scholarly journals METODE PERHITUNGAN MASSA GAS CO2 YANG DISERAP FOTOBIOREAKTOR DENGAN PERSAMAAN GAS IDEAL

2016 ◽  
Vol 11 (2) ◽  
pp. 239
Author(s):  
Arif Dwi Santoso

BPPT conducted the mass of CO2 gas calculation in the gas absorption experiments with phytoplankton cultivation in the photobioreaktor (FBR) batch and continous syatem using the ideal gas equation. This study stated that the method of calculation with the ideal gas equation is more simple and practical in providing data analysis compared with biomass methods. Some things to note in this method include good knowledge about the movement of the gas flow diagram of inputs and outputs FBR, an appropriate gas sampling, and accuracy of measuring instruments. The required data in the mass calculation of CO2 gas in a batch photobioreactor system was resultant CO2 concentration during measurement. Meanwhile in a continuous systems, the requireddata was CO2 concentration at the reactor input and output , the rate and duration of the injection gas.Keywods : massa gas CO2, dry weight, ideal gas formula

Author(s):  
Michael James Martin

Gas flow through arrays of rectangular nano-fins is modeled using the linearized free-molecular drag and heat transfer equations. These are combined with the one-dimensional equations for conservation of mass, momentum, and energy, and the ideal gas law, to find the governing equations for flow through the array. The results show that the pressure gradient, temperature, and local velocity of the gas are governed by coupled ordinary differential equations. The system of equations is solved for representative arrays of nano-fins to find the total heat transfer and pressure drop across a 1 cm chip.


2018 ◽  
Vol 9 (2) ◽  
pp. 42
Author(s):  
S Setiadi ◽  
Dijan Supramono ◽  
Nur Istiqomah

Efforts to improve the performance of CO2 absorption using bubbling columns and liquid jet flow have consistently been developed. The advantage of the present column is the presence of gas entrainment by suction of nozzle and the gas dispersed throughout the bulk of liquid by the formation of bubble clouds. The selection of liquid jet flow configuration used parameters of nozzle position and liquid jet inclination. The configurations have been examined by hydrodynamic test by measuring the ratio of volumetric rate of gas to that of liquid exiting nozzle (QG/QL) and gas holdup. Absorption test to the best configuration used NaOH solution with flowrate of 5 litres/min at atmospheric pressure and CO2 gas feed of 96.6%. The results showed that the configurations of liquid jet flow gave significant effect on hydrodynamics and that the best configurations had gas hold-up in the range of 0.55-0.6 and QG/QL 1.3-1.8. Absorption tests showed that CO2 concentration can be reduced into 0.01%-0.07% in less than five minutes and the absorption should proceed with the chemical reaction up to 10 minutes with no indication of CO2 desorption. The bubbles were generated in the column predominantly in the diameter range of 0.00097-0.00184 mm.Keywords: Configurations of liquid jet, bubble column, gas entrainment, CO2 gas absorption AbstrakUpaya meningkatkan kinerja absorpsi gas CO2 yang memanfaatkan kolom gelembung dan liquid jet flow telah banyak dilakukan. Keunggulan kolom gelembung dalam riset ini adalah kolom menyebabkan gas entrainment (pengisapan gas) dan dispersi gas ke dalam cairan yang membentuk awan gelembung. Pemilihan konfigurasi liquid jet flow terbaik berdasarkan posisi nosel dan arah sudut tembakannya dan dengan mengukur rasio laju volumetrik aliran gas entrainment terhadap laju volumetrik aliran cairan (QG/QL) serta gas hold-up untuk setiap konfigurasi. Konfigurasi terbaik digunakan untuk menentukan kinerja kolom gelembung untuk mendapatkan kinerja kemampuan absorpsi yang setinggi-tingginya. Uji absorpsi dilakukan terhadap konfigurasi terbaik dengan menggunakan absorben larutan NaOH dengan laju alir 5 L/min pada tekanan atmosferik dan umpan gas CO2 dengan kadar 96,6%. Hasil penelitian menunjukkan bahwa konfigurasi memberikan pengaruh cukup signifikan dan bahwa konfigurasi terbaik memberikan gas hold-up kisaran 0,55-0,65 dan rasio QG/QL bernilai 1,3-1,8. Uji absorpsi menunjukkan berkurangnya kadar CO2 menjadi 0,01% hingga 0,07% setelah absorpsi kurang dari 5 menit dan tetap tidak berubah sampai 10 menit. Hal ini menandakan bahwa absorpsi terjadi secara kimiawi antara gas CO2 dan NaOH and tidak terjadi desorpsi walaupun kolom gelembung tetap resirkulasi. Populasi gelembung menunjukkan distribusi ukuran gelembung lebih dominan pada rentang diameter antara 0,00097-0,00184 mm.Kata Kunci: Konfigurasi liquid jet, kolom gelembung, gas entrainment, absorpsi gas CO2


