Thermo-catalytic Pyrolysis Research Articles

SECONDARY POLYMERS AS A PROSPECTIVE RAW MATERIAL FOR THE PRODUCTION OF HIGH-OCTANE AUTOMOBILE GASOLINE

The article analyzes the possibility of expanding the raw material base of the production process of commercial high-octane automobile gasoline of the A-92 and A-95 brands due to the involvement of secondary polymer raw materials. The types of raw materials that will make it possible to obtain basic fractions or components of commercial gasolines that will be used in the production of commercial automobile gasolines that, according to their chemical composi- tion and properties, will meet the requirements of environmental safety standards adopted in Ukraine and the countries of the European Union have been determined. It was established that the main raw material capable of replacing oil and gas condensate is secondary polyolefin raw material, represented by polyethylene (HDPE and LDPE) and polypropylene (PP), and the main process of its processing is thermal or thermocatalytic pyrolysis. Priority is given to raw materials that are directly generated in production in the form of waste and raw materials that come from sorting points. At the same time, secondary polymer raw materials, regardless of their source of origin, must undergo a stage of preliminary preparation, which includes sorting, crushing, washing and drying of raw materials. Practical studies have shown that this process is implemented on reactor-type installations at temperatures of 320–450 °C and pressures of 0.1–3.5 MPa and allows obtaining a significant yield (35–70 %) of the liquid product of pyrolysis – a gasoline fraction with a boiling point of 30–200 °C. Along with liquid products, more than 15 % of gases (ethylene, propylene and butylene) are formed, which should be processed into polymer gasoline (base fraction) and high-octane components – alkylates. As a result of the research, a scheme for the production of commercial high-octane automobile gasoline from secondary polymer raw materials (HDPE, LDPE and PP) is proposed, which is based on the rational use of production resources and production by-products.

Cu MOF-biocarbon functional catalysts as adsorbent for oxygen-linked carbon capture via thermo-catalytic pyrolysis: A low-carbon fuel synthesis strategy

Low-carbon fuel synthesis is encouraged as it is environmentally benign and aims to lessen the impact of global warming. This experimental investigation examines the synthesized Bombax ceiba oil (Bio-oil) based pyrolyzed oil utilizing Cu MOF-biocarbon catalysts (0.15 wt.%) via thermo-catalytic cracking and adsorption. The structural and thermal characteristics of the developed Cu MOF - biocarbon catalysts are investigated using Field Emission – Scanning Electron Microscopy/Energy Dispersive Spectroscopy (FE-SEM/EDAX), Attenuated Total Reflectance-Infrared Spectroscopy (ATR-IR), X-Ray Diffraction (XRD), Thermogravimetry-Differential Thermal Analysis (TG-DTA) and Brunauer-Emmett-Teller (BET). Following a thermo-catalytic reaction with a hot plate magnetic stirrer (600 rpm, 100 °C, and 1 h), the oily Cu MOF-biocarbon catalysts are separated from the pyrolyzed green fuel using high-speed centrifugation. The cracking and adsorption of the pyrolyzed green oil compounds are studied using 1H NMR, GC–MS, and thermal conductivity. The results indicate that alkane compounds increase from 3.25 to 6.70 % whereas oxygen incorporated compounds decrease from 96.75 to 93.30 % in the pyrolyzed oil. Furthermore, the GC–MS study shows that the separated oily catalysts adsorb 44.52 % of hydrocarbon (CH) and oxygen-linked (CHO) hydro-carbon compounds. Overall, the newly synthesized Cu MOF-biocarbon is considered as a potential functional catalyst for cracking and adsorption of alkane/oxygen bonded compounds (e.g., CH, CO etc.,), promoting the pyrolyzed oil as low-carbon fuel for better sustainable environment.

Thermocatalytic Pyrolysis of Waste Areca Nut into Renewable Fuel and Value-Added Chemicals.

