Thermolytic Conversion of Waste Polyolefins into Fuels Fraction with

Subscriber access provided by - Access paid by the | UCSB Libraries

Environmental and Carbon Dioxide Issues

Thermolytic conversion of waste polyolefins into fuels fraction with the use of reactive distillation and hydrogenation with the syngas under atmospheric pressure Anna Matuszewska, Adam Handerek, Krzysztof Biernat, and Pawel Bukrejewski Energy Fuels, Just Accepted Manuscript • DOI: 10.1021/acs.energyfuels.8b03664 • Publication Date (Web): 02 Jan 2019 Downloaded from http://pubs.acs.org on January 8, 2019

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

1

Thermolytic conversion of waste polyolefins into fuels fraction with the use of reactive

2

distillation and hydrogenation with the syngas under atmospheric pressure

3

Anna Matuszewska1, Adam Hańderek2, Krzysztof Biernat1*, Paweł Bukrejewski1

4

1

[email protected]

5 6 7 8

Automotive Industry Institute, Jagiellońska 55, 03-311 Warsaw, Poland;

2

Recycling Technologies Adam Hańderek, Orzeszkowej 1, 43-300 Bielsko-Biała, Poland; [email protected]

* Correspondence: [email protected]; Tel.: +48 22 77-77-211

9 10

Abstract: Authors studied a method of thermolytic conversion of waste polyolefins in an

11

innovative packed bed reactor which operates on the principle of a distillation column.

12

Vapours of cracked polymers, with a boiling point below 360°C, are transported with the use

13

of a carrier gas to the next reactor where they are catalytically hydrogenated under

14

atmospheric pressure using syngas. Waste polyolefins obtained from the landfill were used

15

as a raw material. To determine the effect of the carrier gas composition on the quality of the

16

liquid fraction, nitrogen, syngas and its mixtures were used in conducted experiments. The

17

chemical composition and the selected physicochemical properties of the liquid product were

18

investigated in the laboratory. Mixtures of nitrogen and syngas were tested as a carrier gas

19

which also played the role of the hydrogenation agent in the whole process. Conducted

20

research indicated that the best level of hydrogenation was obtained when only syngas was

21

used as the carrier gas in the cracking reactor and as the hydrogen donor during

22

hydrogenation. The obtained liquid product can be distilled into diesel fuel and gasoline

23

fractions which can be used for fuels production.

24

Keywords: waste plastics; thermolysis; syngas; fuels fractions 1 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 35

25

1. Introduction

26

Plastics are key material in many sectors of the economy such as automotive, packaging,

27

textile, healthcare, electronics and construction. This group of materials includes different

28

substances. The largest share in the market from the point of view of their production and

29

application have such polymers like: polyethylene (PE), polypropylene (PP), polyvinyl

30

chloride (PVC), polystyrene (PS), polyurethane (PU) and polyethylene terephthalate (PET)

31

[1]. Global production of plastics continuously increases due to their growing demand and

32

reached 322 million tonnes in 2015 [2]. Such an extensive use of plastic materials creates

33

some problems. One of the main problems, which arguably is the most critical problem, is

34

the disposal of waste plastics. In 2014 alone, the 30 European countries generated

35

approximately 26 million tonnes of plastic wastes (PW). Greater attention has been given to

36

the fact that post-consumer PW can be a very valuable raw material for different industries,

37

yet almost 31% of PW accumulates in landfills [2]. Plastic materials are non-biodegradable

38

staying in the environment a long period of time and create a hazard to nature [3]. Therefore,

39

any method leading to the increased recycling of PW and the search for effective

40

technologies for their processing continues to be an important subject of scientific research.

41

There are several main methods of PW recycling [4]: 1) material recycling in which the

42

plastics are reprocessed into new materials; 2) recovery of energy realized by the

43

incineration of WP; 3) feedstock recycling with the use of methods like pyrolysis,

44

gasification, hydrogenation; and 4) chemical recycling (depolymerisation). Sometimes the

45

last two of mentioned processes are classified to one group – chemical recycling [3,5].

46

Pyrolysis is one of the methods that can be used to convert PW (including polyolefins) into

47

value-added chemicals. It is a well-known technology – a number of research works have

48

been done in this area [6–10], and review papers concerning pyrolysis of plastics were

49

published [11–13]. The polymer chain can be degraded in several ways under process 2 ACS Paragon Plus Environment

Page 3 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

50

conditions: 1) by depolymerisation into a monomer, 2) by the scission of the chain in random

51

places into smaller fragments of different lengths, 3) by removal of side groups or reactive

52

substitutes, 4) by cross-linking in case of thermosetting polymers during heating [14]. These

53

mechanisms can occur simultaneously. The development of this technology is demonstrated

54

by the fact that there exists a number of commercial scale technologies that use pyrolysis to

55

convert plastics into oil or fuel, for example: Cynar Plc (Ireland), PlastOil (Switzerland), P-

56

Fuel Ltd. (Australia), Blest (Japan) [15].

57

The advantage of pyrolytic treatment of WP is the possibility to use relatively contaminated

58

feedstock containing a mixture of polymers (PP, PE, PS) that do not need special pre-

59

treatment [16]. Moreover, it is a process with lower cost in comparison to pyrolysis and

60

conventional hydrogenation of unsaturated compounds contained in a pyrolysis oil (process

61

is carried out under high pressure). Pyrolysis is conducted at high temperatures in an oxygen

62

free atmosphere (with or without a catalyst) and leads to the decomposition of organic

63

materials into several mine products: high-calorific gas, condensable hydrocarbon oil, solid

64

phase (ash, carbon). In case of the processing of polyolefins, waxes are an additional

65

pyrolysis product [17].

66

Composition of pyrolysis products and their yield depend on the process parameters,

67

especially temperature. The temperature range used in this process is wide – from 350°C to

68

900°C [18]. Higher reaction temperature leads to a decrease in oil fraction yield, an increase

69

in gaseous products and char. It is caused by the increase in the intensity of secondary

70

cracking reactions, isomerization and aromatization at elevated temperatures [19,20].

