16 research outputs found
Evaluation of Carbon Emission Factors in the Cement Industry: An Emerging Economy Context
The cement industry is a major contributor to carbon emissions, responsible for 5–8% of global emissions. This industry is expanding, particularly in emerging economies, and it is expected that CO2 emissions will rise by 4% by 2050. To address this critical concern, this paper identifies ten factors that contribute to carbon emissions in the cement production process through an extensive literature review and prioritises these factors using the Bayesian best–worst method. The data was gathered by conducting a methodical online survey with seven cement industry professionals in Bangladesh, with the aim of gaining insights into the emerging economy. The results illustrate that fuel burning and electricity consumption are the two greatest contributors to CO2 emissions in the cement production process. This research provides guidelines for cement industries in emerging economies on how to reduce CO2 emissions as well as suggesting areas of future research for sustainable cement production
Combustion characteristics of aluminium hydride flame
The combustion characteristics of Al hydride and Al were compared using a combustion chamber. Burning rate, ignition energy and temperature at atmospheric temperature and pressure in carbon dioxide and O2 were tested with a volumetric flow rate that ranged from 10 to 50% in Ar. A spark ignition system was used to ignite the Alane and Aluminum. The combustion rate was measured using a high speed camera. Results showed the combustion rate of Alane and Aluminum decreases with increasing volumetric flow rate of oxidizer. And the combustion rate of Alane is higher than that of Aluminum. Alane needs more ignition energy than Aluminum to burn, which was measured using a high voltage probe and multimeter. A scanning electronic microscope (SEM) was used to obtain the morphology of the sample before the experiment to ensure the sample was pure enough to conduct the experiment. SEM was also used to obtain the morphology after burning to investigate the change in morphology. EDAX analysis was completed to obtain the quantitative analysis of the element and find the O2 content before the experiment, which is the indication of purity in the sample. EDAX analysis was also completed after the experiment to obtain the percentage of O2, which indicates the efficiency of the combustion reactions because O2 is one of the main products after combustion. Flame evolution from high speed camera and thermal camera images suggest that flame quality Alane is better than that of Al in each condition. The flame temperature measured by K type thermocouple indicates flame temperature of Alane is higher than Aluminum for a given condition
Effect Of Multi-Tube Injector Geometry On Flame Stability And NOx Emission In A High Pressure Gas Turbine Combustor
Future generation gas turbine combustors for power production are expected to have the capability of operating on high hydrogen content fuels. To ensure the implementation of high hydrogen content (HHC) fuel in a power generation unit without negotiating with operational or emission advantages, the study of the flame stability regime and behavior of (HHC) fuel under gas turbine condition leads to the necessity of the development of an optically accessible high-pressure combustor. This Dissertation first presents the design of an optically high-pressure combustor facility based on 500 kW power and 1.5 MPa pressure which is the representative pressure of a real gas turbine. The combustion chamber is designed to accommodate multiple geometrical configurations including a non-swirl stabilized and center-body stabilized swirl flow. The combustor is made of stainless steel 410. It has four primary modular parts: outer stainless steel chamber, inner quartz chamber, front cap and end cap. It has three optically accessible windows and three instrumentation ports for a broad range of investigation techniques. Finite element analysis has performed to get the wall thickness. The test chamber is also fitted with a variable area flow restrictor to control the desired pressure across the combustion chamber. Cooling system is also included in the design to extract heat and avoid structural failure. The outer stainless steel chamber will be equipped with copper coiling using cooling water as a driving fluid and inner quartz chamber will be convectively cooled using nitrogen. The use of a variable throat area restrictor, multiple cooling systems, as well as removable modular sections and optical access will allow the combustor to be compatible to work in a wide range of operations and have the flexibility operating with variable syngas compositions. This will allow analysis of the flame stability, flow field characterization, pollutant emissions in high hydrogen content fuel under realistic gas turbine conditions.
The ignition and control systems of this high pressure combustor have also been developed in the present work. LabVIEW was used as the controlling interface that controls the proportional valves, and solenoiod valves. A modified spark plug was used as an ignition source. In order to ignite the main fuel-air stream, a diffusion flame was used. Functional test of the equipment, leak test and pressure testing were carried out prior to conducting the ignition experiments. The system has the capability to withstand the maximum pressure allowed by the air compressor which is 758 kPa.