Pyrolytic oil is currently in its early stages of production and distribution but has the potential to grow into a significant renewable energy source. It may be processed into a variety of useful substances, including chemicals, and used for heating, transportation, and energy production. The present investigation involves the production and characterization of pyrolytic oil from areca nut husk (ANH), with and without ZSM-5. The pyrolysis experiment was conducted in a semibatch tubular reactor at 600 °C and a heating rate of 80 °C min-1 using ZSM-5 at 20 wt %. The pyrolytic oil was examined via elemental analysis, viscosity, density, moisture content, GC-MS, FTIR, higher heating value (HHV), and ash content. The analysis of kinetics verified that the activation energy rises in proportion to the conversion rate. Additionally, employing ZSM-5 in catalytic pyrolysis at 20 wt % boosted the yield of pyrolytic oil by 11% compared to thermal pyrolysis. Employing ZSM-5 at 20 wt % resulted in a decrease in viscosity, oxygen content, and density by approximately 43.40 cSt, 15.20%, and 168 MJ kg-1, respectively. Moreover, it led to an increase in higher heating value (HHV) and carbon content by 11.71 MJ kg1- and 14.06%, respectively. An FTIR study of pyrolytic oil revealed the occurrence of hydrocarbons, aromatics, phenols, alcohols, and oxygenated chemicals. Moreover, GC-MS analysis indicated a significant increase in hydrocarbons (10.31%) and a decrease in phenols (2.36%), acids (6.38%), and oxygenated compounds with the introduction of the catalyst. Consequently, it can be inferred that utilizing ZSM-5 at 20 wt % during the pyrolysis of ANH aids in enhancing both the yield and characteristics of the resulting pyrolysis oil.

Перспективи виробництва синтетичного бензину в Україні

DOI: 10.31081/1681-309X-2024-0-1-34-40 Specialty 161. U.D.C. 662.7 PROSPECTS FOR THE PRODUCTION OF SYNTHETIC PETROL IN UKRAINE © K.V. Shevchenko, Ph.D. in Technical Sciences, A.B. Grigorov, Doctor of Technical Sciences (National Technical University "Kharkiv Polytechnic Institute", 2, Kyrpychova str., Kharkiv, 61002, Ukraine) The article analyses the possibility of using various hydrocarbon feedstocks (including secondary ones) in the technology of synthetic motor petrol production, which, together with petrol produced by classical technology (from oil or gas condensate), can satisfy the existing demand for this type of motor fuel. It is shown that, taking into account the possible production volumes and demand for raw materials, as well as the complexity (energy intensity) of their technological processing, the most promising types of raw materials are biomass, solid fossil fuels and secondary polymers. Biomass (mainly agricultural waste) is a feedstock for biogas production, which is currently being used quite successfully in the European Union. The product of this production is methane, which can be used for energy purposes or processed into petrol and biomethanol. Another promising area in biomass processing is the direct production of alcohols (biomethanol and bioethanol), which can be used as a raw material for organic synthesis and for the production of blended petrol (e.g., grades E5, E7 and E10). Given Ukraine's reserves of various grades of coal, its processing into synthetic gasoline by gasification followed by synthesis using the Fischer-Tropsch method or hydrogenation can also be considered very promising. However, to date, these processes have not been widely used in industry due to their high energy intensity. It has been determined that secondary polymers - production and consumption wastes represented by polyethylenes (HPDE and LPDE) and polypropylene (PP) - are more promising for Ukraine than other types of raw materials. The main process for their processing is thermal or thermocatalytic pyrolysis, which produces both liquid petrol fractions (boiling point 30-210 °C) and gases, represented by ethylene, propylene and butylene. Given their conversion rate (70-90 % and 100 %, respectively), propylene and butylene can be processed into polymer gasoline, which, after purification, will be suitable for use in mixed or synthetic commercial motor gasoline. Keywords: natural gas, biomass, solid fossil fuels, polymers, processing, hydrogenation, synthesis, pyrolysis, methane, propylene, butylene, synthetic petrol. Corresponding author: A.B. Grigorov, e-mail: grigorovandrey@ukr.net

Thermo-catalytic decomposition of cotton seed press cake over nickel doped zeolite Y, hydrogen: enhanced yield of bio-oil with highly selective fuel-range hydrocarbons.

