scholarly journals Vehicular Quality Biomethane Production from Biogas by Using an Automated Water Scrubbing System

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
R. Chandra ◽  
V. K. Vijay ◽  
P. M. V. Subbarao
Keyword(s):  
Steady State ◽  
Control Systems ◽  
Flow Rate ◽  
Packed Bed ◽  
Operating Pressure ◽  
Absorption Column ◽  
Automatic Control Systems ◽  
Steady State Operation ◽  
Biomethane Production ◽  
Column Pressure

This paper presents the results of an automated water scrubbing system used for enrichment of methane content in the biogas, to produce vehicular grade biomethane fuel. Incorporation of automatic control systems for precisely regulating the water level and maintaining constant operating pressure in the packed bed absorption column of water scrubbing system resulted in steady-state operation of the scrubbing system and a consistent supply of methane-enriched biogas from the gas outlet. The improved automated water scrubbing system was found to enrich 97% methane at an operating column pressure of 1.0 MPa with 2.5 m3/h biogas in-flow rate and 2.0 m3/h water in-flow rate into the scrubbing column unit.

Performance Enhancement by Dynamic Valve Timing of a Multistage Vacuum Micropump

2010 ◽  
Author(s):  
Karthik Kumar ◽  
Luis P. Bernal ◽  
Khalil Najafi
Keyword(s):  
Steady State ◽  
Flow Rate ◽  
Pressure Difference ◽  
Performance Enhancement ◽  
High Vacuum ◽  
Operating Pressure ◽  
Transient Operation ◽  
Valve Timing ◽  
Steady State Operation ◽  
Valve Leakage

This paper presents the results of a theoretical analysis of dynamic valve timing on the performance of a multistage peristaltic vacuum micropump. Prior work has shown that for optimum steady state performance a fixed valve timing which depends on the operating pressure can be found. However, the use of a fixed valve timing could hinder performance for transient operation when the pump is evacuating a fixed volume. At the beginning of the transient the pump operates at low pressure difference and a large flow rate would be desirable. As the pump reaches high vacuum the pressure difference is large and the flow rate is necessarily small. Astle and coworkers1–3 have shown using a reduced order model that for steady state operation short valve open time results in lower inlet pressure and flow-rate and conversely. Here we extend the model of Astle and coworkers to include transient operation, multiple coupled stages and non-ideal leaky valves, and show that dynamic valve timing (DVT) reduces the transient duration by 30% compared to high vacuum pressure valve timing. The results also show a significant reduction in resonant frequency of the pump at low pressures, and quantify the effect of valve leakage.

scholarly journals Calculation of acoustic flow-rate measurements error with the help of Fermat’s principle

2018 ◽  
Vol 211 ◽  
pp. 04007
Author(s):  
Alexander Petrov ◽  
Semyon Shkundin
Keyword(s):  
Control Systems ◽  
Cross Section ◽  
Flow Rate ◽  
Three Dimensional ◽  
Air Flow Rate ◽  
Velocity Measurements ◽  
Three Dimensional Flow ◽  
Automatic Control Systems ◽  
A Value ◽  
Flow Changes

The establishment of dispatching and automatic control systems for mine ventilation is impossible without the availability of perfect air flow rate sensors. Existing anemometers (tachometer, heat) do not meet these requirements. The error of average in cross section velocity measurements with such sensors reaches 15-20, sometimes 30%. The reason - the speed measured at one point is interpreted as the average over the cross section. The reliability of the sensors is small, because they are exposed to the damaging effect of a dusty atmosphere. Stationary installed anemometers clutter cross section, which is not always allowed. Fermat’s variational principle is used for derivation of the formula for the time of propagation of a sonic signal between two set points A and B in a steady three-dimensional flow of a fluid or gas. It is shown that the fluid flow changes the time of signal reception by a value proportional to the flow rate independently of the velocity profile. The time difference in the reception of the signals from point B to point A and vice versa is proportional with a high accuracy to the flow rate. It is shown that the relative error of the formula does not exceed the square of the largest Mach number. This makes it possible to measure the flow rate of a fluid or gas with an arbitrary steady subsonic velocity field

scholarly journals Capturing CO2 from Biogas by MEA (Monoethanolamine) using Packed Bed Scrubber

2020 ◽  
Vol 4 (2) ◽  
pp. 105
Author(s):  
Iqbal Nur Daiyan ◽  
Leila Kalsum ◽  
Yohandri Bow
Keyword(s):  
Flow Rate ◽  
Combustion Process ◽  
Packed Bed ◽  
Co2 Absorption ◽  
Absorption Column ◽  
Fossil Energy ◽  
Spray Tower ◽  
Biogas Purification ◽  
Carbon Dioxide Co2 ◽  
Reduction Of Co2

