Advanced Materials Research Vol. 917

Abstract: There is a need to search for efficient material that reduce CO₂ content and enhance the hydrogen composition in the product gas from biomass steam gasification particularly for large scale production. The present study was carried out to perform the characterization of commercial quicklime as CO₂ absorbent and Ni powder as catalyst. The chemical composition of the materials perform using x-ray fluorescence (XRF) indicated high amount of CaO and Ni in the bulk samples. Using XRF and SEM analyses, it was found that both materials showed high crystalinity. The adsorption isotherm from physisorption analysis suggested that the materials exhibits Type II category according to the IUPAC classification scheme. These types of material exhibit mesoporous structure which was also verified by the pore size of the samples found via BET analysis. The BET surface area reported was 4.16 m²/g and 0.78 m²/g for quicklime and Ni powder, respectively. In conclusion, commercial quicklime has the potential as CO₂ absorbent, based on the pore size and surface area. Conversely, the surface properties of the Ni powder were found relatively lower as compared to other commercial catalysts available for biomass steam gasification.

Abstract: There is a need to search for efficient material that reduce CO₂ content and enhance the hydrogen composition in the product gas from biomass steam gasification particularly for large scale production. The present study was carried out to perform the characterization of commercial quicklime as CO₂ absorbent and Ni powder as catalyst. The chemical composition of the materials perform using x-ray fluorescence (XRF) indicated high amount of CaO and Ni in the bulk samples. Using XRF and SEM analyses, it was found that both materials showed high crystalinity. The adsorption isotherm from physisorption analysis suggested that the materials exhibits Type II category according to the IUPAC classification scheme. These types of material exhibit mesoporous structure which was also verified by the pore size of the samples found via BET analysis. The BET surface area reported was 4.16 m²/g and 0.78 m²/g for quicklime and Ni powder, respectively. In conclusion, commercial quicklime has the potential as CO₂ absorbent, based on the pore size and surface area. Conversely, the surface properties of the Ni powder were found relatively lower as compared to other commercial catalysts available for biomass steam gasification.

Abstract: Carbon dioxide (CO₂) is the major cause of accelerating global warming. It is important to employ efficient method to capture CO₂. Absorption is the most established technique to separate CO₂ and amines are most commonly used as solvent. In this study, density and viscosity of an amine based novel solvent named Stonvent were investigated at temperature ranging from 298.15 K to 338.15 K. CO₂ solubility in Stonvent was measured at varying pressures, temperatures and concentrations. The experiments were conducted at temperatures (303.15, 318.15 and 333.15) K, and at pressures (0.5, 1, 1.5 and 3) MPa over a wide range of concentration (10, 20, 30 and 100) mass %. Solubility of CO₂ was determined from pressure drop due to absorption of CO₂ into solvent within equilibrium cell. Absorption capacity of Stonvent increases significantly with increasing pressure. Solubility of CO₂ in Stonvent is higher compared to Monoethanolamine (MEA), 1-amino-2-propanol (MIPA) and 2-amino-2-methyl-1,3-propanediol (AMPD) at elevated pressure, hence posing Stonvent as an attractive alternative for acid gas absorption in high pressure conditions. Substantial increase in CO₂ loading was observed when concentration of Stonvent is increased and when temperature is decreased.

Abstract: Symmetric and asymmetric polysulfone membranes were fabricated using different of solvents; N-methyl-pyrrolidone (NMP), Tetrahydrofuran (THF) and Dimethylacetamide (DMAC) at different polymer concentration (15 and 20%) to study the influence of varying type of solvents and polymer concentration in membrane fabrication. The membranes were characterized using Field Emission Scanning Electron Microscopy (FESEM), Thermogravimetric Analyzer (TGA), Universal Testing Machine (UTM) and Fourier Transform Infra-Red (FTIR).The results disclosed that the symmetric, higher polymer concentration membrane contributed to better thermal and mechanical stabilities. PSF/THF membrane showed good mechanical strength while PSF/DMAC membrane illustrated great thermal stability. 20% of polymer concentration and PSF/THF membrane led to the thicker skin layer and dense structure formation.

Abstract: Various theoretical models on CO₂ permeation were discussed that included Maxwell model, Bruggeman model, Lewis-Nielson model and Pal model. These models were used for comparing the relative permeance of CO₂ with the previously published experimental data on silica nanoparticles filled polysulfone/polyimide (PSF/PI) mixed matrix membranes (MMMs). The results showed that the deviation was in the increasing order: Lewis-Nielsen model< Maxwell model< Pal model< Bruggeman model. All these models assumed that the fillers are spherical in shape. A scanning electron microscope (SEM) cross-sectional image indicated that the silica particles were prolate ellipsoids that were dispersed in the matrix. To investigate the prolate effect, the Maxwell-Wagner-Sillar (MWS) model was employed. The evaluation from cross-sectional image of the membrane structure indicated that the shape factor along z-direction gave a minimum deviation of 17.52%-20.10% at 2-10 bar feed pressure respectively.

