Simulation of Plastic Gasification: Approach and Preliminary results

Conversion of Waste plastic to Energy. A modeling approach to the problem

A process model is developed for Polyethylene gasification in a tubular reactor using Aspen Plus simulator. The proposed model (s) addresses the kinetic modeling. Effects of parameters that control gasification are tabulated in detail.

Ahsan Qayum7/7/2011

Contents1. Introduction............................................................................................................................................4

2. Theory....................................................................................................................................................5

Table 1:......................................................................................................................................................6

Table 2.......................................................................................................................................................7

3. Objectives & Goals of Research............................................................................................................8

Problem Statement.....................................................................................................................................9

4. Literature review..................................................................................................................................10

Previous studies on Plastic gasification:..................................................................................................10

Previous work on modeling.....................................................................................................................11

Table 3.....................................................................................................................................................14

Table 4.....................................................................................................................................................15

Table 5.....................................................................................................................................................16

Table 6.....................................................................................................................................................17

5. Methodology and principles................................................................................................................18

Process assumptions:...............................................................................................................................18

Process simulation software.....................................................................................................................18

Thermodynamic equilibrium models:......................................................................................................20

Process Model Development:..................................................................................................................22

Reaction kinetics:.....................................................................................................................................22

Devolitization:......................................................................................................................................22

Volatiles combustion...........................................................................................................................22

Char gasification..................................................................................................................................23

Kinetic Modeling.....................................................................................................................................23

Selection criteria......................................................................................................................................23

Preliminary results for the kinetic model:................................................................................................24

Table 7.....................................................................................................................................................24

Kinetic Model 1-1[13].............................................................................................................................25

Parameter studied : Temperature.............................................................................................................25

Parameter studied : Steam to fuel ratio....................................................................................................26

Parameter studied : Equivalence ratio......................................................................................................27

Kinetic Model 1-2 [13]................................................................................................................................28

2




Future work..............................................................................................................................................32

6. References:...........................................................................................................................................33

7. Appendices...........................................................................................................................................35

Gibbs Model 1..............................................................................................................................................35




Kinetic Model 2-1[8]...............................................................................................................................38




Kinetic Model 2-2 [8]..............................................................................................................................41




Kinetic Model 3-1[16].............................................................................................................................44




Kinetic Model 4-1[22].............................................................................................................................47




Kinetic Model 4-2[22].............................................................................................................................50




3

1. Introduction

Recent study shows that around 11 billion plastic bags were used in U.A.E in 2010. 53.7% of the

bags used were non-biodegradable [1]. This means nearly 120,000 tonnes of non-biodegradable

plastic waste was generated in 2010 alone. This creates a problem as not every plastic bag in

circulation can be recycled and they eventually end up as litter or in landfills.

Furthermore, plastics are notoriously difficult to recycle. The process of collecting them for

recycling or sending to landfill is expensive. And with the ever increasing environmental

concerns and restrictions, it is becoming difficult to properly dispose plastic without damaging

the environment.[2]

The solution to this problem can be the conversion of the waste plastics into useful energy. This

can be done in various ways such a pyrolysis, incineration and gasification [3]. Each of the

methods has its own advantages and disadvantages. For our study and research, gasification is

chosen over the other two technologies purely because of the fact that this process gives a higher

yield of synthesis gas (syngas). Syngas produced from this process can then be cooled down,

cleaned and combusted in gas turbines to produce electricity [4].

The early use of gasification date backs to 1800s. Having developed in the 19 th century, its main

use was to provide “town gas” (a low heating value gas used for lighting and heating purposes).

With the introduction of natural gas in the 20th century, and the decline of the town gas industry,

gasification became a specialized niche technology with limited application. However, with time,

the gasification process improved and with the technological progress, the capacities of the

system expanded steadily. [5]

4

2. Theory

By definition, gasification is the conversion of hydrocarbon-based fuel in the presence of water

and oxygen to produce syngas, a mixture of hydrogen and carbon monoxide. These reforming

reactions are endothermic and the energy required is provided by the exothermic combustion

reactions, which comes from burning a portion of the hydrocarbon feedstock. [6]

As discussed earlier, gasification is the chosen process for our study and polyethylene, a

commonly used plastic, is the fuel of interest to us. A number of studies have been done on the

gasification of plastics including waste plastics and polymers such as polystyrene and PVC.

However, the gasification of polyethylene is a nascent area and limited information is available

about the process in the literature. [4, 7-12].

Gasification in simple terms means conversion of carbonaceous fuels to gas. Gasification is the

result of chemical reactions between carbon in the feed and steam, carbon dioxide, and hydrogen

in the gasifier vessel as well as chemical reactions between resulting gases [5] . Gasification

reactions, their ∆H and kinetic parameters are presented in Table 1:

Table 1: Reaction no.

Reactions: ∆H (MJ/kmol) K (value)

K (units)

Order of reaction (n)

EA

(value)

EA

(units)References

1 C + H2O→CO + H2

+75 2.0×105 s-1 1 11922 Cal/mol [13]

1.4×108 s-1 1 42.87 Cal/mol [14]

6474.7 atm-1 1 3136047 Cal/mol [8]

1.05×107 m s-1 1 55412 Cal/mol [15]

2 C + 2H2→CH4

- 74.8 0.12 s-1 1 35609 Cal/mol [13]

21×103 m s-1 1 55000 Cal/mol [15]

3 C+2H2O →CO2+2H2

0.046 s-1 1 26855 Cal/mol [8]

4 C + CO2 →2 CO

+171 4.40 s-1 13.24×108

Cal/mol

[13]

3.4×107 s-1 1 42.87 Cal/mol [14]

1×107 m s-1 1 3000 Cal/mol [15]

5 CH4+ H2O→CO + 3H2

+206 3×105 s-1 1 29805 Cal/mol [13]

312 s-1 1 30000 Cal/mol [16]

4.225×1015 s-1 1 57347 Cal/mol

2×107 m s-1 1 86000 Cal/mol [15]

6CO + H2O→CO2 + H2

-35 106exp (-6370/T)

Kw=520exp(-7230/T)

1 Cal/mol [13]

1.955×106 s-1 1 16033.7 Cal/mol [16]

7×103 m s-1 1 7165.4 Cal/mol [15]

7 C+O2 →CO2

-111 9.35×104 s-1 139.3

Cal/mol [14]

8CH4+ 2H2O→CO2 + 4H2

+222.35 1.020×1015 s-1 1 58254.5

Cal/mol [16]

6

Table 2. Ultimate and proximate analysis of polyethylene:[17]

Moisture content (wt %) 0.02

Proximate analysis (wt%, dry basis)

Volatile matter 99.85

Fixed carbon 0

Ash 0.15

Ultimate analysis (wt%, dry basis)

Carbon 85.81

Hydrogen 13.86

Oxygen 0

Nitrogen 0.12

Sulphur 0.06

7

3. Objectives & Goals of Research

The primary goal of this research is to compile the kinetic parameters available for the

gasification reactions and to build a kinetic model in Aspen Plus that would simulate the

gasification of Polyethylene. The model would then be used to generate results that are

qualitatively comparable to the available literature. Parameters such as temperature, equivalence

ratio, steam to fuel ratio would be studied.