Biogas adalah salah satu sumber energi terbarukan yang dapat dimanfaatkan sebagai pengganti energi fosil. Biogas sebagian besar mengandung metan (CH4) dan karbon dioksida (CO2). Kandungan CO2 pada biogas mengurangi efisiensi pada proses pembakaran dan dapat menyebabkan korosi pada komponen-komponen logam yang kontak langsung dengan biogas. Pemurnian biogas dengan absorpsi merupakan suatu cara untuk menurunkan kadar CO2 yang terkandung, dan meningkatkan kandungan CH4 pada biogas sehingga biogas yang dihasilkan dapat digunakan sebagai bahan bakar. Penelitian ini ditujukkan untuk mempelajari pengaruh konsentrasi monoethanolamine (MEA) dan laju alir absorben terhadap penurunan kadar CO2 yang terkandung dalam biogas. Proses absorpsi CO2 dilakukan pada scrubber tipe spray tower, scrubber yang digunakan pada penelitian ini berbahan akrilik dengan diameter 64 mm, panjang scrubber 750 mm, tinggi packing pada scrubber 500 mm dan dengan kapasitas 1.5 m3. Laju alir biogas yang digunakan 26 L/menit dengan variasi laju alir larutan MEA sebesar 0,5, 1 dan 1,5 L/menit dan variasi konsentrasi larutan MEA sebesar 1, 3, 5, dan 7M. Hasil penelitian menunjukkan pada laju alir larutan MEA 1,5 L/menit dengan konsentrasi larutan MEA 7M dapat menurunkan CO2 dari 8,53% menjadi 0,10%, dan dapat meningkatkan kandungan metana (CH4) dari 69,24% menjadi 81,20%.Biogas is a renewable energy source that can be used as a substitute for fossil energy. Biogas mostly contains methane (CH4) and carbon dioxide (CO2). The content CO2 in biogas reduces the efficiency of the combustion process and cause corrosion in metal components when direct contact with biogas. Biogas purification using absorption method can reduce levels of CO2 contained and increase levels of CH4  then the biogas produced can be used as fuel. This research study the effect of monoethanolamine (MEA) concentration and absorbent flow rate on the reduction of CO2 contained in biogas. CO2 absorption process is carried out by a spray tower type scrubber. It consisted of an acrylic absorption column (64 mm in diameter, 750 mm in height, 500 mm in packing height and 1.5 m3 in capacity). Biogas flow rate used is 26 L/min with variation of the flow rate of MEA 0.5, 1, and 1,5 L/min and concentration of MEA solution 1, 3, 5, and 7M. The results showed that the flow rate of MEA 1.5 L/min with a concentration of 7M MEA solution can reduce CO2 from 8.53% to 0.10% and can increase the methane (CH4) load from 69.24% to 81.20%.

scholarly journals Effect of Liquid Flow Rate and Amine Concentration on CO2 Removal from Natural Gas at High Pressure Operation in Packed Absorption Column

2015 ◽  
Vol 773-774 ◽  
pp. 1291-1295 ◽  
Author(s):  
Hairul Nazirah Abdul Halim ◽  
Mohd Shariff Azmi ◽  
Mohammad Azmi Bustam
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Ghg Emissions ◽  
Offshore Platforms ◽  
Operating Pressure ◽  
Absorption Column ◽  
Absorption Performance

Greenhouse gas (GHG) emissions such as carbon dioxide (CO2) and methane (CH4) from oil and natural gas operation at offshore platforms have significant contribution to global warming. The reduction of these GHG emissions is possible through CO2 capture technology. This study reports the absorption performance of monoethanolamine (MEA) for the removal of CO2 from natural gas (NG) at high pressure conditions. The absorption experiments were performed in an absorption column packed with Sulzer Metal Gauze Packing at 5.0 MPa operating pressure. The absorption performance was evaluated in terms of CO2 removal (%) with liquid flow rate ranging from 1.81 to 4.51 m3/m2.h and MEA concentration of 1.0 - 4.0 kmol/m3. It was found that CO2 removal (%) had increased with increasing liquid flow rate and MEA concentration.

Basic Principles of Automatic Control Systems

1948 ◽  
Vol 159 (1) ◽  
pp. 25-45 ◽  
Author(s):  
A. Porter
Keyword(s):  
Steady State ◽  
Automatic Control ◽  
Control Systems ◽  
Servo System ◽  
Main Element ◽  
Small Scale ◽  
Basic Operation ◽  
Basic Principles ◽  
Automatic Control Systems ◽  
Automatic Regulator

The importance of automatic control systems in a wide field of industrial and military applications has been accentuated during the past few years. The object of this paper is to review some of the basic principles of the subject, with special reference to automatic regulating systems. A major difficulty at present is the lack of standardization of the terminology associated with automatic control systems; in this paper an attempt has been made to co-ordinate, albeit on a small scale, generally recognized industrial usage with the recommendations of the Ministry of Supply Servo Nomenclature Panel. It is convenient, for example, to consider an automatic regulator system as a special type of servo-system. In order to present the nomenclature in a manner which may be readily assimilated, the operation of a simple automatic speed regulator is described in detail. The performance of an automatic control system is usually assessed by ( a) the speed of response of the system subsequent to a sudden disturbance, ( b) the nature of the response, and ( c) the magnitude of the steady-state errors. In the case of complex control systems, such as fire-control systems, it is sometimes desirable to study, in addition, the frequency response characteristics of each main element, and to determine the overall performance of the system by the application of vector methods. The latter have been used widely in the solution of acoustical problems, and in the design of electronic feed-back amplifiers, and their adaptation to the analogous problems of servo-system design has considerably facilitated progress. The stabilization of automatic control systems, and the elimination of steady-state errors can often be achieved by the incorporation of subsidiary feed-back loops. For example, a comparison of the basic operation of a typical position control servo-system with that of a typical automatic regulator shows that certain lags in the operation of the latter can be short-circuited by introducing “disturbance feed-back”. This approach to the problem of improving the performance of these systems does not appear to have been treated extensively in the literature. Its value is demonstrated in the paper by comparing the responses of certain idealized automatic thermal regulating systems, some incorporating “disturbance feed-back”, and others with straightforward controllers.

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