Greenhouse gases mitigation by CO<Subscript>2</Subscript> reforming of methane to hydrogen-rich syngas using praseodymium oxide supported cobalt catalyst

This study focuses on the potential of hydrogen-rich syngas production by CO₂ reforming of methane over Co/Pr₂O₃ catalyst. The Co/Pr₂O₃ catalyst was synthesized via wet-impregnation method and characterized for physicochemical properties by TGA, XRD, BET, H₂-TPR, FESEM, EDX, and FTIR. The CO₂ reforming of methane over the as-synthesized catalyst was studied in a tubular stainless steel fixed-bed reactor at feed ratio ranged 0.1–1.0, temperature ranged 923–1023 K, and gas hourly space velocity (GHSV) of 30,000 h^?1 under atmospheric pressure condition. The catalyst activity studies showed that the increase in the reaction temperature from 923 to 1023 K and feed ratio from 0.1 to 1.0 resulted in a corresponding increase in the reactant’s conversion and the product’s yields. At 1023 K and feed ratio of 1.0, the activity of the Co/Pr₂O₃ catalyst climaxed with CH₄ and CO₂ conversions of 41.49 and 42.36 %. Moreover, the catalyst activity at 1023 K and feed ratio of 1.0 resulted in the production of H₂ and CO yields of 40.7 and 40.90 %, respectively. The syngas produced was estimated to have H₂:CO ratio of 0.995, making it suitable as chemical building blocks for the production of oxygenated fuel and other value-added chemicals. The used Co/Pr₂O₃ catalyst which was characterized by TPO, XRD, and SEM-EDX show some evidence of carbon formation and deposition on its surface.     

Catalysis of semihydrogenation of acetylene to ethylene: current trends,challenges, and outlook

Ethylene is an important feedstock for various industrial processes, particularly in the polymer industry. Unfortunately, during naphtha cracking to produce ethylene, there are instances of acetylene presence in the product stream, which poisons the Ziegler–Natta polymerization catalysts. Thus, appropriate process modification, optimization, and in particular, catalyst design are essential to ensure the production of highly pure ethylene that is suitable as a feedstock in polymerization reactions. Accordingly, carefully selected process parameters and the application of various catalyst systems have been optimized for this purpose. This review provides a holistic view of the recent reports on the selective hydrogenation of acetylene. Previously published reviews were limited to Pd catalysts. However, effective new metal and non-metal catalysts have been explored for selective acetylene hydrogenation. Updates on this recent progress and more comprehensive computational studies that are now available for the reaction are described herein. In addition to the favored Pd catalysts, other catalyst systems including mono, bimetallic, trimetallic, and ionic catalysts are presented. The specific role(s) that each process parameter plays to achieve high acetylene conversion and ethylene selectivity is discussed. Attempts have been made to elucidate the possible catalyst deactivation mechanisms involved in the reaction. Extensive reports suggest that acetylene adsorption occurs through an active single-site mechanism rather than via dual active sites. An increase in the reaction temperature affords high acetylene conversion and ethylene selectivity to obtain reactant streams free of ethylene. Conflicting findings to this trend have reported the presence of ethylene in the feed stream. This review will serve as a useful resource of condensed information for researchers in the field of acetylene-selective hydrogenation.     

Degree of stability of geodesic domes with independent loading parameters

Solution techniques and guidelines for convergence and error controls are presented for static and dynamic stability investigations of imperfection-sensitive reticulated space structures. The structure may be subjected to independent loading parameters and finite disturbances. The state of stability investigations of reticulated space structures is briefly described and reflected by the references cited. The determination of the static stability parameters including the degree of stability of equilibrium, which forms the basis of a sufficient condition of dynamic stability, is illustrated for a geodesic dome model.     

A comprehensive view of agent-oriented patterns

This paper presents a comprehensive framework for classifying, analyzing and describing agent-oriented software patterns. We present a two dimensional scheme for classifying agent-oriented patterns. We define agent-oriented pattern attributes and use these attributes in a process for analyzing and placing agent-oriented patterns within the classification scheme. Using the proposed classification scheme, we classify 28 patterns written by a variety of agent researchers, chosen from almost 100 patterns which we have studied.     

Effects of raw materials,processing conditions and packaging on the quality of plantain chips

The effects of raw material, processing conditions and packaging on the quality of plantain chips were investigated. Two cultivars of plantain Musa spp—Agbagba and Obino lewai—as well as cooking banana were used for the study. The fruits were at stages 1 to 4 of the banana ripening chart. The study started with a consumer survey aimed at product definition. This was followed by series of experiments to determine the effects of raw material, processing conditions and packaging on the quality of plantain chips. A correlation analysis was also carried out on the physical and chemical characteristics of raw plantain. The work revealed that the stage of ripeness of raw material had some effect on the quality of chips as there was gradual increase in pulp/peel ratio and sugar was significantly different (P < 0·05). Moisture content of pulp/texture of pulp, texture of pulp/sugar content of pulp and texture of pulp/ripening stages were negatively correlated, while pulp/peel ratio and moisture content of pulp were positively correlated. Chips packed in 80 μm high-density polyethylene pouches and stored at various relative humidities had extended shelf-life compared with the low-density polyethylene packed chips stored at the same relative humidities. This was due to the inadequacy of the low-density polyethylene in giving the required protection against moisture transmission thereby resulting in soggy chips in shorter periods. The implication of the findings on the formulation of a guideline for the processing of a good-quality plantain chips for the marketing system is discussed.     