71

Generally, the pyrolysis process is conducted under isothermal conditions. In situations

72

where the effect of process temperature on the products was examined, the reactor

73

temperature was changed during tests [21–23]. In some cases, the polymer was preheated

74

before loading to the reactor but the process temperature remained constant [24]. The 3 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 35

75

effectiveness of heat transfer during the liquefaction of WP may vary depending on the type

76

of reactor. Several types of reactors have been reported in the literature: fixed bed reactors

77

[25–27], conical spouted bed reactors [28] or the most frequently used – fluidized bed

78

reactors [29–31]. Generally, in the literature there is a lack of experiments conducted under

79

non-isothermal conditions, both for biomass as well as for waste plastics. There are a few

80

researches realized under non-isothermal regime of reactor work. However, most of them are

81

connected with a study of a kinetic pyrolysis process that could occurs in a reactor, but these

82

investigations were carried out with the use of thermogravimetric techniques [32,33].

83

Moreover, research works only studied the kinetics of the pyrolysis process during smooth

84

changes of temperature within a certain range, for example from 380°C to 490°C [26] or

85

from 300°C to 500°C [34].

86

In most described research works, the pyrolysis of plastics was carried out in a nitrogen

87

atmosphere. Sometimes argon [35] and helium [36] were used as a carrier gas, or hydrogen –

88

especially when process was conducted with the use of a catalyst [37]. There is no

89

information about tests realised under the atmosphere of other gases.

90

Pyrolytic oil (one of process products) obtained from thermal degradation of WP contained

91

heavy hydrocarbons. Composition of this product could be improved by replacing the

92

thermal process with the thermocatalytic one what leads to higher yield of middle

93

hydrocarbons fraction [38]. The presence of a catalyst not only modifies the product’s

94

composition but also decreases the consumption of energy (lower temperature of process)

95

[18]. Nevertheless, the catalytic pyrolysis of plastics have some drawbacks such as: a)

96

difficulty to recover the catalyst after use, b) rapid deactivation of the catalyst due to

97

deposition of carbonaceous matter which can contain impurities (chlorine, sulphur and

98

nitrogen) acting as a poison on its surface, c) due to the high molecular size of bulky

99

polymer, their diffusion through the catalyst micropores is impeded, reducing catalyst 4 ACS Paragon Plus Environment

Page 5 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

100

activity [39]. These disadvantages can be overcome by separating the pyrolysis process from

101

catalytic reforming that could be realized in the next reactor [39–41]. In the first step, the

102

plastics liquefaction to waxes and pyrolytic oil. Pyrolytic oil contains unsaturated

103

hydrocarbons so it needs additional upgrading, for example by catalytic hydrogenation, in

104

the next step. This process is crucial to conversion of pyrolytic oil fractions to fuel [42].

105

Hydrogenation is usually carried out with the use of a catalyst such as palladium, nickel or

106

platinum, under hydrogen atmosphere and at high pressure. During this process, a

107

combination of hydrogenation and hydrocracking take place and some compounds

108

containing oxygen are transformed into aromatic hydrocarbons [43]. The drawback of this

109

process is the high cost of the plant connected with the conditions of its operation. The

110

authors of this paper have not found in the literature, a description of hydrogenation under

111

atmospheric pressure and with using gas other than hydrogen.

112

The purpose of this work was to conduct the thermolysis of waste plastics into sustainable

113

value-added fuels with the use of a two-step process where the first was the plastics

114

liquefaction in a reactor with a distribution of temperature throughout its whole length and

115

the second – a catalytic hydrogenation. In their research, the authors of this article used a

116

reactor operating as a reactive distillation for polyolefins liquefaction. This is an innovative

117

method, because such a reactor and the process conditions (non-isothermal) are not used for

118

the decomposition of polymer waste. The second innovation of the described research is the

119

hydrogenation process. Saturation was conducted under atmospheric pressure using

120

synthesis gas.

121

2. Materials and Methods

122

2.1. Description of the thermolysis process

5 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 35

123

Thermolysis process of waste polyolefins was carried out in a vertical reactor packed with

124

Raschig rings made of aluminum. In the first step, dried waste polymer was cut and sifted to

125

remove impurities. Then it was mixed with the packing elements and fed into the top of the

126

reactor. Next, the reactor was closed and heated. As the temperature increased, the plastic

127

began to melt and cover rings with a layer of liquid material. The polymer moved down of the

128

reactor with gravity and underwent a thermal decomposition process. The reactor was heated

129

only in the lower part where the temperature was higher (450°C) than in the upper part

130

(360°C). In the reactor, under the influence of the supplied heat, a thermal degradation of

131

waste plastics occurred. Vapours of the decomposed polymer (a mixture of saturated,

132

unsaturated and aromatic hydrocarbons) with the boiling point below 360°C left from the top

133

of the reactor . Vapours of heavy hydrocarbon fractions with the boiling point above 360°C

134

condensed on the colder rings in the upper section of the reactor. Condensed vapours stayed

135

in reactor and continued to undergo the cracking process until they reach the correct

136

temperature and were able to leave the reactor. The whole process was supported by the

137

carrier gas (N2/syngas) which was fed into the bottom part of the reactor. The flow rate of the

138

carrier gas controlled the residence time of the vapours of the thermolysed material in the

139

heated zone of the reactor.

140

Vapours of decomposed polymers that left the thermolysis reactor were directed to the

141

hydrogenation and isomerisation reactor. In this reactor, with the use of platinum catalysts,

142

the saturation of double and triple bonds of unsaturated hydrocarbons occurred. These

143

reactions proceeded at a temperature of 320 – 360°C and under atmospheric pressure with the

144

use of syngas as a hydrogen carrier. When the whole process was developing four

145

hydrogenation tests with the use of H2 under atmospheric pressure were carried out. In two

146

tests the pure hydrogen was fed in excess to the hydrogenation reactor and in next two tests

147

hydrogen was fed to the thermolysis reactor from which its mixture with vapours of cracked 6 ACS Paragon Plus Environment

Page 7 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

148

polymers was passed to the hydrogenation reactor. The analysis of the samples showed that

149

they contain unsaturated compounds in the range between 48% and 53%. It indicated that the

150

hydrogenation under such conditions did not occur. It was also stated that hydrogenation with

151

the use of a platinum catalyst under atmospheric pressure was possible only when carbon

152

monoxide was present in the hydrogenation gas (like in the syngas). When pure hydrogen was

153

used, the hydrogenation of unsaturated hydrocarbons did not occur.

