Operation of a Circulating Fluidised Bed Biomass Gasifier

2004 ◽  
Author(s):  
Guanyi Chen ◽  
Gang Li ◽  
Michel P. Glazer ◽  
Chunlei Zhang ◽  
J. Andries
Keyword(s):  
Large Scale ◽  
Fixed Bed ◽  
Calorific Value ◽  
Producer Gas ◽  
Fluidised Bed ◽  
Fuel Gas ◽  
Promising Alternative ◽  
Tar Cracking ◽  
Shift Reaction ◽  
Circulating Fluidised Bed

Energy generation from the use of biomass is gaining an increasing attention. Gasification of biomass at present, is widely accepted as a popular technical route to produce fuel gas for the application in boilers, engine, gas/micro turbine or fuel cell. Up to now, most of researchers have focused their attentions only on fixed-bed gasification and fluidised bed gasification under air-blown conditions. In that case, the producer gas is contaminated by high tar contents and particles which could lead to the corrosion and wear of blades of turbine. Furthermore, both the technologies, particularly fixed bed gasification, are not flexible for using multiple biomass-fuel types and also not feasible economically and environmentally for large scale application up to 10∼50 MWth. An innovative circulating fluidised bed concept has been considered in our laboratory for biomass gasification thereby overcoming these challenges. The concept combines and integrates partial oxidation, fast pyrolysis (with an instantaneous drying), gasification, and tar cracking, as well as a shift reaction, with the purpose of producing a high quality of gas, in terms of low tar level and particulates carried out in the producer gas, and overall emissions reduction associated with the combustion of producer gas. This paper describes our innovative concept and presents some experimental results. The results indicate that the gas yield can be above 1.80Nm3/kg with the calorific value of 4.5–5.0MJ/Nm3, and the fluctuation of the gas yield during the period of operation is 3.3%–3.5% for the temperature of 750–800 °C. In genera, the results achieved support our concept as a promising alternative for the gasifier coupled with micro/gas turbine to generate electricity.

Dynamic Characteristics of a Small Fixed-Bed Gasifier Stove

1996 ◽  
Vol 210 (1) ◽  
pp. 35-45
Author(s):  
D Beedie ◽  
N Syred ◽  
T O'Doherty
Keyword(s):  
Fixed Bed ◽  
Calorific Value ◽  
Fuel Gas ◽  
Mixture Ratio ◽  
Biomass Stove ◽  
Air Inlet ◽  
Multi Stage ◽  
Air Supply ◽  
Simple Measurement ◽  
Secondary Air

This paper describes work directed at characterizing the dynamic behaviour of a small gasifying fixed-bed biomass stove. The system comprises a primary gasification chamber, followed by a multi-stage secondary combustor which can allow for the considerable variation in quantity and calorific value of fuel gas produced by forming a series of flamelets which move along the length of the secondary combustor as a function of the local mixture ratio. The typical cycle time is about 60 minutes and once warmed up the unit is capable of operating with low emissions, providing appropriate guidelines are followed. Correlation of temperature and gas concentration measurements on the unit with velocity and flow visualization measurements on a perspex model of the secondary combustor show that improvements can be made to the flow patterns in the bottom of the secondary combustion chamber by reducing the size and shape of the recirculation zones formed and revising the location of the mid-section secondary air inlet. Control of the system is indicated using a simple measurement of temperature in the secondary combustor to determine appropriate air supply rates.

Measures to reduce chlorine in deposits: Application in a large-scale circulating fluidised bed boiler firing biomass

Fuel ◽  
2011 ◽  
Vol 90 (4) ◽  
pp. 1325-1334 ◽  
Author(s):  
Håkan Kassman ◽  
Markus Broström ◽  
Magnus Berg ◽  
Lars-Erik Åmand
Keyword(s):  
Large Scale ◽  
Fluidised Bed ◽  
Circulating Fluidised Bed

scholarly journals Fuel Gas Production From Self-Sustaining Smouldering Combustion of Lignocellulosic Waste

2021 ◽  
Author(s):  
Hons K Wyn ◽  
Muxina Konarova ◽  
Greg Perkins ◽  
Luis Yermán
Keyword(s):  
Moisture Content ◽  
Waste Treatment ◽  
Agricultural Waste ◽  
Fixed Bed ◽  
Calorific Value ◽  
Treatment Method ◽  
Gas Production ◽  
Wood Pellets ◽  
Fuel Gas ◽  
Smouldering Combustion

