Tanveer Iqbal

Implementation Issues of PSM in a Fertilizer Plant: An Operations Engineer's Point of View

In this article, guidelines are provided for implementation of the elements of process safety management (PSM) such as management of change (MOC), process hazard analysis (PHA), incident investigation, emergency planning, and response. The role of mechanical integrity, operating procedures, compliance audits, pre‐start‐up safety review, contractors, training, work permits, and process safety information for implementation of the PSM in a fertilizer plant are discussed. Implementation of MOC is an important step for the adoption of PSM standards and a necessary condition for internal and external audits of the plant. There are many issues linked with implementation of PHA like plant modifications, shut downs, and production losses as well as the behaviour of the design engineer whenever modifications are required. Consequence analysis, an evaluation of an incident in terms of its effects on environment, equipment, and people is of great help. Incident reporting for a company can be improved by ensuring confidentiality and not exposing the reporting person. Improvement in the operating procedures and preserving mechanical integrity of the process plant are necessary conditions for the implementation of the standards. Internal and external audits of the company are the most important part of the PSM implementation. In general, the PSM implementation requires much effort and time but pays off well if implemented fully.

CONTINUOUS STIFFNESS MODE NANOINDENTATION RESPONSE OF POLY(METHYL METHACRYLATE) SURFACES

Indentation is a comparatively simple and virtually nondestructive method of determining mechanical properties of material surfaces by means of an indenter inducing a localized deformation. The paper present experimental results of the load-displacement curves, the hardness and the elastic modulus data, and associated analysis for poly(methyl methacrylate) (PMMA) surfaces as a function of contact displacement. The experimental results include continuous stiffness indentations performed using constant loading rate and constant displacement rate experiments. The continuous stiffness indentation involves continuous calculation of a material stiffness, and hence hardness and elastic modulus of surfaces, during discrete loading-unloading cycles, as in a conventional indentation routine, and in a comparatively smaller time constant. The dependence of the compliance curves, the hardness, the elastic modulus and the plasticity index upon the imposed penetration depth, the applied normal load and the deformation rate are described. Tip area and load frame calibrations for the continuous stiffness indentation are also reported. The paper includes practical considerations encountered during indentation of polymers specifically at low penetration depths. The experimental results show a peculiarly harder response of PMMA surfaces at the submicron (near to surface) layers.

Nanoindentation Response of Scratched Polymeric Surfaces

The effects of imposed strains on the polymeric surfaces during scratching on the material deformation below the visible surface have not been reported in the literature. The major concern for the polymeric surfaces is the problems related to the effective sectioning for imaging/scanning unlike metal and ceramics. This article describes an experimental qualitative methodology, based on nanoindentation data, to analyze subsurface deformations of polymers resulting from scratch deformations. Poly(styrene), a brittle polymer, poly(methylmethacrylate), a ductile polymer, and poly(etheretherketone), a semicrystalline polymer, were selected for the present study. Nanoindentation responses of the scratched poly(styrene), the scratched poly(methylmethacrylate), and the scratched poly(etheretherketone) surfaces were analyzed with emphasis on the detection of subsurface crazing damage. The polymers were scratched using a 900 conical indenter on a pendulum sclerometer. The scratched polymeric surfaces were assessed using scanning electron microscopy (SEM). The polymeric surfaces were observed to be deformed by a well-known ductile ploughing mechanism. The deformed polymeric surfaces were indented using an MTS Nanoindenter. The data show that the hard asperity scratching initiates subsurface damage, which may tentatively lead to the development of subsurface voidage or crazing in certain areas of the deformed polymers, particularly within the base of the scratch groove. Major conclusions of the work are that the nanoindentation of damaged polymeric surfaces provides a qualitative methodology to estimate the subsurface damage and craze formation. This methodology is important in the context of polymers where conventional effective sectioning of the damaged surface to analyze the subsurface deformations might not be possible.

Scratch deformations of poly (ether ether ketone) composites

The experimental results obtained from scratching a semicrystalline poly (ether ether ketone) surfaces, (PEEK), and its composites are presented in this paper. A semicrystalline PEEK and a carbon fiber oriented PEEK were scratched using conical indenters on a pendulum sclerometer. The carbon fiber oriented PEEK composites were scratched in the parallel, the orthogonal and the transverse direction to the fiber orientation. Subsequent deformations of the surfaces were assessed through subjective evaluation of the images obtained from a scanning electron microscope (SEM). The semicrystalline PEEK samples were found to be deformed by ductile ploughing and brittle deformation mechanism. In addition a fibrillation of the crystalline lamella of the polymer was also seen to be formed in case of severe brittle deformations. Fiber matrix debonding, matrix material debris formation, and fiber breakage were observed to be the dominant deformation mechanisms of the carbon fiber oriented composites. The scratch deformations of fiber oriented polymers were found to be highly dependent on fiber orientation angle relative to the scratching direction.