154

Vapours of saturated hydrocarbons leaving the hydrogenation reactor were cooled. The

155

obtained liquid product can be separated into fuel fractions via distillation. One of products of

156

whole process was non-condensable hydrocarbon gases. They can be used to supply burners

157

that heat the thermolysis reactor or for syngas production. Part of the residue post-process

158

gases could be directed to the engine of a power generator. The scheme of process is

159

presented in Figure 1.

160 161

Figure 1. Scheme of the waste polyolefins thermolysis


Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 35

162 163

2.2. Test parameters during thermolysis of waste polyolefinef

164

The raw material for the thermolysis process was a mixture of waste polyolefins. The

165

characteristics of the raw material were as follows:

166

•

Low density and high density polyethylene and polypropylene wastes obtained from

167

the sieve fraction of municipal waste where the proportion of polymers was

168

approximately 70% w/w and 30% w/w respectively;

169

•

Fineness – 3 mm x (15 – 30) mm;

170

•

Moisture content: 15% – 20% (w/w).

171

The appearance of the raw material is shown in Figure 2.

172 173

Figure 2. The raw material used to the thermolysis process

174

The thermolysis reactor was flushed with nitrogen before and after process. The liquefaction

175

was carried out with a slight positive pressure (about 40 mbar higher than atmospheric) with 4

176

dm3/min flow rate of carrier gas. The hydrogenation was conducted with the use of platinum

177

catalyst on an aluminum oxide, at 360°C and with a similar positive pressure as mentioned

178

above. The flow rate of the carrier gas during this process was 2 dm3/min.


Page 9 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

179

Authors investigated the influence of carrier gas composition on the quality of final liquid

180

product. They carried out the tests with different carrier gases (see Table 1); the other

181

parameters of the tests were unchanged.

182

Table 1. Composition of carrier gas at particular tests

Carrier gas Sample

183

Thermolysis

Hydrogenation

1

N2

without this process

2

syngas

syngas

3

N2

syngas

4

N2 : syngas (1:1)

N2 : syngas (1:1)

syngas in a molar ratio of hydrogen to carbon monoxide of 2:1

184 185

2.3. Pysicochemical tests of obtained products

186

The physicochemical properties such as density at 15°C and 20°C by PN - EN ISO 12185

187

using the Anton Paar DMA 4500M apparatus, fractional composition by PN - EN ISO 3405

188

using the HERZOG HDA 627 apparatus and iodine number by PN - EN 14104 for obtained

189

liquid products were investigated. Iodine number was used to determine the amount of

190

unsaturated bonds and it is the mass of iodine that is consumed by 100 grams of a tested

191

substance. Higher the iodine number means that the substance contains more unsaturated

192

bonds. Fractional composition was determined by distillation of chemical mixture into groups

193

of chemicals with similar boiling points. Fractional composition is one of most important

194

characteristic of fuels. It is responsible for proper running of an engine (start-up, the process

195

of combustion, fuel consumption).

196

The qualitative composition of obtained liquid products by means of infrared spectroscopy

197

and gas chromatography coupled with mass spectrometer was determined. Infrared spectra 9 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 10 of 35

198

were recorded in KBr cell (thickness – 0.065 mm), in the absorbance mode over the range

199

from 4000 to 400 cm-1, at a resolution of 4 cm-1 using the Nicolet Magna-IR 750 apparatus.

200

Gas chromatography was carried out with the use of Agilent 7890 apparatus equipped with a

201

capillary HP-5MS column of 30 m length and a 0.250 mm diameter. The thickness of the

202

stationary phase was 0.25 μm. The sample was diluted in a non-polar solvent in a volume

203

ratio of 1: 9 before the injection to the column. Conditions of analysis were as follows:

204

•

sample injector temperature – 250°C

205

•

oven temperature program: 40°C – 4 min, 10°C/min to a temp. 180°C

206

•

split 1: 50

207

•

carrier gas flow (He) – 1 mL/min;

208

•

ion source temperature – 230°C

209

•

detector – Agilent 5975C mass spectrometer

210

Composition of the post-process gases was analysed for Sample 3 (after hydrogenation) with

211

the use of gas chromatography equipped with a FID and TCD detectors. Conditions of

212

analysis:

213

•

columns: six packed columns separated into three channels,

214

•

carrier gas flow (He) – 25 mL/min,

215

•

oven temperature program: 60°C – 3 min, 10°C/min to a temp. 150°C.

216

FID detector parameters:

217

•

temperature – 190°C,

218

•

hydrogen flow – 5.0 mL/min,

219

•

air flow – 350.0 mL/min.

220

TCD detector parameter: 10 ACS Paragon Plus Environment

Page 11 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

221

•

222

3. Obtained results and discussion

223

During the all tests the reactor was fed with 6 kg of waste plastics. 5 kg (6.3 L) of liquid

224

product, 0.9 kg of gases and 0.1 kg of solid phase (carbon and impurities) were extracted from

225

thermolysys reactor. The liquid phase (Sample 1) obtained in this process had a dark yellow

226

colour. What is important to note, no waxes were visually observed and the sample was stable

227

(deposit formation was not detected) during storage at ambient temperature. This indicated

228

that during the polyolefins liquefaction process, conducted with the use of the developed

229

reactor operating as a reactive distillation (without any catalyst), it is possible to get a stable

230

liquid product. Moreover, by conducting the liquefaction reaction in that way, wax formation

231

is avoided. Waxes as high boiling (above 360°C) hydrocarbons condense in the higher, cooler

232

zone of the reactor and flow down as condensate to the lower, warmer zone. They are

233

subjected to further cracking to lower boiling hydrocarbons until they reach a sufficiently low

234

boiling point and automatically leave the reaction zone.