This research reports the yield of bio-oil from cotton seed press cake (CSPC) via an optimized thermo-catalytic pyrolysis using nickel impregnated zeolite Y, hydrogen catalyst. The catalyst, raw biomass and catalyst impregnated biomass were characterized using different analytical techniques. The ideal temperature, duration, and catalyst concentration for pyrolysis experiments were determined to be 300 °C, 20 minutes, and 5% of Ni-doped zeolite Y, hydrogen, respectively, in order to achieve the best bio-oil yield (35%). Gas chromatography-mass spectrometry (GC-MS) of pyrolytic bio-oil depicted the presence of C2-C26 hydrocarbons. The findings of this investigation showed that the synthesis of bio-oil with highly selective fuel-range hydrocarbons could be efficiently induced through the pyrolysis of CSPC biomass employing nickel impregnated zeolite Y, hydrogen catalyst. Moreover, thermogravimetric analysis (TGA) of cotton seed press cake with catalyst was carried out at various heating rates to find out the kinetic parameters. Employing Kissinger model, activation energy (E a) and frequency factor (A) for various components of biomass i.e., hemicellulose, cellulose and lignin were calculated as 83.14 kJ mol-1, 99.76 kJ mol-1, 124.71 kJ mol-1 and 1.9 × 107 min-1, 1.0 × 108 min-1, 1.0 × 1010 min-1, respectively. It can be concluded from the results that cotton seed press cake waste has potential for use as a pyrolysis feedstock in large-scale bio-fuel production.

Thermo-catalytic pyrolysis of lignosulfonate from the sulfite process

Thermo-catalytic pyrolysis of lignosulfonate from the sulfite process

Energy generation from waste packaging plastic via thermo-catalytic pyrolysis using catalysts produced from spent aluminum hydroxide nanoparticles

Energy generation from waste packaging plastic via thermo-catalytic pyrolysis using catalysts produced from spent aluminum hydroxide nanoparticles

Performance and emission characteristics analysis of a CI engine fueled with distilled pyrolytic waste plastic oil/ethanol/diesel blends.

The current energy challenges in agriculture, industry, and transportation are aggravated by insufficient liquid petroleum fuels, strained by rapid depletion, and higher demand in the international market. Existing environmental pollution due to higher fossil fuel consumption, certainly draws the attention of many researchers to identify a better alternative fuel concerning engine efficiency and exhaust emissions. Waste plastic oil (WPO) derived by thermo-catalytic pyrolysis is found to be a promising alternative fuel due to it's similar fuel properties to diesel. WPO contains long-chain hydrocarbons and high-molecular-weight aromatics which can be eliminated by fractional distillation, resulting in the production of distilled waste plastic oil (DPO). Ethanol is added in addition to DPO in the diesel fuel mixture in order to improve combustion for better performance and reduce emissions. The current study focused on the preparation of homogenous fuel mixtures (DPO/ethanol/diesel) to evaluate it's engine efficiency and exhaust emissions as compared to pure diesel and confirmed that it has the potential to be an alternate fuel for the CI engine. Test engine trials were performed to determine thepotential engine characteristics, for instance, thermal efficiency, specific fuel consumptions, and exhaust temperature, by using various fuel mixtures (80D10DPO10E, 70D15DPO15E, 60D20DPO20E, 50D25DPO25E) under different loading conditions of the test engine. Major pollutants including unburned hydrocarbon, carbon monoxide, and nitrogen oxides were measured by a standard emission analyzer. The BTE was increased by 3.7%, and the BSFC was 16.67% less for the 60D20DPO20E mixture so as to diesel at full load. CO emission was found to comparatively increase at higher concentrations and decrease at higher loads. Compared to diesel, the NOx and HC emission were shown to be lowered at low loads and increased at higher loads. The study concluded that the fuel mixture of 60D20DPO20E showed the best engine performance and reduced emissions as compared to diesel.