Author(s):  
Lucian Hanimann ◽  
Luca Mangani ◽  
Ernesto Casartelli ◽  
Damian Vogt ◽  
Marwan Darwish

In the majority of compressible flow CFD simulations, the standard ideal gas state equation is accurate enough. However, there is a range of applications where the deviations from the ideal gas behaviour is significant enough that performance predictions are no longer valid and more accurate models are needed. While a considerable amount of the literature has been written about the application of real gas state equations in CFD simulations, there is much less information on the numerical issues involved in the actual implementation of such models. The aim of this article is to present a robust implementation of real gas flow physics in an in-house, coupled, pressure-based solver, and highlight the main difference that arises as compared to standard ideal gas model. The consistency of the developed iterative procedures is demonstrated by first comparing against results obtained with a framework using perfect gas simplifications. The generality of the developed framework is tested by using the parameters from two different real gas state equations, namely the IAPWS-97 and the cubic state equations state equations. The highly polynomial IAPWS-97 formulation for water is applied to a transonic nozzle case where steam is expanded at transonic conditions until phase transition occurs. The cubic state equations are applied to a two stage radial compressor setup. Results are compared in terms of accuracy with a commercial code and measurement data. Results are also compared against simulations using the ideal gas model, highlighting the limitations of the later model. Finally, the effects of the real gas formulations on computational time are compared with results obtained using the ideal gas model.


2013 ◽  
Vol 135 (9) ◽  
Author(s):  
Michael James Martin

Gas flow through arrays of rectangular nanofins is modeled using the linearized free-molecular drag and heat transfer equations. These are combined with the one-dimensional equations for conservation of mass, momentum, and energy, and the ideal gas law, to find the governing equations for flow through the array. The results show that the pressure gradient, temperature, and local velocity of the gas are governed by coupled ordinary differential equations. The system of equations is solved for representative arrays of nanofins to find the total heat transfer and pressure drop across a 1 cm chip.


REAKTOR ◽  
2014 ◽  
Vol 15 (1) ◽  
pp. 37
Author(s):  
Hadiyanto Hadiyanto ◽  
W Widayat

Mikroalga memiliki potensi dalam membiofiksasi CO2 dan dapat dimanfaatkan untuk mengurangi kadar CO2 dalam gas pencemar. Pertumbuhan mikroalga sangat dipengaruhi oleh konsentrasi gas CO2 di dalam gas pencemar. Tujuan penelitian ini adalah untuk mengeetahui kemampuan mikroalga Chlamydomonas sp yang dikultivasi dalam photobioreaktor tubular dalam penyerapan gas CO2 serta untuk mengetahui konsentrasi maksimum gas CO2 dalam umpan untuk memproduksi biomasa mikroalga yang optimal. Percobaan dilakukan dnegan memvariasi laju alir dari 0.03 -0.071 L/menit dan konsentrasi CO2 dalam umpan 10-30%. Hasil penelitian menunjukkan bahwa biomasa mikroalga dapat diproduksi dengan maksimal dengan konsentrasi gas CO2 20% dengan laju alir 0.07 L/min. Semakin tinggi laju alir maka produksi biomasa alga semakin besar. Kecepatan pertumbuhan alga maksimum terjadi pada 0.31 /hari. Pada konsentrasi gas CO2 30%, terjadi substrate inhibition yang disebabkan carbon dalam bentuk ion bicarbonate tidak dapat dikonsumsi lagi di dalam kultur alga. Kata kunci : Mikroalga, chlamydomonas sp, biofiksasi CO2, biogas Abstract Microalgae have a potential for CO2 biofixation and therefore can be used to reduce the CO2 concentration in the gas pollutants. Moreover, microalgae growth is strongly affected by the concentration of CO2 in the exhaust gas pollutants. The objective of this research was to investigate the ability of microalgae Chlamydomonas sp which was cultivated in a tubular photobioreactor for CO2 absorption as well as to determine the maximum concentration of CO2 in the feed gas to obtain optimum microalgae biomass. The experiments were performed by varying the gas flow rate of 0.03 -0.071 L / min and the concentration of CO2 in the feed of 10-30%. The results showed that the maximum biomass of microalgae can be produced with CO2 concentration of 20% vol with a flow rate of 0.07 L / min. The result also showed that increasing the gas flow rate, the greater of the production of algal biomass and the maximum algae growth rate occurred at 0.31 / day. At a concentration of 30% CO2 gas, it occurs a substrate inhibition due to inefficient of bicarbonate use by algae culture.


