CO2 Co-feeding Research Articles

Improving the Selectivity and Stability of Supported Cobalt Catalysts via Static Bi-Doping and Dynamic Trace CO2 Co-Feeding During Propane Dehydrogenation.

Simultaneously enhancing selectivity and stability on supported propane dehydrogenation (PDH) catalysts remains a formidable challenge. Here, we report a combined static and dynamic strategy to address these issues synergistically. Firstly, we demonstrate a feasible sol-gel method for preparing atomically-dispersed Bi-decorated metal nanoparticle catalysts (MBi/Al2O3, M=Fe, Co, Ni, and Zn). In PDH testing, the total selectivity of by-products (CH4 and C2H6) significantly decreases to 4 % for CoBi catalysts due to the static Bi-doping, compared with 16 % for Co-supported catalysts. Secondly, to enhance catalytic stability, we introduce a dynamic trace CO2 co-feeding route. 10CoBi/Al2O3 catalysts exhibit superior durability against coke formation for 330 hours in PDH under a 40 % C3H8 atmosphere followed by pure C3H8 conditions at 600 °C while maintaining propylene selectivity at 96 %. Notably, introducing trace CO2 leads to a remarkable 6-fold decrease in the deactivation rate constant (kd). Multiple characterizations and density functional theory calculations reveal that charge transfer from atomically-distributed Bi to Co nanoparticles benefits lowering the energy of C3H6 adsorption thereby suppressing by-products. Furthermore, the dynamic co-feeding of trace CO2 facilitates coke removal, suppressing catalyst deactivation. The static Bi-doping and dynamic trace CO2 co-feeding strategy contributes simultaneously to increased selectivity and stability on supported PDH catalysts.

Oxygen-tolerant CO2 electroreduction over covalent organic frameworks via photoswitching control oxygen passivation strategy

The direct use of flue gas for the electrochemical CO2 reduction reaction is desirable but severely limited by the thermodynamically favorable oxygen reduction reaction. Herein, a photonicswitching unit 1,2-Bis(5’-formyl-2’-methylthien-3’-yl)cyclopentene (DAE) is integrated into a cobalt porphyrin-based covalent organic framework for highly efficient CO2 electrocatalysis under aerobic environment. The DAE moiety in the material can reversibly modulate the O2 activation capacity and electronic conductivity by the framework ring-closing/opening reactions under UV/Vis irradiation. The DAE-based covalent organic framework with ring-closing type shows a high CO Faradaic efficiency of 90.5% with CO partial current density of −20.1 mA cm−2 at −1.0 V vs. reversible hydrogen electrode by co-feeding CO2 and 5% O2. This work presents an oxygen passivation strategy to realize efficient CO2 electroreduction performance by co-feeding of CO2 and O2, which would inspire to design electrocatalysts for the practical CO2 source such as flue gas from power plants or air.

Methane conversion to syngas by chemical looping on La0.8Sr0.2FexCo1-xO3 (x = 0, 0.25, 0.50, 0.75) perovskites with CO2 co-feeding

Partial oxidation of methane (POM) by chemical looping with CO2 co-feeding on La0.8Sr0.2FeO3 (LSF) perovskite catalyst yielded a highly selective operation and enabled to extend the duration of reduction cycle. In this work, the conversion of methane to syngas was studied on La0.8Sr0.2Fe(x)Co(1-x)O3 (x = 0, 0.25, 0.5, 0.75) perovskites in chemical-looping mode, co-feeding CO2 and methane. The reaction was conducted at 850 °C, 15 min reduction (10% methane in N2, 0–3% CO2), and 10 min oxidation (10% O2 in N2) cycles. The perovskites activity decreased with increasing Co content, in the absence of CO2, due to intensified coke deposition on the catalyst. Addition of CO2 during the reduction step (1–3%) reduced coke accumulation. A run conducted on La0.8Sr0.2CoO3 (LSC) with continuous feeding of CO2 and periodical (on–off) methane feeding indicated that CO2 reacts with the accumulated coke in reverse-Boudouard reaction, increasing CO selectivity without affecting the methane conversion. XRD analysis of reduced Co-containing perovskites indicates a decreasing perovskite content. Metallic Co and La2O3 phases increased as the Co content in the fresh perovskite increased, increasing coke deposition. As the Co content increased, the process shifts from POM with oxygen replenishment (LSF) to cracking followed by reverse-Boudouard reaction (LSC).