A complete sensitivity analysis will also be performed once the model is up and running giving

qualitatively results. The model will provide a good starting point on the simulation of

Polyethylene as so far, a simulation model of Polymer gasification is missing. The model should

be able to predict the optimum conditions of gasification for a lab scale gasifier. (Optimum

conditions = Temperature, Steam to fuel ratio, Equivalence ratio)

Furthermore, the data generated would then be used to calculate several response variables. The response

variables are:

Carbon to gas conversion

Carbon monoxide efficiency

Hydrogen efficiency

Combined carbon monoxide and hydrogen efficiency

Energy efficiency

8

Note: All the initial models have already been prepared and the preliminary results generated from them

are given in the appendices. Besides the effects of parameters, two response variables, namely carbon

monoxide efficiency and hydrogen efficiency have also been plotted.

Problem Statement

“Effects of kinetic parameters on the yield of syngas”. This project is focused on finding and

reporting the kinetic parameters for the gasification reactions, their variations from author to

author and their effects on the yield of syngas and response variables when physical parameters

such as Temperature, Equivalence ratio and steam to fuel ratio are varied.

9

4. Literature review

Previous studies on Plastic gasification:Tsuji and Hayatama in 2007 investigated the gasification of waste plastics PE and PS

(Polyethylene and Polystyrene respectively) using steam reforming. They found that the carbon

conversion increased with the increase in temperature. High temperature favours steam

reforming which in turn increases hydrogen and decreases the methane formation. The yield of

carbon monoxide was also found to increase with the increasing temperature. By varying

steam/carbon (S/C) ratio at fixed temperature (1023 K), it was found that carbon conversion

increases by increasing S/C ratio. Increasing the S/C ratio also increased the gas compositions of

Hydrogen and carbon dioxide according to water gas shift reactions.

Wu and Williams [10] in their study of pyrolysis-gasification of post consumer municipal plastic

wastes concluded that gasification temperature had an important influence on the product yield

and gas composition. The hydrogen composition in the gas increased with increasing

temperature, as did the overall gas yield. The composition of carbon monoxide also increased

with increasing the gasification temperature. Steam to fuel (S/F) ratio was also studied and it was

reported that increasing the S/F ratio increases the hydrogen production and decreases the carbon

monoxide production. These results concurred with their other studies of polypropylene [9, 11].

Similar studies have been repeated by the same authors and the results when changing the

parameters on the outlet gas composition remains the same.

He et al [17] analyzed the syngas production from catalytic gasification of waste polyethylene.

Their work consisted of steam gasification of waste polyethylene using NiO/γ-Al2O3 as a catalyst

in a fixed bed reactor. Gas compositions were studied at different temperatures. Higher

temperatures favoured the endothermic reactions according to Le Chatelier’s principle and

10

therefore the increase in the contents of H2 and CO with an increase in temperature was

attributed to water gas shift reaction, Boudouard reactions and carbon gasification reactions. A

significant decrease in the methane production was also reported. The lower heating value of

syngas decreased when temperature was increased.

Mastral et al [4] in 2003 carried out experiments to analyze the gas compositions under various

conditions. Both pyrolysis and gasification experiments were performed but the results of

gasification experiments have been considered for our study. At temperatures higher than 700C,

air was used as a gasifying medium. The CO yield increased with temperature favoured by

Boudouard and water shift reactions. H2 yield increases at higher temperatures. Methane is too

strongly influenced by high temperatures and the yield increases at higher temperature.

Previous work on modeling

Nikoo et al [8] proposed a model for biomass gasification in an atmospheric fluidized bed using

Aspen Plus simulator. The proposed model addressed both the reaction kinetic modeling and

hydrodynamic parameters. Using 4 reactors, they were able to model gasification in a fluidized

bed [18]. An RYIELD model was used to break the biomass into its basic constituents followed

by volatile combustion in an RGIBBS reactor. Two RCSTRs were used in series to simulate the

char gasification in a fluidized with each RCSTR representing the bed-zone and other freeboard

zone. External written FORTRAN subroutines for hydrodynamics and kinetics nested in Aspen

Plus were used to simulate the gasification process.

The model was used to study the performance of the gasifier and the gas yields under various

conditions. From the model, it was observed that temperature increases the production of

hydrogen and improves the carbon conversion efficiency whilst increasing the equivalence ratio

increases the carbon dioxide production and carbon conversion efficiency. They also observed

11

that increasing steam to biomass ratio increased hydrogen production and carbon conversion

efficiency whereas the biomass particle size (0.25-0.75mm) did not affect the composition of the

outlet gases.

In 2009, Doherty et al [19] also developed a model using Aspen Plus. The model was based on

minimizing the Gibbs free energy and a restricted equilibrium method used to calibrate and

compare it against the experimental data [20]. Operating parameters were varied and studied over

a range. The increase in temperature (of the gasifier) increased the production hydrogen and

carbon monoxide. Meanwhile the increasing the equivalence ratio (ER) maximized the hydrogen

and carbon monoxide production. The optimum operating conditions without air preheating were

found to be ER = 0.34-0.345 and gasifier temperature = 837-874 C. Effects of air-preheating

were also considered and it was concluded that air preheating increases the production of

combustible gases, Hydrogen and Carbon monoxide, which in turn improves the product gas

heating value and the gasifier cold gas efficiency. It was also noted that air preheating is

effective at low ERs and should not be used for ERs greater than 0.35. The steam injection

increased the hydrogen content in the syn-gas.

Mitta et al [7] in 2006 studied the effects of gasification temperature, steam to fuel (S/F) ratio

and equivalence ratio (ER) on the gasification of tyres. Sensitivity analysis was performed to

monitor the dependence of the parameters listed above on the composition of the produced gas

from the gasifier. Their model was based on an equilibrium reactor (RGIBBS). They also

incorporated a RSTOIC and RYIELD to dry and breakdown the feed respectively. Hydrogen and

carbon monoxide production increased when increasing the temperature of the gasifier whereas a

decrease was observed in the yield of carbon dioxide and methane. This effect was attributed to

12

the steam methane reforming and CO2 reforming reactions. Increasing the ER led to the

increase of hydrogen and carbon monoxide production whilst increasing the S/F ratio caused the

hydrogen production to fall while registering a slight increase in carbon monoxide yield.