235

When the hydrogenation process was carried out in addition to liquefaction, the resulting

236

liquid products had a brighter colour. Colour of the final product depends on the composition

237

of the carrier gas and thus on the degree of hydrogenation (Figure 3). The composition of the

238

carrier gas affects the degree of hydrogenation of the sample and the degree of hydrogenation

239

affects the color. The unsaturated bonds can form chromophore groups and cause a darker

240

color of the sample. The fewer unsaturated hydrocarbons in the sample, the brighter the

241

colour. As we can see, Sample 1 without hydrogenation is the darkest (Figure 3a), Sample 3

242

(Figure 3b) and Sample 4 (Figure 3c), which are partially hydrogenated, have an intermediate

243

colour, and Sample 2 (Figure 3d) with largest degree of hydrogenation has a bright yellow

244

colour. Physicochemical properties of research samples (before and after hydrogenation

245

process) are presented in Table 2.

temperature – 150°C.


Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 12 of 35

246

(a)

(b)

(c)

(d)

247

Figure 3. Photographs of samples obtained in the tested process: a) Sample 1 (thermolysis under N2, without

248

hydrogenation), b) Sample 3 (thermolysis under N2, hydrogenation under syngas), c) Sample 4 (both

249

thermolysis and hydrogenation under syngas mixture N2 and in ratio 1:1), d) Sample 2 (both thermolysis and

250

hydrogenation under syngas)

251

Table 2. Physicochemical properties of liquid samples of thermolysed polyolefins

Sample 1

Sample 2

Sample 3

Sample 4

Density in 15°C, kg/m3

779.1

773.4

769.2

778.7

Density in 20°C, kg/m3

774.7

768.3

767.8

775.2

Iodine number, mg I2/100 g

147.0

68.2

107.0

92.6

Initial boiling point (IBP), °C

43.0

82.3

50.0

63.9

10%(V/V) recovered at, °C

102.3

133.0

104.0

124.9


204.6

185.7

192.8

232.8


315.7

226.3

265.7

307.6


–

239.0

284.8

322.6

To 180°C distils, %(V/V)

39.9

44.3

45.4

29.7


70.1

96.5

80.6

58.6

Fractional composition


Page 13 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

To 340°C distils,%(V/V)

92.6

–

–

–


93.4

–

–

–


–

–

–

–

94.8

97.4

97.0

97.6

357.2

260.6

301.1

332.8

Percent of the total amount of distillate Final boiling point (FBT), °C 252 253

Data presented in Table 2 show that all samples after hydrogenation have lower iodine

254

number than sample before this process (Sample 1). It means that amount of unsaturated

255

bonds in the samples after this process is lower in comparison to Sample 1. The largest

256

decrease in the iodine number is shown for Sample 2, where the syngas was used as a carrier

257

gas during both thermolysis and hydrogenation. In case of Sample 4, where the mixture of N2

258

and syngas in ratio 1:1 was a carrier gas, the saturation of multiple bonds is smaller in

259

comparison with Sample 2. The poorest hydrogenation took place for Sample 3 where the

260

thermal decomposition was conducted with nitrogen and the hydrogenation – with syngas.

261

Due to the large number of unsaturated bonds, this sample may be less stable, more reactive,

262

and more susceptible to oxidation than other samples. These results indicated that the

263

composition of the carrier gas can significantly affect the quality of the products. The higher

264

the proportion of syngas in both thermolysis and hydrogenation processes, the higher the

265

proportion of saturated hydrocarbons in the obtained product. While it is understandable in

266

the case of the hydrogenation process (more syngas greater hydrogen content), the role of

267

syngas during thermolysis is ambiguous and requires detailed research.

268

A similar dependence on the carrier gas type is observed in the case of density. The highest

269

value of this parameter is observed for Sample 1 and Sample 4 but the lowest – for Sample 2

270

and Sample 3. The decrease in density can be related, inter alia, to an increase in the number 13 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 35

271

of saturated hydrocarbons. In the group of three hydrocarbons having the same number of

272

carbon atoms: alkane, alkene, and alkyne, the alkyne will be characterized by largest density,

273

alkene by lower, and alkane by least value of this parameter. In turn, in the same group of

274

compounds higher boiling point indicates a higher degree of saturation of the compound.

275

Thus, we can say that Sample 1 and Sample 4 contain the highest amount of unsaturated

276

compounds (the lowest temperature), and Sample 2 – least of these compounds (the highest

277

temperature). It should be taken into account that the values of density and boiling point also

278

depend on other chemical structures like: branching of chain, presence of others groups or an

279

aromatic structure. Therefore, in order examine chemical composition of tested samples the

280

IR spectra and gas chromatography were conducted.

281

From the point of view of fuel applications, the best properties were shown in Sample 2,

282

where the both processes thermolysis and hydrogenation were conducted under syngas

283

atmosphere. Therefore, in the next part of the article, most of the presented results of research

284

concern this sample and its comparison with Sample 1 (only after thermolysis).

285

Figure 4 presents FTIR spectrum of Sample 1 after thermolysis of polyolefins (without

286

hydrogenation). This spectrum was used as a reference spectrum in comparing the changes

287

occurring in the spectra recorded for samples subjected to hydrogenation. The signal with

288

high intensity about 3078 cm-1 is characteristic for =C-H stretching vibrations in olefins and

289

in aromatic compounds. The presence in a spectrum of several bands in the range 1825-1640

290

cm-1 (stretching vibrations of –C=C–and overtones of =C-H) may indicates the presence of

291

unsaturated compounds with various substituents. Carbonyl groups also give signals at this

292

range, but no other signals of carbonyl compounds were detected in the spectrum.

293

Furthermore, strong bands in low waver number region, 1000-650 cm-1, were detected – at:

294

992 cm-1, 909 cm-1 and 888 cm-1. These bands could be attributed to the bending vibration of

295

=C-H groups. 14 ACS Paragon Plus Environment

Page 15 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

296 297

Figure 4. FTIR spectrum of Sample 1.