Manipulating the Cobalt Species States to Break the Conversion–Selectivity Trade-Off Relationship for Stable Ethane Dehydrogenation over Ligand-Free-Synthesized Co@MFI Catalysts

Nonoxidative dehydrogenation of low-cost alkanes provides a promising route to produce valuable olefins. Herein, we hydrothermally synthesized various non-noble-metal-based, environment-friendly, and Al-free Co@MFI catalysts without the assistance of any additional coordination agents. The Co2+ species were successfully incorporated into well-crystallized MFI to form a stable and atomically dispersed −Coδ+–Oδ−– structure. The Co@MFI catalyst could show a stably high activity for ethane dehydrogenation with equilibrium-approached conversions at 600 °C and at the same time gave an extremely high selectivity to ethylene (∼99%), which is owed to the relatively unreducible −Co–O– species and its appropriate chemical state at the right reaction-temperature window. However, the Co@MFI catalyst showed equilibrium-deviated conversions at lower temperatures (such as 550 °C) and a suppressed activity in the H2O or CO2 co-feeding tests. Then, with characterizations, density functional theory calculations, and abundant experiments over different catalysts, including impregnated Co/MFI and amorphous Co@MFI, this study has impressively demonstrated that the chemical state of Coδ+ species manipulates the conversion–selectivity trade-off relationship in the conversion of alkanes. It is suggested that Co with a lower valence like Co0 promotes both C–C and C–H bond scissions of alkanes into coke and CH4, while Co with a higher one shows a decreased activity or even inactivity for alkane dehydrogenation. In this study, the possible causes for the success in the synthesis of the ligand-unassisted Co@MFI catalyst, the catalyst deactivation modes and the strategies for improving catalyst stability were also demonstrated in detail. This work not only contributes a performance-advanced Co-based catalyst for alkane dehydrogenation but also provides new insights into incorporation of a metal into zeolites.

Process analysis for the simultaneous production of aromatics and syngas from shale gas and CO2

The production of benzene, toluene, and xylene (BTX) from shale-derived CH4, C2H6, and C3H8 is considered a promising alternative to their fossil-based counterparts. Herein, we evaluate a production technology for aromatics and hydrogen with non-oxidative and CO2 co-feeding reactions to predict the economics and environmental impact of each process. The optimal process for producing aromatics and hydrogen varies depending on the presence or absence of CO2, and we experimentally confirm the difference in the reaction systems. The operating conditions of both processes are optimized using an experiment-based surrogate model in terms of thermal energy demand and profit of products, which account for the highest portion of BTX production cost. Particularly, the CO2 emissions and economic feasibility of the proposed BTX production processes are compared with those of an ethane cracking center using shale gas and the naphtha reforming/Cyclar process to produce BTX. In the CO2 co-feeding case, the CO2 reduction effect is proven compared to other processes, and the economics was improved by the sale of H2 and CO compared to the non-oxidative BTX production. Furthermore, the BTX production cost reflecting the carbon price is comparable to that of commercial processes; as the carbon price increases, the economics has the potential to outperform existing processes. These findings present a platform for economic evaluation based on CO2 emissions as well as the economic benefits of processes that reduce CO2 emissions for energy-efficient conversion of shale gas into high value-added products.

Exergetic and environmental assessments of hydrogen production via waste tire gasification with co-feeding of CO2 recycled

Hydrogen can be produced from natural gas, coal, biomass, and waste materials as an energy source applicable in many industries. Waste tires can be converted into energy by gasification because they contain numerous organic components, higher heating value, and high volatile content. The purpose of this study is to present the simulation of the hydrogen production via waste tire gasification using recycled CO2 as a gasifying agent. The influences of steam and CO2 to waste tire ratios on hydrogen yield were identified. The energetic and exergetic analyses were applied to evaluate the performance of the waste tire gasification process. From an environmental point of view, the carbon dioxide emission intensity was used to determine the CO2 emission of the waste tire gasification process. The simulation showed that the highest yield of hydrogen occurs at the gasifier temperature of 800 °C with the steam and CO2 to waste tire ratios of 2.0, and 0.1, respectively. The utilization of CO2 as a gasifying agent can enhance the yield of hydrogen, resulting in an increase of energetic and exergetic efficiencies of 59.58 and 49.39%, respectively. In addition, the use of CO2 recycled with a mixture of air and steam produces the lowest CO2 emission intensity of 10.56 tonne CO2/ tonne H2.