Wenyi Tan and Qin Zhong [21] in 2010 studied the effects of gasification temperature, pressure

and S/F ratio on a biomass gasifier. Their model was an isothermal model with no pressure loss

and where the gasification reactions took place at equilibrium. They concluded that an increase

in S/F ratio increased hydrogen yield whilst an increase in temperature or pressure led to a

decrease of hydrogen production. Opposite was observed for the carbon monoxide production.

Important results from the literature review have been summarized in tabular form. It gives a

clear indication on how a certain parameter affects the yield of the product gases. Please refer to

Table 3-6.

Our research is unique as it aims to present a kinetic model to predict the yield of gases formed

during the gasification of Polyethylene. This had not been studied before and it’s a novel area.

The literature presented above clearly shows a gap that needs to be filled in. No researcher has so

far done modeling on gasification of polyethylene. And from the information compiled in Table

6, it is clearly evident that kinetic modeling is rare for the case of biomass and coal, let alone

polymers.

Therefore a clear niche is available and this will be filled in with our research and modeling

work. The kinetic parameters obtained are from literature and have been previously used to

model coal or biomass gasification.

13

Property Studied: Temperature

MaterialParticle

sizeReactor Type Range

(°C)

Measured variables

Gas

Yie

ld

C2-C4

Cha

r/ta

rs

C c

onv.

Eff

Experiment conditions AuthorH2 CH4

CO

CO2

Waste Plastic

5mm flakes

Two-stage tubular furnace

600 -900

↑

cons

tant

↑

cons

tant

↑ ↓ ↓ −Steam gasification. Carrier gas used

is N2[10]

PE 5 mmFixed Bed

Reactor700-900

↑ ↓ ↑ ↓ ↑ ↓ ↓ ↑ Steam catalytic gasification [17]

PP2 mm pellets

Two-stage reac. System

600-900

↑ ↓ ↑ ↓ ↑−

↓−

Steam catalytic gasification. Carrier gas used is N2

[9]

PS2 mm pellets


800-850

↑ ↑ − − ↑−

↓−

Steam catalytic gasification. Carrier gas used is N2 [11]

PP2 mm pellets


800-850

↑ ↓ − − ↑−

↓−


[11]

HDPE2 mm pellets


800-850

↑ ↑ − − ↑−

↓−


[11]

HDPE0.225 mm

flakesFluidized Bed

640-850 ↑ ↑ ↑ ↓ ↑ ↓ ↓ ↑

Air-N2 mixture at low temperature (700°C) and only air at higher

temperatures. T >700°C[4]

Table 3 (↑): Increase in property

(↓): Decrease in property

(−): Not Provided

Table 4Property Studied: Equivalence Ratio (Increase)

Material

Particle size

Reactor Type Range

Measured variables

Gas

Yie

ld

C2-C4

Cha

r/ta

rs

C c

onv.

Eff

Experiment conditions Author

H2 CH4 CO CO2

PS2 mm pellets


0.1-0.4 ↓ ↑ ↓ ↑ ↓ ↑ ↑ −Steam catalytic gasification.

Carrier gas used is N2[11]

PP2 mm pellets




HDPE2 mm pellets




PP 2 mm Fluidized bed0.2-0.45

↓ ↓ ↓ ↑ ↑ − − −Air Gasification

[12]

(↑): Increase in property


(−): Not Provided

15

Table 5Property Studied: Steam to fuel Ratio (Increase)

MaterialParticle

sizeReactor Type

Range (g/h)

Measured variables

Gas

Yie

ld

C2-C4

Cha

r/ta

rs

C c

onv.

Eff

Experiment conditions Author

H2 CH4 CO CO2

PP2 mm pellets


1.9-14.2 ↑ ↓ ↑ ↓ ↑ − − −Steam catalytic gasification.


PS2 mm pellets




PP2 mm pellets




HDPE2 mm pellets




Waste Plastic

5mm flakes

Two-stage tubular furnace

1.9-14.2 ↑ ↓ ↑ ↓ ↑ − − −Steam gasification. Carrier gas

used is N2[10]



(−): Not Provided

16

Table 6Simulation: Effects of Parameters

Material PropertyModel

ConsideredRange

Measured Variables

Gas

Yie

ld

Reactions Author

Comments

H2 CH4 CO CO2

Biomass

Temperature (°C)

Kinetic

700-900 ↑ ↓ ↓ − ↑

1,3 [8]

Fuel feed 0.445 kg/h ; air 0.5 Nm3/h; steam rate 1.2 kg/h.

ER0.19-0.27

− − − ↑ ↑Fuel feed 0.445 kg/h ; Temp 800 °C; steam rate 1.2 kg/h. Optimum ER =

0.23Steam to fuel

ratio0-4 ↑ − − ↑ ↑

Fuel feed 0.445 kg/h ; Temp 800 °C; air 0.5 Nm3/h;

Waste Tyres

Temperature (°C)

Equilibrium

750 -1100

↑ ↓ ↓ − −

− [7]

-

ER 0.2-0.8 ↑ − ↑ − −Temp 950 °C; Pressure 1 bar.

Steam to fuel ratio

0.2-0.8 ↓ − − − −Temp 950 °C; Pressure 1 bar.

Biomass

Temperature (°C)

Gibbs free energy min.

25-825 ↑ ↓ ↑ ↓ -

1,2,4,5,6,7 [19]

For fixed ER = 0.29 temperature was varied.

The optimum operating conditions without air preheating were found to

be: ER 0.34-0.35 and gasifier temperature 837-874°C

ER0.29-0.45

↑ ↓ ↑ ↓ −

Steam to fuel ratio

0-11 kg/h steam

↑ Const ↓ ↓ −



(−): Not Provided

(Const) - No change in value

17

5. Methodology and principles.

Process assumptions:Assumptions made for polyethylene gasification are listed below

1) Polyethylene is represented as non-conventional material. An RYIELD breaks down PE

into its basic constituents; carbon and hydrogen according to the ultimate analysis.

2) Carbon is treated as char (pure carbon solid) in the reactions.

3) Gasifier is operated under steady state conditions

4) Ash is considered inert and hence do not take part in any of the reactions

5) Product gases of PE gasification are hydrogen, carbon monoxide, carbon dioxide and

methane.

Process simulation softwareThere are several simulation packages available that can be used to simulate gasification of

polyethylene. Some of the most common ones are Aspen Plus, Aspen Hysys and ProMax. Aspen

plus is the selected for our study. This simulation package has been used for modeling biomass

and tyre gasification [7-8, 19, 21]. It is a steady state chemical process simulator and was

developed by Massachusetts Institute of Technology (MIT) for the US Department of Energy, to

evaluate synthetic fuel technologies.