Improved bio-oil yield from thermo-catalytic pyrolysis of Citrus limetta waste over pumice: Determination of kinetic parameters using Kissinger method

The focus of this research is on thermo-catalytic conversion of Citrus limetta waste, with and without pumice, using thermo gravimetric analysis and a pyrolysis chamber. TG/DTG results demonstrated weight reduction occurring in four stages i.e., evaporation of water, degradation of hemicellulose, decomposition of cellulose and lignin. Activation energy (Ea) calculated using Kissinger method for non-catalytic decomposition of hemicellulose, cellulose, and lignin was found as 99.76, 157.96 and 174.59 kJ mol−1 and for catalyzed reactions as 83.14, 91.45 and 149.65 kJ mol−1respectively. Thermal degradation of Citrus limetta waste produced 30 % oil in the range of C2–C24, while catalytic pyrolysis produced more than 45 % pyrolysis oil with a wide range of components from C4 to C32 which shows, that pumice has not only decreased the activation energy of the pyrolysis reaction but improved the quality of bio-oil making it suitable for energy on upgradation.

Thermocatalytic pyrolysis of agriculture waste biomass for the production of renewable fuels and chemicals

ABSTRACT The present work highlights the thermocatalytic pyrolysis of three different waste biomasses (Groundnut Stalk, Indian Rosewood, and Rice Straw) using meso and microporous catalysts for the effective conversion to fuels and chemicals. Thermocatalytic pyrolysis was found to be highly significant under optimum conditions (Temperature = 500°C, Heating rate = 90°C/min, Biomass particle size = 0.4 mm, and Sweeping gas flow rate = 100 mL/min). All the synthesized catalysts (KIT-6, NbKIT-6, and ZIF-8) were found to be highly efficient, and the maximum liquid yield was observed at 20 wt% of catalyst loading, i.e. 49.35% (KIT-6); 56.57% (NbKIT-6); and 52.74% (ZIF-8), respectively. The results revealed that compared to KIT-6, the maximum liquid yield was observed with NbKIT-6 catalyst i.e. 56.57% (Groundnut Stalk); 58.45% (Indian Rosewood); and 57.57% (Rice Straw), respectively. The proposed strategy will be highly economical and sustainable and the selected biomass could be a promising alternative and renewable energy source.

Thermo-catalytic pyrolysis of Azadirachta indica seeds over CaO and CuO: Pyrolysis kinetics, impact of catalysts on yield, fuel properties and its chemical compositions

Pyrolysis oil and distribution is still in the incipient stages, though it is a potential source of energy and valueable chemicals. The current work focused on the kinetics study and thermo-catalytic pyrolysis of Azadirachta indica seeds (AZI) over CaO and CuO. The kinetic behaviour of AZI is studied in a TGA under an inert atmosphere at dynamic heating rates (10, 20 and 30 °C min−1) using Starink method (ST) and Vyazovkin model (VM). Further, AZI were pyrolyzed in a semi-batch tubular reactor at 500 °C, 50 °C min−1 heating rate and 100 mL min−1 nitrogen flow rate at 20 wt% catalyst loading. The biomass and pyrolysis liquid were characterised via proximate analysis, elemental analysis, thermal stability, FTIR, viscosity, density, acidity, moisture content, GC-MS etc. Kinetic analysis of AZIs confirmed that biomass decomposition takes place in a multifaceted route, and the activation energy is associated with conversion and temperature. Thermal pyrolysis exhibited 39.53 wt% liquid yields; however, introducing 20 wt% catalyst has improved the yield to 46.53 wt% and 45.36 wt% for CaO and CuO, respectively. The findings of the thermal and catalytic pyrolytic oil demonstrated that the addition of catalysts significantly enhanced the properties of pyrolytic oil by lowering viscosity and oxygen content while raising heating value and acidity. Finally, GC-MS results displayed that the use of catalysts resulted in a considerable decline in the proportion of oxygenated compounds, acids, and phenols and an increase in the proportion of hydrocarbons, aldehydes and alcohols.