The high-pressure combustion chamber design allows for testing in realistic gas turbine conditions. Fuels that show promise as an energy source are high-hydrogen content fuels derived from coal which have a much higher specific heat, higher diffusivity, flammability limits and higher laminar flame speed compared to other hydrocarbons. These properties induce flame flashback especially when the hydrogen content in the fuels is high. A multi-tube injector has been designed to mitigate the flashback of high hydrogen content fuel.
The present work studies the blowout characteristics of syngas mixtures emitted from a novel multi-tube injector. Compositions are varied for syngas from 10% to 30% hydrogen concentration by volume in carbon monoxide (CO). Three different conditions were tested for these compositions: 1) where jet velocity was greater than the laminar flame speed 2) where the jet velocity was equal to the flame speed and 3) where jet velocity was less than the laminar flame speed. Results were used to model the blowout behavior of the designed injector. The critical velocity gradient gB which was defined as the ratio of laminar burning velocity to blow-off distance was used to make a correlation between blowout behavior of different syngas compositions. A dimensionless parameter, Peclet number, was used to capture the blowout characteristics of the injector. Results showed that the degree of blowout tendencies decreased with increasing hydrogen concentration for this multi-tube injector. The Peclet model showed a good agreement yielding approximately similar correlation constants for different syngas compositions at different conditions. A cold flow numerical simulation of the designed multi-tube injector was also done to characterize the fluid flow behavior of the injector and assist in the present and future design of similar injector systems. Also presented in this paper is a numerical simulation of NOx emission. The models used for syngas fuel combustion consist of the k-ÃÂ¥ model for turbulent flow, mixture fractions/PDF model for partially premixed premixed gas combustion, and P-1 radiation model. Numerical results revealed the flame location and maximum NOx emission values of 4, 42 and 52 ppm were measured at an equivalence ratio of 0.5, 0.75 and 1 respectively
Combustion Characteristics Of AlH3 Flame
The combustion characteristics of Al hydride and Al were compared using a combustion chamber. Burning rate, ignition energy and temperature at atmospheric temperature and pressure in carbon dioxide and O2 were tested with a volumetric flow rate that ranged from 10 to 50% in Ar. A spark ignition system was used to ignite the Alane and Aluminum. The combustion rate was measured using a high speed camera. Results showed the combustion rate of Alane and Aluminum decreases with increasing volumetric flow rate of oxidizer. And the combustion rate of Alane is higher than that of Aluminum. Alane needs more ignition energy than Aluminum to burn, which was measured using a high voltage probe and multimeter. A scanning electronic microscope (SEM) was used to obtain the morphology of the sample before the experiment to ensure the sample was pure enough to conduct the experiment. SEM was also used to obtain the morphology after burning to investigate the change in morphology. EDAX analysis was completed to obtain the quantitative analysis of the element and find the O2 content before the experiment, which is the indication of purity in the sample. EDAX analysis was also completed after the experiment to obtain the percentage of O2, which indicates the efficiency of the combustion reactions because O2 is one of the main products after combustion. Flame evolution from high speed camera and thermal camera images suggest that flame quality Alane is better than that of Al in each condition. The flame temperature measured by K type thermocouple indicates flame temperature of Alane is higher than Aluminum for a given condition
Methodological Approaches for Next Generation Supply Chains
Collaborative management research approaches (e.g. Action research, Intervention research)
emerged to overcome what is considered as a lack of integration between empiricism and
theoretical knowledge. In such approaches, researchers will not be just observing the phenomenon,
however, they should be immersed in the empirical settings, and the research process will be
performed collaboratively through engaging all the stakeholders (researchers, practitioners, policy
makers). Through a content analysis, the present research draws on the findings of scholarly
publications which employed collaborative management approaches in their research design. The
paper presents a research agenda for knowledge co-generation between different supply chain
stakeholders. The potential drawbacks of adopting collaborative management research approaches
in supply chain research - for instance concerns on the methodological rigor - are also scrutinised.
