174 research outputs found
Iron Based Nano-hydrotalcites Promoted with Cu as Catalysts for Fischer-tropsch Synthesis in Biomass to Liquid Process
No full textTwo different groups of MgCuFe catalysts derived from hydrotalcite-like precursors were prepared through ultrasound-assisted (US) co-precipitation and solvent-free ball milling methods (BM). The catalysts were activated at 623°K, 1.5 MPa for 4 h in syngas, and their performances in the production of fuels through Fischer–Tropsch (FT) synthesis were evaluated in a fixed bed reactor at temperatures ranging from 473° to 573°K and 2 MPa and H2/CO molar ratio of 2. The physicochemical properties of the fresh and spent catalysts were investigated and characterized using different methods, including XRPD, ICP-OES, SEM, and TEM. Catalysts displayed similar catalytic activity for both BM and US with minor differences when operating at temperatures from 473° to 523°K. The results hint at the possibility of using synthetic hydrotalcites as Fe-based catalysts for the Fischer–Tropsch synthesi
Determination of vapour pressures of FAME industrial mixtures by ebullioscopic and thermogravimetric experimental methods
No full textVapour pressure (VP) is a parameter that characterizes, by principle, only pure compounds. Nevertheless, it can refer also to mixtures in order to characterize their volatility or to be inserted in technical documents. The measurement of VP for mixtures is strongly dependent on the possible variation of the composition, during experiments, due to the different volatility of the constituent compounds. It is possible to calculate the VP of the mixture starting from its composition, but different thermodynamic scenarios must be considered. Moreover, for industrial samples, possible effects due to the presence of impurities must be considered. In this work, two different experimental methods have been employed to determine VP of some acetates esters and two industrial mixtures of fatty acid methyl esters (FAME). The first method is a direct ebullioscopic method, while the second is an indirect thermogravimetric analysis (TGA). An error function was calculated to compare the experimental results of VPs obtained with the two methodologies with the theoretical ones. Ebullioscopic measures resulted suitable only for acetates esters, as FAME mixtures are characterized by VPs too low to be quantified with this technique. On the contrary, TGA methodology is more accurate for FAME than acetates. It allows the collection of a great number of VP values with a very fast analysis. This method is less accurate than others, but it can be useful for a fast screening of the FAME mixtures, also contaminated with light impurities
Simulated-Experimental Cross Validation of Multistage Batch Distillation for Water/Propylene Glycol Separation as Educational Exercise
No full textThis study describes an educational exercise concerning the multistage batch distillation of the mixture water-propylen glycol (PG). The research study consisted of three primary components: practical experimentation using a batch distillation setup, computer simulations, utilizing the AVEVA PRO/IITM software, and the development and operation of a multistage system. The initial experiment was centred around the process of distillation involving mixtures of n-heptane/toluene and water/PG. This phase aimed to establish a fundamental understanding that would be crucial for conducting further simulations using the AVEVA PRO/IITM platform. The utilisation of these simulations is the basic background in customizing the design and optimizing the performance parameters of the multistage distillation plant, hence guaranteeing the highest possible level of separation efficiency
Metallosilicates as an iron support to catalyze Fischer-Tropsch synthesis
No full textMetallosilicates are tunable molecular sieves that have been applied in Fischer-Tropsch synthesis as supports and promoters of cobalt-based catalysts. Here, for the first time, we synthesize iron based catalysts over Ce, Zr, V, and Ti metallosilicates with an nonhydrolytic surfactant assisted sol–gel method adapted from literature. The catalysts were activated at 350 ∘C, 0.4 MPa for 4 h in syngas (H2:CO = 2). The reactor operated at 2 MPa and from 200 ∘C 350 ∘C for 90 h at a feed ratio (H2:CO = 2). The BET surface area of Fe/Zr/SiO2 was highest at (335 m2 g−1) followed by Fe/Ti/SiO2 at 228 m2g −1. Despite its low surface area, (54 m2 g − 1), Fe/Ce/SiO2 converted the most CO (68%)while the Fe/Ti/SiO2, converted the least of the CO at 7%. CO conversion increased with temperature for all catalysts. Product selectivity to C7+ (corresponding to the α = 0.72) exceeded 60% for all catalysts and was highest at 250∘. The C2+ selectivity follows the order V (18%) < Ti (20%) < Zr (52%) < Ce (68%). The catalyst activity was stable up to 120 h on stream
Copper, potassium promoted iron on metallosilicate and aluminum oxide supports synthesized via a non-hydrolytic sol-gel for Fischer-Tropsch
No full textInflöde-bearbetning-utflöde : En studie om språk- och kunskapsutvecklande arbetssätt i internationella klasser.
