Biomass Gasification with Air in an Atmospheric Bubbling Fluidized Bed. Effect of Six Operational Variables on the Quality of the Produced Raw Gas

Narváez, Ian; Orío, Alberto; Aznar, María Pilar Matud; Corella, José

doi:10.1021/ie9507540

Cited by 553 publications

(404 citation statements)

References 11 publications

Supporting

Mentioning

352

Contrasting

Unclassified

Order By: Relevance

“…By increasing gasifier temperature from 950 to 1050 K, syngas H 2 concentration increased by an average of 107% at ERs of 0.25, 0.30, and 0.35. This is in agreement with markedly increased H 2 levels at higher gasification temperatures found by other authors (Gungor, 2011;Narváez et al, 1996). CH 4 concentrations were observed to decrease by an average of 24%, and CO 2 concentrations increased by an average of 6% in this same temperature range.…”

Section: Operating Parameterssupporting

confidence: 92%

“…More moisture in the feedstock results in a lower bed temperature, as a significant amount of energy is required to heat and vaporize the free water (Narváez et al, 1996). However, an increased concentration of water vapor will result in more H 2 .…”

Section: Sewage Sludge Compositionmentioning

confidence: 99%

“…fuel-H to d.a.f. fuel-C. A higher fuel-H to fuel-C ratio is expected to result in increased formation of H 2 and CH 4 in the DD zone, as evidenced by previous studies (Ratnadhariya and Channiwala, 2009;Narváez et al, 1996). Following the devolatilization, all the products are assumed to flow upwards into the kinetic zones of the gasification model.…”

mentioning

confidence: 91%

See 2 more Smart Citations

Development of a chemical kinetic model for a biosolids fluidized-bed gasifier and the effects of operating parameters on syngas quality

Champion

Cooper

Mackie

et al. 2013

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

In an effort to decrease the land disposal of sewage sludge biosolids and to recover energy, gasification has become a viable option for the treatment of waste biosolids. The process of gasification involves the drying and devolatilization and partial oxidation of biosolids, followed closely by the reduction of the organic gases and char in a single vessel. The products of gasification include a gaseous fuel composed largely of N 2 , H 2 O, CO 2 , CO, H 2 , CH 4 , and tars, as well as ash and unburned solid carbon. A mathematical model was developed using published devolatilization, oxidation, and reduction reactions, and calibrated using data from three different experimental studies of laboratory-scale fluidized-bed sewage sludge gasifiers reported in the literature. The model predicts syngas production rate, composition, and temperature as functions of the biosolids composition and feed rate, the air input rate, and gasifier bottom temperature. Several data sets from the three independent literature sources were reserved for model validation, with a focus placed on five species of interest (CO, CO 2 , H 2 , CH 4 , and C 6 H 6 ). The syngas composition predictions from the model compared well with experimental results from the literature. A sensitivity analysis on the most important operating parameters of a gasifier (bed temperature and equivalence ratio) was performed as well, with the results of the analysis offering insight into the operations of a biosolids gasifier.Implications: As gasification becomes a more prominent waste disposal option, understanding the effects of feedstock composition and gasifier parameters on the production of syngas (rate and quality) becomes increasingly important. A model has been developed for the gasification of dried sewage sludge that will allow for prediction of changes in syngas quality (and energy recovery from the waste), and should be helpful in assessing the benefits of new gasification projects. IntroductionGasification is the thermochemical conversion of organic feedstock into a synthetic gaseous fuel at high temperatures using a limited amount of air. The gaseous fuel produced by a gasifier is referred to as syngas or producer gas. Gasification lies between combustion and pyrolysis, and is a process that utilizes a substoichiometric amount of oxygen for partial oxidation of the feedstock. This in turn provides heat for the largely endothermic reduction reactions that produce the syngas, as well as the initial devolatilization of the biomass within the gasifier.Gasification is an efficient process for reducing the volume of waste, and is a process capable of delivering net energy gains (Greenhouse Gas Technology Center [GGTC], 2012; PuigArnavat et al., 2010). The remaining solids from the process are composed of the mineral ash that was contained in the feed and small amounts of organic ash, principally unreacted solid carbon (char). It is estimated that 7.2 million dry tons of sewage sludge are generated annually in the United States (North East Biosolids and Res...