The findings of this paper contribute to a better understanding of managing collaborative research
processes, which engages practitioners in the research process, and involves researchers in the
practitioners’ system
Implementation of Linear Programming and Decision-Making Model for the Improvement of Warehouse Utilization
Warehouses are used to store raw materials, finished goods, defective products, tools, machinery, and other company assets until needed. In addition, the warehouse is a staging area for the storage and packaging of products delivered to the customer for consumer industries. Ideally, storage time, storage space, and delivery lead times are minimized by improving warehouse management. This study implements an integration of linear programming (LP) and decision-making models. The LP model provides decision-makers with the optimum quantity of products that can be stored in the warehouse based on different case scenarios considered in this study. Furthermore, the criteria affecting the space utilization of warehouses at total capacity are identified. An integrated approach of rough analytical hierarchical process (AHP) and rough technique for order preference by similarity to ideal solution (TOPSIS) is utilized to determine the best pallet placement on the respective rack. Additionally, this technique identifies the storage racks that require improvements in warehouse space utilization for the products. This methodological approach will help many industries and logistics teams make optimal decisions and improve productivity
Implementation of Linear Programming and Decision-Making Model for the Improvement of Warehouse Utilization
Warehouses are used to store raw materials, finished goods, defective products, tools, machinery, and other company assets until needed. In addition, the warehouse is a staging area for the storage and packaging of products delivered to the customer for consumer industries. Ideally, storage time, storage space, and delivery lead times are minimized by improving warehouse management. This study implements an integration of linear programming (LP) and decision-making models. The LP model provides decision-makers with the optimum quantity of products that can be stored in the warehouse based on different case scenarios considered in this study. Furthermore, the criteria affecting the space utilization of warehouses at total capacity are identified. An integrated approach of rough analytical hierarchical process (AHP) and rough technique for order preference by similarity to ideal solution (TOPSIS) is utilized to determine the best pallet placement on the respective rack. Additionally, this technique identifies the storage racks that require improvements in warehouse space utilization for the products. This methodological approach will help many industries and logistics teams make optimal decisions and improve productivity.peerReviewe
Internal Visibility of External Supplier Risks and the Dynamics of Risk Management Silos
This paper investigates the factors behind silo-based risk management practices in organizations. Based on interviews with different actors working with the supply management processes within and across different organizational levels in a major multinational manufacturing corporation, it reveals how silos of risk management activities are formed. The findings show that there are profound differences in risk visibility between different actors due to differences in their hierarchical levels, organizational positions, and business contexts. Drawing on the theoretical lenses of bounded rationality and contingency theory, the paper reveals how these differences in visibility create silo-based risk management processes and discusses the pros and cons of such configurations. It concludes that silo-based behaviors are inherent features of any complex organization and that the implications of managing risks in silos are strongly influenced by the types of dependences (positive or negative) among risks. Therefore, it is elemental for organizations to be aware of this phenomenon and configure their risk management processes accordingly based on the dependences among the various risks to which the organizations are exposed
Comparative analysis and case briefs of preparedness and security of supply
The CORE (sCience & human factOr for Resilient sociEty) project deals with human factors and social, societal, and organisational aspects for disaster-resilient societies. CORE aims to identify and use best practices, knowledge, and learnings from certain countries which experienced high levels of different hazards (e.g., seismic, and volcanic risks in Italy). The overall objective of CORE is to develop a harmonised vision of crisis management, awareness, and capability. Thereby, Work Package 4 (WP4) focuses on three types of cascades that impact the security of supply, including cascading events or disasters, cascading impacts of disaster risk reduction (DRR) decisions across sectors, and cascading through supply chain disruptions. The main aims of WP4 are to (1) map the causes of detrimental impacts on the security of supply through these cascades; (2) establish the directions and the links between events, sectors, and supply chain disruptions; (3) produce a framework that assesses the risks of potential cascades of DRR decisions across sectors events, and supply chains; and (4) raise awareness for the impact of supply chain disruptions on the security of supply. This report (Deliverable 4.2) presents a comparative analysis and case briefs of preparedness and security of supply. We map how the security of supply is organised within disaster management and discuss DRR frameworks of selected EU countries (i.e., Finland, Sweden, Italy, and Austria). This report presents the differences in preparedness and DRR mechanisms concerning pre-positioning, training, framework contracts, and supplier management. We also discuss how preparedness activities result in societal resilience in these case countrie