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Exergetic Analysis of the Biodiesel Production Process in a Biofuel Plant
Get PDF This paper deals with the exergy analysis of the biodiesel production process from the binary mixture of soybean oil and beef tallow. The biodiesel is produced by transesterification of the methyl group and through basic catalysis. Thus, it was investigated the biofuel production process of a specific plant in the State of Minas Gerais, Brazil, characterizing the parameters of the main equipment and analyzing the raw material and by-products of the process and quantifying the mass and energy. The exergy analysis methodology followed the mass balance of each step, calculating irreversibility and exergetic balance and efficiency of the plant. The calculation of chemical exergy of the compounds of biomass from soybean oil and beef tallow, biodiesel, glycerol and free fatty acids was accomplished by raising the calorific value of the compounds by their chemical composition and mass percentage. Moreover, they were also calculated the specific irreversibility of methanol and process inputs, the irreversibility concerning electricity, mechanical work and steam. It was found that the useful exergy was 63.4%, however, considering that the glycerin can be sold as a final product and that some raw materials can be reused, the useful exergy of the system could be equal to 94.2%. The exergy efficiency of the plant is 71.7%, due to the irreversibility of the system. The exergy destroyed was 5.8% and could be minimized by changing variables such as temperature, reaction time and type of catalyst
Research and Application of a New Method for Calculating Dynamic Reserves
Get PDF Reserves are the basis of oilfield development, and determination of reserves accurately has great significance for future adjustment of oil fields development. Due to distinct characteristics of offshore oilfield development, it is difficult to obtain dynamic reserves accurately using conventional methods. To overcome the limitations of existing methods, in this paper, a new model for calculating dynamic reserves is established through theoretical derivation with innovative introduction of relative permeability ratio and the quadratic power function of water saturation based on Buckley-Leveret function and frontal movement equation. The result shows that this approach is simple to use and with good applicability, and only needs typical oil field dynamic data. The results of the study facilitates better recalculation of oil field reserves and implementation of oilfield adjustment well. More importantly, it has laid out a new methodology for increasing oil production and exploration in Bohai oil field and provided theoretical foundation for subsequent oilfields’ efficient development
Typical Features Contrast of Hot Water Flooding and Steam Flooding
Get PDF Steam flooding and hot water flooding are the two main important thermal recovery methods for heavy oil reservoirs. Due to physicochemical properties difference of steam and hot water, the mechanism and production performance of hot water and steam flooding vary greatly. In this paper, steam and hot water flooding experiments under different temperature were conducted using Qi 40 heavy oil in Liaohe Oilfield in China to obtain typical features such as displacement efficiency, relative permeability, water cut and dimensionless productivity index of the two. The results show that steam and hot water flooding performance are quite different from each other under the same temperature. Compared with water flooding, displacement efficiency of steam flooding is 8.98%, 10.97% higher under 100℃ and 200℃ respectively, in addition, oil relative permeability is much higher and residual oil saturation is much lower at the same temperature. Water state and temperature are main reasons of displacement efficiency, relative permeability and productivity index difference; vapor state and higher temperature resulting in higher oil recovery, oil relative permeability and oil production index
Structural Performance Analysis of Simple Offshore Platforms under Ice-Vibrations in Bohai Sea
Get PDF In China, the oil and natural gas resources of Bohai Sea are mainly marginal oil fields. It is necessary to build both ice-resistant and economical offshore platforms. So, several simple offshore oil platforms with a jacket sub-structure or with a single pillar have been deployed. There are very good economic benefits in the manufacture, installation, removal, and other aspects. These platforms were primarily designed to withstand extreme static ice forces. However, sea ice motion can induce significant vibrations for the platforms in the region. The structural ice-resistant performances have not been well developed. In this paper, combined with the field monitored data of some simple platforms in Bohai Sea, ice-induced vibrations are analyzed. The results show that even though these structures may effectively resist extreme static ice forces, the ice-induced acceleration is more significant. Then, spectral-based method is provided to analyze the fatigue life of a real simple platform. Lastly, the ice-resistant strategy is presented, which provides a basis for the design of these platforms in ice zone
Suggestions for Developing Integrated Risk Assessment Method for High-Rise Buildings in Korea: Based on Analysis of FEMA’s IRVS