Thermo-catalytic pyrolysis of marine debris: A waste to wealth conversion study for energy recovery

The rapid increase in marine waste has resulted in the accumulation of plastic marine debris (PMD), which is of concern to the scientific community due to the need for its safe disposal worldwide. PMD primarily consists of non-degradable polymeric waste, namely thermoplastics, which contain a substantial amount of energy as they are made from petroleum-based sources. Proper disposal and energy reclamation of this waste have become pressing topics. This study aimed to investigate PMD through thermogravimetric analysis followed by pyrolysis in the temperature range of 450–600 °C. Additionally, two catalysts, 10% nickel impregnated activated alumina (10% Ni/Al2O3) and sodium aluminosilicate (AlNaO6Si2), were incorporated (non-contacting method) to evaluate their effect on product yield and quality. During the non-catalytic process, the highest yield (∼78%) was achieved at a temperature of 550 °C while the presence of a catalyst had a minimal effect on oil density (0.74–0.76), and the percentage yield decreased to ∼ 58 and ∼ 62% using AlNaO6Si2 and 10% Ni/Al2O3 at 550 °C. The catalyst had a significant effect on the fraction of oxygenated compounds in the oil, reducing it by ∼ 18% from the non-catalytic process. AlNaO6Si2 resulted in a higher fraction of gasoline-range compounds, while 10% Ni/Al2O3 showed a higher similarity towards diesel fractions. Gas chromatography-mass spectrometry (GC–MS) analysis identified the presence of alkanes, alkenes, aromatics, alcohols, and other compounds in the oil product, with variations observed depending on the catalyst used. The results showed that among all hydrocarbons, propane had the maximum fraction, followed by ethane, methane, and butane in the gaseous compounds. Based on the degradation mechanism, yield distribution, and component evolution, the dissociation mechanism for both processes was explained.

Thermo-catalytic pyrolysis of sawdust by a synthesized NiO/Al2O3 composite catalyst: investigation on its reaction mechanism, kinetics, and thermodynamics

Thermo-catalytic pyrolysis of sawdust by a synthesized NiO/Al2O3 composite catalyst: investigation on its reaction mechanism, kinetics, and thermodynamics

Multiple Biogenic Waste Valorization via Pyrolysis Technologies in Palm Oil Industry: Economic and Environmental Multi-objective Optimization for Sustainable Energy System

Agricultural biomass is one of the major wastes in the world. Most of these wastes end up in landfills and incineration, causing significant environmental problems that are detrimental to human health and other species on the Earth. Thermochemical conversion can solve this issue by utilizing the energy embedded inside the biomass, mainly organic matter, into high-grade fuels and chemicals. Fast pyrolysis is one of the technologies that can convert biomass waste to a high yield of bio-oil, which can then be used as biofuels in vehicles. In this study, palm oil biomass wastes are valorized to generate bio-oil sustainably via several pyrolysis technologies such as conventional pyrolysis, microwave pyrolysis, and thermo-catalytic pyrolysis in a multi-objective optimization framework. The formulated multi-objective mixed-integer linear programming problems are solved using the ɛ-constraint method. The Pareto-optimal solutions have illustrated a clear trade-off between two conflicting objectives: total annualized profit and the global warming potential. The most profitable solution economically has an annualized profit of $237 per ton of biomass with an emission of 628 kg CO2 equivalent per ton of biomass. On the other hand, the most environmentally sustainable solution, while still generating positive income, has an annualized profit of $122 per ton of biomass with an emission of 132 kg CO2 equivalent per ton of biomass. A second scenario with a case study presented on the palm oil industry in Malaysia has also demonstrated the selection of biomass during feedstock blending when a constraint on biomass feedstock availability is pre-defined. The proposed model is robust for planning bioenergy complex, especially those involving multiple biomass feedstocks. In fact, this study has addressed the research gap in comparison of multiple distinctive pyrolysis processes with respect to multiple palm biomass feedstocks.