Effect of CO2 on activity and coke formation over gallium-based catalysts for propane dehydrogenation

This work investigated the effects of support and CO2 co-feeding on the activity and coke formation over gallium-based catalysts for propane dehydrogenation (PDH). The prepared catalysts were characterized by XRD, NH3-TPD, CO2-TPD, O2-TPO, pyridine-IR, Raman and tested in CO2 assisted propane dehydrogenation. The results revealed Ga/HZSM-5 as a highly active and carbon resistant catalyst, more so in the presence of CO2. The structure of coke species was investigated and found to be different over these gallium based catalysts as characterized by O2-TPO and Raman techniques. Coke formation behavior is shown to be directly related to the acid density and strength as well as the topological structure of the support. Moreover, the introduction of CO2 leads to an increase in propane conversion and a decrease in coke selectivity over Ga/HZSM-5 catalysts, although coke species become more graphitic in nature. Lastly, PDH reaction with different co-feeding agents (H2, CO2 and O2) were performed and the results indicate CO2 co-feeding yields the highest propane conversion and lower coke deposition, exhibiting a good application prospect.

System-level analysis for continuous BTX production from shale gas over Mo/HZSM-5 catalyst: Promotion effects of CO2 co-feeding on process economics and environment

Benzene, toluene, and xylene (BTX) production from shale-derived CH4, C2H6, and C3H8 is considered an energy-efficient technology substituting their naphtha-cracking counterparts. However, the economics of BTX production from shale gas remains questionable because of the rapid deactivation of the catalyst, originating from the coke generation. Herein, we present a BTX production strategy with CO2 co-feeding for catalyst stability enhancement and additional H2 production. Our process prevents coke deposition on the active sites of Mo and zeolite, and improves the operation time of reactors compared to that of shale gas without CO2 co-feeding. Concurrently, H2 and CO are produced with BTX owing to the dry reforming reaction of hydrocarbons over the Mo/HZSM-5 catalyst. Most importantly, the economics of BTX production with CO2 co-feeding is evaluated using individual system components integrated with two different CH4 conversion processes (steam-reforming-based H2 and methanol production). The BTX production with CO2 co-feeding lowers the methanol production cost by additionally producing methanol generated by CO from the BTX reactor, while the H2 production cost increases. Moreover, the life cycle assessment proves that the CO2 emission during the methanol production process is significantly reduced by recycling the CO2 produced in the subsequent process.

Combined Syngas and Hydrogen Production using Gas Switching Technology.

This paper focuses on the experimental demonstration of a three-stage GST (gas switching technology) process (fuel, steam/CO2, and air stages) for syngas production from methane in the fuel stage and H2/CO production in the steam/CO2 stage using a lanthanum-based oxygen carrier (La0.85Sr0.15Fe0.95Al0.05O3). Experiments were performed at temperatures between 750–950 °C and pressures up to 5 bar. The results show that the oxygen carrier exhibits high selectivity to oxidizing methane to syngas at the fuel stage with improved process performance with increasing temperature although carbon deposition could not be avoided. Co-feeding CO2 with CH4 at the fuel stage reduced carbon deposition significantly, thus reducing the syngas H2/CO molar ratio from 3.75 to 1 (at CO2/CH4 ratio of 1 at 950 °C and 1 bar). The reduced carbon deposition has maximized the purity of the H2 produced in the consecutive steam stage thus increasing the process attractiveness for the combined production of syngas and pure hydrogen. Interestingly, the cofeeding of CO2 with CH4 at the fuel stage showed a stable syngas production over 12 hours continuously and maintained the H2/CO ratio at almost unity, suggesting that the oxygen carrier was exposed to simultaneous partial oxidation of CH4 with the lattice oxygen which was restored instantly by the incoming CO2. Furthermore, the addition of steam to the fuel stage could tune up the H2/CO ratio beyond 3 without carbon deposition at H2O/CH4 ratio of 1 at 950 °C and 1 bar; making the syngas from gas switching partial oxidation suitable for different downstream processes, for example, gas-to-liquid processes. The process was also demonstrated at higher pressures with over 70% fuel conversion achieved at 5 bar and 950 °C.