2011 ◽  
Vol 1 (3) ◽  
Author(s):  
Lal. Singh ◽  
Dheerendra Singh ◽  
Subedar Ram

AbstractThis paper investigates the problem of propagation of planar and non-planar weak shock waves in a non-ideal medium. The mathematical formulation developed in this work leads to a closed system of coupled transport equations which efficiently describes the strength of a shock wave and the first order discontinuities induced behind it. The influence of the parameter of non-idealness and the non planar configuration of the wavefront on the nonlinear distortion, attenuation and shock formation of pulses, are discussed in detail. An analytical expression for the shock formation distance is obtained and a direct comparison between the ideal versus the non ideal gas flow is established. Also, the usual asymptotic decay laws for weak shock are recovered.


Author(s):  
Kevin H. Hunter ◽  
Jon-Marc G. Rodriguez ◽  
Nicole M. Becker

Beyond students’ ability to manipulate variables and solve problems, chemistry instructors are also interested in students developing a deeper conceptual understanding of chemistry, that is, engaging in the process of sensemaking. The concept of sensemaking transcends problem-solving and focuses on students recognizing a gap in knowledge and working to construct an explanation that resolves this gap, leading them to “make sense” of a concept. Here, we focus on adapting and applying sensemaking as a framework to analyze three groups of students working through a collaborative gas law activity. The activity was designed around the learning cycle to aid students in constructing the ideal gas law using an interactive simulation. For this analysis, we characterized student discourse using the structural components of the sensemaking epistemic game using a deductive coding scheme. Next, we further analyzed students’ epistemic form by assessing features of the activity and student discourse related to sensemaking: whether the question was framed in a real-world context, the extent of student engagement in robust explanation building, and analysis of written scientific explanations. Our work provides further insight regarding the application and use of the sensemaking framework for analyzing students’ problem solving by providing a framework for inferring the depth with which students engage in the process of sensemaking.


2016 ◽  
Vol 30 (26) ◽  
pp. 1650186
Author(s):  
B. Yavidov ◽  
SH. Djumanov ◽  
T. Saparbaev ◽  
O. Ganiyev ◽  
S. Zholdassova ◽  
...  

Having accepted a more generalized form for density-displacement type electron–phonon interaction (EPI) force we studied the simultaneous effect of uniaxial strains and EPI’s screening on the temperature of Bose–Einstein condensation [Formula: see text] of the ideal gas of intersite bipolarons. [Formula: see text] of the ideal gas of intersite bipolarons is calculated as a function of both strain and screening radius for a one-dimensional chain model of cuprates within the framework of Extended Holstein–Hubbard model. It is shown that the chain model lattice comprises the essential features of cuprates regarding of strain and screening effects on transition temperature [Formula: see text] of superconductivity. The obtained values of strain derivatives of [Formula: see text] [Formula: see text] are in qualitative agreement with the experimental values of [Formula: see text] [Formula: see text] of La[Formula: see text]Sr[Formula: see text]CuO4 under moderate screening regimes.


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