Thermodynamic study on vapour-liquid equilibrium of toluene and several types of oil as absorbent

Thermodynamic study on vapour-liquid equilibrium of toluene and several types of oil as absorbent Gas cleaning system is one of important step in the utilization of biomass via gasification process. The producer gas obtained from the gasification process must be very clean before it is used in an internal combustion engine. In order to gaseous fuel get cleaned with a tar content below 100 mg/Nm3, a gas cleaning system using scrubbing oil is being developed and taking the advantage of a lower vapour pressure of oil than scrubbing water. Study on vapour-liquid equilibrium is being conducted to understand the phenomena taking place in the absorption of tar with oil. In our present study, the producer gas containing tar is represented using air containing toluene. This producer gas model with a toluene or benzene concentration then bubbled with a rate of 27.6 mL/min into a bath of oil at a various temperature. The progress of absorption of tar model in oil measured gas chromatography until saturated condition. Considering that the concentration of toluene in the gas stream is very low, the toluene and oil vapour-liquid equilibrium follows the Henry’s law. Prediction of Henry’s constants is also carried out using UNIFAC-FV model which is known to be suitable for hydrocarbon gases and high-boiling point hydrocarbon solvent. Keywords: tar, oil, Henry’s constant AbstrakSistem pembersihan gas merupakan salah satu langkah penting dalam pemanfaatan biomassa melalui proses gasifikasi. Gas produser yang dihasilkan dari proses gasifikasi harus sangat bersih sebelum digunakan dalam mesin pembakaran internal. Untuk mendapatkan bahan bakar gas yang bersih dengan kandungan tar di bawah 100 mg/Nm3. Sebuah sistem pembersihan gas dengan menggunakan minyak sebagai media penyerap dikembangkan dengan mengambil keuntungan dari tekanan uap minyak lebih rendah air penyerap. Studi kesetimbangan uap-cair yang dilakukan untuk memahami fenomena yang terjadi dalam penyerapan tar dengan minyak. Dalam kami studi ini, gas produser yang mengandung direpresentasikan dengan udara yang mengandung toluena. Model gas produser ini dibuat dengan menggelembungkan konsentrasi benzena atau toluena dengan laju 27,6 mL/menit ke dalam bak minyak pada berbagai suhu. Kemajuan penyerapan model tar dalam minyak diukur dengan cromathograpy gas sampai dengan kondisi jenuh. Mengingat konsentrasi toluena dalam aliran gas sangat rendah, maka kesetimbangan uap-cair toluena dan minyak mengikuti hukum Henry. Konstanta Henry juga dapat diprediksi dengan menggunakan model UNIFAC-FV yang cocok untuk gas hidrokarbon dan pelarut hidrokarbon dengan titik didih tinggi. Kata kunci: tar, minyak, konstanta Henry

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Quality assessment of gas produced from different types of biomass pellets in gasification process

Energy Exploration & Exploitation ◽

10.1177/0144598719875272 ◽

2019 ◽

Vol 38 (2) ◽

pp. 406-416 ◽

Cited By ~ 2

Author(s):

Marcel Mikeska ◽

Jan Najser ◽

Václav Peer ◽

Jaroslav Frantík ◽

Jan Kielar

Keyword(s):

Gas Turbines ◽

Combustion Engine ◽

Calorific Value ◽

Internal Combustion ◽

Combustion Gas ◽

Gas Cleaning ◽

Gasification Process ◽

Different Types ◽

Before And After ◽

Cleaning Technology

Gas from the gasification of pellets made from renewable sources of energy or from lower-quality fuels often contains a number of pollutants. This may cause technical difficulties during the gas use in internal combustion gas engines used for energy and heat cogeneration. Therefore, an adequate system of gas cleaning must be selected. In line with such requirements, this paper focuses on the characterization and comparison of gases produced from different types of biomass during gasification. The biomass tested was wood, straw, and hay pellets. The paper gives a detailed description and evaluation of the measurements from a fix-bed gasifier for the properties of the produced gases, raw fuels, tar composition, and its particle content before and after the cleaning process. The results of elemental composition, net calorific value, moisture, and ash content show that the cleaned gases are suitable for internal combustion engine-based cogeneration systems, but unsuitable for gas turbines, where a different cleaning technology would be needed.