Several reasons to support our decision are:

Polyethylene can be entered as a non conventional feed in Aspen plus and then based on

its ultimate and proximate analysis; it can be modeled as a fuel.

Aspen plus provides a good selection of different reactors that form building blocks of a

gasifier

Sensitivity analysis provides a good option of studying effects of certain variables on the

outlet gases.

The drawback with ProMax is that polyethylene feed is defined as pseudo oil. This may

be true for HDPE but for LDPE, nitrogen and sulphur content do affect the product yields

of the desire gases. Another disadvantage of using ProMax is its inability to handle

chemical kinetics when a user-defined feed is entered, such as in our case.

The simulation of our model is based on a lab scale tubular reactor. A Plug flow reactor will be

used in Aspen plus with integrated kinetics to give the output yield. To validate the model, its

results will be compared to an Equilibrium model (RGibbs) and parameters such as effect of

temperature, equivalence ratio, steam to fuel ratio on output gases will be studied.

19

Thermodynamic equilibrium models:

Basic thermodynamic equilibrium models have also been developed for our research but they

have a few drawbacks and therefore their use would be limited to providing guidance on the

values obtained as gas outlet yield.

At chemical equilibrium, a reacting system is at its most stable composition, a condition

achieved when the entropy of the system is maximized while its Gibbs free energy is minimized.

Equilibrium models have two general approaches: stoichiometric and non stoichiometric.

The stoichiometric approach basically requires a reaction mechanism that incorporates all

chemical reactions and species involved. In a non-stoichiometric approach, no particular reaction

mechanisms or species are involved in numerical simulation. The only input needed to specify

the feed is its ultimate analysis data. The non-stoichiometric equilibrium model is based on

minimizing Gibbs free energy in the system without specifying the possible reactions taking

place. The stoichiometric chemical equilibrium model is based on selecting those species that are

present in the largest amounts, i.e. those which have the lowest value of free energy of formation.

20

The two approaches are essentially equivalent. There are a few assumptions made when using

this model. These assumptions also act as a drawback to this type of model. They are:

The reactor is implicitly considered to be a zero dimensional.

The gasifier is often regarded as a perfectly insulated apparatus.

The model assumes that gasification rates are fast and residence time is long enough to

reach the equilibrium state.

Perfect mixing and uniform temperature are assumed for the gasifier although different

hydrodynamics are observed in practice.

Tars are not modeled

No information about reaction pathways and formation of intermediates is given in the

model

21

Process Model Development:My process model would be one based on reaction kinetics i.e. it would be a kinetic model. The

kinetics of carbonaceous fuel gasification has been and still is a subject of intensive investigation

and it is still not as developed as is its thermodynamics [5]

Reaction kinetics:The kinetic parameters for the gasification reactions are listed in Table 1. First order kinetic

model of reactions have been considered for simplicity and because of availability in literature.

A simple sequence of gasification process would be:

Devolitization: The first step is the heating up of the polyethylene particles (feed). It is one sense the

simplest part of the process. Nonetheless, the speed at which it takes place has an

influence on the subsequent steps, so it is of great importance in any accurate model.

Devolitization takes place at low temperature and in parallel with heating up of the

polyethylene feed. The rate of heating of the polyethylene particles influences the way in

which devolitization takes place.

Volatiles combustionDevolitization of any carbon based fuel produces a variety of species such as

hydrocarbon liquids and gases including hydrogen, carbon monoxide, carbon dioxide,

methane, water (gaseous state) and so forth. This material reacts with the oxidant

surrounding the fuel particle. The extent to which the oxidant is completely or only

partially depleted depends on the amount of volatiles produced. There is not much kinetic

data available on volatiles combustion. It is however clearly established that this process,

being a reaction between gases, is much more rapid than char gasification.

22

Char gasificationThe slowest reactions in gasification, and therefore those that govern the overall

conversion rate, are the heterogeneous reactions with carbon – namely the water gas,

Boudouard and hydrogenation reactions (see Table 1)

The gasification process consists of several competing reactions which are char gasification,

methanation, methane steam reforming, water gas shift and Boudouard. The sequence is actually

picked up from literature and each author uses a set of reactions from the available 8 reactions.

Kinetic ModelingModeling work is carried out after careful consideration on reaction scheme that has been done

according to the literature review (see Table1). Each author reviews a certain number of

reactions and provide data for their kinetic parameters [8, 13-14, 16, 22]. Based on the reactions

and kinetic parameters considered, five gasification models have been prepared on Aspen Plus.

The results from these models are in the appendices. Some of the results from these models are

in conformity with the literature. A selection criterion is used to select the best available model.

Selection criteriaA model has been selected. It selection was based on fulfilling several important criteria such as

1. The model should consider maximum number of possible reactions

2. It should give no errors while executing

3. Its results should be in qualitative agreement with the available literature and

experimental data.

4. Its results are comparable to the Gibbs Minimization model.

Based on the above criteria model has been prepared. Its kinetics were provided by Inayat et

al[13].

23

Preliminary results for the kinetic model:

The figure above is the PFD of the kinetic model in Aspen Plus. The reactor is a plug flow reactor. The kinetics entered in the reactor are presented in Table 7

Table 7Reaction no.

Reactions: ∆H (MJ/kmol)

K (value)

K (units)

Order of reaction (n)

EA

(value)

EA

(units)References

1 C + H2O→CO + H2

+75 2.0×105 s-1 1 11922 Cal/mol [13]

2 C + 2H2→CH4 - 74.8 0.12 s-1 1 35609 Cal/mol [13]

3 C + CO2 →2 CO+171 4.40 s-1 1

3.24×108Cal/mol

[13]

4 CH4+ H2O→CO + 3H2

+206 3×105 s-1 1 29805 Cal/mol [13]

5CO+H2O→CO2 + H2

-35 106exp (-6370/T)

Kw=520exp(-7230/T)

1 Cal/mol [13]

The preliminary results from the simulation are on the next page:

24

Kinetic Model 1-1[13]

Parameter studied : TemperatureER S/F Temperature

(C) HYDROGEN

CO CO2 CH4 WATER

0.2 1.33 650 0.31255447 0.046289 6.57E-03 7.74E-14 0.215393040.2 1.33 700 0.32894737 0.063616 0.0087 2.06E-13 0.188152710.2 1.33 750 0.3476928 0.08477 0.010573 4.94E-13 0.156571840.2 1.33 800 0.36829424 0.109805 0.011875 1.09E-12 1.21E-010.2 1.33 850 0.39017919 1.39E-01 0.012344 2.21E-12 0.083112950.2 1.33 900 0.41281618 0.170636 0.011846 4.20E-12 4.29E-02