Tailoring the Physicochemical Properties of Mg Promoted Catalysts via One Pot Non-ionic Surfactant Assisted Co-precipitation Route for CO2 Co-feeding Syngas to Methanol

Tailoring the Physicochemical Properties of Mg Promoted Catalysts via One Pot Non-ionic Surfactant Assisted Co-precipitation Route for CO2 Co-feeding Syngas to Methanol

Numerical simulation of commercial scale autothermal chemical looping reforming and bi-reforming for syngas production

Autothermal Chemical Looping Reforming (a-CLR) is an emerging technology that facilitates CO2 capture and minimizes energy losses in syngas production. The dual-fluidized bed process uses a bubbling fuel reactor (FR) and a riser air reactor (AR). A 1-D multiscale model was developed that couples fluidized bed hydrodynamics with intrinsic reaction kinetics, including catalyst deactivation by oxidation and coke formation. An a-CLR unit with a capacity equivalent to 50 conventional reformer tubes was considered to demonstrate feasibility. The effects of the catalyst activity, main operation conditions and CO2 co-feeding on the performance were then analyzed. The results confirm a-CLR is feasible with realistic reactors dimensions and solids circulation rate. To avoid the risk of sintering and catalyst deactivation, the oxygen carrier should only be slightly oxidized in the AR. Autothermal operation then requires an oxygen-to-CH4 feed ratio of around 1.2. The high catalyst-to-gas feed ratio in the FR and bubble-emulsion phase mass transfer limitations result in a low sensitivity of the methane conversion to the catalyst activity. A low H2O-to-CH4 feed ratio introduces a risk for coke formation in the bottom of the FR, but part of the feed methane is fully oxidized, producing H2O and CO2 in the emulsion phase and mitigating this risk. Co-feeding CO2 with CH4 and H2O is seen to allow adjusting the H2/CO-ratio of the syngas, but increases the risk of coke formation. Finally, heat recovery from the flue gas and syngas from both reactors by preheating the feed gases further increases the energy efficiency.

Study on carbon rearrangements of CO2 co-feeding pyrolysis of corn stover and oak wood

Pyrolysis has been broadly applied to biomass valorization process to convert solid biomass waste into three phase value-added products such as biochar, pyrolytic oil, and pyrolytic gas. The carbon rearrangement process is highly affected by contents of cellulose, hemicellulose, and lignin due to their different structures. In this respect, this study laid great emphasis on the thermolytic behaviors of cellulosic corn stover (CS) and lignin-rich oak wood (OW) to understand carbon reallocations of them as a case study. In addition, CO2 was employed as a reaction medium for biomass pyrolysis to control the carbon redistribution between CO2 and CS/OW in line with the achievement of sustainable thermo-chemical conversion of biomass consuming a greenhouse gas (i.e., CO2). Lignin-rich OW showed higher tolerance to thermal degradation, thereby resulting in more biochar and less pyrolytic oil formations. During the CO2-assisted pyrolysis, carbon redistribution was appeared between liquid and gas phase products. This showed the gas phase reactions (GPRs) between volatilized liquid pyrolysates and CO2 with additional CO formation. To expedite the GPRs, Ni/SiO2 catalyst was employed. The CO2-assisted catalytic pyrolysis of CS and OW significantly improved dehydrogenation and deoxygenation, showing more than one order of magnitude higher production of H2 and CO.

Ni-Fe-Al mixed oxide for combined dry reforming and decomposition of methane with CO2 utilization

The chemical looping dry reforming of methane can be used to convert greenhouse gases into products with much desirable specification. However, developing an oxygen carrier with coke-tolerance and high oxygen exchange rate usually requires the use of rare-earth metals or lanthanides. In this study, by utilizing deposited surface carbon as a reaction intermediate rather than suppressing it, complete methane conversion was possible even with the earth-abundant metal oxide particles. To establish an optimized H2/CO ratio for the hydrocarbon synthesis, the CH4 feedstock was partially replaced with CO2. By itself, Ni-Al oxide exhibited deactivation due to the agglomeration arising from methane decomposition over the redox cycle. Fe-Al oxide had stable performance over cycles, but a sudden performance decline was observed when the amount of CO2 co-feeding exceeded a certain point. Incorporating Ni into the Fe-Al oxide was found to overcome these problems. The formation of a spinel phase with Fe alleviated the agglomeration, and enhanced CH4 activation under high CO2 partial pressure. The introduction of Ni also improved carbon gasification kinetics with CO2.

