Yield Of Gaseous Products Research Articles

Catalytic steam reforming of waste tire pyrolysis volatiles using a tire char catalyst for high yield hydrogen-rich syngas

The production of hydrogen and syngas (H2/CO) from waste tires by pyrolysis catalytic steam reforming was investigated in a two-stage fixed bed reactor. In this study, tire char served as a sacrificial catalyst, facilitating the combination of catalytic steam reforming and char steam gasification reactions. The tire char acted as both a catalyst and a gasification reactant, enhancing the gas product yield. The process parameters investigated were, a reforming temperature range of 700–1000 °C, steam space velocity between 2 and 12 g h−1 g−1char and reaction times of 0.5–2 h. The influence of the parameters on the yield and composition of the product gases and the characteristics of the used catalyst were analyzed in detail. The results indicated that higher temperature and steam space velocity increased H2 and CO yields in the presence of a tire char catalyst. Elemental analysis of the used tire char, surface morphology and pore structure provided insights into the extent of tire char consumption in the reaction. Prolonged reaction time allowed for more thorough reactions between the pyrolysis volatiles and tire char, promoting the production of H2. At a reaction time of 2 h, the H2 yield reached 223 mmol g−1, representing 74 wt% of the maximum hydrogen yield.

Impact of CO2 on the Pyrolysis of Mixed Polymer Wastes into Combustible Fuel: A Case Study for Footwear Waste

Plastic waste is a promising resource for producing liquid fuels that can be integrated into existing hydrocarbon infrastructures. However, the heterogeneous nature of plastic-derived liquid fuels limits direct application in internal combustion engines, necessitating their refinement into a usable form. To address these issues, this study explored the enhancement of combustible gaseous fuels derived from plastic waste, footwear waste, as a viable alternative. This approach involves the introduction of carbon dioxide as a reactive feedstock during the pyrolysis process. Analytical techniques were employed to precisely determine the types and compositions of four polymers present in footwear waste. The compositional matrices of the primary pyrogenic products were also identified. However, incorporating carbon dioxide into pyrolysis leads to its interaction with volatile compounds, converting them into lighter gaseous products, particularly carbon monoxide. The homogeneous reactivity of carbon dioxide was further enhanced by the application of heat and a nickel-based catalyst. The gaseous product yield from catalytic pyrolysis in the presence of carbon dioxide increased proportionally with the test temperature. Specifically, the use of carbon dioxide led to a 1.92-fold increase in gaseous product yield at 700 ˚C, in reference to the results from nitrogen. This study demonstrates a technical advancement in pyrolytic valorisation of footwear waste by incorporating carbon dioxide and provides a detailed investigation into its mechanical role in maximising the production of combustible gaseous fuels.

Catalytic pyrolysis of straight-run naphtha to light olefins: Experiment and molecular-level kinetic modeling study

In this work, molecular-level kinetic modeling was developed for the fluid catalytic pyrolysis of straight-run naphtha based on the structural unit and bond-electron matrix framework. The kinetic parameters were tuned and optimized using systematic experimental data from a fluidized bed under different conditions, the predicted values of the fraction yield, naphtha composition, and gas product yield were in agreement with the experimental data. The model can obtain the typical reaction rate of naphtha with different carbon numbers and structure compositions at the molecular level under typical conditions. The model can also quantify and compare the effects of eliminating different side reactions on the light olefins production, and different optimized reaction types of naphtha feedstocks under two typical conditions were revealed, quantitative model calculations show a significant boost in light olefin yield of 15–33 percentage points without hydrogen transfer.

