Modeling and Performance Analysis of Biomass Fast Pyrolysis in a Solar-Thermal Reactor

Bashir, M.D.; Yu, Xi; Hassan, Mohamed I.; Makkawi, Yassir

doi:10.1021/acssuschemeng.6b02806

Cited by 41 publications

(11 citation statements)

References 48 publications

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“…5 would be negative. Another interesting example is solar fast pyrolysis of biomass (Zeng, et al, 2017;Bashir et al, 2017), in which the biomass is thermally decomposed in the absence of an oxidizing agent such as steam or oxygen. Depending on the feedstock, this process can become net exothermic (Di Blasi et al, 2017), but a heat source is still required for the rapid heating of the feedstock and starting the decomposition.…”

Section: Energy Efficiencymentioning

confidence: 99%

Performance Indicators for Benchmarking Solar Thermochemical Fuel Processes and Reactors

2021

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Concentrated solar energy offers a source for renewable high-temperature process heat that can be used to efficiently drive endothermic chemical processes, converting the entire spectrum of solar radiation into chemical energy. In particular, solar-driven thermochemical processes for the production of fuels include reforming of methane and other hydrocarbons, gasification of biomass, coal, and other carbonaceous feedstock, and metal oxide redox cycles for splitting H2O and CO2. A notable issue in the development of these processes and their associated solar reactors is the lack of consistent reporting methods for experimental demonstrations and modelling studies, which complicates the benchmarking of the corresponding technologies. In this work we formulate dimensionless performance indicators based on mass and energy balances of such reacting systems, namely: energy efficiency, conversion extent, selectivity, and yield. Examples are outlined for the generic processes mention above. We then provide guidelines for reporting on such processes and reactors and suggest performance benchmarking on four key criteria: energy efficiency, conversion extent, product selectivity, and performance stability.

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Section: Energy Efficiencymentioning

confidence: 99%

Performance Indicators for Benchmarking Solar Thermochemical Fuel Processes and Reactors

2021

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“…Figure 2 shows the conceptual model formulated to reduce waste streams, increase energy efficiency and reduce the overall environmental impact. The model involves the use of fast pyrolysis regime to improve overall quality of oil, quantity of dry oil obtained in first two condensers and the recovery of energy from waste char (Gooty, 2012), (Bashir et al, 2017). Figure 2.…”

Section: Figure 1 Pyrolysis Flow Diagram Used In Experimentsmentioning

confidence: 99%

A preliminary environmental analysis for a sustainable pyrolysis process of Acacia tortilis encroacher bush.

Charis

Muzenda

Danha

2021

Preprint

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A shortcut method of environmental assessment was applied procedurally to an Acacia Tortillis pyrolysis project which is in early stages of process development. The method uses mass balance data from the process simulation, which is done in ChemCAD. The ChemCAD model was developed using characterization data for raw biomass and the product bio-oil and data from literature. The shortcut assessment method started off by scoring the impact of inputs and outputs as high (A=1), medium (B= 0.3) and very low (C= 0) under impact categories such as raw material availability, use of critical materials, chronic toxicity, global warming potential, odour and eutrophication potential. An aggregated metric called the general effect index (GEI) was then calculated using this data and mass indices derived from mass balance. The GEI was calculated for inputs, outputs and the overall process. It fell within the scale of 0-1, with values below 0.5 indicating a low environmental impact, while those above that threshold indicated high impact. A GEI of 0 for the inputs reflected on the renewability of biomass and neutral impact of nitrogen and air. A GEI of 0.370 for the outputs showed they do have a significant effect on the environment and organisms, though overall, the process is relatively benign. The impact could be further reduced by utilizing the fuel gas waste stream which has a high methane content. The results obtained generally tally with other literary findings on biomass pyrolysis.

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“…The pyrolysis step is simulated using a global model that describes devolatilization as a single reaction in Eq. 7 [26], [27], [28]. The stoichiometric coefficients ( ) for beech wood pyrolysis reaction are derived based on the method developed by Boateng and Mtui [26].…”

Section: Gasification Chemistry In Cfd Modelmentioning

confidence: 99%

CFD and experimental studies on a circulating fluidised bed reactor for biomass gasification

Blanco

Makkawi

et al. 2018

Chemical Engineering and Processing - Process Intensification

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Biomass gasification has been extensively studied in different thermochemical systems, as has the potential to produce fuel gas for chemicals, fuel and electricity applications. Circulating fluidised bed systems (CFB) are of particular interest due to the high reaction rates and thermal efficiency. The study of varying particle properties and gas velocities during the solids recirculation in a CFB system has been proved to greatly influence the overall biomass gasification process. A comparison between experimental and modelling gas-solid interactions can represent a comprehensive and analytical approach for further understanding and scaling up this reaction system. However, running several experiments is expensive and time-consuming. In this work, a reliable and accurate computational fluid dynamics (CFD) framework has been developed to evaluate the hydrodynamics performance of a CFB gasifier. The multiphase CFD model was validated using a pilot-scale CFB gasifier and silica sand. The CFD and experimental data showed good agreement for the solid recirculation tests, for example when comparing predicted and measured the spatial distribution of pressure up the gasifier's riser. It is the first time that the spatial distribution of solids around a CFB system has been numerically predicted, which can provide guidance to evaluate the hydrodynamics performance of CFB.

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Modeling and Performance Analysis of Biomass Fast Pyrolysis in a Solar-Thermal Reactor

Cited by 41 publications

References 48 publications

Performance Indicators for Benchmarking Solar Thermochemical Fuel Processes and Reactors

Performance Indicators for Benchmarking Solar Thermochemical Fuel Processes and Reactors

A preliminary environmental analysis for a sustainable pyrolysis process of Acacia tortilis encroacher bush.

CFD and experimental studies on a circulating fluidised bed reactor for biomass gasification

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