Abstract: Many publications have reported about 37% of major accidents in petroleum, chemical, nuclear, aviation, and in the other process industries that occurred worldwide were due to human error. One of the keys contributing factors that could prevent these accidents is to provide appropriate training to the plant personnel. However, accidents still can happen if training is poorly managed and improperly trained personnel handling the operation of the plant. One of the established industrial standards to manage the training is Training element of Process Safety Management (PSM) 29 CFR 1910.119(g). This paper presents a system to manage training for safe operation following 29 CFR 1910.119(g) namely Operational Training Management System (OPTRAMS). It provides strategies to manage information and documentation related to training. OPTRAMS was implemented at the CO2-Hydrocarbon Absorption System (CHAS) pilot plant at Universiti Teknologi PETRONAS as a case study. The study showed that all operational training can be managed efficiently with OPTRAMS and also assists end users to identify the gaps that hinder training of PSM compliance. The implementation of this technique could help end users to prevent and minimize catastrophic accidents and comply with training of PSM standard.

Abstract: Inherent safety concept has been introduced to overcome the shortcoming of traditional hazard assessments by allowing modification to be made at any stage of lifecycle of a process plant. However, most of the proposed inherent safety modifications were suitable to prevent fire, explosion and toxic hazards assessment but less attention on human and organizational factor. Therefore, this paper introduces the inherently safer analysis for human and organizational factor to be implemented during design stage or process operation. Analytic Hierarchy Process model integrated with fuzzy logic and known as FAHP was employed to rank identified inherently safer strategies. The model was applied to select inherently safer strategies to reduce collision risk of a floating production, storage and offload and the authorized vessel. The result shows that minimization of hazardous procedure when the procedure is unavoidable is the best strategy to increase human performance. It is proven that the proposed methodology is capable to select the inherently safer strategy without requiring a bunch of precise information to transfer expert judgment in human performances perspective.

Abstract: . Carbon dioxide (CO₂) commonly exists as undesirable component in natural gas streams. The continuous growing of the global demand makes it necessary to overcome the high CO₂ content obstacle of stranded reserves. A wide variety of acid gas removal technologies have been developed, including chemical and physical absorption processes but none of them can combine the high efficiency and economic energy consumption. Each process has its own advantages and disadvantages. Using of adsorbents increasingly being selected for newer projects, especially for applications that have large flow, high CO₂ content and located in remote locations such as offshore where compact and highly effective technology is required. This review highlights the importance of adsorbent modification on CO₂ removal from natural gas reserve at high pressure and temperature using physical adsorbents such as zeolite and molecular sieve. Then, the focus is turned on the adsorbents chemical modification using organic amines to improve the adsorption efficiency towards CO₂.

Abstract: In this work, the CO₂ solubility predicted for amines of DEA and MDEA by using the OConnell (1964) expression as a base model. This expression fits between the solvent compositions and the thermodynamic properties beside the gas solubility. The solvent activity coefficient, Gibbs energy and Henrys law constants have been generated using Aspen plus data analysis tools. The self-interaction binary parameters (Margules parameters) have been calculated based on Henry constants values. The data input for this work depends on the amine system process conditions (temperature range between 298.15 K and 393.15 K), materials composition (concentrations of 10 wt%, 20 w% and 30 wt %). For both of the DEA and MDAE and the pressure fixed to be 101.3 KPa. The solubility values of this work give satisfactory results compared to the literature data.

Abstract: Micro-mesoporous mixed oxides containing nickel, cobalt and aluminum have been synthesized using conventional coprecipitation method. FESEM and HRTEM analyses demonstrated the flower and hexagonal plate-like nanostructured of mixed oxides. Different mixed oxide formation, homogenous metal dispersion, textural properties were investigated using XRD, ICP-MS and BET (N₂ adsorption-desorption) techniques. nanostructured mixed oxides exhibited 2.6 wt% hydrogen adsorption that were studied using temperature programmed reduction-adsorption-desorption (H₂-TPR/TPD) and thermogravimetric and differential thermal analysis (TGA-DTA) techniques. Investigation corresponds that morphologies, textural properties and surface energy of mixed oxides are important in hydrogen adsorption.