PE : 0.1 kg/hr, Steam: 0.1333 kg/hr and Air: 0.3266 kg/hr

Mole Fraction vs temperature

625 675 725 775 825 875 9250

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

HYDROGEN CO CO2 CH4 WATER

Temperature C

Mo

le F

racti

on

650 700 750 800 850 9000

10

20

30

40

50

60

70

80

90

100

CO efficiencyH2 efficiency

Temperature C

Efficie

ncy

25

Parameter studied : Steam to fuel ratioTemperature(C)

ER S/F HYDROGEN

CO CO2 CH4 WATER

455.0773070.2 1

0.29814965 0.0124370.00072149 1.02E-15 0.21793

462.4081430.2 2

0.24319538 0.009980.00116557 9.26E-16 0.363306

467.7292070.2 3

0.20547106 0.0082670.00140241 8.43E-16 0.462927

471.754933 0.2 4 0.17793783 0.007021 0.0015176 7.73E-16 0.535505

474.8990690.2 5

0.15694053 0.0060840.00156062 7.13E-16 0.590759

PE : 0.1 kg/hr, Steam: varies and Air: 0.3266 kg/hr

Mole fraction vs S/F ratio

0.5 1.5 2.5 3.5 4.5 5.5 6.50

0.1

0.2

0.3

0.4

0.5

0.6

0.7


Steam to Fuel ratio

Mol

e fr

acti

om

26

1 2 3 4 5 60

10

20

30

40

50

60

70

80

90

100


Steam to fuel ratio

Efficie

ncy

Parameter studied : Equivalence ratioTemperature (C)

S/F ER HYDROGEN

CO CO2 CH4 WATER

450.703783 1.33 0.1 0.35427723 0.014131 0.001108 1.14E-15 0.350529454.538357 1.33 0.15 0.31105198 0.012675 0.000998 1.06E-15 0.307098457.80463 1.33 0.2 0.27725552 0.011513 0.000899 9.89E-16 0.273243460.620754 1.33 0.25 0.25009285 0.010563 0.00081 9.31E-16 0.246107463.078722 1.33 0.3 0.22778824 0.009768 0.000732 8.80E-16 0.223875465.241175 1.33 0.35 0.20914142 0.009093 0.000662 8.34E-16 0.205328

PE : 0.1 kg/hr, Steam: 0.1333kg/hr and Air: varies

Mole fraction vs Equivalence ratio

27

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.40

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4


Equivalene Ratio

Mol

e Fr

ation

0.1 0.15 0.2 0.25 0.3 0.350

10

20

30

40

50

60

70

80

90

100


Equivalence ratio

Efficie

ncy

Kinetic Model 1-2 [13]

A slightly varied version of the same model is studied. In this model, an RGIBBS reactor is used

for volatile combustion, in conformity with the assumption that volatile reactions follow the

Gibbs equilibrium. This model gives slightly better results than the original one.

28

Parameter studied : Temperature

ER S/F Temperature(C)

HYDROGEN

CO CO2 CH4 WATER

0.2 1.33 650 0.240244 0.04809 1.40E-02 0.04310155 0.223980650.2 1.33 700 0.260138 0.064855 0.017336 0.04217231 0.194155870.2 1.33 750 0.282377 0.085924 0.019985 0.04107008 0.160194940.2 1.33 800 0.30642 0.111328 0.021655 0.03980423 1.23E-010.2 1.33 850 0.331641 1.41E-01 0.022085 3.84E-02 0.082777820.2 1.33 900 0.357459 0.174095 0.021158 3.68E-02 4.11E-02



625 675 725 775 825 875 9250

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4


Temperature C

Mol

e Fr

acti

on

650 700 750 800 850 9000

10

20

30

40

50

60

70

80

90

100


Temperature C

Efficie

ncy

29


ER S/F HYDROGEN

CO CO2 CH4 WATER

390.08944 0.2 1 0.20096372 0.013039 0.000565 0.049067 0.246264407.955384 0.2 2 0.16331958 0.010888 0.001212 0.039404 0.391598420.857295 0.2 3 0.13805088 0.009099 0.001801 0.032926 0.489239430.629532 0.2 4 0.11982651 0.007669 0.002245 0.028282 0.559488438.2517 0.2 5 0.10597336 0.006566 0.002521 0.024787 0.612564



30

0.5 1.5 2.5 3.5 4.5 5.5 6.50

0.1

0.2

0.3

0.4

0.5

0.6

0.7


Steam to Fuel ratio

Mol

e fr

acti

om

1 2 3 4 5 60

10

20

30

40

50

60

70

80

90

100


Steam to fuel ratio

Efficie

ncy


S/F ER HYDROGEN

CO CO2 CH4 WATER

430.485268 1.33 0.1 0.23566584 0.018949 0.00197 0.055891 0.366234410.022346 1.33 0.15 0.20357125 0.014422 0.001119 0.049097 0.325162390.562748 1.33 0.2 0.17926958 0.011432 0.000656 0.043742 0.291795372.586808 1.33 0.25 0.16026669 0.00938 0.000405 0.039422 0.26427356.225267 1.33 0.3 0.14499115 0.007928 0.000258 0.035868 0.24127341.452346 1.33 0.35 0.13243741 0.006864 0.000171 0.032895 0.221816


31


0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.40

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4


Equivalene Ratio

Mol

e Fr

ation

0.1 0.15 0.2 0.25 0.3 0.350

10

20

30

40

50

60

70

80

90

100


Equivalence ratio

Efficie

ncy

Future workAs the problem has been clearly defined, now the pathway forward is carved. The future work

will involve:

Capturing the variations in kinetic parameters and their effects on the yield of product

gases and their effects on response variables.

32

Assessing the effect of property methods used on the yield of outlet gases and the effects

on response variable.

Studying further features in Aspen and estimating the initial setup cost of the equipment

been modeled

Possibility of using optimization toolbox feature in Aspen

Providing a table of best known kinetic parameters for maximum number of reactions.

6. References:1. Farah, N., Fee likely to be imposed on use of plastic bags, in Gulf News. 2011, Al

Nisr Publishing: Abu Dhabi.2. Baeyens, J. RECYCLING PLASTICS. 2010 [cited 2010 05/04/11]; Available

from: http://www2.warwick.ac.uk/knowledge/engineering/recycling.3. Arena, U., L. Zaccariello and M.L. Mastellone, Tar removal during the fluidized

bed gasification of plastic waste. Waste Management, 2009. 29(2): p. 783-791.4. Mastral, F.J., E. Esperanza, C. Berrueco, M. Juste and J. Ceamanos, Fluidized bed

thermal degradation products of HDPE in an inert atmosphere and in air-

33

http://www2.warwick.ac.uk/knowledge/engineering/recycling

nitrogen mixtures. Journal of Analytical and Applied Pyrolysis, 2003. 70(1): p. 1-17.