THERMAL TRANSFORMATIONS OF MALTENES AND OILS FROM HEAVY METHANE BASE CRUDES

The paper considers changes of composition of oils and maltenes during thermal cracking process. The oils and maltenes (mixture Oils+Resins) were isolated from crudes from two oil fields: Zyuzeevskoye (Republic of Tatarstan) and Zuunbayanskoye (Mongolia). Both crudes relate to methane type, but differ by content of saturated, aromatic hydrocarbons, resins, asphaltenes and sulfur. Cracking of oils and (O+R) mixtures was carried out at 450 °С for 120 min in isothermal mode. Data on the mass balance of process, composition of gaseous and liquid cracking products were obtained. It was shown the С1-С5 hydrocarbons are predominate in the composition of gaseous cracking products of oils and (O+R) mixtures. Independent of cracking object their content changes in a series: C1 > C2 > C3 > С4-С5. The dynamics of group hydrocarbon composition changes in thermolysates was studied. It was shown the thermal transformations of hydrocarbons steer in the direction of destruction reactions during cracking of oils with high content of saturated hydrocarbons, as it indicated by gaseous products yield. Condensation reactions are dominated during cracking of oils, in composition of which aromatic hydrocarbons are prevail. It was shown the addition of resins into the complex multicomponent mixture of hydrocarbons leads to directivity change of cracking free radical reaction behavior. Differences in structural-group characteristics of average resins molecules reflect not only on the yield of solid and gaseous cracking products of (O+R) mixture, but also affect on the directivity of hydrocarbons thermal transformations. Moreover it is impossible to exclude the effect of differences in the content of saturated and aromatic hydrocarbons in the composition of oils on the components thermal transformations during cracking process of (O+R) mixtures. For citation: Voronetskaya N.G., Pevneva G.S. Thermal transformations of maltenes and oils from heavy methane base crudes. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 8. P. 59-67. DOI: 10.6060/ivkkt.20246708.4t.

Production of a high-energy solid biofuel from biochar produced from cashew nut shells

The aim of the study is to produce a solid biofuel of high physico-mechanical and energetic quality from heat-treated cashew nut shells. Raw cashew nut shells are heat treated at 300 °C for 120 min at a heating rate of 1 °C/s. The resulting biochar is milled to 74 μm. Sugar cane molasses was incorporated into the biochar powder at a rate of 10% without the addition of water. The mass yields of solid, liquid and gaseous products obtained were 46.5%, 27.6% and 25.9% respectively. The solid biofuel produced has slightly improved physicochemical and energy properties over biochar, except ash and moisture content. Thus, the addition of binder and densification increased the ash and moisture content of the solid biofuel compared to the biochar obtained. With a higher calorific value of 33.02 MJ/kg, the solid biofuel has high water resistance and meets the quality requirements of class A1 of the NF EN ISO 17225-6 standard in terms of density and mechanical strength. Solid biofuel is ideal for use in households and biomass power stations.

Pyrolysis of biomass to produce H-rich gas facilitated by simultaneously occurring magnesite decomposition

This study investigated how biomass pyrolysis varies with the different fractions of magnesite mixing into biomass. The pyrolysis occurred with simultaneous decomposition of magnesite without use of any gasification reagent, and was analyzed in terms of producer gas yield and quality. As magnesite fraction increased from 0 to 30 %, the yield of producer gas and its calorific value increased from 48.6 % to 66.3 % and 8.29 to 8.93 MJ/Nm3, respectively. The carbon and hydrogen conversion increased from 44.1 % to 60.7 % and 43.1 % to 66.2 %, respectively. The characterization results revealed that magnesite particles facilitated the conversion of fixed carbon and the thermal/catalytic cracking of tar to produce H-rich gas. The in-situ generated CO2 from magnesite decomposition could be reduced to CO/CH4 in the reductive atmosphere of the pyrolysis products. This study proposes the concept of converting low-energy–density biomass into gas without oxygen and provides a novel approach for producing H-rich gas from biomass.