Abstract Smouldering combustion has shown to be an effective application for soil remediation and as a waste treatment method for solids with high moisture content. The experimental set-up of smouldering combustion reactors is similar to autothermal fixed-bed gasification, updraft reactor configuration. In this study, smouldering experiments were conducted using lignocellulosic agricultural waste. The moisture content of lignocellulosic biomass was varied between 10 % to 50 %. Air flux was varied between 1.8 and 7.4 cm/s. Experiments were also conducted with varying oxygen concentration in the airflow (3.6 – 21 %), addition of sand (4 and 8 g/g) and other lignocellulosic material (wood pellets, and residual berry plant). Fuel gas with maximum H2, CO, CH4, CO2 concentrations of 7.7, 32.6, 2.3, and 57.4 % (N2 free) respectively were obtained with 10 % moisture content and 7.4 cm/s air flux. The smouldering yielded 1.24 Nm3/kgfeed_dry of gas with calorific value of 1.82 MJ/Nm3 (HHV).

scholarly journals Pemanfaatan gasifikasi batubara untuk unit pengeringan teh

2018 ◽  
Vol 5 (2) ◽  
pp. 443
Author(s):  
Ari Susandy Sanjaya ◽  
S Suhartono ◽  
Herri Susanto
Keyword(s):  
Coal Gasification ◽  
Fixed Bed ◽  
Calorific Value ◽  
Diesel Oil ◽  
Fuel Oil ◽  
Dual Fuel ◽  
Processing Unit ◽  
Producer Gas ◽  
Downdraft Gasifier ◽  
Gasification Process

Coal gasification utilization for tea drying unit. Anticipating the rise of fuel oil, the management of a tea plantation and drying plant has considered to substitute its oil consumption with producer gas (gaseous fuel obtained from gasification process). A tea drying unit normally consumes 70 L/h of industrial diesel oil and is operated 10 hours per day. The gasification unit consisted of a down draft fixed bed gasifier (designed capacity of about 100 kg/h), gas cooling and cleaning systems. The gas producer was delivered to the tea processing unit and burned to heat the drying oil: Low calorific value coal (4500 kcal/kg) and wood waste (4000 kcal/kg) have been used as fuel. The gasification unit could be operated as long as 8 hours without refueled since the coal hopper on the toppart of gasifier has a capacity of 1000 kg. Sometimes, the gasification process must be stopped before coal completely consumed due to ash melting inside the gasifier. Combustion of producer gas produced a pale-blue flame, probably due to a lower calorific value of the producer gas or too much excess air. Temperature of heating-air heated by combustion of this producer gas was only up to 96 oC. To achieve the target temperature of 102 oC, a small oil burner must he operated at a rate ofabout 15 L/h. Thus the oil replacement was about 78%.Keywords:  Fuel oil, Producer gas, Downdraft gasifier, Dual fuel, Calorific value, Burner. AbstrakKenaikan harga bahan bakar minyak untuk industri pada awal 2006 telah mendorong berbagai pemikiran dan upaya pemanfaatan bahan bakar alternatif. Sebuah unit gasifikasi telah dipasang di pabrik teh sebagai penyedia bahan bakar alternatif. Unit gasifikasi tersebut terdiri dari gasifier, pendingin, pembersih gas, dan blower. Unit gasifikasi ini ditargetkan untuk dapat menggantikan konsumsi minyak bakar 70 L/jam. Gasifier dirancang untuk kapasitas 120 kg/jam batubara, dan memiliki spesifikasi sebagai berikut: downdraft gasifier; diameter tenggorokan 40 cm, diameter zona reduksi 80 cm. Bunker di bagian atas gasifier memiliki kapasitas sekitar 1000 kg batubara agar gasifier dapat dioperasikan selama 8 jam tanpa pengisian-ulang. Bahan baku gasifikasi yang telah diuji-coba adalah batuhara kalori rendah (4500 kcal/kg) dan limbah kayu (4000 kcal/kg). Gas produser (hasil gasifikasi) dibakar pada burner untuk memanaskan udara pengering teh sampai temperatur target 102 oC. Pembakaran gas produser ternyata menghasilkan api biru pucat yang mungkin disebabkan oleh rendahnya kalor bakar gas dan tingginya udara-lebih. Temperatur udara pengering hasil pemanasan dengan api gas produser hanya mencapai 96 oC. Dan untuk mencapai temperatur udara pengering 102 oC, burner gas prod user harus dibantu dengan burner minyak 15 L/jam. Jadi operasi dual fued ini dapat memberi penghematan minyak bakar 78%.Kata kunci: Minyak bakar, Gas produser, Downdraft gasifier, Dual fuel, Kalor bakar, Burner. 