5. Higman, C. and M. van der Burgt, Gasification (2nd Edition), Elsevier.6. Robinson, P.J. and W.L. Luyben, Simple Dynamic Gasifier Model That Runs in

Aspen Dynamics. Industrial & Engineering Chemistry Research, 2008. 47(20): p. 7784-7792.

7. Mitta, N.R., S. Ferrer-Nadal, A.M. Lazovic, J.F. Parales, E. Velo and L. Puigjaner, Modelling and simulation of a tyre gasification plant for synthesis gas production, in Computer Aided Chemical Engineering, W. Marquardt and C. Pantelides, Editors. 2006, Elsevier. p. 1771-1776.

8. Nikoo, M.B. and N. Mahinpey, Simulation of biomass gasification in fluidized bed reactor using ASPEN PLUS. Biomass and Bioenergy, 2008. 32(12): p. 1245-1254.

9. Wu, C. and P.T. Williams, Effects of Gasification Temperature and Catalyst Ratio on Hydrogen Production from Catalytic Steam Pyrolysis-Gasification of Polypropylene. Energy & Fuels, 2008. 22(6): p. 4125-4132.

10. Wu, C. and P.T. Williams, Pyrolysis-gasification of post-consumer municipal solid plastic waste for hydrogen production. International Journal of Hydrogen Energy, 2010. 35(3): p. 949-957.

11. Wu, C. and P.T. Williams, Pyrolysis-gasification of plastics, mixed plastics and real-world plastic waste with and without Ni-Mg-Al catalyst. Fuel, 2010. 89(10): p. 3022-3032.

12. Xiao, R., B. Jin, H. Zhou, Z. Zhong and M. Zhang, Air gasification of polypropylene plastic waste in fluidized bed gasifier. Energy Conversion and Management, 2007. 48(3): p. 778-786.

13. Inayat, A., M.M. Ahmad, Abdul Mutalib, M.I. Yunus and M. Khairuddin, Kinetic Modeling of Biomass Steam Gasification System for Hydrogen Production with CO2 Adsorption. Proceedings of International Conference for Technical Postgraduates (TECHPOS 2009), 2009.

14. Fletcher, D.F., B.S. Haynes, F.C. Christo and S.D. Joseph, A CFD based combustion model of an entrained flow biomass gasifier. Applied Mathematical Modelling, 2000. 24(3): p. 165-182.

15. Ahmad, M.M., A. Inayat, S. Yusup and C.K. Chiew, Simulation of Integrated Pressurized Steam Gasification of Biomass for Hydrogen Production using iCON. Journal of Applied Sciences 2011.

16. Xu, J. and G.F. Froment, Methane steam reforming, methanation and water-gas shift: I. Intrinsic kinetics. AIChE Journal, 1989. 35(1): p. 88-96.

17. He, M., B. Xiao, Z. Hu, S. Liu, X. Guo and S. Luo, Syngas production from catalytic gasification of waste polyethylene: Influence of temperature on gas yield and composition. International Journal of Hydrogen Energy, 2009. 34(3): p. 1342-1348.

34

18. Lv, P.M., Z.H. Xiong, J. Chang, C.Z. Wu, Y. Chen and J.X. Zhu, An experimental study on biomass air-steam gasification in a fluidized bed. Bioresource Technology, 2004. 95(1): p. 95-101.

19. Doherty, W., A. Reynolds and D. Kennedy, The effect of air preheating in a biomass CFB gasifier using ASPEN Plus simulation. Biomass and Bioenergy, 2009. 33(9): p. 1158-1167.

20. Li, X.T., J.R. Grace, C.J. Lim, A.P. Watkinson, H.P. Chen and J.R. Kim, Biomass gasification in a circulating fluidized bed. Biomass and Bioenergy, 2004. 26(2): p. 171-193.

21. Tan, W. and Q. Zhong, Simulation of Hydrogen production in biomass gasifier by ASPEN PLUS. IEEE, 2010.

22. Lü, P., X. Kong, C. Wu, Z. Yuan, L. Ma and J. Chang, Modeling and simulation of biomass air-steam gasification in a fluidized bed. Frontiers of Chemical Engineering in China, 2008. 2(2): p. 209-213.

7. Appendices

Gibbs Model 1


(C) HYDROGEN

CO CO2 CH4 WATER

0.2 1.33 650 0.344631 0.138183 8.65E-02 0.01927417 0.105140470.2 1.33 700 0.362341 0.159402 0.072346 0.00595016 0.101548530.2 1.33 750 0.36425 0.170161 0.063885 0.00161416 0.10423368

35

0.2 1.33 800 0.361003 0.176795 0.057866 0.00045514 1.09E-010.2 1.33 850 0.356847 1.82E-01 0.052958 1.41E-04 0.113198590.2 1.33 900 0.352867 0.186121 0.048756 4.79E-05 1.17E-01



625 675 725 775 825 875 9250

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4


Temperature C

Mol

e Fr

acti

on

650 700 750 800 850 9000

10

20

30

40

50

60

70

80

90

100


Temperature C

Efficie

ncy


ER S/F HYDROGEN

CO CO2 CH4 WATER

713.88722 0.2 1 0.3609064 0.192366 0.05413 0.007311 0.066649698.082971 0.2 2 0.35573322 0.116868 0.090988 0.002612 0.16957685.837626 0.2 3 0.33279634 0.076271 0.102927 0.001298 0.260105673.219076 0.2 4 0.30737675 0.052423 0.104934 0.000793 0.335929660.934577 0.2 5 0.2833748 0.037522 0.1027 0.000545 0.399135



36

0.5 1.5 2.5 3.5 4.5 5.5 6.50

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5


Steam to Fuel ratio

Mol

e fr

acti

om

1 2 3 4 5 60

10

20

30

40

50

60

70

80

90

100


Steam to fuel ratio

Efficie

ncy


S/F ER HYDROGEN

CO CO2 CH4 WATER

595.6478 1.33 0.1 0.34798921 0.121423 0.109244 0.09984269 0.11389437635.7595 1.33 0.15 0.36710205 0.145593 0.088003 0.04056058 0.10054568707.0547 1.33 0.2 0.36325989 0.161371 0.0709 0.00496286 0.10167734910.2973 1.33 0.25 0.30260044 0.162997 0.055776 1.87E-05 0.135309781110.933 1.33 0.3 0.24614212 0.155472 0.049263 2.83E-07 0.163667811283.374 1.33 0.35 0.20039049 0.144913 0.047469 1.43E-08 0.18469243