Get PDF The purpose of this study was to develop the integrated risk assessment system for high-rise buildings reflecting the Korean Building Code and guidelines of Preliminary Disaster Inspection and Consultation Systems based on the analysis of FEMA’s IRVS in US. Through reviewing various hazards’ assessment factors, a classification system and methodology for evaluating risk scores in IRVS, applicable factors, limitation of systems to apply to a Korean future system and improvement to verify the assessment methodology are determined. The results of this study will be used to provide the framework and establish the practical goals for developing a Korean risk assessment system for high-rise buildings
Computing Quality of Information for Wireless Sensor Networks
Get PDFWireless sensor networking research is a structural and computer related design that mainly focused on internal wireless sensor network issues such as MAC and routing protocols, energy saving, hard ware design and to some extent on the architecture of gateways that connect a wireless sensor network with the rest of the world. They offer a low-cost solution that provides a high data density. Information obtained from such systems are imprecise in nature but is used for important decision making tasks. This precipitates the need to dynamically compute the quality of information (QoI) based on sensor observations. However, the sensors deployed in an environment do not have the same belief level due to their differences in capabilities and imprecision in sensing and processing. The belief in a sensor represents the level of accuracy in accomplishing a task that can be computed either by comparing the current observation with a reference data set or by performing a physical investigation. It is essential to understand how the sensors are performing with respect to the objective tasks. In this paper we propose a modified Information-driven sensor query (IDSQ) algorithm using reward-and-punishment mechanism to dynamically compute the belief in sensors by leveraging the differences of the individual sensor’s opinion. In this structural, results show the suitability of utilizing the dynamically computed belief as an alternative to the accuracy of the sensors. The structural can then be used to distribute the model processing into the wireless sensor network
Beneficial Reuse of Dredged Marine Soils (DMS) with the Inclusion of Cement and Granular Material for Engineering Applications
Get PDF Plenty of geowaste in Malaysia namely dredged marine soils (DMS) has been increasing over the year. The management of DMS after dredging has become a worldwide problem. Conventionally, the materials are disposed back to the sea. As the minimization of the dredged material during dredging is impossible, extensive work has been done by researchers to develop various economical and viable solutions, such as beneficial reuse of DMS. Series of one-dimensional test by using oedometer were tested on DMS with the inclusion cement and mining sand. Based from the results, the cement- and sand-treated DMS have resulted with low settlement reduction, thus increase its effective yield stress and improve its compressibility. As conclusion, it is suggested that DMS can be beneficially reuse for engineering application such as land reclamation or backfills
Methods of Determining Retardation Coefficients of Organic Compounds in Aquifers
Get PDF Sorption is an important mechanism that affects the mobility of organic compounds in the subsurface environment. Sorbed compounds move slower than that of groundwater, causing retardation in their movement. Accurate determination of retardation coefficients (R) of organic compounds in aquifers is critical for understanding their movement, fate, and remediation. Several methods, including predictive tools, laboratory experiments, and field experiments have been utilized for determining sorption-related retardation. The objective of this paper was to review and compare between the different methods used for the determination of R of organic compounds, with emphasis on predictive- and laboratory-based approaches. Predictive tools are based on the use of quantitative structure-activity relationships (QSARs). Laboratory methods utilize different types of reactors including batch, stirred-flow, circulation-through-column, or miscible displacement through packed columns. In addition, data from the column method have been analyzed in various ways to determine R. Discrepancies between results from different methods or from different analysis approaches have been reported. This create uncertainty about the suitability of some of these methods or the used analysis approaches. This paper highlights the possible causes for the observed discrepancy and establishes the limitations and appropriateness of the used methods and analysis approaches
Ceramic Water Filters as a Response Technology to Geo-Hazards
Get PDF Geo-hazards, a collective term for earthquakes, floods, windstorms, famine and drought, are intensifying with time and are obstacles to attainment of sustainable development. In particular, issues of availability of safe water are major disruptive elements causing the spread of diarrheal diseases during, and post, these geo-hazard events. Given that ceramic water filters (CWFs) have been shown to effectively remove E.-coli (and, by similar attributes, is effective in the removal of cholera), CWFs as a Point-of-Use (POU) technology are described as an effective option for the post-disaster phase of geo-hazards. As described herein, important dimensions of CWFs are provided, showing they can be stored effectively without suffering deterioration, are inexpensive, and are an easy technology to explain to users. Pertinent rationale for serious consideration of CWFs as a post-disaster POU is provided
Performance Analysis of Isopropanol-Acetone-Hydrogen Chemical Heat Pump
Get PDF This paper presents an experimental system of isopropanol-acetone-hydrogen chemical heat pump (IAH CHP) for the recovery of low-grade