Experimental investigations and modeling of devolatilization based on superimposed kinetics of biomass

Anna Trubetskaya, Anker Degn Jensen

Research output: Contribution to conferenceConference abstract for conferenceResearchpeer-review

68 Downloads (Pure)

Abstract

A non-isothermal one-dimensional model has been developed to describe biomass pyrolysis at fast heating rate (600-104 Ks-1), high temperatures (up to 1500C) and is valid for different biomass particle sizes (< 10 mm). The model was developedto estimate the yields of volatile gas and char. The model relies on the concept applied in fast pyrolysis of cellulose throughthe formation of an intermediate liquid (so called metaplast) which reacts further to char and gas. The kinetics of the fastpyrolysis was described by the Broido-Shafizadeh scheme.The influence of particle size and shape was included in the model. Cylindrical representation of a biomass particle shapewas chosen to be the most suitable in the pyrolysis model. The evolution of devolatilization time required for the completepyrolysis showed that the particles with a mean diameter < 0.45mm may be considered as thermally thin at high heatingrates. The predicted results by one-dimensional model are in agreement with the experimental work, and emphasize a keyrole of intra-particle heat conduction in biomass particles > 0.45 mm.The potassium influence on the char yield was implemented in the model based on the experimental results in the wire meshand drop tube reactors with respect to the stronger catalytic effect of potassium on the char yield at low and intermediateheating rates compared to pyrolysis at high heating rates. The heating rate and potassium content affected significantly thechar yield as evi denced from the experimental data obtained in the wire mesh and drop tube reactors. Thus, the modelincluding these two parameters provides an acceptable fit of char yield to the experimental data. The present results showedthat the proposed kinetic model for the fast biomass pyrolysis is relatively simple and predicts reasonably accurately the charyield of woody and herbaceous biomass particles < 10mm using one fixed set of kinetic parameters valid for woody andherbaceous biomass.
Original languageEnglish
Publication date2016
Number of pages1
Publication statusPublished - 2016
Event2016 AIChE Annual Meeting - Hotel Nikko San Francisco, San Francisco, CA, United States
Duration: 13 Nov 201619 Nov 2016
http://www.aiche.org/conferences/aiche-annual-meeting/2016

Conference

Conference2016 AIChE Annual Meeting
LocationHotel Nikko San Francisco
CountryUnited States
CitySan Francisco, CA
Period13/11/201619/11/2016
Internet address

Cite this

Trubetskaya, A., & Jensen, A. D. (2016). Experimental investigations and modeling of devolatilization based on superimposed kinetics of biomass. Abstract from 2016 AIChE Annual Meeting, San Francisco, CA, United States.
Trubetskaya, Anna ; Jensen, Anker Degn. / Experimental investigations and modeling of devolatilization based on superimposed kinetics of biomass. Abstract from 2016 AIChE Annual Meeting, San Francisco, CA, United States.1 p.
@conference{b10c37d689ed44a59abc51b215bffc6c,
title = "Experimental investigations and modeling of devolatilization based on superimposed kinetics of biomass",
abstract = "A non-isothermal one-dimensional model has been developed to describe biomass pyrolysis at fast heating rate (600-104 Ks-1), high temperatures (up to 1500C) and is valid for different biomass particle sizes (< 10 mm). The model was developedto estimate the yields of volatile gas and char. The model relies on the concept applied in fast pyrolysis of cellulose throughthe formation of an intermediate liquid (so called metaplast) which reacts further to char and gas. The kinetics of the fastpyrolysis was described by the Broido-Shafizadeh scheme.The influence of particle size and shape was included in the model. Cylindrical representation of a biomass particle shapewas chosen to be the most suitable in the pyrolysis model. The evolution of devolatilization time required for the completepyrolysis showed that the particles with a mean diameter < 0.45mm may be considered as thermally thin at high heatingrates. The predicted results by one-dimensional model are in agreement with the experimental work, and emphasize a keyrole of intra-particle heat conduction in biomass particles > 0.45 mm.The potassium influence on the char yield was implemented in the model based on the experimental results in the wire meshand drop tube reactors with respect to the stronger catalytic effect of potassium on the char yield at low and intermediateheating rates compared to pyrolysis at high heating rates. The heating rate and potassium content affected significantly thechar yield as evi denced from the experimental data obtained in the wire mesh and drop tube reactors. Thus, the modelincluding these two parameters provides an acceptable fit of char yield to the experimental data. The present results showedthat the proposed kinetic model for the fast biomass pyrolysis is relatively simple and predicts reasonably accurately the charyield of woody and herbaceous biomass particles < 10mm using one fixed set of kinetic parameters valid for woody andherbaceous biomass.",
author = "Anna Trubetskaya and Jensen, {Anker Degn}",
year = "2016",
language = "English",
note = "2016 AIChE Annual Meeting ; Conference date: 13-11-2016 Through 19-11-2016",
url = "http://www.aiche.org/conferences/aiche-annual-meeting/2016",

}

Trubetskaya, A & Jensen, AD 2016, 'Experimental investigations and modeling of devolatilization based on superimposed kinetics of biomass', 2016 AIChE Annual Meeting, San Francisco, CA, United States, 13/11/2016 - 19/11/2016.