37

0.05 0.15 0.25 0.35 0.450

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4


Equivalene Ratio

Mol

e Fr

ation

0.1 0.15 0.2 0.25 0.3 0.350

10

20

30

40

50

60

70

80

90

100


Equivalence ratio

Efficie

ncy



(C) HYDROGEN

CO CO2 CH4 WATER

0.2 1.33 650 0.245368 1.70E-01 7.13E-05 0 0.264693120.2 1.33 700 0.245609 1.70E-01 0.000212 0 0.264370990.2 1.33 750 0.24623 1.70E-01 0.000564 0 0.263574460.2 1.33 800 0.247653 1.70E-01 0.001373 0 2.62E-010.2 1.33 850 0.25065 1.69E-01 0.003084 0.00E+00 0.257867730.2 1.33 900 0.256561 1.69E-01 0.006454 0.00E+00 2.50E-01


38


625 675 725 775 825 875 9250

0.05

0.1

0.15

0.2

0.25

0.3


Temperature C

Mol

e Fr

acti

on

650 700 750 800 850 9000

10

20

30

40

50

60

70

80

90

100


Temperature C

Efficie

ncy


ER S/F HYDROGEN

CO CO2 CH4 WATER

984.26517 0.2 1 0.30402666 0.177655 2.38E-02 0 0.160079926.47308 0.2 2 0.23019672 0.148966 7.63E-03 0 0.332821870.34743 0.2 3 0.1892652 0.12738 0.002738 0 0.440858824.64413 0.2 4 0.16247006 0.111152 0.001147 0 0.516276787.57096 0.2 5 0.14296192 0.098339 0.000537 0 0.573066



39

0.5 1.5 2.5 3.5 4.5 5.5 6.50

0.1

0.2

0.3

0.4

0.5

0.6

0.7


Steam to Fuel ratio

Mol

e fr

acti

om

1 2 3 4 5 60

10

20

30

40

50

60

70

80

90

100


Steam to fuel ratio

Efficie

ncy


S/F ER HYDROGEN

CO CO2 CH4 WATER

635.8778 1.33 0.1 0.26050674 0.076252 0.118641 0.086126 0.133493594.1506 1.33 0.15 0.2754451 0.086518 0.111179 0.063188 0.123861572.1078 1.33 0.2 0.29526403 0.10617 0.095506 0.024074 0.111472558.4317 1.33 0.25 0.28633111 0.120292 0.079727 0.002097 0.116738549.2986 1.33 0.3 0.2388275 0.120084 0.068749 0.000107 0.141672542.8972 1.33 0.35 0.26050674 0.076252 0.118641 0.086126 0.133493


40


0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.40

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0.045


Equivalene Ratio

Mol

e Fr

ation

0.1 0.15 0.2 0.25 0.3 0.350

10

20

30

40

50

60

70

80

90

100


Equivalence ratio

Efficie

ncy

Kinetic Model 2-2 [8]


(C) HYDROGEN

CO CO2 CH4 WATER

0.2 1.33 650 0.171994 0.163867 6.85E-03 0.04257745 0.278073590.2 1.33 700 0.172264 0.163834 0.006995 0.04257164 0.27774130.2 1.33 750 0.17294 0.163781 0.007363 0.04255546 0.276895240.2 1.33 800 0.174494 0.163632 0.008206 0.04251985 2.75E-010.2 1.33 850 0.177776 1.63E-01 0.00999 4.24E-02 0.270874870.2 1.33 900 0.184237 0.162766 0.013502 4.23E-02 2.63E-01


41


625 675 725 775 825 875 9250

0.05

0.1

0.15

0.2

0.25

0.3


Temperature C

Mol

e Fr

acti

on

650 700 750 800 850 9000

10

20

30

40

50

60

70

80

90

100


Temperature C

Efficie

ncy


ER S/F HYDROGEN

CO CO2 CH4 WATER

984.26517 0.2 1 0.23484886 0.171211 0.034723 0.04449 0.16297926.47308 0.2 2 0.16723191 0.14261 0.01473 0.037057 0.345377870.34743 0.2 3 0.1334193 0.121268 0.008138 0.031508 0.456544824.64413 0.2 4 0.11290298 0.105215 0.005628 0.027341 0.532746787.57096 0.2 5 0.09858168 0.092859 0.004439 0.024128 0.589222



42

0.5 1.5 2.5 3.5 4.5 5.5 6.50

0.1

0.2

0.3

0.4

0.5

0.6

0.7


Steam to Fuel ratio

Mol

e fr

actio

m

1 2 3 4 5 60

10

20

30

40

50

60

70

80

90

100


Steam to fuel ratio

Efficie

ncy


S/F ER HYDROGEN

CO CO2 CH4 WATER

844.0428 1.33 0.1 0.22547423 0.113241 0.012264 0.05405 0.34586987.1529 1.33 0.15 0.2069093 0.16733 0.029227 0.039931 0.2151881135.659 1.33 0.2 0.20763116 0.12778 0.063941 0.036423 0.1773771077.94 1.33 0.25 0.16870183 0.138146 0.03767 0.033402 0.1843741033.048 1.33 0.3 0.14459737 0.138271 0.024061 0.03084 0.181397970.5989 1.33 0.35 0.20633158 0.160775 0.025504 0.041778 0.235289


43


0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.40

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4


Equivalene Ratio

Mol

e Fr

ation

0.1 0.15 0.2 0.25 0.3 0.350

10

20

30

40

50

60

70

80

90

100


Equivalence ratio

Efficie

ncy



(C) HYDROGEN

CO CO2 CH4 WATER

0.2 1.33 650 0.171994 0.163867 6.85E-03 0.04257745 0.278073590.2 1.33 700 0.172264 0.163834 0.006995 0.04257164 0.27774130.2 1.33 750 0.17294 0.163781 0.007363 0.04255546 0.276895240.2 1.33 800 0.174494 0.163632 0.008206 0.04251985 2.75E-010.2 1.33 850 0.177776 1.63E-01 0.00999 4.24E-02 0.270874870.2 1.33 900 0.184237 0.162766 0.013502 4.23E-02 2.63E-01

44



625 675 725 775 825 875 9250

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45


Temperature C

Mol

e Fr

acti

on

650 700 750 800 850 9000

10

20

30

40

50

60

70

80

90

100


Temperature C

Efficie

ncy


ER S/F HYDROGEN

CO CO2 CH4 WATER

569.7109 0.2 1 0.25074578 0.098891 0.108998 0.097947 0.089738542.7941 0.2 2 0.257083 0.051882 0.121004 0.069907 0.219347525.9212 0.2 3 0.23435748 0.036665 0.110905 0.055038 0.328729514.3282 0.2 4 0.21034359 0.030153 0.098583 0.045434 0.41407505.5626 0.2 5 0.189601 0.02681 0.087495 0.038518 0.480844