Effects of processing conditions and packaging material on the quality attributes of dry‐roasted peanuts

Five different processing conditions of raw shelled unblanched peanuts were investigated. The first two treatments involved soaking the peanuts in tap water for 10 and 30 min respectively, then mixing thoroughly with dry NaCl before roasting. Another two treatments involved soaking the peanuts in saturated brine solution for 10 and 30 min respectively before roasting. Unsalted roasted peanuts served as the control. Packaging and storage studies were carried out by packaging the differently treated dry‐roasted peanuts in four different packaging materials and storing them under three different relative humidities for 3 months at ambient temperature. Proximate composition, NaCl content, peroxide value and thiobarbituric acid value were determined and sensory evaluation tests were carried out. Salting was found to improve the taste, flavour and overall acceptability of dry‐roasted peanuts but had no effect on shelf‐life. Peanuts treated in saturated brine solution for 30 min before roasting were the most preferred. The control packaging material, 18 µm transparent polyethylene, was found to be inadequate for protecting the quality attributes of dry‐roasted peanuts, with mould growth being observed on the 42nd day of storage at 80% relative humidity. However, acceptable results were obtained with 45 µm transparent polypropylene. The mean sensory scores and objective tests were found to be negatively correlated. © 2002 Society of Chemical Industry     

Numerical Simulation Software for Oil Sand Slurry Flow in Flexible Pipelines

In order to optimize the hydraulic transportation system efficiency and cost in the surface extraction of Athabasca oil sand deposits in Canada, there is a desire to extend the hydraulic transport system to production faces in oil sands mines using mobile train of Flex-Rite-based flexible pipelines. Hydraulic transportation system based on flexible-pipe arrangement has been shown to be more competitive than the dump-truck transportation system. This flexible arrangement introduces a unique set of hydraulic transport problems which needs rigorous modeling, experimentation, and analysis to understand the system production capacities and efficiency. Part of the work presented here is an attempt to provide multiphase oil sand slurry simulation and modeling by developing a slurry flow simulator, a graphical user interface-based software, for Flex-Rite flexible-pipe train, a form of hydraulic transportation system. Such software provides a tool/platform for rigorous experimentation and analysis of flow and production capacities.     

First steps toward best practice SEA in a developing nation: lessons from the central Namib uranium rush SEA

The intent of this study is to contribute to the discussion of strategic environmental assessment (SEA) best practice based on experience gained in a recent SEA initiative: the central Namib (Namibia) uranium rush SEA. We evaluate this SEA process against internationally established characteristics of ‘best practice’ SEA to improve and strengthen future practice in Namibia. The study draws primarily on the final assessment report as well as inputs from six informants involved in the assessment. The results reveal some elements of good practice as well as areas for improvement, and in particular, the need for improved baseline data collection; adequate consideration of alternatives; committing to preferred scenario/options; enforceability; and a more robust institutional capacity. We offer insight into how consideration of these factors may help to strengthen SEA practice in Namibia. Overall, the SEA may not represent a ‘best practice’ example according to international standards, but it does suggest a potentially bright future for SEA practice in Namibia.     

Challenges to integrating planning and policy-making with environmental assessment on a regional scale – a multi-institutional perspective

Abstract

Regional environmental assessment (EA) requires the participation of policy- and plan-making institutions to formulate, implement and monitor regional environmental management strategies. However, there is little understanding of what effective integration is in the context of regional EA and from the perspectives of planners and policy-makers involved. This paper seeks to explore how institutional actors perceive cross-domain integration vis-à-vis their own involvement in regional EAs. Thirty-eight participants from four regional EA initiatives in Canada shared their perspectives in an online survey. Three types of silo effects are identified: (1) institutional – intricately linked to factors such as coordination, goals and expectations, leadership and capacity; (2) disciplinary – characterized by limited communication and scepticism around data sharing; and (3) transactional – tendency of actors to emphasize individual narrow perspective rather than collective social and environmental outcomes. Additional findings reveal the importance of learning and multiple domain expertise as opportunities for enhancing cross-domain integration in regional EA practice. Finally, the study concludes that proactive consideration of potential silo effects is necessary for improved regional EA outcomes, and to facilitate more effective regional resource governance.