Nor Aishah Saidina Amin

Pretreatment of empty palm fruit bunch for production of chemicals via catalytic pyrolysis

The effect of chemical pretreatments using NaOH, H(2)O(2), and Ca(OH)(2) on Empty Palm Fruit Bunches (EPFB) to degrade EPFB lignin before pyrolysis was investigated. Spectrophotometer analysis proved consecutive addition of NaOH and H(2)O(2) decomposed almost 100% of EPFB lignin compared to 44% for the Ca(OH)(2), H(2)O(2) system while NaOH and Ca(OH)(2) used exclusively could not alter lignin much. Next, the pretreated EPFB was catalytically pyrolyzed. Experimental results indicated the phenolic yields over Al-MCM-41 and HZSM-5 catalysts were 90 wt% and 80 wt%, respectively compared to 67 wt% yield for the untreated sample under the same set of conditions. Meanwhile, the experiments with HY zeolite yielded 70 wt% phenols.

Optimization of levulinic acid from lignocellulosic biomass using a new hybrid catalyst

Conversion of glucose, empty fruit bunch (efb) and kenaf to levulinic acid over a new hybrid catalyst has been investigated in this study. The characterization and catalytic performance results revealed that the physico-chemical properties of the new hybrid catalyst comprised of chromium chloride and HY zeolite increased the levulinic acid production from glucose compared to the parent catalysts. Optimization of the glucose conversion process using two level full factorial designs (2(3)) with two center points reported 55.2% of levulinic acid yield at 145.2 °C, 146.7 min and 12.0% of reaction temperature, reaction time and catalyst loading, respectively. Subsequently, the potential of efb and kenaf for producing levulinic acid at the optimum conditions was established after 53.2% and 66.1% of efficiencies were reported. The observation suggests that the hybrid catalyst has a potential to be used in biomass conversion to levulinic acid.

Microwave assisted biodiesel production from Jatropha curcas L. seed by two-step in situ process: Optimization using response surface methodology

The synthesis of fatty acid ethyl esters (FAEEs) by a two-step in situ (reactive) esterification/transesterification from Jatropha curcas L. (JCL) seeds using microwave system has been investigated. Free fatty acid was reduced from 14% to less than 1% in the first step using H2SO4 as acid catalyst after 35 min of microwave irradiation heating. The organic phase in the first step was subjected to a second reaction by adding 5 N KOH in ethanol as the basic catalyst. Response surface methodology (RSM) based on central composite design (CCD) was utilized to design the experiments and analyze the influence of process variables (particles seed size, time of irradiation, agitation speed and catalyst loading) on conversion of triglycerides (TGs) in the second step. The highest triglycerides conversion to fatty acid ethyl esters (FAEEs) was 97.29% at the optimum conditions:<0.5mm seed size, 12.21 min irradiation time, 8.15 ml KOH catalyst loading and 331.52 rpm agitation speed in the 110 W microwave power system.

A review on removal of pharmaceuticals from water by adsorption

Pharmaceuticals and personal care products are recognized as emerging pollutants in water resources. Various treatment options have been investigated for the removal of pharmaceuticals that include both conventional (e.g., biodegradation, adsorption, activated sludge) and advanced (e.g., membrane, microfiltration, ozonation) processes. This article reviews literature for adsorptive removal of pharmaceuticals from water sources. Adsorbents from various origins were reviewed for their capacity to remove pharmaceuticals from water. These adsorbents include carbonaceous materials, clay minerals, siliceous adsorbents, and polymeric materials. The adsorption capacity of adsorbents to adsorb pharmaceuticals from water is discussed in this study. The review discusses the mechanism for adsorption of pharmaceuticals onto adsorbents as well. Finally, effectiveness of processing parameters during adsorption processes is presented.

Recent advances in reactors for low-temperature Fischer-Tropsch synthesis: process intensification perspective

Abstract The low-temperature Fischer-Tropsch (LTFT) process aims to produce heavy cuts such as wax and diesel. For many years, there have been studies and improvements on the LTFT process to make the existing reactors more efficient. Recent studies have proposed innovative configurations such as monolithic loop and membrane reactors as well as microchannel reactor, which improved the performance of LTFT synthesis. This persuades us to update the existing knowledge about the available reactors. Some fundamental features of the current reactors, which belong to the classes of conventional reactors (fixed-bed reactors and slurry reactors) and innovative reactors, are discussed to assist the selection of the most efficient reactors specifically for heavy-cuts production. Published experimental and theoretical works with respect to developments in reactor technology and significant advances in catalysis (such as using structured packing, foams, and knitted wire as catalyst supports due to their excellent radial mixing properties) of the FT process are analyzed and discussed. Consequently, it is shown that the LTFT innovative reactors have higher CO conversions and selectivity of desired heavy cuts. Furthermore, the place of innovative reactors among conventional reactors in terms of effective process parameters on the product distribution has been estimated.

Optimization of lignin production from empty fruit bunch via liquefaction with ionic liquid

The production of lignin from empty fruit bunch (EFB) has been carried out using liquefaction method with 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) ionic liquid (IL), in presence of sulfuric acid (H2SO4) as a catalyst. Response surface methodology (RSM) based on a factorial Central Composite Design (CCD) was employed to identify the optimum condition for lignin yield. The result indicated that the second order model was adequate for all the independent variables on the response with R(2)=0.8609. The optimum temperature, time, ionic liquid to EFB ratio, and catalyst concentration were 150.5 °C, 151 min, 3:1 wt/wt and 4.73 wt%, respectively for lignin yield=26.6%. The presence of lignin liquefied product was confirmed by UV-Vis and FTIR analysis. It was also demonstrated lignin extraction from lignocellulosic using recycled IL gave sufficient performance.