Direct conversion of syngas into aromatics over a bifunctional catalyst: inhibiting net CO2 release.

Tandem catalysis via methanol intermediate is a promising route for the direct conversion of syngas into aromatics. However, the simultaneous formation of CO2 is a serious problem. Here, we demonstrate that CO2 was formed by the water-gas shift (WGS) reaction (CO + H2O → CO2 + H2) over a ZnO-ZrO2/H-ZSM-5 catalyst, and the net CO2 formation could be inhibited without affecting the formation of aromatics by co-feeding CO2.

Sorbents screening for post-combustion CO2 capture via combined temperature and pressure swing adsorption

Adsorption-based post-combustion CO2 capture is enjoying significant research attention due to its potential for significant reductions in energy penalty, cost and environmental impact. Recent sorbent development work has focussed on polyethyleneimine (PEI) and dry sorbents that exhibit attractively low regeneration energy requirements. The main objective of this study is to identify best suitable sorbent for the recently published swing adsorption reactor cluster (SARC) concept. The screening results of four sorbents indicated two PEI sorbents to be good candidates for SARC application: a PEI sorbent functionalized with 1,2-epoxybutane supported on silica (referred to as EB-PEI in the rest of the document) and a PEI sorbent supported on mesoporous silica containing confined metal organic framework nanocrystals (referred to as PEI-MOF in the rest of the document). High resolution single-component isotherms revealed substantial differences in adsorption capacity and optimal operating temperatures for the two PEI sorbents, and CO2 and H2O isotherm models were derived from this data. Subsequently, breakthrough experiments and lab-scale reactor tests showed that co-feeding of CO2 and H2O had no significant effect, allowing the single-component isotherm models to be safely used in large-scale reactor simulations. Such a reactor model was then employed to illustrate the effect of the sorbent adsorption characteristics on the efficiency of the novel swing adsorption reactor cluster, which combines pressure and temperature swings. The EB-PEI and PEI-MOF sorbents were compared to a previously published PEI sorbent with distinctly different adsorption behaviour and recommendations for future sorbent development work were made.

An Approach Using Oxidative Coupling of Methane for Converting Biogas and Acid Natural Gas into High-Calorific Fuels

Biogas is a renewable resource with prospects in production of commodity chemicals or for power generation. The latter implies co-usage of biogas and natural gas in gas distribution nets but puts a restriction on the higher heating value (HHV) of all gases pumped into the net. In this contribution, we analyzed and experimentally validated the potential of the oxidative coupling of methane (OCM) as a method for upgrading biogas HHV. The effects of the reaction conditions, i.e., reaction temperature, feed CH4/O2 ratio, and co-feeding of CO2 or H2O, on HHV of the resulting gas mixtures were studied. The highest HHV of 11.48 kW·h·m–3 after water condensation was obtained when performing the OCM reaction over Mn–Na–WOx/SiO2 catalyst at 800 °C using a feed with CH4/O2 ratio of 12 and 30 vol% water. This performance was possible thanks to 86% selectivity to C2 hydrocarbons (C2H4 and C2H6) at 15.2% methane conversion. It was also possible to increase the selectivity to 100% when carbon oxides formed in the OCM re...

Chemical looping partial oxidation of methane with CO2 utilization on the ceria-enhanced mesoporous Fe2O3 oxygen carrier

The high-purity syngas production with a molar ratio of H2 to CO equal to 2 was achieved through a chemical looping process with a CH4-CO2 feed mixture on a ceria-enhanced mesoporous Fe2O3/Al2O3 oxygen carrier. The presence of CO2 in the mixture feed enables the H2/CO ratio to be maintained as 2 desirable for the syngas-to-liquid hydrocarbon process by suppressing the methane decomposition even when the amount of reducible oxygen carrier was sufficiently small. By incorporating a small amount of CeO2 (molar Ce/Fe ratio = 0.15) to the iron oxide mesoporous oxygen carrier by the sol-gel method, the syngas selectivity also increased although the amount of reducible oxygen was large enough to cause the total combustion. Due to the co-feeding of CO2 with CH4 and the textural property of the ceria-enhanced Fe2O3/Al2O3 mesoporous oxygen carrier, the enhanced redox activity for the chemical looping process was demonstrated under the CO2/CH4 feed ratio of 0.28 with the redox performance of CH4 conversion = 93.11%, CO selectivity = 93.23%, average carbon deposit = 0.048 molC/molsyngas, and average H2/CO ratio = 2.04. The fluctuation of the H2/CO ratio with the reaction time was minimized by adjusting the real-time CO2/CH4 feed ratio and then, the consistent syngas production was realized even in the fixed bed chemical looping process.