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Developing an adsorption-based gas cleaning system for a dual fluidized bed gasification process

Biomass Conversion and Biorefinery ◽

10.1007/s13399-020-00999-1 ◽

2020 ◽

Author(s):

J. Loipersböck ◽

G. Weber ◽

R. Rauch ◽

H. Hofbauer

Keyword(s):

Fluidized Bed ◽

Gas Cleaning ◽

Gasification Process ◽

Cleaning System ◽

Dual Fluidized Bed

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CO2 gasification of microalgae (N. Oculata) – A thermodynamic study

MATEC Web of Conferences ◽

10.1051/matecconf/201815401002 ◽

2018 ◽

Vol 154 ◽

pp. 01002 ◽

Cited By ~ 1

Author(s):

Muflih Arisa Adnan ◽

Mohammad Mozahar Hossain

Keyword(s):

Performance Evaluation ◽

Atmospheric Pressure ◽

High Performance ◽

Aspen Plus ◽

Thermodynamic Study ◽

Producer Gas ◽

System Efficiency ◽

High Concentration ◽

New Model ◽

Gasification Process

A new model of CO2 gasification has been developed in the Aspen Plus. The potential of microalgae (N. oculata) for CO2 gasification also has been investigated. The present gasification process utilizes the CO2 at atmospheric pressure as the gasifying agent. The steam is also injected to the gasification to enhance the H2 production. The composition of the producer gas and gasification system efficiency (GSE) are used for performance evaluation. It is found that the CO2 gasification of microalgae produces a producer gas with a high concentration of CO and H2. The GSE indicates that the process works at high performance.

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A Measurement Device for Online Monitoring of Total Tar in Gasification Systems

Journal of Energy Resources Technology ◽

10.1115/1.4032730 ◽

2016 ◽

Vol 138 (4) ◽

Cited By ~ 7

Author(s):

A. Gredinger ◽

D. Schweitzer ◽

H. Dieter ◽

G. Scheffknecht

Keyword(s):

Online Monitoring ◽

Filter Material ◽

Thermal Conversion ◽

Producer Gas ◽

Gas Cleaning ◽

Flame Ionization ◽

Gasification Process ◽

Difference Measurement ◽

The University

Tars produced during the thermal conversion of coal or especially biomass is one of the major obstacles for the application of gasification systems. They limit the use of the producer gas in engines or turbines or, in further processes like in methanization or conversion to other secondary fuels or chemicals, without further gas cleaning. The determination of the tar content with conventional methods is very time consuming and does not allow continuous online monitoring of the gas quality. One approach to avoid these drawbacks is an automatic system developed at the University of Stuttgart that monitors the tar concentration in the producer gas online and semicontinuous during the gasification process. The technique is based on a flame ionization detector (FID) difference measurement of the hydrocarbons in the producer gas, where the condensable hydrocarbons—the tars—are condensed on a suitable filter material. This work shows the further development of the measurement technique, the choice of a suitable tar filter material for the underlying difference measurement, and a first verification of the system with real producer gas at a 20 kWth bench scale gasifier.

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Application of Recycle System on a Cocoa Pod Husks Gasification in a Fixed-Bed Downdraft Gasifier to Produce Low Tar Fuel Gas

Jurnal Rekayasa Kimia & Lingkungan ◽

10.23955/rkl.v14i2.14160 ◽

2019 ◽

Vol 14 (2) ◽

pp. 120-129

Author(s):

Sunu Herwi Pranolo ◽

Joko Waluyo ◽

Jenni Prasetiyo ◽

Muhammad Ibrahim Hanif

Keyword(s):

Combustion Engine ◽

Fixed Bed ◽

Gravimetric Method ◽

Producer Gas ◽

Fuel Gas ◽

Downdraft Gasifier ◽

Gasification Process ◽

Cold Gas Efficiency ◽

Volumetric Rate ◽

Cocoa Pod Husks

Biomass gasification is potentially generating not only producer gas but also tarry components. Practically, the gas may substitute traditional fuel in an internal combustion engine after reducing the tar. This research examined a producer gas recycle system to reduce tar component of producer gas generated with cocoa pod husks gasification using air as gasifying agent in a fixed-bed downdraft gasifier. Cocoa pod husks feed sizes were +1” sieve, -1”+ 0.5” sieve, and -0.5” sieve. The gasification process was operated at the temperature range of 491 – 940oC and at various gasifying agent volumetric rates of 62.84; 125,68; and 188.53 NL/min or at equivalent ratio range of 0.014 – 0.042. A recycle system of outlet producer gas to gasifier was set at volumetric rates of 0.139; 0.196; and 0.240 L/min. The performance of the system was evaluated with analyzing the tar component using gravimetric method of ASTM D5068-13, and the gas component of CO, H2, CO2 and CH4 compositions in producer gas were analyzed using Gas Chromatography GC-2014 Shimadzu sensor TCD-14. This recycle system succeeded in reducing tar content as much as 97.19% at 0.139 L/min of recycle volumetric rate and at biomass feed size of -1”+0.5” sieve. The producer gas contained CO, H2, CO2 and CH4 of 23.29%, 2.66%, 13.30%, and 14.18% respectively. The recycle system cold gas efficiency was observed 65.24% at gasifying agent volumetric rate of 188.53 L/min and at biomass feed size of +1” sieve.