Dual-Bed Catalytic System for Direct Conversion of Methane to Liquid Hydrocarbons

The feasibility of upgrading natural gas that primarily consists of methane to valuable chemicals, especially liquid fuel has been investigated for years. However, the high cost and inefficient processes have hampered the widespread exploitation of natural gas. Accordingly, a system comprising of a dual-bed catalytic has been investigated in this study to overcome the limitations and permit the direct conversion of methane to liquid hydrocarbons. In this dual-bed system, methane is converted in the first stage to Oxidative Coupling of Methane(OCM) products over La/MgO and the second bed comprises of H-ZSM-5 that has been tested as an oligomerization function to convert the OCM products to liquid hydrocarbons. The influence of SiO2/Al2O3 ratio of H-ZSM-5, temperature and CH4/O2 ratio on the process has been studied. The results implied that the Bronsted acid sites of H-ZSM- 5 were the active centers responsible for the oligomerization of primary ethylene products. Oxygen was absolutely necessary for the formation of the methyl radicals from methane, but it should be provided at a controllable manner in order to avoid undesired oxidation. The partial destruction and dealumination of H-ZSM-5 at higher temperature had caused the deactivation of the H-ZSM-5 catalyst for the oligomerization reaction. Investigation on the catalytic activity of various metals loaded H-ZSM-5 showed that incorporating nickel into H-ZSM-5 significantly enhances the yield of liquid hydrocarbons. The central composite design (CCD) coupled with response surface methodology (RSM) was successfully applied to map the response and to obtain the optimal reaction design. The results indicated that the optimum C5+ yield of 8.91% was attained at reaction temperature = 742 ÂoC, CH4/O2 ratio = 9.7 and Ni loading = 0.67 wt%. This exploration suggests that the concept of this dual-bed catalytic system is an interesting candidate for application in methane utilization to produce liquid hydrocarbons

Synthesis and characterization of carbon cryogel microspheres from lignin–furfural mixtures for biodiesel production

The aim of this work was to study the potential of biofuel and biomass processing industry side-products as acid catalyst. The synthesis of carbon cryogel from lignin-furfural mixture, prepared via sol-gel polycondensation at 90°C for 0.5h, has been investigated for biodiesel production. The effect of lignin to furfural (L/F) ratios, lignin to water (L/W) ratios and acid concentration on carbon cryogel synthesis was studied. The carbon cryogels were characterized and tested for oleic acid conversion. The thermally stable amorphous spherical carbon cryogel has a large total surface area with high acidity. Experimental results revealed the optimum FAME yield and oleic acid conversion of 91.3wt.% and 98.1wt.%, respectively were attained at 65°C for 5h with 5wt.% catalyst loading and 20:1 methanol to oleic acid molar ratio. Therefore, carbon cryogel is highly potential for heterogeneous esterification of free fatty acid to biodiesel.

Progress in Reactors for High-Temperature Fischer–Tropsch Process: Determination Place of Intensifier Reactor Perspective

Abstract High-temperature Fischer–Tropsch (HTFT) process aims to produce lighter cuts such as gasoline and diesel. For many years there have been studies and improvements on HTFT process to make the existing reactors more efficient. Recent studies proposed new configurations such as dual-type membrane reactor and coupling configurations reactor, which improved the performances of this process. This achievement persuades us to update the existing knowledge about the available reactors for HTFT process. In this article, features and performances overview of two classes of reactors are reviewed. The first class consists of the reactors which are based on older studies, and the second one includes recent studies which are called product intensifier reactors. Finally, it is shown that the product intensifier reactors have higher CO conversions and lower selectivity of undesired by-products which results in higher production yield of gasoline. Furthermore, the place of product intensifier reactor among common reactors with regard to the influence of the process parameters on the product distribution has been estimated.

Complex gas - Liquid reactions: Feedback from bulk liquid to liquid - Side film

Abstract The extensive literature on gas-liquid reactions has, with a few exceptions, been devoted to reactions that are considered to be completed entirely in liquid film or bulk liquid for the sake of simplification of modeling and design. A different perspective for modeling of gas-liquid reactors is provided here considering multiple (series-parallel) reactions occurring over the entire liquid phase, with at least one species participating in the reaction scheme being volatile. The two-way linkages between liquid film and bulk liquid are properly accounted for in the present approach. The dispositions of concentration profiles for reactant and product species in the liquid film are presented and discussed for a perfectly mixed reactor. The implications of these dispositions on parameters such as augmentation and enhancement factors and distribution of the extent of a reaction between liquid film and bulk liquid are discussed. Expressions for species concentrations in different portions of the two phases are obtained analytically for linear kinetics. Numerical illustrations demonstrate that an unwarranted confinement of liquid phase reactions to either liquid film or bulk liquid can lead to incorrect design of and erroneous prediction of performance of gas-liquid reactors. Variation in relative importance of reactions in liquid film with respect to reactions in bulk liquid with variations in process parameters and effectiveness of the reactions in the presence of mass transfer resistances are also examined.