Chemical Recycling of Waste Polypropylene via Thermocatalytic Pyrolysis over HZSM‐5 Catalysts

AbstractThe present work deals with the chemical recycling of waste polypropylene via thermocatalytic pyrolysis over HZSM‐5 zeolite catalysts. The main aim was to systematically investigate the influence of reactor configuration, zeolite acidity, polypropylene wastes, obtained from different sources, as well as catalyst regeneration on the product distribution. It was demonstrated that the reactor configuration and the acid site density of HZSM‐5 catalysts strongly influence the product yields and distributions. The different types of polypropylene waste, on the other hand, showed a comparatively small yet noticeable effect on the product distribution. Moreover, it was demonstrated that the HZSM‐5 catalysts exhibit good regeneration capacity during regeneration‐reaction cycles.

A Thermo-Catalytic Pyrolysis of Polystyrene Waste Review: A Systematic, Statistical, and Bibliometric Approach.

Global polystyrene (PS) production has been influenced by the lightness and heat resistance this material offers in different applications, such as construction and packaging. However, population growth and the lack of PS recycling lead to a large waste generation, affecting the environment. Pyrolysis has been recognized as an effective recycling method, converting PS waste into valuable products in the chemical industry. The present work addresses a systematic, bibliometric, and statistical analysis of results carried out from 2015 to 2022, making an extensive critique of the most influential operation parameters in the thermo-catalytic pyrolysis of PS and its waste. The systematic study showed that the conversion of PS into a liquid with high aromatic content (84.75% of styrene) can be achieved by pyrolysis. Discussion of PS as fuel is described compared to commercial fuels. In addition, PS favors the production of liquid fuel when subjected to co-pyrolysis with biomass, improving its properties such as viscosity and energy content. A statistical analysis of the data compilation was also discussed, evaluating the influence of temperature, reactor design, and catalysts on product yield.

Economic Feasibility Assessment of the Thermal Catalytic Process of Wastes: Açaí Seeds (Euterpe oleracea) and Scum from Grease Traps

In this work, a techno-economic assessment of the production of bio-oil, coke and gas, via thermo-catalytic pyrolysis followed by distillation, is accomplished. The raw materials were two solid wastes: lipid-based material (residual fat/scum from a fat retention box from the University Restaurant at the Federal University of Pará—UFPA) and a lignin-cellulosic material of açaí seed (Euterpe oleracea Mart.). From the literature, a review is made of the physicochemical analysis of the raw materials, of the bio-oil, and of the chemical composition of the biofuels produced (kerosene, light diesel, and heavy diesel). The bio-oil yields for each experiment of pyrolysis and distillation are also presented and compared with the literature. The economic indicators for the evaluation of the most viable cracking (pyrolysis) and distillation process of bio-oils were: (a) the simple payback criterion, (b) discounted payback, (c) net present value (NPV), (d) internal rate of return (IRR), and (e) index of profitability (IP). The analysis of the indicators showed the economic viability of the lipid-based material and unfeasibility for the açai seed (Euterpe oleracea Mart.). The breakeven point obtained was 1.28 USD/L and the minimum fuel selling price (MFSP) obtained in this work for the biofuels was 1.34 USD/L). The sensibility analysis demonstrated that the pyrolysis and distillation yields are the most important variables to affect the minimum fuel selling price (MFSP).

