scholarly journals Effect of Operating Conditions on Catalytic Gasification of Bamboo in a Fluidized Bed

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Thanasit Wongsiriamnuay ◽  
Nattakarn Kannang ◽  
Nakorn Tippayawong
Keyword(s):  
Fluidized Bed ◽  
Conversion Efficiency ◽  
Steam Gasification ◽  
Operating Conditions ◽  
Carbon Conversion ◽  
Catalytic Gasification ◽  
Heating Value ◽  
Product Gas ◽  
Reactor Temperature ◽  
Tar Reforming

Catalytic gasification of bamboo in a laboratory-scale, fluidized bed reactor was investigated. Experiments were performed to determine the effects of reactor temperature (400, 500, and 600°C), gasifying medium (air and air/steam), and catalyst to biomass ratio (0 : 1, 1 : 1, and 1.5 : 1) on product gas composition, H2/CO ratio, carbon conversion efficiency, heating value, and tar conversion. From the results obtained, it was shown that at 400°C with air/steam gasification, maximum hydrogen content of 16.5% v/v, carbon conversion efficiency of 98.5%, and tar conversion of 80% were obtained. The presence of catalyst was found to promote the tar reforming reaction and resulted in improvement of heating value, carbon conversion efficiency, and gas yield due to increases in H2, CO, and CH4. The presence of steam and dolomite had an effect on the increasing of tar conversion.

scholarly journals Process Simulation of Steam Gasification of Torrefied Woodchips in a Bubbling Fluidized Bed Reactor Using Aspen Plus

2021 ◽  
Vol 11 (6) ◽  
pp. 2877
Author(s):  
Nhut M. Nguyen ◽  
Falah Alobaid ◽  
Bernd Epple
Keyword(s):  
Fluidized Bed ◽  
Conversion Efficiency ◽  
Process Model ◽  
Aspen Plus ◽  
Fluidized Bed Reactor ◽  
Steam Gasification ◽  
Operating Conditions ◽  
Carbon Conversion ◽  
Bubbling Fluidized Bed ◽  
Biomass Ratio

A comprehensive process model is proposed to simulate the steam gasification of biomass in a bubbling fluidized bed reactor using the Aspen Plus simulator. The reactor models are implemented using external FORTRAN codes for hydrodynamic and reaction kinetic calculations. Governing hydrodynamic equations and kinetic reaction rates for char gasification and water-gas shift reactions are obtained from experimental investigations and the literature. Experimental results at different operating conditions from steam gasification of torrefied biomass in a pilot-scale gasifier are used to validate the process model. Gasification temperature and steam-to-biomass ratio promote hydrogen production and improve process efficiencies. The steam-to-biomass ratio is directly proportional to an increase in the content of hydrogen and carbon monoxide, while gas yield and carbon conversion efficiency enhance significantly with increasing temperature. The model predictions are in good agreement with experimental data. The mean error of CO2 shows the highest value of 0.329 for the steam-to-biomass ratio and the lowest deviation is at 0.033 of carbon conversion efficiency, respectively. The validated model is capable of simulating biomass gasification under various operating conditions.

scholarly journals IMPROVE THE PYROLYTIC GAS PRODUCTION BY USING THE CO-PYROLYSIS TECHNIQUE : AN EXPERIMENTAL STUDY

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Abo . Zahra A.I ◽  
M.K. Abd El- Wahab ◽  
M.A. Tawfik
Keyword(s):  
Energy Conversion ◽  
Fluidized Bed ◽  
Conversion Efficiency ◽  
Fixed Bed ◽  
Energy Conversion Efficiency ◽  
Gas Production ◽  
Operating Conditions ◽  
Energy Unit ◽  
Heating Value ◽  
Slow Pyrolysis