Steam gasification of lime dried sewage sludge: Effects of temperature and addition of lime

Gasification shows great potential as an alternative method for energy utilization from sewage sludge. Lime (CaO) is a cheap and commonly used dewatering conditioner for sewage sludge. The calcium hydroxide (Ca(OH)2) generated during the drying process with lime can enhance the pH level of the sludge, thereby providing disinfection properties. This paper investigated enhancement mechanism of Ca(OH)2 on hydrogen gas generation and the effect on gas product yield during the steam gasification process of lime-dried sludge. The experiments were conducted in an electrically heated reactor at 500–800 °C. The forms of calcium present in the gasified sludge char samples were analyzed using X-ray diffraction (XRD) analysis to investigate their transformation process. Fourier transform infrared spectroscopy (FTIR) was utilized to obtain information regarding the chemical structure in the gasified sludge char samples, with the aim of exploring the mechanism behind hydrogen production from lime-dried sludge. The results indicate that the CaO generated from Ca(OH)2 dehydration acts both CO2 adsorbent and catalyst during the gasification process. The addition of Ca(OH)2 during the sewage sludge gasification process leads to a reduction in the aromatic CH content in the organic matter, while significantly increasing the content of reactive CH3-chains. It also promotes the ring-opening and rearrangement reactions of aromatic hydrocarbons and nitrogen-containing heterocycles and steam reforming reaction of tar. The combined effects of these factors contribute to an overall increase in hydrogen gas yield.

Influence of a Precursor Catalyst on the Composition of Products in Catalytic Cracking of Heavy Oil

Heavy oils are characterized by a high content of resins and asphaltenes, which complicates refining and leads to an increase in the cost of refinery products. These components can be strongly adsorbed on the acid sites of a supported catalyst, leading to its deactivation. Currently, various salts of group 8 metals are being considered for such processes to act as catalysts during oil cracking. At the same time, the nature of the precursor often has a significant impact on the process of refining heavy oil. In this work, catalytic cracking of heavy oil from the Ashalchinskoye field using different precursors (nanodispersed catalysts formed in situ based on NiO) has been studied. The cracking was carried out at 450 °C with a catalyst content from 0.1 to 0.5 wt.%. The catalytic cracking products were analyzed via SARA, GC, XRD and SEM. Nickel acetate and nitrate promote similar yields of by-products, while formate promotes higher yields of gaseous products. Formate and nickel acetate were shown to produce 1.8 and 2.8 wt.% more light fractions than nickel nitrate. When heavy oil is cracked in the presence of Ni(NO3)2∙6H2O, the maximum decrease in sulfur content (2.12 wt.%) is observed compared to other precursors. It has been found that the composition and morphology of the resulting nickel sulfides and compaction products are influenced by the nature of the catalyst precursor. XRD and SEM analyses of coke-containing catalysts indicate the formation of Ni9S8 and Ni0.96S phases during cracking when nickel nitrate is used and the formation of NiS and Ni9S8 when nickel acetate and formate are used.

Green hydrocarbons and fuels from municipal polymer waste co-fed with natural gas using a batch catalytic slurry process

Landfilled solid waste polymers were converted into high octane green fuels and hydrocarbons by a catalytic depolymerization process. Experiments were conducted in a batch catalytic reactor pressurized with methane as a co-feed. Design of Experiments (DOE) methodology was used for process optimization and parametric study. The operating conditions that maximize the liquids aromatic hydrocarbons were found using response optimizer tool. The reaction temperature and polymer to catalyst ratio (PCR) were found to have significant effects on the responses and methane pressure was not significant for yields of solids, liquids and gaseous products. However, pressurized methane facilitated dehydrocyclization reactions resulting in increased monoaromatic hydrocarbons in the final liquid products. Experiments conducted with methane feed at optimized reaction conditions resulted in 89% aromatic hydrocarbons, 8% paraffins and about 3% other hydrocarbons in liquid products. Aromatic products included benzene (6.5%), toluene (25%), xylenes (27%), ethylbenzene (4.5%), other monoaromatics (22%) and polyaromatic hydrocarbons (4%). Gaseous products contained propylene (47%) and hydrogen (23.9%). The utilization of waste polymers as feedstock materials, flare gas (methane) as a co-feed, and zeolite catalysts makes this batch zeolitic slurry process greener, resulting in green hydrocarbons and green fuels.

