HZSM-5/SAPO-34 based catalysts for the transformation of dimethyl ether into olefins

[EN] The catalytic transformation of dimethyl ether with HZSM-5/SAPO-34 based catalysts has been studied. The process aims to selectively produce light olefins and propylene in particular, attending to their higher market demand, while using a fixed bed reactor and a microporous acid HZSM-5 zeolite, SAPO-34 catalyst and a composite catalyst obtained by physical blending of the previous acid phases. This Bachelor Thesis focuses on exploring the effect of process conditions (including the catalyst) on the reaction indexes (conversion, yield and selectivity). Besides, it will open new research frontiers for the student in terms of catalyst synthesis and characterization, laboratory methods and spectroscopy, among others

Operating Point Optimization of a Hydrogen Fueled Hybrid Solid Oxide Fuel Cell-Steam Turbine (SOFC-ST) Plant

This paper presents a hydrogen powered hybrid solid oxide fuel cell-steam turbine (SOFC-ST) system and studies its optimal operating conditions. This type of installation can be very appropriate to complement the intermittent generation of renewable energies, such as wind generation. A dynamic model of an alternative hybrid SOFC-ST configuration that is especially suited to work with hydrogen is developed. The proposed system recuperates the waste heat of the high temperature fuel cell, to feed a bottoming cycle (BC) based on a steam turbine (ST). In order to optimize the behavior and performance of the system, a two-level control structure is proposed. Two controllers have been implemented for the stack temperature and fuel utilization factor. An upper supervisor generates optimal set-points in order to reach a maximal hydrogen efficiency. The simulation results obtained show that the proposed system allows one to reach high efficiencies at rated power levels.This work has been carried out in the Intelligent Systems and Energy research group of the University of the Basque Country (UPV/EHU) and has been supported by the UFI11/28 research grant of the UPV/EHU and by the IT677-13 research grant of the Basque Government (Spain) and by DPI2012-37363-CO2-01 research grant of the Spanish Ministry of Economy and Competitiveness

Multi revolution finite element model to predict machining induced residual stresses in Inconel 718

Inconel 718 is commonly used in structural critical components of aircraft engines due to its mechanical thermal properties at high temperatures, which makes it to be considered as a difficult to machine material. In these critical parts, such as disk turbines, surface integrity should be assured in order to ensure the expected fatigue life. In order to determine the influence of feed and depth of cut in residual stresses a finite element facing model has been developed. This model takes into account the complex thermo mechanical phenomena that take place during chip formation process as well as the effect of cyclic loading phenomena due to the successive revolutions. Firstly, full stress, strain and temperature fields are obtained with a Deform 3D v10.2 nose turning model. Those fields are introduced in a multi revolution Abaqus/Standard v6.12 machining model. Finally the residual stresses of the model are extracted as an approach of Hole Drilling measurement technique. The results are in good agreement with empirical measurements

Automatic Synthesis of Feedforward Elements in Quantitative Feedback Theory

Recent developments in quantitative feedback theory (QFT) lead to feedforward design problems with both magnitude and phase constraints. In these cases, manual feedforward tuning becomes much more challenging and time consuming than the traditional prefilter shaping taking place on the Bode plot. This article presents a general procedure for the automatic synthesis of such elements. Feedforward bounds in the complex plane are expressed as constraints of a linear programming problem in which the Bode real-complex relation is implicitly considered, ensuring a stable rational solution. The methodology is successfully tested in a well-known benchmark problem.Euskal Herriko Unibertsitatea, Grant/Award Number: GIU16/54; Ministerio de Economia y Competitividad, Grant/Award Number: DPI2015-64985-

ANALISIS KEANDALAN SALURAN UDARA TEGANGAN MENENGAH (SUTM) 20 kV BERDASARKAN SAIDI DAN SAIFI PADA PT. PLN (PERSERO) RAYON DURI RIAU

ANALISIS KEANDALAN SALURAN UDARA TEGANGAN MENENGAH (SUTM) 20 kV BERDASARKAN SAIDI DAN SAIFI PADA PT.PLN (PERSERO) RAYON DURI RIAU OSTOLAZA RENALDI NIM :11455105748 Tanggal Sidang :17 Desember 2021 Program Studi Teknik Elektro Teknik Elektro Fakultas Sains dan Teknologi Universitas Islam Negeri Sultan Syarif Kasim Riau Jl. Soebrantas No. 155 Pekanbaru ABSTRAK Saat ini tingkat keandalan dari suatu sistem distribusi adalah sangat penting guna menjamin kontinuitas supply tenaga listrik kepada konsumen. Serta semakin meningkatnya tuntutan dan kebutuhan pelanggan terhadap Suplai Daya listrik di Indonesia khususnya Unit Pengatur Jaringan (UPJ) Duri dan untuk mencapai penetapan Tingkat Mutu Pelayanan yang telah ditetapkan oleh PT. PLN (Persero). Dengan penilitian dan peninjauan di lapangan di Unit Pelayanan dan Jaringan (UPJ) Duri. Penelitian dilakukan dengan cara mengumpulkan data terkait frekuensi dan durasi gangguan yang terjadi pada tahun 2019,penelitian ini bertujuan untuk menganalis keandalan saluran udara tengangan menengah (SUTM) 20 kV berdasrkan SAIDI dan SAIFI pada PT. PLN (Persero) Rayon Duri Riau. Dari peneletian didapatkan bahwa indek keandalan sistem berdasarkan SAIDI terbesar bulan April yaitu 6,265 dan yang terkecil pada bulan Oktober yaitu 1,434. Dan nilai SAIFI terbersar pada bulan Oktober yaitu 0,05622 dan yang terkecil pada bulan Februari yaitu 0,00238. Dibandingkan dengan ketetapan sistem pada PT. PLN (Persero) Rayon Duri Riau yaitu 1,04 untuk SAIFI, sedangkan untuk nilai SAIDI yaitu 2,12.Nilai ASAI (Averange Service Availability Index) dikategorikan belum handal karena melebihi standard IEEE sebesar 0,999271. Kata kunci : Keandalan, SAIDI, SAIFI, Sistem Distribusi 20 k