Recycling of plastic waste by using pyrolysis reactor: A case study of first marine protected area of Pakistan (Astola Island)

2 Department of planning, development and special initiatives Islamabad (Environment and climate change section) * Correspondence: asmajabeen@fjwu.edu.pk;baloch.Faisal78@gmail.com Abstract: Astola Island is the first marine protected area of Pakistan acknowledged 2017, June 15. It is a rich biodiversity hotspot, Ramsar site inhabiting endangered species like Green turtle, Hawksbill turtle, and Arabian Humpback whale. A saw-scaled Russell’s viper is endemic to Island. Marine ecology of Astola Island is affected by plastic pollution resulting in coral destruction, ocean acidification, global warming, fishing nets blockage, water pollution, and coastal erosion. Zeolite catalyst synthesized from environmentally friendly way by coal fly ash to degrade collected plastic waste from Island into useful products in pyrolysis reactor.Three type of organosilane are used for functionalization of synthesized catalyts to increase their silica content for better catalytic activity by using(1)Octyltriethoxysilane(OS),(2)Phenyltriethoxysilane(PS),(3)Vinyltriethoxysilane(VS).Zeolite functionalize with octyltriethoxy silane (ZO) shows the highest performance in plastic pyrolysis, resulting in lower degradation temperature, low residue and more product formation may be due to having long chain hydrocarbon and acidic sites. Plastic recycling is the promising solution to tackle plastic blooming issue. Which is negatively impacting all the compartments of ecosystem especially marine environment.

because of maximum active sites accessibilty.It also increases hydrophobicity of zeolites. These modify zeolites have several applications [16].
Pyrolysis is obtained through different catalytic processes like thermal, hydrocarbon and catalytic. Thermal catalysis has a drawback as; it produces more carbon range products. But compared to thermal, catalytic degradation decreased reaction temperature and also increase product yield [17], [18].ZSM-5 zeolite catalyst in the plastic waste pyrolysis plays an important on the color of oil, oil yield and also on capability to decompose the polymer[] 19].Pyrolysis with the help of catalyst in the range of temperature of 300°C -650°C helps to improve bio-oil hydrocarbon range because of zeolite molecular structure and their strong acid sites [20]. Pyrolysis is convenient technique than gasification and high-pressure liquefaction because economically cheap and the manipulation of parameters during process is easy [21].
Pyrolysis put up to the circular economy, waste plastic converted thermo chemically into degradation products using polyethylene and polypropylene feedstock's [22].Production of biodiesel was achieved by renewable resources. In diesel engines used as additive, replace petrol-diesel, reduce gaseous pollutants, increase economy, waste management of biomass and also this leads to acquiring sustainability [23].Plastic recycling has become very lucrative activity aims to achieved sustainable development through providing benefits to the current and future generations, economic prosperity and social equity [24].

Formatting of Mathematical Components
Rate of conversion (%) =Initial mass of plastic -Mass of plastic left in the reactor x100 (1) Initial mass of plastic.
Yield of oil = Mass of the obtained oil x 100 Initial weight of plastic waste sample Oil recovery= Volume of oil recovered (ml) x100 Weight of sample material (Kg)   C-H group stretch around(3000-2800cm-1 )were more intense bands and angular deformation occued at (1464cm-1-1379cm-1 ).Carbonyl absorption band (1750 -1735 cm-1 ) and aliphatic ester absorption band (1300-100 cm-1 ) shows the presence of biodisel in the samples.Low intensity bands (675-900 cm-1 ) are aromatic compounds [30]. In figure (a) and table (b) shows the degradation of plastic waste using pyrolysis reactor. All catalysts decreased the initial degradation temperature which is more expressive for the catalyst ZO that is 180 0 C and total reaction time was 63 minutes. The more product formation with ZP catalyst that was 80ml (oil).Pyrolysis is a circular economy change waste product  Zeolite without functionalization exhibited a lower degradation rate compared to others, so ZO showed higher catalytic activity may be associated with the greater number of strong acidic sites.

Discussion
3.1Fourier transformation infrared spectroscopy (FTIR): 3.1.1FTIR of Zeolite catalyst: Functional group zeolites were determined by FTIR analysis [25].FTIR of the zeolite was done in the laboratory using KBr pellets at room temperature after background correction. The FTIR spectra of zeolite catalyst are in the range of 4,000 to 400 cm− 1 .FTIR analysis of zeolites shows absorption band in the 3424 cm-1 region which attributed (Si-OH) terminal silanol group [26]. Functional group of each collected fuel was determined by FTIR analysis. Sodium chloride cells were used to perform the analysis [28] and sample were diluted in methanol. After distillation this fuel is used as alternative of diesel [29].