Pressurized pyrolysis of mattress residue: An alternative to landfill management

Mattresses are a difficult waste to manage in landfills due to their large volume and low density. Pyrolysis treatment could reduce its volume while producing fuel or products valuable for the chemical industry. Pressurized pyrolysis at 400, 450, and 500 °C is carried out in a lab-scale autoclave at initial pressures 4.2, 8.4, and 16.8 bar. Product gas yield increases slightly along with elevated pressure as well as temperature. However, beyond 8.4 bar the initial pressure makes no discernible differences. CO and CO2 are the major gas species followed by CH4. CO contributes the most to the product gas energy content followed by C3 species, C2H6, and H2. Calculated energy content (heating value) is between 2 and 15 MJ·Nm−3. In terms of product gas energy content, low pressure pyrolysis is favorable over high pressure pyrolysis. According to integration areas of chromatographic measurements the liquid phase contains up to 25 % of N-compounds, with benzonitrile being the most abundant, followed by toluene, o-xylene, and ethylbenzene. The solid char maintains constant properties across operating conditions, with carbon and energy contents of approximately 75 wt% and 30 MJ·kg−1, respectively.

Laboratory Investigation of Biogas Production Using Cow Dungs and Kitchen Wastes Otta

Laboratory Investigation of Biogas Production Using Cow Dungs and Kitchen Wastes Otta

Coal conversion to SNG: Thermochemical insights through kinetic-free modeling in entrained flow gasifier

In this study, a kinetic-free thermodynamic equilibrium model consisting of five units was developed to predict SNG production via coal gasification, using two distinct feeding technologies (SFT and DFT) and two coal ranks (BT and BL) in an entrained flow gasifier using Aspen Plus (V10), and comparing results with empirical data. The alignment between simulation outcomes and experimental observations is verified, and analysis of various parameters' impacts on product gas composition and yield is conducted. Sensitivity analysis reveals consistent trends across different coal ranks. The O2/coal ratio emerged as a key factor, demonstrating notable effects on syngas composition and yield. Specifically, increasing the O2/coal ratio from 0.3 to 1.0 enhanced H2 and CO2 proportions in the syngas which are beneficial for SNG production, as hydrogen is a key component for SNG. Elevating the O2/Coal ratio from 0.2 to 0.6 (optimal) favors CGE, facilitating high-quality syngas production. Additionally, increasing the CO2 flow rate up to 3 ton/hr improves the HHV of syngas, beyond which HHV declines. Raising the W/C ratio from 0.3 to 1.0 leads to decreased HHV for BL and BT coal. Additionally, increasing the W/C ratio from 0.3 to 1.0 decreases HHV. Therefore, it is crucial to undergo the production of SNG within the optimal ranges, and these findings provide crucial insights into optimizing gasification parameters for enhanced syngas production across various feed technologies and coal types to produce desired syngas results.

THERMAL PROCESSING OF OIL FLAX BONES INTO ACTIVATED CARBON

Flax shives – waste generated during the primary processing of flax in the textile industry, make up 70% of the total mass of oil flax stalks. The results of an experimental study of the thermal processing of oil flax bonfires by the method of slow conductive pyrolysis in the temperature range of 400–650 °C are presented. An experimental bench for thermal decomposition of flax fire and activation of carbon residue by superheated water vapor is presented. The required temperature regimes of pyrogenetic decomposition were established, which are in the range of 500–600 °C. An analysis of the physicochemical properties of experimental samples of biochar obtained by pyrogenetic decomposition of flax fires has been carried out. At low temperatures of 400–430 °C, the specific gravity of carbon is in the range of 80–82%. Under temperature conditions of 500–600 °C, the specific gravity of carbon was 91–93%. At higher temperature conditions, the yield of gaseous products increases, and the ash content in the solid carbonaceous residue increases. The modes of steam activation of biochar from flax fires have been established, so to achieve the best sorption values, water vapor should be at a temperature of 900 °C. A comparative analysis of the sorption abilities of experimentally obtained activated carbon with BAU-A activated carbon is given. Based on the data obtained, it was concluded that the activated carbon from the fire of flax corresponds to the parameters of GOST 6217-74.

