scholarly journals Conceptualization of CO2 Terminal for Offshore CCS Using System Engineering Process

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4350
Author(s):  
Hyonjeong Noh ◽  
Kwangu Kang ◽  
Cheol Huh ◽  
Seong-Gil Kang ◽  
Seong Jong Han ◽  
...  

In this study, the basic configuration and operation concept of a CO2 terminal were identified by conducting a system engineering process. The performance goal of a CO2 terminal was determined by requirement analysis. Then, functions and timelines were derived by functional analysis to meet the performance goal. Equipment to perform the functions were defined and finally, a process flow block diagram of the CO2 terminal was acquired. The CO2 terminal in this study consisted of three parts. First, the CO2 loading/unloading part is responsible for liquid CO2 unloading from the carrier and loading vapor CO2 onto the carrier. Secondly, the liquid CO2 transmission part extracts liquid CO2 from the storage tanks and increases the pressure until it satisfies the offshore pipeline transportation condition. The vapor-treatment part collects boil-off gas, generates vapor CO2, and charges the storage tanks with vapor CO2 to control the pressure of the storage tanks that discharge liquid CO2. Finally, the study results were compared with a liquefied natural gas (LNG) terminal. The biggest difference between the CO2 terminal in this study and the LNG terminal is that a vaporizer is essential in the CO2 terminal due to the smaller storage capacity of the CO2 terminal and, therefore, the lower amount of boil-off gas.

Author(s):  
Tomasz Piechowiak ◽  
Bartosz Skóra ◽  
Katarzyna Grzelak-Błaszczyk ◽  
Michał Sójka

AbstractThe purpose of this study was to investigate the biological properties of an extract obtained from the waste of blueberry fruit. The study covered the optimization of extraction of antioxidants from blueberry pomace and the determination of antioxidant properties of the extract using HaCaT as the model organism. Research showed that the yield of antioxidants extraction from blueberry waste was dependent on the applied extraction conditions. Based on the mathematical models, the optimal conditions of extraction process in which the maximum quantity of antioxidant compounds is achieved from the waste mass unit, i.e., the relation of the waste mass to the volume of ethanol equal to 1:17.36, and process time equal to 1000 s. The obtained extract was characterized by high antioxidant activity, which was shaped by high content of polyphenols, mainly anthocyanins. Moreover, the extract showed a high ability to protect HaCaT cells from the occurrence of oxidative stress induced by H2O2. Cells treated with the extract and H2O2 generated a lower amount of ROS than cells treated with H2O2 only. The obtained results will be base of further studies on applying the extract in production of diet supplements and functional foods with increased antioxidant activity. Moreover, the main research material is blueberry pomace which is a troublesome waste material for juice producers. Consequently, according to a sustainable development idea, the study results will provide an opportunity to increase interest in the problem of rational use of the waste material to a certain extent.


Author(s):  
Hoang Nam Phan ◽  
Fabrizio Paolacci

Liquid storage tanks are vital lifeline structures and have been widely used in industries and nuclear power plants. In performance-based earthquake engineering, the assessment of probabilistic seismic risk of structural components at a site is significantly affected by the choice of ground motion intensity measures (IMs). However, at present there is no specific widely accepted procedure to evaluate the efficiency of IMs used in assessing the seismic performance of steel storage tanks. The study presented herein concerns the probabilistic seismic analysis of anchored above-ground steel storage tanks subjected to several sets of ground motion records. The engineering demand parameters for the analysis are the compressive meridional stress in the tank wall and the sloshing wave height of the liquid free surface. The efficiency and sufficiency of each alternative IM are quantified by results of time history analyses for the structural response and a proper regression analysis. According to the comparative study results, this paper proposes the most efficient and sufficient IMs with respect to the above demand parameters for a portfolio of anchored steel storage tanks.


Author(s):  
Y-T Tsai ◽  
Y-Y Hsu

A good diagnostic policy can not only shorten the detection time of faults but also improve the effectiveness of system maintenance. This paper presents a function-based diagnosis strategy that provides a helpful methodology for fault identification. The diagnosis trees of the systems are constructed based on a functional block diagram consisting of function elements (FEs) and test points (TPs). The correlations between the FEs and the TPs are first analysed according to system information flows. Two weighted indexes for fault detection and fault isolation are defined to determine the priority of these TPs in testing. Several parameters related to diagnostic ability are also introduced to provide an evaluated approach for system testability. The diagnostic steps and costs between traditional sequential testing and the function-based diagnosing are compared. The study results may be useful in planning diagnosis actions and testability design for a system. A hydraulic system is used as an example in order to depict the proposed methods.


2017 ◽  
Vol 15 (03) ◽  
pp. 395-416 ◽  
Author(s):  
Ehsan Mousakhani ◽  
Mohammadreza Yavarkhani ◽  
Soheyla Sohrabi

Purpose Road construction projects are one of the strategic industries in each country and their construction and development requires spending huge funds. Regarding the increased demand and resource constraints; a technique which reduces costs by maintaining and improving the functioning is of great importance for the authorities of each country. Value engineering is a comprehensive and coherent means based on innovation and team work which, in addition to maintaining the quality and improving the project function, reduces its cost and is not limited to the design and construction phase; however, it includes exploitation and maintenance as well. This study aims to present a practical model for the implementation and application of value engineering process in a construction project located in a special region (in terms of tourism, positioning in an economic growth path, and the East-West strategic axis of the region). In this regard, after reviewing the advisor's design, considering the interests of the project stakeholders, reviewing design criteria and assessment methods and with the use of value engineering techniques, a new option was presented which led to a significant reduction in costs and time and an increase of quality, safety, and environmental factors. Finally, including initial costs, repair, maintenance, income and expenses, the relative value index of this option, compared to the advisor's option, increased from 0.9 to 3.5. Based on the increased need for development of roads in the country, exploiting this model in similar projects can significantly improve the project value and the effectiveness of investments. Design/methodology/approach This research project was selected with regard to the extremely high credit of the project and its potential in terms of Value Engineering implementation. In this study, technical and financial information were first collected after forming a value engineering team including a value engineering expert who was responsible for coordinating the work, some representatives of the employer, designer, executor, and budget estimator. In functional analysis phase with the use of FAST graph, advantageous, costly, and risky functions were identified. In the creativity phase, ideas related to selected functions were created and investigated and developed in the evaluation phase. Finally, calculating the value index, two variants with higher value index than the baseline plan, were proposed and implemented. Findings Since the determining criteria of designing and implementation of road construction projects including increased safety, reduced travel time, user satisfaction, ease of implementation, cost of construction and maintenance and so on are almost similar in most projects, using this study results and implementing its practical framework in other construction projects can be beneficial. These parameters lead to an increase in quality, value, and safety of the project. With regard to done steps and resulted incomes, this essay can be known as a practical and theoretical model to promote the value of crucial projects especially in developing countries. Research limitations/implications Sanandaj-Hamedan road with the length 176km connects central provinces of Iran. This study is regarding the first part of this route. Based on the specific topography of the region and the existing road limitations, selecting a good variance with all the features of an ideal road from geometric, economic, and safety aspects is a difficult task. Originality/value Employers and project sponsors are always looking for products with greater value and lower cost; therefore, present a practical model for the implementation and application of value engineering process in a construction project and providing a similar work experience can encourage the use of value engineering techniques and significantly improve the project value and the effectiveness of investments.


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