3.2.
Energy dispersive x-ray (Edx) analysis: 3.3. Degradation of plastic waste by using pyrolysis reactor: Pyrolysis reactor setup according to method proposed [32].All catalysts decreased the initial degradation temperature which is more expressive for the catalyst ZO that is 180 0 C and total reaction time was 63 minutes. The more product formation with ZP catalyst that was 80ml (oil).It was found that chemical action on plastic waste within the temperature varies 175 0 C -500 0 C depending on Because of chemical action degradation of plastic waste upon heating, to get 5 kg wax, 10 kg charcoal, 5 kg of gas and maximum 80 ml liquid product.

3.4.Analysis of pyrolysis fuel:
Two type of analysis generally one is physical and other is chemical analysis.

Physical analysis of pyrolysis oil:
• Color of the oil The colors were identified visually, light yellow to orange in color due to different polymer composition.

Viscosity of oil:
Viscosity of oil produced from plastic was measured by using Ostwald Viscometer. The viscometer was filled with the oil up to mark .after the suction was done to pull it to the upper reserivor.The suction was removed and the oil was allowed to go back to the lower reservoir. During this movement from upper to lower mark on each reservoir, the time was measured using stopwatch. Water was used as a reference material for the viscometer as its density is well-known and calculated relative viscosity of the oil by using Oswald equation. Thermal Decomposition Analysis about half dozen mg of HDPE and PP was heated by a non-isothermal temperature program, from 30 0 C temperature to 800 0 C at twenty 0 C/min of heating rate underneath sixty mL/min of atomic number 7 atmosphere, using a TGA (Pyris Diamond, Perkin-Elmer, Waltham, MA, USA).For the chemical change TG analysis, 6 mg of catalyst was mixed with plastics and the same temperature program was applied. TGA studies showed that without catalyst more residues left but with the addition of zeolite catalyst having different organo silane modifications are fewer residues and more product formation.

Materials and Methods
The study area was visualized through ArcGIS (10.7.1) to select the sampling sites. Sampling was carried out in March, 2020 and weather conditions were mostly sunny Samples were collected on five different beaches including Ormara, Jabbal Juddi, Jabbal zareen, Pasni creek beach and Astola Island (first marine protected area).
Coal fly ash was provided by National Cleaner Production (NCPC) Rawalpindi Pakistan, Sodium Meta silicate (BDHL), Aluminum isoprop-oxide (Sigma Aldrich), tri ethoxy octyl silane, phenyl tri ethoxy silane, trimethoxy vinyl silane, potassium hydroxide, sodium hydroxide purchased from Merck. All the chemicals were of analytical grade and used without further purification. Representative plastic samples were prepared by cuttings of plastic 2cm 2 of area.

Synthesis of zeolite using hydrothermal method
Zeolite is synthesized sodium Meta silicate by using hydrothermal method reported by [33].For this purposes, 8.9g of sodium Meta silicate was mixed with 2g NaOH anhydrous form and grounded into fine powder mixture using a pestle and mortar. The dried mixture was transferred into a crucible and placed in a furnace at 500°C for 2 hours. The resultant solid mixture and grounded again into fine powder and mixed with 100 ml of deionized water and small quantity of aluminum isopropoxide added and stirred at 600 rpm. The suspended slurry mixture was then placed for autoclave (120mmHg; 2 hours). The solid was filtered and washed until pH 8 was attained. Then, dried in oven at 100 °C for 12 hours.

Functionalization with organosilane
Organosilane was used for the surface modification of zeolites [34].Functionalization with silane derivatives containing octal group was carried out by refluxing a mixture of zeolite 2g and trimethoxyoctylsiane (2ml) in toluene (70 mL) for 5 hours. After Centrifugation the solid was washed with toluene. Silane containing-phenyl group was carried out by refluxing a mixture zeolite (2

Conclusions
The synthesized catalyst ZO showed the highest performance in plastic pyrolysis, resulting in lower degradation temperature, low residue and more product formation might be due to having long chain hydrocarbon and acidic sites. This is the first study to focus