298

Wide, strong bands in high frequency region, 3000-2800 cm-1, consist of few asymmetric and

299

symmetric stretching vibrations of CH2 and CH3 groups in alkanes. The confirmation of these

300

groups are strong bands at 1459 cm-1 which represent the bending and scissoring vibrations of

301

C-H, and band at 1378 cm-1 characteristic of symmetric bending vibrations of C-H. The signal

302

at 722 cm-1 is typical of rocking vibrations of CH2 groups in long-chain alkanes containing

303

over four CH2 groups. Thereby, this spectrum suggests that Sample 1 contains different

304

hydrocarbons (aromatic, saturated and unsaturated), including long-chain compounds.

305

The changes observed in IR spectra of samples subjected to hydrogenation and isomerisation

306

(Sample 2, Sample 3 and Sample 4) were similar but the intensity of them was different

307

depending on the kind of gas used for hydrogenation. It means that these reactions proceed in

308

varying degrees, depending on the carrier gas composition. These changes are most evident in

309

the case of Sample 2 (Figure 5) therefore in the paper the analysis of observed changes was

310

carried out only for this spectrum. On the one hand, we observe that some bands, for instance

311

at: 3078 cm-1, 1821 cm-1, 1697 cm-1 and 1641 cm-1 (typical of unsaturated compounds) are

312

significantly weaker or disappeared. On the other hand, the signals at 1606 cm-1 and 675 cm-1


Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 16 of 35

313

(characteristic of aromatic compounds) as well as signals of CH2 and CH3 groups in the

314

aliphatic hydrocarbons became stronger (spectrum 2 in Figure 5). These results indicate that it

315

is possible to realise hydrogenation reaction under atmospheric pressure with the use of

316

syngas as a reaction gas. To confirm these findings the gas chromatography analysis was

317

performed.

318 319

Figure 5. FTIR spectrum of: 1) Sample 1 (before hydrogenation), 2) Sample 2 (after hydrogenation and

320

isomerisation with syngas)

321

Data obtained from GC-MS indicated that in all three hydrogenated samples (Sample 2,

322

Sample 3 and Sample 4), irrespective of the composition of the carrier gas, there was no

323

presence of compounds with triple bonds and the sum of unsaturated compounds (including

324

aromatic hydrocarbons) decreases – Table 3. We can observe that after hydrogenation the

325

amount of saturated compounds doubled. The greatest reduction of compounds with double

326

bonds is observed for Sample 2. For all tested samples, there is an increase in content of

327

aromatic compounds. The largest amount of aromatic hydrocarbons was detected in Sample 2,

328

and the smallest in Sample 4. The explanation of why the content of aromatic compounds

329

increases during the isomerization and hydrogenation requires more detailed research.

330

Generally we can say that composition of carrier gas during both hydrogenation and

331

isomerisation processes is crucial to liquid product composition. 16 ACS Paragon Plus Environment

Page 17 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

332

Table 3. The sum of saturated and unsaturated compounds in the tested samples Sample 1

Sample 2

Sample 3

Sample 4

40.61

83.50

87.14

88.94

59.39

16.50

12.86

11.06

49.07

0.39

7.52

7.10

8.44

0.00

0.00

0.00

1.87

16.12

5.33

3.96

The sum of saturated compounds, % (w/w) The sum of unsaturated compounds, % (w/w) The sum of unsaturated compounds with a double bond, % (w/w) The sum of unsaturated compounds with a triple bond, % (w/w) The sum of aromatic compounds, % (w/w)

333 334

Since the changes in the GC-MS data (in comparison with Sample 1) were greatest in the case

335

of Sample 2, the results of the analysis of this sample are presented below. Examples of GC

336

spectra recorded for sample before (Sample 1) and after hydrogenation and isomerisation

337

process with syngas (Sample 2) are presented in Figure 6. Comparison of these spectra

338

indicated that in the spectrum of the sample after only thermolysis process, there are more

339

signals and the last signals have longer retention time (about 18 minutes). It means that in

340

Sample 1 we have a greater variety of compounds. After hydrogenation, some changes in

341

spectrum are observed – the retention time for last signals is shorter (about 12 minutes), there

342

are fewer signals and their intensity are higher. It indicates that hydrogenation caused the

343

decrease in some compounds and the increase in the content of others.

344


Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

(a)

Page 18 of 35

(b)

345

Figure 6. GC spectra of tested samples: a) before hydrogenation (Sample 1), b) after hydrogenation and

346

isomerisation with syngas (Sample 2)

347

Analysis of MS spectra shown that samples after hydrogenation and isomerisation processes,

348

contain less unsaturated compounds and more saturated and aromatic hydrocarbons compared

349

to Sample 1. For instance, the presence of decene was stated (see Table 4 and Figure 7) in

350

Sample 1 (before hydrogenation) and the lack of this compound in Sample 2 (after

351

upgrading). At the same time, an increase in the content of decane in sample after

352

hydrotreatment was observed – see Table 4. Decreasing amounts of compounds with multiple

353

bonds and increase in their saturated counterparts means that hydrogenation of multiple bonds

354

can be successfully carried out using synthesis gas under atmospheric pressure.

355

Table 4. Percentage concentration of selected compounds in the tested samples

Percentage concentration of selected hydrocarbons, % (w/w) decane

decene

toluene

Sample 1

2.118

3.533

0.528

Sample 2

15.982

0.000

2.520

356

During the isomerization process of hydrocarbons with the use of a palladium catalyst,

357

aromatic hydrocarbons are also formed in addition to the isomers. The increase in content of

358

these compounds in Sample 2 in comparison to Sample 1 means that such reactions have 18 ACS Paragon Plus Environment

Page 19 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

359

occurred in the process under investigation. An increased amount of these compounds is

360

advantageous in the potential use of the liquid fraction to gasoline production. Analysis of MS

361

spectra of toluene confirmed the aromatic compounds formation in the second reactor of the

362

plant. For instance, in MS spectra of toluene (Figure 8) the signal at m/z = 91, that is

363

characteristic of the ion generated during fragmentation of benzene with alkyl substituent, is

364

twice higher (abundance 1300000) for Sample 2 (Figure 8b) than for Sample 1 (Figure 8a)

365

before hydrogenation (abundance 550000). It indicated that concentration of toluene

366

increased. However, an explanation of the mechanism of formation of aromatic compounds

367

under the conditions of the process requires more detailed studies. Generally, we can say that

368

GC-MS analysis showed that it is possible to conduct hydrogenation and isomerization under

369

atmospheric pressure with the use of syngas.