Strategic use of CO2 for co-pyrolysis of swine manure and coal for energy recovery and waste disposal

Here in this study, the genuine role of CO2 in co-pyrolysis of swine manure and coal was mainly investigated to increase the thermal efficiency of the thermo-chemical process. The TGA test of swine manure and coal revealed that the CO2 co-feeding impact on any reactions (≤740°C) between CO2 and the sample surface (i.e., heterogeneous reaction) should be excluded. A batch-type co-pyrolysis revealed two genuine CO2 co-feeding impacts on co-pyrolysis of swine manure and coal. First, CO2 can be an additional source for C and O through a plausible reaction between pyrolytic oil and CO2, which led to the enhanced generation of CO by the conversion of volatile organic carbons (VOCs) evolved from thermal deconstruction of pyrolytic substrate. Second, CO2 expedite the thermal cracking of VOCs, which also resulted in the more generation of H2 and CH4. Two genuine roles of CO2 in co-pyrolysis of swine manure and coal occurred independently. All experimental findings will be directly applicable to the gasification process since pyrolysis is an intermediate step for the gasification.

Effect of CO2 co-feeding on the conversion of syngas derived from waste to liquid fuel over a bi-functional Co/H-ZSM-5 catalyst

A bi-functional Co-HZSM-5 catalyst was synthesised by the Incipient Wetness Impregnation (IWI) of cobalt onto H-ZSM-5 and effect of CO2-co-feeding on the performance of the catalyst during Fischer Tropsch (F-T) was investigated. Physico-chemical property of the catalyst was checked with N2 physisorption (for BET surface area), Transmission Electron Microscopy and Scanning Electron Microscopy equipped with EDS. Effect of CO2 co-feeding was investigated at Gas Hourly Space Velocity (GHSV):1200mlh−1g−1; pressure: 15bar, temperature: 250°C; and H2/CO ratio: 2.5; with a syngas mixture containing 5% CO2. Pre-calibrated GCs were used to analyse the reaction products. The BET surface area, the pore volume and the pore size of the catalyst were 292m2/g, 0.18cm3/g and 2.83nm, respectively. TEM images showed that cobalt particles were well dispersed within the support. In the presence of CO2 co-feeding, CO conversion was 73% and CO conversion was 53% without CO2 co-feeding. In addition, the co-fed CO2 was converted to hydrocarbons and a CO2 conversion of 63% was obtained. The selectivity of the catalyst to methane was 53%, 34% to C2, <4% to C4-C5 and <10% to C6+ in the presence of CO2 co-feeding. Co-feeding CO2 also affected the selectivity of the catalyst to olefin as well. Selectivity of the catalyst to C3 decreased from 43% to 35% while C4 increased from 25% to 32% during CO2 co-feeding. However, selectivity of the catalyst to C6+ olefin hydrocarbon increased from 9% to 15% during CO2 co-feeding.

Polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) mitigation in the pyrolysis process of waste tires using CO2 as a reaction medium

Our work reported the CO2-assisted mitigation of PAHs and VOCs in the thermo-chemical process (i.e., pyrolysis). To investigate the pyrolysis of used tires to recover energy and chemical products, the experiments were conducted using a laboratory-scale batch-type reactor. In particular, to examine the influence of the CO2 in pyrolysis of a tire, the pyrolytic products including C1-5-hydrocarbons (HCs), volatile organic carbons (VOCs), and polycyclic aromatic hydrocarbons (PAHs) were evaluated qualitatively by gas chromatography (GC) with mass spectroscopy (MS) as well as with a thermal conductivity detector (TCD). The mass balance of the pyrolytic products under various pyrolytic conditions was established on the basis of their weight fractions of the pyrolytic products. Our experimental work experimentally validated that the amount of gaseous pyrolytic products increased when using CO2 as a pyrolysis medium, while substantially altering the production of pyrolytic oil in absolute content (7.3–17.2%) and in relative composition (including PAHs and VOCs). Thus, the co-feeding of CO2 in the pyrolysis process can be considered an environmentally benign and energy efficient process.