45

0.5 1.5 2.5 3.5 4.5 5.5 6.50

0.1

0.2

0.3

0.4

0.5

0.6


Steam to Fuel ratio

Mol

e fr

actio

m

1 2 3 4 5 60

10

20

30

40

50

60

70

80

90

100


Steam to fuel ratio

Efficie

ncy


S/F ER HYDROGEN

CO CO2 CH4 WATER

832.327 1.33 0.177551 0.26050674 0.076252 0.118641 0.086126 0.133493849.983 1.33 0.2 0.2754451 0.086518 0.111179 0.063188 0.123861

891.6013 1.33 0.25 0.29526403 0.10617 0.095506 0.024074 0.111472969.68 1.33 0.3 0.28633111 0.120292 0.079727 0.002097 0.116738

1054.369 1.33 0.35 0.2388275 0.120084 0.068749 0.000107 0.141672PE : 0.1 kg/hr, Steam: 0.1333kg/hr and Air: varies

46


0.1 0.15 0.2 0.25 0.3 0.35 0.40

0.05

0.1

0.15

0.2

0.25

0.3

0.35

HYDROGEN CO CO2 CH4

Equivalene Ratio

Mol

e Fr

ation

0.177551020770512

0.2 0.25 0.3 0.350

10

20

30

40

50

60

70

80

90

100


Equivalence ratio

Efficie

ncy



(C) HYDROGEN

CO CO2 CH4 WATER

0.2 1.33 650 0.267245 2.05E-10 2.75E-06 3.61E-14 0.290201520.2 1.33 700 0.267245 9.97E-10 5.28E-06 1.69E-13 0.290201520.2 1.33 750 0.267245 4.15E-09 9.51E-06 6.78E-13 0.290201510.2 1.33 800 0.267245 0 1.75E-05 2.39E-12 0.290199870.2 1.33 850 0.267246 0 2.77E-05 7.56E-12 0.290199740.2 1.33 900 0.267246 0 4.26E-05 2.16E-11 0.29019958


47


625 675 725 775 825 875 9250

0.05

0.1

0.15

0.2

0.25

0.3

0.35


Temperature C

Mol

e Fr

acti

on

650 700 750 800 850 9000

10

20

30

40

50

60

70

80

90

100


Temperature C

Efficie

ncy


ER S/F HYDROGEN

CO CO2 CH4 WATER

499.910712 0.2 1 0.23484886 0.171211 0.034723 0.04449 0.16297499.959073 0.2 2 0.16723191 0.14261 0.01473 0.037057 0.345377499.991237 0.2 3 0.1334193 0.121268 0.008138 0.031508 0.456544500.014155 0.2 4 0.11290298 0.105215 0.005628 0.027341 0.532746500.031305 0.2 5 0.09858168 0.092859 0.004439 0.024128 0.589222



48

0.5 1.5 2.5 3.5 4.5 5.5 6.50

0.1

0.2

0.3

0.4

0.5

0.6

0.7


Steam to Fuel ratio

Mol

e fr

acti

om

1 2 3 4 5 60

10

20

30

40

50

60

70

80

90

100


Steam to fuel ratio

Efficie

ncy


S/F ER HYDROGEN

CO CO2 CH4 WATER

499.8733 1.33 0.1 0.34312856 6.82E-13 3.00E-07 1.36E-16 0.372604499.9045 1.33 0.15 0.30046785 5.98E-13 2.63E-07 1.20E-16 0.326279499.9293 1.33 0.2 0.26724455 5.32E-13 2.34E-07 1.06E-16 0.290202499.9495 1.33 0.25 0.24063306 4.80E-13 2.11E-07 9.60E-17 0.261304499.9663 1.33 0.3 0.21884287 4.37E-13 1.92E-07 8.73E-17 0.237642499.9805 1.33 0.35 0.20067279 4.01E-13 1.76E-07 8.01E-17 0.217911


49


0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.40

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4


Equivalene Ratio

Mol

e Fr

ation

0.1 0.15 0.2 0.25 0.3 0.350

10

20

30

40

50

60

70

80

90

100


Equivalence ratio

Efficie

ncy



(C) HYDROGEN

CO CO2 CH4 WATER

0.2 1.33 650 0.152626 9.97E-09 4.96E-04 0.06661106 0.308420010.2 1.33 700 0.15267 0 0.000509 0.06659728 0.308387970.2 1.33 750 0.152715 1.01E-08 0.000521 0.06658307 0.308358260.2 1.33 800 0.152658 0 0.000507 0.06660022 3.08E-010.2 1.33 850 0.152813 7.42E-09 0.000549 6.66E-02 0.308291840.2 1.33 900 0.152779 8.99E-09 0.000541 6.66E-02 3.08E-01

50



625 675 725 775 825 875 9250

0.05

0.1

0.15

0.2

0.25

0.3

0.35


Temperature C

Mol

e Fr

acti

on

650 700 750 800 850 9000

10

20

30

40

50

60

70

80

90

100


Temperature C

Efficie

ncy


ER S/F HYDROGEN

CO CO2 CH4 WATER

527.9254 0.2 1 0.16543736 0 0.00056 0.072152 0.250628522.5652 0.2 2 0.13239979 1.01E-08 0.000472 0.057668 0.400664519.0782 0.2 3 0.11025542 1.01E-08 0.00038 0.048059 0.500719516.4498 0.2 4 0.09452412 0 0.000336 0.041176 0.572093514.2942 0.2 5 0.08286272 0 0.000337 0.035978 0.625491


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0.5 1.5 2.5 3.5 4.5 5.5 6.50

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8


Steam to Fuel ratio

Mol

e fr

actio

m

1 2 3 4 5 60

10

20

30

40

50

60

70

80

90

100


Steam to fuel ratio

Efficie

ncy


S/F ER HYDROGEN

CO CO2 CH4 WATER

531.6775 1.33 0.1 0.19973321 0 0.000654 0.087159 0.403567528.6473 1.33 0.15 0.17296194 0 0.000548 0.075534 0.349682525.9709 1.33 0.2 0.15264469 1.55E-08 0.000501 0.066605 0.308406523.7844 1.33 0.25 0.1365859 0 0.00046 0.059568 0.275849521.8459 1.33 0.3 0.12365828 0 0.000443 0.053855 0.249464520.4178 1.33 0.35 0.11280388 0 0.000383 0.049191 0.227795


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0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.40

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45


Equivalene Ratio

Mol

e Fr

ation

0.1 0.15 0.2 0.25 0.3 0.350

10

20

30

40

50

60

70

80

90

100


Equivalence ratio

Efficie

ncy

53

Simulation of Plastic Gasification: Approach and Preliminary results

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Transcript of Simulation of Plastic Gasification: Approach and Preliminary results