370

371 372

Figure 7. MS spectrum of decene in sample before hydrogenation (Sample 1)

373


Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

(a)

Page 20 of 35

(b)

374

Figure 8. MS spectra of toluene in tested samples: a) before hydrogenation (Sample 1), b) after hydrogenation

375

(Sample 2)

376 377

An additional GC analysis of the post-process gases generated during the third process

378

(thermolysis with a nitrogen, hydrogenation with a syngas) was performed. It showed that

379

approximately 58% (w/w) of gases was nitrogen but 42% (w/w) was a mixture of hydrogen

380

and light hydrocarbons, both saturated (methane, ethane, propane, n-butane, n-pentane) and

381

unsaturated (etene, propene, 1-butene, isobutene, C6 and C6 hydrocarbons). Such large

382

amounts of hydrocarbons gives the possibility to convert the post-process gas into syngas to

383

feed the liquefaction and hydrogenation steps or use it as a gas fuel for heating reactors.

384

In summary, performed analysis with the use of infrared spectroscopy and GC-MS

385

chromatography showed that the hydrogenation and aromatization reactions took place in the

386

developed process. It was stated that a higher content of saturated hydrocarbons and aromatic

387

compounds can be received when both processes of liquefaction and hydrogenation are

388

conducted under syngas atmosphere.

389 390

4. Conclusions 20 ACS Paragon Plus Environment

Page 21 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

391

Conducted research showed that proposed by the authors the technology of waste polyolefins

392

processing into liquid fraction of hydrocarbons under syngas atmosphere is very effective.

393

This high effectiveness was possible by using an innovative solution of a reactor working on

394

the principle of reactive distillation, i.e. under non-isothermal conditions. Usage of such a

395

reactor for waste plastics thermolysis enabled us to obtain a stable light liquid product

396

(boiling point below 360°C) and avoid waxes formation. As the product of thermolysis

397

contains unsaturated compounds, the entire process should be proceeded in two stages, where

398

the second is hydrogenation. This process is generally realised with the use of hydrogen under

399

high pressure. Conducted research showed that it is possible to carry out hydrogenation under

400

atmospheric pressure with the use of mixture of H2 and CO (syngas). It also was indicated that

401

the composition of carrier gas is crucial for final liquid product. Analysis carried out with the

402

use of infrared spectroscopy and gas chromatography indicated that the most interesting

403

composition of the liquid phase from the view-point of fuel composition was obtained when

404

the syngas was used as a carrier gas in both thermolysis and hydrogenation process. It means

405

that presence of hydrogen during the liquefaction affects the composition of the final product,

406

although the process is carried out without catalyst. Final liquid phase contains saturated

407

hydrocarbons with an a mixture of aromatic compounds and can be distilled into fuels

408

fractions (diesel fuel, gasoline) or other chemicals. However, an explanation of the

409

mechanism of formation of aromatic compounds under the conditions of the process requires

410

more detailed studies.

411

In comparison with similar processes like thermal or catalytic pyrolysis described in literature.

412

this process enables to receive a product containing light hydrocarbons (similarly as catalytic

413

pyrolysis), but without any catalyst during liquefaction stage. This allows to avoid the

414

additional costs connected with the purchase of the catalyst and its recovering from the

415

products. Another advantage of presented process is the possibility to conduct hydrogenation 21 ACS Paragon Plus Environment

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 22 of 35

416

of oil fraction under atmospheric pressure with the use of syngas as a hydrogen carrier what

417

also affects the reduction of costs. Hydrogenation without using pressure (traditionally 40 to

418

300 Bar) reduces the cost of the process by the cost of: generating such pressure, purchase of

419

high-pressure equipment, systems of process control in terms of explosion protection, clean

420

hydrogen production, hydrogen storage.

421

The proposed technology entirely fits into the framework of a circular economy and allows

422

for obtaining high quality fuel components. The technology enables to achieve both value

423

added product and management of wastes not suitable for material recycling, which is

424

significant for the environment. Additionally, fuels produced from hydrocarbons obtained

425

during mentioned process have an important advantage – the raw material for their production

426

(waste plastics) is characterized by zero GHG emissions (according to renewable energy

427

directive – RED). Taking it into account, the production of such fuels is more

428

environmentally friendly during their whole life cycle in comparison with conventional fuels.

429

References

430

1.

Plastics - the Facts 2014/2015. An analysis of European plastics production, demand and waste

431

data.

432

final_plastics_the_facts_2014_2015_260215.pdf (accessed 06.01.2018).

433

2.

http://www.plasticseurope.org/documents/document/20150227150049-

Plastics - the Facts 2016. An analysis of European plastics production, demand and waste data.

434

http://www.plasticseurope.org/Document/plastics---the-facts-2016-15787.aspx?FolID=2

435

(accessed 06.01.2018).

436

3.

Achilias D.S.; Roupakias C.; Megalokonomos P.; Lappas A.A.; Antonakou E. Chemical

437

recycling of plastic wastes made from polyethylene (LDPE and HDPE) and polypropylene (PP).

438

J. Hazard. Mater. 2007, 149, 536–542, https://doi.org/10.1016/j.jhazmat.2007.06.076.

439

4.

Fortelný I.; Michálková D.; Kruliš Z. An efficient method of material recycling of municipal

440

plastic

441

https://doi.org/10.1016/j.polymdegradstab.2004.01.024.

waste.

Polym.

Degrad.

Stab.

2004,

85,

975–979,


Page 23 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

442

Energy & Fuels

5.

443 444

Goto M. Chemical recycling of plastics using sub- and supercritical fluids. J. Supercrit. Fluids 2009, 47, 500–507, https://doi.org/10.1016/j.supflu.2008.10.011 .

6.

López A.; de Marco I.; Caballero B.M.; Laresgoiti M.F.; Adrados A.; Torres A. Pyrolysis of

445

municipal plastic wastes II: Influence of raw material composition under catalytic conditions.