The target of the biomass co-pyrolysis is improvingthe heating value of the produced bio-products of a certain type of feedstock, besides disposal of more than one residue in the same time. Thus, this work aims to operate a local fabricated fixed-bed pyrolyzer to improve the pyrolytic gas yield produced by the ground pieces of three biomass residues namely Mango trees Pruning Logs (MPL), Sugarcane bagasse (SB) and Rice straw (RS) using an affordable slow pyrolysis technique. This work was carried out under slow pyrolysis conditions represented in final pyrolysis temperature of 400 °C, vapor residence time of 4 min, heating rate of 0.01-1 °C/s in full absence of oxygen. The pyrolytic gas production was assessed under different feedstock mixing ratios of (1:2:1), (1:1:2) and (2:1:1) as ratio of (RS: SB: MPL), particle lengths of 1-5, 10-15 and 20-25 mm, with and without sandy bed at the bottom of pyrolysis chamber as a fluidized bed. The obtained results showed that, using the fluidized fixed-bed pyrolyzer under slow co-pyrolysis conditions gave the optimum results where in, the pyrolytic gas concentration, gas yield, higher heating value of pyrolytic gasand energy conversion efficiency were 55%, 1.09 Nm3 /kg, 14.97 MJ/Nm3 and 85.43%, respectively, and 53.7%, 1.08 Nm3 /kg, 13.75 MJ/Nm3 ,77.71% in case of using the pyrolyzer without fluidized bed under the same operating conditions. So, the pyrolyzer with fluidized bed achieves an increment in the higher heating value and energy conversion efficiency by about 8.15% and 9.03%, respectivly over the pyrolyzer without fluidized bed.Furthermore, the cost per energy unit of pyrolytic gas produced by the fluidized bed pyrolyzer is lower than the common two fossil gaseous fuels of natural gas and LPG costs by about 28.57% and 80%, respectively.

scholarly journals Effect of limestone catalyst on co-gasification of coconut fronds and wood chips

2018 ◽  
Vol 225 ◽  
pp. 06009 ◽  
Author(s):  
Muddasser Inayat ◽  
Shaharin A. Sulaiman ◽  
Tham W. Hung ◽  
Fiseha M. Guangul ◽  
Firdaus Basrawi
Keyword(s):  
Conversion Efficiency ◽  
Fossil Fuels ◽  
Biomass Energy ◽  
Wood Chips ◽  
Catalyst Loading ◽  
Carbon Conversion ◽  
Heating Value ◽  
Air Passage ◽  
Tar Reforming ◽  
By Products

Biomass energy via gasification is an attractive substitute of fossil fuels. The distribution of biomass on the earth is scattered, so transportation and collection of biomass complicates the supply of biomass especially when the gasification rely on one type of biomass. Therefore, cogasification of different biomass is proposed as a potential solution for interruption-free gasification. Beside, unwanted by-products such as tar that cause blockage in downstream equipment can be minimized through the use of catalyst in gasification to accelerate tar reforming process. In this study, catalytic co-gasification of blended feedstock of 70% wood chips and 30% coconut fronds was carried out in a downdraft gasifier using limestone as primary catalyst. The effects of catalyst loading (0%, 30%, 50%, and 70% w/w) on syngas composition, gas yield, carbon conversion efficiency and heating value of syngas were investigated. The results showed that at 50% biomass to catalyst ratio, maximum H2 content of 11.39%, CO of 17.88%, carbon conversion efficiency of 69.49%, gas yield of 1.68 Nm3/kg and higher heating value of syngas 5.11 MJ/Nm3 were achieved. Higher catalyst loading (70%) blocked the air passage, which caused poor gasification. No more than 50% catalyst suggested for stable co-gasification operation.

Experimental Studies on H2-Rich Gas Production by Co-Gasification of Coal and Biomass in an Intermittent Fluidized Bed Reactor

2013 ◽  
Vol 724-725 ◽  
pp. 1127-1131 ◽  
Author(s):  
Li Qun Wang ◽  
Zhao Sheng Chen
Keyword(s):  
Fluidized Bed ◽  
Experimental Studies ◽  
Fluidized Bed Reactor ◽  
Gas Production ◽  
Molar Ratio ◽  
Carbon Conversion ◽  
Mass Ratio ◽  
Heating Value ◽  
Product Gas ◽  
Gasification Temperature

This paper illustrates the experimental results of co-gasification of biomass and coal in an intermittent fluidized bed reactor, aiming to investigate the effects of gasification temperature (T) and steam to biomass mass ratio (SBMR) on the composition, yield, low heating value (LHV) and carbon conversion efficiency of the product gas. The results show that H2-rich gas with a high LHV is generated, in the range of 12.22-18.67 MJ/Nm3, and the H2 content in the product gas is in the range of 28.7-51.4%. Increases in temperature lead to an increase in CO and H2 content. The H2/CO molar ratio in the product gas is close to 1 at temperature above 925 °C. With steam addition, the H2 content increases gradually, while the content of CO increases first and then decrease correspondingly. The molar ratio of H2/CO is close to 1 with the smallest supplied amount of steam addition (SBMR =0.4).