show abstract

Section: Operating Parameterssupporting

confidence: 92%

Section: Sewage Sludge Compositionmentioning

confidence: 99%

See 1 more Smart Citation

Development of a chemical kinetic model for a biosolids fluidized-bed gasifier and the effects of operating parameters on syngas quality

Champion

Cooper

Mackie

et al. 2013

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

show abstract

“…These rates were significantly lower than those reported for traditional biomass such as pine wood sawdust, i.e., more than 2.0 m 3 per 1 kg of dry, ashfree biomass (Narvaez et al 1996). On the other hand, a study investigating the gasification of the microalga Spirulina to produce methanol reported that the gas yield ranges from 1.06 and 1.55 m 3 per 1 kg of algal biomass at temperatures between 850 °C and 1000 °C, respectively (Hirano et al 1998).…”

Section: Producer Gas and Condensables Yieldscontrasting

confidence: 57%

Gasification of Phycoremediation Algal Biomass

Sharara¹,

Sadaka²

2015

BioResources

View full text Add to dashboard Cite

Microalgae have been utilized in wastewater treatment strategies in various contexts. Uncontrolled algal species are a cheap and effective remediation strategy. This study investigates the thermochemical potential of wastewater treatment algae (phycoremediation) as a means to produce renewable fuel streams and bio-products. Three gasification temperature levels were investigated in an auger gasification platform: 760, 860, and 960 °C. Temperature increases resulted in corresponding increases in CO and H2 concentrations in the producer gas from 12.8% and 4.7% at 760 °C to 16.9% and 11.4% at 960 °C, respectively. Condensable yields ranged between 15.0% and 16.6%, whereas char yields fell between 46.0% and 51.0%. The high ash content (40% on a dry basis) was the main cause of the elevated char yields. On the other hand, the relatively high yields of condensables and a high carbon concentration in the char were attributed to the low conversion efficiency in this gasification platform. Combustion kinetics of the raw algae, in a thermogravimetric analyzer, showed three consecutive stages of weight loss: drying, devolatilization, and char oxidation. Increasing the algae gasification temperature led to increases in the temperature of peak char oxidation. Future studies will further investigate improvements to the performance of auger gasification.

show abstract

“…Low heat generation and electrical efficiency of biomass gasification CHP using gas engine (Table 1) is due to the fact that synthesized gas has a rather low heating value, i.e. typical lower heating value of biomass synthesized gas is between 4-14 MJ/nm 3 [16,17]. Low heat generation efficiency of the gas and steam turbine combined cycle CHP using bio-methane is due to heat consumption of gasification and methanation processes.…”

Section: Methodsmentioning

confidence: 99%

Technological Alternatives or Use of Wood Fuel in Combined Heat and Power Production

Rusanova¹,

Markova²,

Bažbauers³

et al. 2013

Scientific Journal of Riga Technical University. Environmental and Climate Technologies

View full text Add to dashboard Cite

-Latvia aims for 40% share of renewable energy in the total final energy use. Latvia has large resources of biomass and developed district heating systems. Therefore, use of biomass for heat and power production is an economically attractive path for increase of the share of renewable energy. The optimum technological solution for use of biomass and required fuel resources have to be identified for energy planning and policy purposes. The aim of this study was to compare several wood fuel based energy conversion technologies from the technical and economical point of view. Three biomass conversion technologies for combined heat and electricity production (CHP) were analyzed:• CHP with steam turbine technology;• gasification CHP using gas engine;• bio-methane combined cycle CHP. Electricity prices for each alternative are presented. The results show the level of support needed for the analyzed renewable energy technologies and time period needed to reach price parity with the natural gas -fired combined cycle gas turbine (CCGT) CHPss. The results also show that bio-methane technology is most competitive when compared with CCGT among the considered technologies regarding fuel consumption and electricity production, but it is necessary to reduce investment costs to reach the electricity price parity with the natural gas CCGT.

show abstract

Biomass Gasification with Air in an Atmospheric Bubbling Fluidized Bed. Effect of Six Operational Variables on the Quality of the Produced Raw Gas

Cited by 553 publications

References 11 publications

Development of a chemical kinetic model for a biosolids fluidized-bed gasifier and the effects of operating parameters on syngas quality

Development of a chemical kinetic model for a biosolids fluidized-bed gasifier and the effects of operating parameters on syngas quality

Gasification of Phycoremediation Algal Biomass

Technological Alternatives or Use of Wood Fuel in Combined Heat and Power Production

Contact Info

Product

Resources

About