Experimental investigations and modeling of devolatilization based on superimposed kinetics of biomass. / Trubetskaya, Anna; Jensen, Anker Degn.

2016. Abstract from 2016 AIChE Annual Meeting, San Francisco, CA, United States.

Research output: Contribution to conferenceConference abstract for conferenceResearchpeer-review

TY - ABST

T1 - Experimental investigations and modeling of devolatilization based on superimposed kinetics of biomass

AU - Trubetskaya, Anna

AU - Jensen, Anker Degn

PY - 2016

Y1 - 2016

N2 - A non-isothermal one-dimensional model has been developed to describe biomass pyrolysis at fast heating rate (600-104 Ks-1), high temperatures (up to 1500C) and is valid for different biomass particle sizes (< 10 mm). The model was developedto estimate the yields of volatile gas and char. The model relies on the concept applied in fast pyrolysis of cellulose throughthe formation of an intermediate liquid (so called metaplast) which reacts further to char and gas. The kinetics of the fastpyrolysis was described by the Broido-Shafizadeh scheme.The influence of particle size and shape was included in the model. Cylindrical representation of a biomass particle shapewas chosen to be the most suitable in the pyrolysis model. The evolution of devolatilization time required for the completepyrolysis showed that the particles with a mean diameter < 0.45mm may be considered as thermally thin at high heatingrates. The predicted results by one-dimensional model are in agreement with the experimental work, and emphasize a keyrole of intra-particle heat conduction in biomass particles > 0.45 mm.The potassium influence on the char yield was implemented in the model based on the experimental results in the wire meshand drop tube reactors with respect to the stronger catalytic effect of potassium on the char yield at low and intermediateheating rates compared to pyrolysis at high heating rates. The heating rate and potassium content affected significantly thechar yield as evi denced from the experimental data obtained in the wire mesh and drop tube reactors. Thus, the modelincluding these two parameters provides an acceptable fit of char yield to the experimental data. The present results showedthat the proposed kinetic model for the fast biomass pyrolysis is relatively simple and predicts reasonably accurately the charyield of woody and herbaceous biomass particles < 10mm using one fixed set of kinetic parameters valid for woody andherbaceous biomass.

AB - A non-isothermal one-dimensional model has been developed to describe biomass pyrolysis at fast heating rate (600-104 Ks-1), high temperatures (up to 1500C) and is valid for different biomass particle sizes (< 10 mm). The model was developedto estimate the yields of volatile gas and char. The model relies on the concept applied in fast pyrolysis of cellulose throughthe formation of an intermediate liquid (so called metaplast) which reacts further to char and gas. The kinetics of the fastpyrolysis was described by the Broido-Shafizadeh scheme.The influence of particle size and shape was included in the model. Cylindrical representation of a biomass particle shapewas chosen to be the most suitable in the pyrolysis model. The evolution of devolatilization time required for the completepyrolysis showed that the particles with a mean diameter < 0.45mm may be considered as thermally thin at high heatingrates. The predicted results by one-dimensional model are in agreement with the experimental work, and emphasize a keyrole of intra-particle heat conduction in biomass particles > 0.45 mm.The potassium influence on the char yield was implemented in the model based on the experimental results in the wire meshand drop tube reactors with respect to the stronger catalytic effect of potassium on the char yield at low and intermediateheating rates compared to pyrolysis at high heating rates. The heating rate and potassium content affected significantly thechar yield as evi denced from the experimental data obtained in the wire mesh and drop tube reactors. Thus, the modelincluding these two parameters provides an acceptable fit of char yield to the experimental data. The present results showedthat the proposed kinetic model for the fast biomass pyrolysis is relatively simple and predicts reasonably accurately the charyield of woody and herbaceous biomass particles < 10mm using one fixed set of kinetic parameters valid for woody andherbaceous biomass.

M3 - Conference abstract for conference

ER -

Trubetskaya A, Jensen AD. Experimental investigations and modeling of devolatilization based on superimposed kinetics of biomass. 2016. Abstract from 2016 AIChE Annual Meeting, San Francisco, CA, United States.