Biodiesel Effects on Influencing Parameters of Brake Fuel Conversion Efficiency in a Medium Duty Diesel Engine

2010 ◽  
Vol 132 (12) ◽  
Author(s):  
Joshua A. Bittle ◽  
Jesse K. Younger ◽  
Timothy J. Jacobs
Keyword(s):  
Conversion Efficiency ◽  
Energy Content ◽  
Combustion Efficiency ◽  
Operating Conditions ◽  
Biodiesel Fuel ◽  
Mass Energy ◽  
Fuel Conversion ◽  
Heating Value ◽  
Lower Heating Value ◽  
Lower Heating

Biodiesel remains an alternative fuel of interest for use in diesel engines. A common characteristic of biodiesel, relative to petroleum diesel, is a lowered heating value (or per mass energy content of the fuel). For same torque engine comparisons, the lower heating value translates into a higher brake specific fuel consumption (amount of fuel consumed per unit of power produced). The efficiency at which fuel energy converts into work energy, however, may remain unchanged. In this experimental study, evaluating nine unique engine operating conditions, the brake fuel conversion efficiency (an assessor of fuel energy to work energy efficiency) remains unchanged between 100% petroleum diesel fuel and 100% biodiesel fuel (palm olein) at all conditions, except for high load conditions. Several parameters may affect the brake fuel conversion efficiency, including heat loss, mixture properties, pumping work, friction, combustion efficiency, and combustion timing. This article describes a study that evaluates how the aforementioned parameters may change with the use of biodiesel and petroleum diesel, and how these parameters may result in differences in the brake fuel conversion efficiency.

scholarly journals Dual fluidized bed steam gasification: Change of product gas quality along the reactor height

Energy ◽  
2019 ◽  
Vol 173 ◽  
pp. 1256-1272 ◽  
Author(s):  
A.M. Mauerhofer ◽  
J.C. Schmid ◽  
F. Benedikt ◽  
J. Fuchs ◽  
S. Müller ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Steam Gasification ◽  
Product Gas ◽  
Dual Fluidized Bed ◽  
Reactor Height

scholarly journals Parametric Study on the Heating Values of Products as via Steam Gasification of Palm Waste Using CaO as Sorbent Material

2016 ◽  
Vol 1133 ◽  
pp. 654-658 ◽  
Author(s):  
Abrar Inayat ◽  
Murni Melati Ahmad ◽  
Mohamed Ibrahim Abdul Mutalib ◽  
Suzana Yusup ◽  
Zakir Khan
Keyword(s):  
Hydrogen Production ◽  
Steam Gasification ◽  
Published Data ◽  
Heating Value ◽  
Syngas Production ◽  
Sorbent Material ◽  
Product Gas ◽  
Biomass Ratio ◽  
Lower Temperature ◽  
Palm Waste

In Malaysia, due to abundance of oil palm waste, it is a good candidate to be used as a feedstock for syngas and hydrogen production. Biomass steam gasification is one of the promising methods for syngas production. This work focuses on the steam gasification with in-situ CO2 capture using CaO as absorbent materials for hydrogen production from palm oil empty fruit bunch (EFB). Three parameters (temperature, steam/biomass ratio and sorbent/biomass ratio) has been studied on the lower heating value (LHV) and higher heating value (HHV) of product gas. The results shows that the current study gives higher value of LHV at lower temperature of 823K. The higher value of LHV is obtained due to the lower concentration of CO2 caused by using CaO as sorbent material. Furthermore, CaO materials enhanced the concentration of concentration of the CO, H2 and CH4 in the product gas. The results are also compared against published data as well.