446

Waste Manage. 2011, 31, 1973–1983, https://doi.org/10.1016/j.wasman.2011.05.021.

447

7.

448 449

Kaminsky W.; Zorriqueta I.N. Catalytical and thermal pyrolysis of polyolefins. J. Anal. Appl. Pyrolysis 2007, 79, 368–374, https://doi.org/10.1016/j.jaap.2006.11.005 .

8.

Adrados A.; de Marco I.; Caballero B.M.; López A.; Laresgoiti M.F.; Torres A. Pyrolysis of

450

plastic packaging waste: A comparison of plastic residuals from material recovery facilities with

451

simulated

452

https://doi.org/10.1016/j.wasman.2011.06.016.

453 454 455

9.

plastic

waste.

Waste

32,

826–832,

by the Fast Pyrolysis of Polyolefins. Energy Fuels 2007, 21, 561–569, DOI: 10.1021/ef060471s. 10. Çit I.; Sınağ A.; Yumak T.; Ucar S.; Mısırlıoglu Z.; Canel M. Comparative pyrolysis of polyolefins

457

https://doi.org/10.1007/s00289-009-0225-x.

459

2012,

Arandes J.M.; Torre I.; Castano P.; Olazar M.; Bilbao J. Catalytic Cracking of Waxes Produced

456

458

Manage.

(PP

and

LDPE)

and

PET.

Polym.

Bull.

2010,

64,

817–834,

11. Kunwar B.; Cheng H.N.; Chandrashekaran S.R.; Sharma B.K. Plastics to fuel: a review. Renew. Sust. Energ. Rev. 2016, 54, 421–428, https://doi.org/10.1016/j.rser.2015.10.015 .

460

12. Panda A.K; Singh R.K.; Mishra D.K. Thermolysis of waste plastics to liquid fuel. A suitable

461

method for plastic waste management and manufacture of value added products—A world

462

prospective.

463

https://doi.org/10.1016/j.rser.2009.07.005.

464 465 466

Renew.

Sust.

Energ.

Rev.

2010,

14,

233–248,

13. Almeida D.; Marques M. Thermal and catalytic pyrolysis of plastic waste. Polímeros 2016, 26, 44-51, http://dx.doi.org/10.1590/0104-1428.2100. 14. Buekens A.G.; Huang H. Catalytic plastics cracking for recovery of gasoline-range hydrocarbons

467

from

468

https://doi.org/10.1016/S0921-3449(98)00025-1.

municipal

plastic

wastes.

Resour.

Conserv.

Recycl.

1998,

23,

163–181,


Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 24 of 35

469

15. Conversion technology: A complement to plastic recycling, American Chemistry Council, 4R

470

Sustainability, Inc., 2011, https://plastics.americanchemistry.com/Plastics-to-Oil/ (accessed

471

06.01.2018).

472

16. Al-Salem S.M.; Lettieri P.; Baeyens J. Recycling and recovery routes of plastic solid waste

473

(PSW):

474

https://doi.org/10.1016/j.wasman.2009.06.004.

475 476

A

review.

Waste

Manage.

2009,

29,

2625–2643,

17. Achilias D.S.; Antonakou E.; Roupakias C.; Megalokonomos P.; Lappas A. Recycling Techniques of Polyolefins From Plastic Wastes. Global NEST J. 2008, 10, 114–122.

477

18. Miskolczi N.; Angyal A.; Bartha L.; Valkai I. Fuels by pyrolysis of waste plastics from

478

agricultural and packaging sectors in a pilot scale reactor. Fuel Process. Technol. 2009, 90, 1032–

479

1040, https://doi.org/10.1016/j.fuproc.2009.04.019.

480

19. Jung S.H.; Cho M.H.; Kang B.S.; Kim J.S. Pyrolysis of a fraction of waste polypropylene and

481

polyethylene for the recovery of BTX aromatics using a fluidized bed reactor. Fuel Process.

482

Technol. 2010, 91, 277–284, https://doi.org/10.1016/j.fuproc.2009.10.009.

483

20. Onwudili J.A.; Insura N.; Williams P.T. Composition of products from the pyrolysis of

484

polyethylene and polystyrene in a closed batch reactor: Effects of temperature and residence time.

485

J. Anal. Appl. Pyrolysis 2009, 86, 293–303, https://doi.org/10.1016/j.jaap.2009.07.008.

486

21. Abbas-Abadi M.S.; Nekoomanesh Haghighi M.; Yeganeh H. The effect of temperature, catalyst,

487

different carrier gases and stirrer on the produced transportation hydrocarbons of LLDPE

488

degradation

489

https://doi.org/10.1016/j.jaap.2012.02.007.

in

a

stirred

reactor.

J.

Anal.

Appl.

Pyrolysis

2012,

95,

198–204,

490

22. Lee K.H; Shin D.H. Characteristics of liquid product from the pyrolysis of waste plastic mixture

491

at low and high temperatures: Influence of lapse time of reaction. Waste Manage. 2007, 27, 168–

492

176, https://doi.org/10.1016/j.wasman.2005.12.017.

493

23. López A.; de Marco I.; Caballero B.M.; Laresgoiti M.F.; Adrados A. Influence of time and

494

temperature on pyrolysis of plastic wastes in a semi-batch reactor. Chem. Eng. J. 2011, 173, 62–

495

71, https://doi.org/10.1016/j.cej.2011.07.037.


Page 25 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

496

Energy & Fuels

24. Miskolczi N.; Bartha L.; Deák G.; Jóver B. Thermal degradation of municipal plastic waste for

497

production

498


of

fuel-like

hydrocarbons.

Polym.

Degrad.

Stab.

2004,

86,

357–366,

499

25. Williams E.A.; Williams P.T. The pyrolysis of individual plastics and a plastic mixture in a fixed

500

bed reactor. J. Chem. Technol. Biotechnol. 1997, 70, 9–20, DOI: 10.1002/(SICI)1097-

501

4660(199709)70:13.0.CO;2-E.

502

26. Ballice L. A kinetic approach to the temperature-programmed pyrolysis of low- and high-density

503

polyethylene in a fixed bed reactor: determination of kinetic parameters for the evolution of n-

504

paraffins

505

2361(01)00067-9.