No full textLanguage is the basis for all communication. Man needs a rich and nuanced language to understand and be understood. With a new language is a new culture, a new identity and a new need to be included in a community. Language develops only if it is used. The use of the language through conversation, reading and writing, working in various forms, gives the student capability to process the inflow of a future outflow. Arian Asinger is the author of this essay written at Södertörn University spring semester 2009. Instructor for the paper has been Per Sundgren. The essay has been named "Inflow - processing - output. A study of language- and knowledge based development approach in international classes". This work puts forward four teachers teaching methods in international classes in a school in central Sweden. With international classes meant preparation classes to newly arrived refugees and immigrants with a different mother tongue than Swedish. The main purpose of this study is to present the teaching methods of research considers the promotion of pupils' learning and language skills development. This has been lodged against the teachers working in reality and what teaching methods they use. The material is collected from a qualitative research through interviews. The result is then analyzed against previous research which shows differences in teaching methods and educational philosophy which might depend on teachers' educational background in the subject Swedish as a second language
Inflöde-bearbetning-utflöde : En studie om språk- och kunskapsutvecklande arbetssätt i internationella klasser.
No full textLanguage is the basis for all communication. Man needs a rich and nuanced language to understand and be understood. With a new language is a new culture, a new identity and a new need to be included in a community. Language develops only if it is used. The use of the language through conversation, reading and writing, working in various forms, gives the student capability to process the inflow of a future outflow. Arian Asinger is the author of this essay written at Södertörn University spring semester 2009. Instructor for the paper has been Per Sundgren. The essay has been named "Inflow - processing - output. A study of language- and knowledge based development approach in international classes". This work puts forward four teachers teaching methods in international classes in a school in central Sweden. With international classes meant preparation classes to newly arrived refugees and immigrants with a different mother tongue than Swedish. The main purpose of this study is to present the teaching methods of research considers the promotion of pupils' learning and language skills development. This has been lodged against the teachers working in reality and what teaching methods they use. The material is collected from a qualitative research through interviews. The result is then analyzed against previous research which shows differences in teaching methods and educational philosophy which might depend on teachers' educational background in the subject Swedish as a second language
Roman primacy and the development of the synodal institution in the period of the Arian controversy
No full textThe object of this study is process of evolution of church organization in the 4th century, especially the relationships between Roman primacy and synodal institution in the epoch of the Arian controversy. The author examines evolution of the institution of the Roman synod and practice of participation of the Roman See in church councils outside Rome, focusing on the unsuccessful attempt to convene the general council in Rome in 382. Analysis of historical data shows that the ability of the Roman see to organize in a short time a representative council (mainly of the Italian bishops) allowed Rome to claim for a special status within the church communion. In the same time the Roman See did not become in the 4th century the center of conciliar activity at the universal level. Participation of Rome in Ecumenical and Western councils was quite passive. In the second part of the paper the author attempts to reconstruct various models of church organization, which were typical for the western and the eastern episcopate in the 4th century. The author concludes that the real initiator of the development of universal primacy of Rome was not originally the pope, but the western episcopate (council of Serdica, 343). In the second part of the 4th century pope Damasus developed this conception, putting the principle of primacy of the Roman See as the chair of Peter above principle of synodal consensus. At the same time eastern bishops considered the Roman chair as the center of the West, rather than the head of the whole Church. Sometimes they invited bishop of Rome and other western bishops to act as arbiters in the eastern conflicts, but more often they defended the idea of full autonomy of the East
Addressing Safety and Risk Mitigation in Academic Laboratories: a Case Study
No full textThis study addresses the critical need for effective risk assessment and mitigation strategies in academic research environments. As research laboratories engage in increasingly complex projects, ensuring the safety of personnel, equipment, and the surrounding environment becomes paramount. These settings are prone to various vulnerabilities, including manual operations, transient states, and diverse training backgrounds.
This work presents a case study focusing on the potential hazards and risks associated with Fischer-Tropsch synthesis. The analysis examines critical factors such as catalyst use, high-temperature reactions, potential by-products, and the influence of human error during manual operations.
Utilizing a systematic approach that incorporates interaction matrices and HAZOP analysis, the study identifies potential undesired scenarios, ranging from minor incidents to severe consequences, and evaluates their likelihood and impact. In response to the identified risks, the paper proposes targeted mitigation measures specifically designed for the Fischer-Tropsch experimental setting, structured as layers of protection.
The findings of this research offer valuable insights into laboratory safety in academic settings, providing a risk assessment and mitigation model adaptable to various experimental setups. By integrating theoretical frameworks with practical applications, this study aims to enhance safety standards in academic laboratories conducting Fischer-Tropsch synthesis and establish a foundation for continuous improvement in laboratory practices
Biographies of ancient and modern celebrated freethinkers : reprinted from an English work, entitled "Half-hours with the freethinkers" /
No full textOn cover: Half hours with freethinkers.Thomas Hobbes.--Lord Bolingbroke.--Condorcet.--Spinoza.--Anthony Collins.--Des Cartes.--M. de Voltaire.--John Toland.--Compte de Volney.--Charles Blount.--Percy Byssche Shelley.--Claude Arian Helvetius.--Frances W. D'Arusmont.--Epicurus.--Zeno.--Matthew Tindal.--David Hume.--Dr. Thomas Burnet.--Thomas Paine.--Baptiste de Mirabaud.--Baron d'Holbach.--Robert Taylor.--Joseph Barker.Mode of access: Internet
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