A Fluidic Regenerative Filtration System for Hot Gas Cleaning

1983 ◽  
Vol 105 (3) ◽  
pp. 185-191 ◽  
Author(s):  
Ieuan Owen ◽  
Nick Syred ◽  
G. P. Reed
Keyword(s):  
High Pressures ◽  
Elevated Temperatures ◽  
Calorific Value ◽  
Particulate Material ◽  
Switching Function ◽  
Fluidised Bed ◽  
Fuel Gas ◽  
Gas Cleaning ◽  
Filtration System ◽  
Hot Gas Cleaning

Combined power cycles are being developed in which low calorific value fuel gas is produced by a fluidised bed coal gasifier at high temperatures and pressures (up to 1000°C and 20 bar) to be burned and expanded through a gas turbine. The turbine specifications required the removal of all particulate material greater than 5 μm. To ensure adequate collection efficiencies it may be necessary to use filtering media such as granular beds or ceramic fibres. Filters, however, need to be replaced or regenerated at regular intervals in order to maintain the pressure differentials across them to within specified levels. This paper describes how fluidic valves (vortex amplifiers) can be used in the hostile conditions to provide the switching capability in a regenerative filtration system. A penalty is incurred in using the valves in that they require an extraneous control fluid to perform the switching function. Results of experiments at elevated temperatures together with an analysis of the system at high pressures show that in a practical system the dilution of the mainstream fuel gas by the control gas can be reduced to 0.35 percent. The fluidic switching circuit is shown to be a highly effective system for handling gas flows at elevated temperatures and pressures.

scholarly journals Pyrolysis of Lemon Peel Waste in a Fixed-bed Reactor and Characterization of Innovative Pyrolytic Products

2021 ◽  
Author(s):  
Samira ABIDI ◽  
Aïda Ben Hassen Trabelsi ◽  
Nourhène Boudhrioua Mihoubi
Keyword(s):  
Large Scale ◽  
Fixed Bed ◽  
Chemical Characterization ◽  
Calorific Value ◽  
Economic Benefits ◽  
Fixed Bed Reactor ◽  
Engine Fuel ◽  
Ftir Characterization ◽  
Bio Oil ◽  
Pharmaceutical Industries

Abstract The pyrolysis of LPW was carried out in a laboratory fixed-bed reactor at final temperature of 300°C, 400°C and 500°C with an incremental heating rate of 10°C/min, under N2 atmosphere. The maximum yields of bio-oil, biochar and gas were 16.66 wt.% (at 400°C), 66.89 wt.% (300°C) and 54.6 wt.% (500°C), respectively. The recovered biochar FTIR characterization reveals that it is a promising precursor to produce carbon materials, biofertilizer and for solid fuel applications. The bio-oil chemical characterization (GC-MS and FTIR analyzes) shows its richness with innovative compounds such as squalene, d-limonene, ß-Sitosterol and phenol, suitable for applications agriculture, biochemical and pharmaceutical industries. The pyrolytic oil presents also good properties, suitable for its use as an engine fuel or as a potential source for synthetic fuels. The recovered pyrolytic gas has a maximum calorific value around 12 MJ/kg with an average composition of CO (up to 75.87 vol.%), of CH4 (up to 5.25 vol.%) and of CnHm (up to 1.48 vol.%). The results could be applied by citrus farmers and agri-food industrials for large scale application to ensure a sustainable waste management of their citrus by-products and to guarantee economic benefits.

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

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.

scholarly journals Experimental verification of the scaling laws for CFB boilers of different designs

2016 ◽  
Vol 37 (2) ◽  
pp. 281-291
Author(s):  
Paweł Mirek ◽  
Marcin Klajny
Keyword(s):  
Large Scale ◽  
Scaling Laws ◽  
Scale Factor ◽  
Similarity Criteria ◽  
Fluidised Bed ◽  
Flow Dynamic ◽  
Suspension Density ◽  
Density Distributions ◽  
Scaling Models ◽  
Circulating Fluidised Bed

Abstract In the paper flow dynamic similarity criteria have been presented to reflect the macroscopic flow pattern in the combustion chamber of large-scale circulating fluidised bed boilers. The proposed scaling rules have been verified on two cold models of CFB boilers operating in Tauron Wytwarzanie S.A. - El. Lagisza division (scale factor 1/20) and Fortum Power and Heat Poland Sp. z o. o. Czestochowa division (scale factor 1/10) – working with the power of 966 MWth and 120 MWth, respectively. As follows from the results of measurements, regardless of CFB boiler’s geometry the use of a defined set of criterial numbers allows to obtain satisfactory agreement between the suspension density distributions registered in the CFB boilers and scaling models.

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