5 h. At longer milling time, the more regular particle size is formed which comes from highly energy transfer of milling.

Cd2+ and Cr3+ Cation Immobilization by Using Geopolymer Based on PT. IPMOMI Fly Ash

This study investigates the immobilization of Cd2+ and Cr3+ by using geopolymer paste based on PT. IPMOMI fly ash. The best composition of geopolimers paste was determined based on the highest magnitude of its 7 days compressive strength. Geopolymer pastes were prepared by varying SiO2/Al2O3 and Na2O/SiO2 molar ratio of the starting materials. X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) were employed to examined these compositions. The molar ratio of SiO2/Al2O3 6.46 was found to produce the highest compressive strength of the resulting geopolymer paste, i.e 25 MPa and increased to 33.17 MPa by adjusting the ratio of Na2O/SiO2 to 0.65. Cd2+ and Cr3+ cations were added into geopolymers resin at the level of 1000 – 16000 ppm (mg/kg fly ash) and it was found to improve their compressive strength. The addition of 4000 ppm of Cd2+ increased the compressive strength to 38.6 MPa while the inclusion of 6800 ppm of Cr3+ reached 47.83 MPa. Further addition of cations reduced these values and the lowest compressive strength was observed on the addition of 16000 ppm of Cd2+ and Cr3+, i.e 8.65 MPa and 4.39 MPa, respectively. Leaching test was conducted by using Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) and the distribution of heavy metal cations were examined by using SEM-EDX. The results showed that geopolymer pastes were able to immobilize Cr3+ at the studied level as there was no trace of Cr3+ detected after 6.5 hours of leaching. Geopolymer pastes were also found to completely immobilize Cd2+ at the level of 1000 ppm albeit the addition of 16000 ppm results in 6.26% leached out of this cation.

Solvothermal and electrochemical synthetic method of HKUST-1 and its methane storage capacity

A comparison synthetic strategy of Metal-Organic Frameworks, namely, Hongkong University of Techhnology-1 {HKUST-1[Cu3(BTC)]2} (BTC = 1,3,5-benzene-tri-carboxylate) through solvothermal and electrochemical method in ethanol:water (1:1) has been conducted. The obtained material was analyzed using powder X-ray diffraction, Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Thermo-Gravimetric Analysis (TGA) and Surface Area Analysis (SAA). While the voltage in the electrochemical method are varied, ranging from 12 to 15 Volt. The results show that at 15 V the texture of the material has the best degree of crystallinity and comparable with solvothermal product. This indicated from XRD data and supported by the SEM image to view the morphology. The thermal stability of the synthesized compounds is up to 320 °C. The shape of the nitrogen sorption isotherm of the compound corresponds to type I of the IUPAC adsorption isotherm classification for microporous materials with BET surface area of 629.2 and 324.3 m2/g (for solvothermal and electrochemical product respectively) and promising for gas storage application. Herein, the methane storage capacities of these compounds are also tested.

AMMONIUM REMOVAL USING BATCH AND FIXED BED COLUMN BY ZEOLITE A-CARBON SYNTHESIZED FROM COAL BOTTOM ASH

Bottom ash is coal ash waste released due to the usage of coal in the electric power plant. According to data reported by Ministry of Environment Indonesia, bottom ash waste was about 58 ton/day (Said, 2010). The coal ash waste is clasified as hazardous and dangerous waste under Indonesian regulation (PP85/1999), because it could cause self burning and negative impact to human health. Therefore, the ash waste must be utilised such as by converting the ash to become zeolite-carbon. On the other hand, ammonium is one of the significant contaminant of wastewater. The excessive presence of ammonium could cause eutrophication of stuaries, rivers, lakes and coastal seas, corrosion or biological fouling problem in industrial water system (Widiastuti et al, 2011). Zeolite is a potensial material to remove ammonium from wastewater. The zeolite framework generates one negative charge on the framework owing to the substitution of aluminum (Al3+) atom for silicon (Si4+) in the three dimensional framework of aluminosilicate tetrahedral (Englert and Rubio, 2005). The negative charge in the zeolite framework is balanced by cations such Na+, that can be exchanged by the ammonium ion. Zeolite A is a type of zeolite that has Si/Al ratio of 1 resulting in high ion exchange. This research focuses on the effectiveness of ammonium removal using batch and fixed bed column by zeolite A-carbon synthesized from coal bottom ash. The zeolite A-carbon was synthesized by fusion method in nitrogen atmosphere followed by a hydrothermal treatment (Yanti, 2009). Adsorption capacity of the synthesized zeolite was determined in batch by varying contact time (Figure 1), initialconcentration of ammonium and pH. The theoritical aspect of adsorption including adsorption isotherm and kinetics were also studied (Table 1).

Adsorption of Cu(II) Ion on Zeolite A Synthesized from Coal Bottom Ash in Fixed Bed Column System

Coal usage as a source of energy in Indonesia is increasing nowdays. In 2003, the usage of coal in the electric power plant was about 14.1% of total energy and in 2025, it will be over 34.6% (Yanti, 2009). The increase in coal usage causes the increase of coal ash waste, which was up to 500-1000 ton per day (Said, 2010). The discharged coal waste may cause self burning or self exploding and have negative effect to human health. Therefore, under Indonesian regulation (PP85/1999), coal ash is clasified as hazardous and dangerous waste (Said, 2010).In order to reduce the piling up, coal ash must be utilised. One of potential utilization of coal ash is to convert the ash to become zeolite minerals.