506 507

and

1-olefins.

Fuel

2001,

80,

1923–1935,

https://doi.org/10.1016/S0016-

27. Bagri R.; Williams P.T. Catalytic pyrolysis of polyethylene. J. Anal. Appl. Pyrolysis 2002, 63, 29–41, https://doi.org/10.1016/S0165-2370(01)00139-5.

508

28. Aguado R.; Olazar M.; Gaisán B.; Prieto R.; Bilbao J. Kinetics of polystyrene pyrolysis in a

509

conical spouted bed reactor. Chem. Eng. J. 2003, 92, 91–99, https://doi.org/10.1016/S1385-

510

8947(02)00119-5.

511

29. Kaminsky W.; Predel M.; Sadiki A. Feedstock recycling of polymers by pyrolysis in a fluidised

512

bed.

513


514 515

Polym.

Degrad.

Stab.

2004,

85,

1045–1050,

30. Smolders K.; Baeyens J. Thermal degradation of PMMA in fluidised beds. Waste Manage. 2004, 24, 849–857, https://doi.org/10.1016/j.wasman.2004.06.002.

516

31. del Remedio Hernández M.; García Á.N.; Marcilla A. Catalytic flash pyrolysis of HDPE in a

517

fluidized bed reactor for recovery of fuel-like hydrocarbons. J. Anal. Appl. Pyrolysis 2007, 78,

518

272–281, https://doi.org/10.1016/j.jaap.2006.03.009.

519

32. Aboulkas A.; El harfi K.; El bouadili A.; Nadifiyine M.; Benchanaa M.; Mokhlisse A. Pyrolysis

520

kinetics of olive residue/plastic mixtures by non-isothermal thermogravimetry. Fuel Process.

521

Technol. 2009, 90, 722–728, https://doi.org/10.1016/j.fuproc.2009.01.016.


Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 26 of 35

522

33. Saha B.; Maiti A.K.; Ghoshal A.K. Model-free method for isothermal and non-isothermal

523

decomposition kinetics analysis of PET sample. Thermochim. Acta 2006, 444, 46–52,

524

https://doi.org/10.1016/j.tca.2006.02.018.

525

34. Kim S.S; Kim J.; Jeon J.K.; Park Y.K.; Park C.J. Non-isothermal pyrolysis of the mixtures of

526

waste automobile lubricating oil and polystyrene in a stirred batch reactor. Renew. Energy 2013,

527

54, 241-247, https://doi.org/10.1016/j.renene.2012.08.001.

528 529

35. Sharma S.; Ghoshal A.K. Study of kinetics of co-pyrolysis of coal and waste LDPE blends under argon atmosphere. Fuel 2010, 89, 3943–3951, https://doi.org/10.1016/j.fuel.2010.06.033.

530

36. Zabaniotou A.A; Stavropoulos G. Pyrolysis of used automobile tires and residual char utilization.

531

J. Anal. Appl. Pyrolysis 2003, 70, 711–722, https://doi.org/10.1016/S0165-2370(03)00042-1.

532

37. Sharypov V.I.; Beregovtsova N.G.; Kuznetsov B.N.; Baryshnikov S.V.; Cebolla V.L.; Weber

533

J.V.; Collura S.; Finqueneisel G.; Zimny T. Co-pyrolysis of wood biomass and synthetic

534

polymers mixtures: Part IV: Catalytic pyrolysis of pine wood and polyolefinic polymers mixtures

535

in

536

https://doi.org/10.1016/j.jaap.2005.12.006.

537 538

hydrogen

atmosphere.

J.

Anal.

Appl.

Pyrolysis

2006,

76,

265–270,

38. Lee K.H. Thermal and catalytic degradation of pyrolytic oil from pyrolysis of municipal plastic wastes. J. Anal. Appl. Pyrolysis 2009, 85, 372–379, https://doi.org/10.1016/j.jaap.2008.11.032.

539

39. Aguado J.; Serrano D.P.; San Miguel G.; Castro M.C.; Madrid S. Feedstock recycling of

540

polyethylene in a two-step thermo-catalytic reaction system. J. Anal. Appl. Pyrolysis 2007, 79,

541

415-423, https://doi.org/10.1016/j.jaap.2006.11.008.

542

40. Artetxe M.; Lopez G.; Amutio M.; Elordi G.; Bilbao J.; Olazar M. Light olefins from HDPE

543

cracking in a two-step thermal and catalytic process. Chem. Eng. J. 2012, 207–208, 27–34,

544

https://doi.org/10.1016/j.cej.2012.06.105.

545

41. Syamsiro M.; Saptoadi H.; Norsujianto T.; Noviasri P.; Cheng S.; Alimuddin Z.; Yoshikawa K.

546

Fuel Oil Production from Municipal Plastic Wastes in Sequential Pyrolysis and Catalytic

547

Reforming

548

https://doi.org/10.1016/j.egypro.2014.01.212.

Reactors.

Energy

Procedia

2014,

47,

180–188,


Page 27 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

549 550

Energy & Fuels

42. Bezergianni S.; Dimitriadis A.; Faussone G.C.; Karonis D. Alternative Diesel from Waste Plastics. Energies 2017, 10, 1750, DOI:10.3390/en10111750.

551

43. Vasile C.; Brebu M.A.; Karayildirim T.; Yanik J.; Darie H. Feedstock recycling from plastics and

552

thermosets fractions of used computers. II. Pyrolysis oil upgrading. Fuel 2007, 86, 477–485,

553

https://doi.org/10.1016/j.fuel.2006.08.010.


Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41

ACS Paragon Plus Environment

Page 28 of 35

Page 29 of 35

Energy & Fuels

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

(a)

(b)


Page 30 of 35

(c)

Page 31 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41

Energy & Fuels


Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

(a)

Page 32 of 35

(b)


Page 33 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41

Energy & Fuels


Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

(a)

Page 34 of 35

(b)


Page 35 of 35

Energy & Fuels

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Thermolytic Conversion of Waste Polyolefins into Fuels Fraction with

Recommend Documents