Thermocatalytic pyrolysis of Sesbania bispinosa biomass over Y-zeolite catalyst towards clean fuel and valuable chemicals

The thermocatalytic pyrolysis of Sesbania bispinosa (SB) biomass was performed in a cylindrical-shaped pyrolyzer to produce renewable fuel and chemicals. The important process parameters, such as temperature, heating rate, and N2 flow rate, were optimized using the response surface methodology (RSM). Pyrolysis of the SB biomass was also performed at different catalyst to biomass ratios (C/B) (1:3, 1:6, 1:9, and 1:12). The pyrolysis findings indicated that normal pyrolysis produced a greater yield of bio-oil (42.53 wt %) than catalytic pyrolysis (40.71 wt %) that obtained at 1:9 C/B ratio. The use of catalyst reduced the yield of bio-oil; however, fuel characteristics get enhanced. FTIR analysis of normal and catalytic bio-oil verified the existence of different functional groups, whereas GCMS result at optimized pyrolysis condition confirmed increased hydrocarbons in the catalytic bio-oil. Further, the characterization result of the biochar revealed its potential for use in a variety of industrial and agricultural applications.

Biofuel Technologies and Petroleum Industry: Synergy of Sustainable Development for the Eastern Siberian Arctic

This article is a compilation of interdisciplinary studies aimed at ensuring the environmental, political, and economic sustainability of oil and gas-producing countries with a focus on areas with many years of permafrost. One of the main concepts adopted in this research was the desire to show that confronting various energy lobbies is not mandatory and that it is necessary to find compromises by finding and introducing innovative technologies for integrated development for the benefit of society, industry, and the state. This is particularly relevant due to the increasing share of hard-to-recover hydrocarbon reserves, widely represented in the fields of the Eastern Siberian Arctic, and because Russia is the leader in flare emissions. We thus present the relevance of using these gases as industrial waste while reducing the carbon footprint. The technology of biofuel production based on the use of supercritical liquid extraction in a well extractor is presented as a result of the development of the presented experimental devices representing the investigation of the processes of extraction in wells and reactors for the distillation of hydrocarbons from heavy oil components. The obtained yield of the desired product (hydrogen) of the thermocatalytic pyrolysis of the test extract was in the range of 44 to 118 L/h, depending on the catalyst. This information can help inform the direction of future ecological engineering activities in the Eastern Siberian Arctic region.

Chemical recycling of waste polystyrene by thermo-catalytic pyrolysis: A description for different feedstocks, catalysts and operation modes

Chemical recycling by thermo-catalytic pyrolysis/degradation offers the possibility of converting waste plastics into their original monomers or other valuable chemicals which can be used as feedstocks in chemical and petrochemical industries. Plastic wastes of polystyrene (PS) based materials can be a good source of styrene as well as mono-aromatic (BTEX: benzene, toluene, ethylbenzene, xylenes) compounds. The selectivity of pyrolysis products can be tuned by choosing the right catalyst as well as appropriate operating conditions/operation modes. In this regard, the focus of the present work was to perform thermo-catalytic pyrolysis of different waste polystyrene (WPS) feedstocks over acid and base catalysts employed in ex-situ and in-situ modes. The main goal was to compare the compositions of pyrolysis products obtained by changing feedstocks, catalysts and operation modes. A further goal was to discuss the suitability of the catalysts employed for the enhanced recovery of desired products from WPS pyrolysis. It was demonstrated that expanded polystyrene gives very similar product distribution as compared to virgin PS, both giving high styrene content. Likewise, hard PS-based random packing materials produce similar results as compared to high impact polystyrene (HIPS). Moreover, it was shown that solid base catalysts influence the composition of the pyrolysis products only slightly as compared to thermolysis. Solid acid catalyst however, showed significant impact on the composition of the pyrolysis products as compared to non-catalytic pyrolysis. These results may provide new insights for the chemical recycling of plastic wastes.