Minimum Fluidization Velocity of mixture of sand and sugarcane bagasse particles

Code: 08.003

Nestor Proenza Pérez, Julio Santana Antunes, Ricardo Alan Verdú Ramos, Jose Luz Silveira

Federal Center of Technological Education Celso Suckow da Fonseca (CEFET/RJ), Angra dos Reis Campus São Paulo State University (UNESP/FEG), Department of Energy Institute of Bioenergy Research (IPBEN-UNESP) 21/11/2017

1

Study of fluid-dynamic behavior of mixtures of the sugarcane bagasse particles and quartz sand

Objectives

21/11/2017 2

• 671.69 million tons of ground sugarcane

• 167 millones de toneladas de bagazo

Introduction

21/11/2017 3

• 671.69 million tons of ground sugarcane • 167 millones de toneladas de bagazo

Introduction

21/11/2017 4

Methodology

21/11/2017 5

Granulometric characterization:

Equipment used for particle size characterization. a) vibrating machine; b) digital balance

The Sauter mean diameter is calculated as:

𝑑𝑝 =

1

𝑥𝑖

𝑑𝑝 ,𝑖 𝑛

𝑖=1

1

𝑑𝑝 ,𝑖 = 𝑥𝑖

2 + 𝑥𝑖+12 ∙ 𝑥𝑖 + 𝑥𝑖+1

4

0,33

1

Where:

Methodology

21/11/2017 6

Physical characterization: - Real Density - Apparent Density - Bulk Density

Equipment used for physical characterization

𝜀𝑚𝑓 = 1 −𝜌𝑏𝑢𝑙𝑘

𝜌𝑝 1

Methodology

21/11/2017 7

Chemical characterization: - Proximate analysis: - High Heating Value (HHV):

Equipment used for chemical characterization

Methodology

21/11/2017 8

FLUID-DYNAMIC TESTS

𝛥𝑃

𝐻𝑓=

150 1 − 𝜀𝑓2

𝜀𝑓3 ∙

𝜇𝑔 ∙ 𝑉𝑠𝑔

𝜙 ∙ 𝑑𝑝2 +

1,75 1 − 𝜀𝑓

𝜀𝑓3 ∙

𝜌𝑔 ∙ 𝑉𝑓2

𝜙 ∙ 𝑑𝑝

𝐴𝑟 =𝑑𝑝

3 ∙ 𝜌𝑔 ∙ 𝜌𝑝 − 𝜌𝑔 ∙ 𝑔

𝜇𝑔2

𝑅𝑒𝑚𝑓 =𝑑𝑝 ∙ 𝑉𝑚𝑓 ∙ 𝜌𝑔

𝜇𝑔

𝑅𝑀𝐴𝐸 = 𝑉𝑚𝑓𝑒 − 𝑉𝑚𝑓𝑡

𝑉𝑚𝑓𝑒. 100

Experimental results

21/11/2017 9

9.5mm 4.75–9.5mm 2.36–4.75mm 1.18–2.36mm

0.59–1.18mm 0.30–0.59mm 0.15–0.30mm 0-0.15mm

dp = 0.7221± 0.08 mm

Experimental results

21/11/2017 10

𝑉𝑚𝑓𝑚𝑖𝑥𝑡𝑢𝑟𝑒 =0,00002 ∙ 𝐴𝑟𝑚

1,7125 ∙ 𝜇𝑔

𝑑𝑝𝑚 ∙ 𝜌𝑔

Experimental results

21/11/2017 11

Experimental results

21/11/2017 12

Inicio

Entrada de dados

Análise elementar do bagaço

Altura do leito estático, m

Potência necessária, kW

Diâmetro da partícula ≤ 9,5mm

Poder Calorífico Superior, kJ/kg

Parâmetros de funcionamento

Utilização de

material inerte

Determinação da Vmf

com o modelo

desenvolvido,

equação (95)

Sim

Determinação da Vmf

com o modelo

desenvolvido,

equação (94)

Não

FIM

Determinação dos parâmetros físicos e

geométricos empregando os modelos

desenvolvidos

Esfericidade, equação (12)

Densidade Aparente, equação (16)

Densidade a Granel, equação (18)

Comprobação

do dp ≤0,3mm

Determinação dos demais parâmetros

fluidodinâmicos

Velocidade Terminal, cm/s

Velocidade das bolha, cm/s

Velocidade de “Slugging”, cm/s

Diâmetro inicial da bolha, cm

Diâmetro da bolha, cm

Altura de mínima fluidização, m

Altura de fluidização completa, m

Porosidade na mínima fluidização, adim

Porosidade do leito expandido, adim

TDH(F), m

TDH(C), m

Determinação da

altura total do reator,

equação (103)

Implementação do

algoritmo para a

determinação do

diâmetro interno.

Figura 47

Experimental results

21/11/2017 13

• The minimum fluidization velocity increases as the mass fraction of

biomass in the mixture increases, as well as the average diameter of

the bagasse particles in the range of 9.5≥dpb>0.225 mm increases.

• For sugarcane bagasse in its natural form with long and thin particles,

2% is the limit of the mass fraction where a good fluidization occurs.

• A new correlation was developed to predict the minimum fluidization

velocities for mixtures of sugarcane bagasse particles and quartz sand.

• A good fluidization regime (with little segregation) for biomass and sand

mixtures was obtained using sugarcane bagasse particles in the range

of diameter of 0.445<dpb<1.77 mm.

Conclusions

21/11/2017 14

The authors are grateful to the Coordination for the

Improvement of Higher Education Personnel (CAPES), from

the Brazilian Ministry of Education (MEC), and to the National

Council for Scientific and Technological Development (CNPq)

(process 150223/2017-0) from the Ministry of Science and

Technology (MCT) because of their generous financial

support to this research. In addition, the authors highly

appreciate Mr. Fernando Araujo for his help and support to

carry out the experimental analysis

Acknowledgments

21/

11/

201

7

15

Laboratório

de otimização

de Sistemas energéticos