Scaling in Electrical Conductivity Measurements and Rheological Measurements of Monarch 700 Dispersions Stabilized by Polymers

For making stable dispersions of graphitic carbon black (Monarch 700), the effectiveness of three dispersants/polymers (hypermer LP1, hypermer B246, and OLOA 11000) in xylene is investigated. Hypermer LP1 (polyhydroxystearic acid) is a homopolymer and hypermer B246 (PEG 30-dipolyhydroxystearate) is a polyhydroxystearic acid/polyethylene oxide/polyhydroxystearic acid ABA block copolymer, while OLOA 11000 (polyisobutylene succinimide) has a polar head group (polyamine) attached to a hydrocarbon chain (polyisobutylene). Well-dispersed graphitic carbon black dispersions were prepared using dispersants at optimum concentrations. Percolation threshold and rheological threshold were determined by analyzing the variations in electrical conductivity and elastic modulus with concentration of carbon black. Above threshold concentration, scaling law was applied to experimental data of rheology (dynamic measurements) and electrical conductivity measurements to evaluate quality of the system. Effectiveness of polymers was investigated on the basis of value of critical exponent (t and t′, respectively) in scaling power law. Hypermer LP1 was proved to be a poor dispersant for Monarch 700 dispersions while other two polymers were found to be effective stabilizers.

Improved transesterification of waste cooking oil into biodiesel using calcined goat bone as a catalyst

ABSTRACT In this study, potassium hydroxide-treated animal bones were employed as a solid heterogeneous catalyst in transesterification of waste cooking oil. This catalyst was characterized by the Fourier-transform infrared spectroscopy (FTIR), and it displayed high-catalytic activity for biodiesel production. Optimum conditions for biodiesel production were catalyst loading 6.0% (w/w) of oil, methanol/oil molar ratio 9:1, calcination temperature 800°C, reaction temperature 65°C, and reaction time of 5 h, which gave maximum biodiesel yield of 84%. Reusability of the catalyst was also confirmed by repeated use of the same catalyst three times without losing much of its activity. Hence, calcined goat bones were found to be a potentially applicable catalyst for biodiesel production at industrial scale.

Effect of demineralization on the physiochemical structure and thermal degradation of acid treated indigenous rice husk

Abstract Energy generation from biomass presents some serious problems like slagging, fouling and corrosion of boilers. To address these problems, demineralization of biomass is performed using different leaching agents. This study is focused on determining the influence of leaching agents and leaching time on the physiochemical structure of rice husk during demineralization. Dilute (5% wt) solutions of HCl and H2SO4 were used for the demineralization of rice husk separately with leaching time of 15, 60 and 120 minutes. It is shown that H2SO4 exhibited higher removal of alkali and alkaline earth metals (AAEM) comparatively as depicted by the 34.2% decrease in ash content along with an increase of 7.10% in the heating value. The acid has been seen to induce more notable changes in physiochemical structure as depicted by the FTIR spectra and SEM micrographs. The thermal degradation behavior of the demineralized rice husk has also been reported.

Adsorption and Rheology of Graphitic Carbon Black Nonaqueous Dispersions Prepared Using Nonionic Surfactants

Rheological and conductivity measurements are reported to investigate the dispersibility of graphitic carbon black dispersions selected as a model for carbon nanotubes. The effectiveness of three dispersants in nonpolar organic solvents were investigated namely polyhydroxystearic acid (Hypermer LP1), PEG 30-dipolyhydroxystearate (Hypermer B246), and polyisobutylene succinimide (OLOA 11000). Hypermer LP1 is homopolymer and Hypermer B246 is polyhydroxystearic acid/polyethylene oxide/polyhydroxystearic acid ABA block copolymer while OLOA 11000 has polar head group (polyamine) attached to a hydrocarbon chain (polyisobutylene). Two nonpolar organic solvents decalin and xylene were selected for the present work. The experimentally determined relative viscosity as a function of effective volume fraction Φ′ curves were compared with the theoretical curves calculated using Kreiger-Dougherty equation for the hard sphere dispersions. The comparison showed that Hypermer B246 and OLOA 11000 dispersions in xylene could be prepared at somewhat higher solid fraction than those dispersions stabilized by Hypermer LP1. Also Hypermer LP1 dispersions do not agree with the Kreiger-Dougherty equation curve, which showed that Hypermer LP1 is not an effective stabilizer. In oscillatory measurements, high values of storage and loss modulus at high volume fractions were obtained indicating strong repulsive interactions between the carbon black particles using Hypermer B246 and OLOA 11000. The dispersions prepared using these surfactants showed lower electrical conductivity as compared to other dispersions prepared without dispersants. Also higher relative conductance was obtained in case of dispersions made by Hypermer LP1 as compared to other dispersions made by Hypermer B246 and OLOA 11000.