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Design and experimental tests of an Imbert type downdraft gasifier prototype and clean-up system for small-scale biomass-based power generation

Renewable Energy and Environmental Sustainability ◽

10.1051/rees/2021057 ◽

2022 ◽

Vol 7 ◽

pp. 10

Author(s):

Miguel Mendonça ◽

Victor Mantilla ◽

João Patela ◽

Valter Silva ◽

Fernanda Resende

Keyword(s):

Power Generation ◽

Combustion Engine ◽

Experimental Tests ◽

Small Scale ◽

Producer Gas ◽

Design Development ◽

Gas Generation ◽

Fuel Gas ◽

Gas Cleaning ◽

Downdraft Gasifier

This paper addresses the design, development and experimental tests of a prototype of fuel gas generation system based on biomass gasification for small-scale applications, around 5 kW. It comprises the small scale downdraft gasifier and the gas cleaning system aiming to clean-up the producer gas to be used in the upstream Internal Combustion Engine (ICE). The design of the downdraft gasifier prototype follows the methodologies that have been reported on the available literature. However, since these methodologies apply to gasifiers with larger rated powers, the adopted methodology is based on the extrapolation of the main parameters used for larger gasifiers design. For runing the ICE the producer gas requires to have a specific gas composition with an acceptable range of impurities. Therefore, a clean-up system was proposed following three stages: in first instance a hot gas clean-up using a cyclone designed to eliminate particles and compounds; then a heat exchanger was used for cooling the gas to condensate tars and water; finally a cold gas clean-up is performed by filtration using two filter steps: the first one using organic material (biomass) and the second one using a polypropylene cartridge filter. Experimental tests were performed using the developed imbert downdraft gasifier prototype, using pellets as feedstock. The preliminary results allow verifying several drawbacks that will difficult an effective integration of the developed prototype for small scale power generation applications based on ICE using low density feedstock.

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Gasification as an optimum alternative for the sludge management

Water Practice & Technology ◽

10.2166/wpt.2011.0080 ◽

2011 ◽

Vol 6 (4) ◽

Cited By ~ 2

Author(s):

C. Peregrina ◽

J. M. Audic ◽

P. Dauthuille

Keyword(s):

Power Generation ◽

Anaerobic Digestion ◽

Sewage Sludge ◽

Combined Heat And Power ◽

Gas Production ◽

Waste Reduction ◽

Fluidised Bed ◽

Sludge Management ◽

Gas Cleaning ◽

Cleaning System

Assimilate sludge to a fuel is not new. Sludge incineration and Combined Heat and Power (CHP) engines powered with sludge-derived anaerobic digestion gas (ADG) are operations widely used. However, they have a room of improvement to reach simultaneously a positive net power generation and a significant level of waste reduction and stabilization. Gasification has been used in other realms for the conversion of any negative-value carbon-based materials, that would otherwise be disposed as waste, to a gaseous product with a usable heating value for power generation . In fact, the produced gas, the so-called synthetic gas (or syngas), could be suitable for combined heat and power motors. Within this framework gasification could be seen as an optimum alternative for the sludge management that would allow the highest waste reduction yield (similar to incineration) with a high power generation. Although gasification remains a promising route for sewage sludge valorisation, campaigns of measurements show that is not a simple operation and there are still several technical issues to resolve before that gasification was considered to be fully applied in the sludge management. Fluidised bed was chosen by certain technology developers because it is an easy and well known process for solid combustion, and very suitable for non-conventional fuels. However, our tests showed a poor reliable process for gasification of sludge giving a low quality gas production with a significant amount of tars to be treated. The cleaning system that was proposed shows a very limited removal performance and difficulties to be operated. Within the sizes of more common WWTP, an alternative solution to the fluidised bed reactor would be the downdraft bed gasifier that was also audited. Most relevant data of this audit suggest that the technology is more adapted to the idea of sludge gasification presented in the beginning of this paper where a maximum waste reduction is achieved with a great electricity generation thanks to the use of a “good” quality syngas in a CHP engine. Audit show also that there is still some work to do in order to push sludge gasification to a more industrial stage. Regardless what solution would be preferred, the resulting gasification system would involve a more complex scenario compared to Anaerobic Digestion and Incineration, characterised by a thermal dryer and gasifier with a complete gas cleaning system. At the end, economics, reliability and mass and energy yields should be carefully analysed in order to set the place that gasification would play in the forthcoming processing of sewage sludge.

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