Characterisation of Tar produced in the Gasification of Biomass with in situ Catalytic Reforming

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Sergio Rapagnà ◽  
Katia Gallucci ◽  
Manuela Di Marcello ◽  
Muriel Matt ◽  
Pier U Foscolo ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Renewable Energy Sources ◽  
Technical Specification ◽  
Steam Gasification ◽  
Outlet Temperature ◽  
Processing Unit ◽  
Reactor Outlet ◽  
Distributed Power Generation ◽  
Product Gas ◽  
Power Generation Systems

This paper concerns the cleaning of the hot gas produced by steam gasification of biomass in a fluidized bed. The cleaning takes place in a catalytic filter candle device placed directly in the freeboard of the bed. Such integration results in a compact processing unit and increased thermal efficiency; the result of the cleaning being carried out directly at the reactor outlet temperature. It thus lends itself to exploitation in distributed power generation systems utilizing renewable energy sources. Results are reported for runs performed in a bench scale fluidized bed steam gasifier fitted with a single full-size catalytic candle filter. Tar and particulates in the product gas were sampled in accord with technical specification CEN/TS 15439 with analysis by UV and fluorescence spectroscopy.

scholarly journals CO2 gasification of biogenic fuels in a dual fluidized bed reactor system

2019 ◽  
Author(s):  
Anna Magdalena Mauerhofer ◽  
Stefan Müller ◽  
Florian Benedikt ◽  
Josef Fuchs ◽  
Alexander Bartik ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Pilot Plant ◽  
Alkali Metals ◽  
Alternative Fuels ◽  
Steam Gasification ◽  
Biomass Ash ◽  
Gasification Process ◽  
Product Gas ◽  
Dual Fluidized Bed ◽  
Shift Reaction

Abstract A 100 kWth dual fluidized bed steam gasification pilot plant has been developed at TU Wien to convert different types of biogenic fuels into a valuable product gas. In this paper, the conversion of different biogenic fuels in combination with the utilization of CO2 as alternative gasification agent was investigated in the mentioned pilot plant. For this purpose, five experimental campaigns were carried out aiming at the investigation of softwood as reference fuel, and rapeseed cake, bark and lignin as alternative fuels. Pure olivine as well as a mixture (90/10 wt%) of olivine and limestone were used as bed materials. The product gas compositions of the different biogenic fuels changed depending on the elemental composition of the biogenic fuels. Thus, a high amount of carbon in the fuel enhanced CO formation, whereas an increased content of oxygen led to higher CO2 contents. Additionally, the presence of alkali metals in the biomass ash favoured the production of CO. The addition of limestone enhanced the H2 and CO contents via the water gas shift reaction as well as steam and dry reforming reactions, but had no significant effect on tar contents. Overall, this paper presents the feasibility of the dual-fluidized bed gasification process of different biogenic fuels with CO2 as gasification agent.

scholarly journals Analysis of Hydrogen Generation through Thermochemical Gasification of Coconut Shell Using Thermodynamic Equilibrium Model Considering Char and Tar

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Shanmughom Rupesh ◽  
Chandrasekharan Muraleedharan ◽  
Palatel Arun
Keyword(s):  
Thermodynamic Equilibrium ◽  
Equilibrium Model ◽  
Equivalence Ratio ◽  
Equilibrium Constants ◽  
Steam Gasification ◽  
Coconut Shell ◽  
Heating Value ◽  
Product Gas ◽  
Biomass Ratio ◽  
Thermodynamic Equilibrium Model

This work investigates the potential of coconut shell for air-steam gasification using thermodynamic equilibrium model. A thermodynamic equilibrium model considering tar and realistic char conversion was developed using MATLAB software to predict the product gas composition. After comparing it with experimental results the prediction capability of the model is enhanced by multiplying equilibrium constants with suitable coefficients. The modified model is used to study the effect of key process parameters like temperature, steam to biomass ratio, and equivalence ratio on product gas yield, composition, and heating value of syngas along with gasification efficiency. For a steam to biomass ratio of unity, the maximum mole fraction of hydrogen in the product gas is found to be 36.14% with a lower heating value of 7.49 MJ/Nm3 at a gasification temperature of 1500 K and equivalence ratio of 0.15.

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