A strategy for industrial waste mitigation—thermal treatment of non-woven polyester fabric debris on ultrahigh-porosity MgO under CO2 atmosphere

Unproperly treated industrial waste creates serious environmental pollution that requires immediate remediation strategies. Non-woven polyester fabrics are widely used in a variety of industrial applications; thus, their debris becomes a major portion of industrial waste. To contribute to advanced industrial waste treatment processes, this study investigated catalytic thermal treatment of non-woven polyester fabric debris on a novel ultrahigh-porosity MgO material under a CO2 environment. The ultrahigh-porosity MgO was synthesized from hydromagnesite via a series of thermal reactions, having a surface area of 208.8 m2 g−1, total pore volume of 0.34 cm3 g−1, and average pore diameter of 2.37 nm. Using the MgO as the catalyst for thermolysis of non-woven polyester fabric debris in CO2 promoted thermal cracking of volatilized species evolved from the non-woven polyester fabric debris thermolysis, thereby increasing the gas product yield and decreasing the liquid product and wax yields. In addition, dehydrogenation and reverse water gas reaction was promoted by the MgO catalyst, leading to more than higher syngas production (up to 16.1 wt% syngas yield) compared to non-catalytic thermolysis (up to 8 wt% syngas yield). The selectivity toward esters was increased, while the selectivities toward benzoic and phthalic acids were decreased, most likely due to the MgO promoting decarboxylation and esterification reactions during the thermolysis. Moreover, the ultrahigh-porosity MgO catalyst was reusable for at least two consecutive cycles. It is hoped that the applicability of the novel material as a catalyst is widened for advanced treatment processes to minimize negative effects of industrial wastes on the environment.

Synergistic effect mechanism of biomass ash-derived K-Ca-Si catalytic system on syngas production and reactivity characteristics of high-sulfur petroleum coke gasification

In this study, three typical biomass ash (BA) components, KCl, CaCO3 and SiO2, are selected as model compounds to construct BA-based key ternary component system for petroleum coke (PC) gasification. Gas product analysis was conducted using gas chromatography to study the influence of different catalysts on the gas product distribution, gas yield and carbon conversion of PC gasification, and clarify the synergistic effects of binary and ternary components in K-Ca-Si catalytic system. In addition, electron scanning microscopy (SEM) and Raman techniques are used to characterize the physicochemical structure of gasification semi-char to reveal the synergistic mechanism of K-Ca-Si system. The results show that the yield of different gases is ordered as H2 > CO > CO2 and the increment of H2 yield, CO yield, syngas yield and carbon conversion in K-Ca-Si catalytic system is 43.41 mmol/g, 26.67 mmol/g, 80.37 mmol/g and 0.49, compared with single PC gasification, respectively. By comparing the theoretical and actual value of gas yield and carbon conversion, it is found that there are synergistic catalytic effects for K-Ca-Si ternary catalyst, but Si will inhibit the activity of K and Ca. Coupled with SEM and Raman analysis, synergistic mechanism of ternary catalytic system can be revealed. KCl and CaCO3 reduce the graphitization degree of semi-char by reacting with carbon matrix, and CaCO3 can stimulate the pore structure development of semi-char, which accelerate reaction between KCl and carbon matrix to form intermediate active sites, thus favoring gasification reaction and exhibiting a synergistic effect. SiO2, on the other hand, will combine with KCl and CaCO3 to form inert silicates, resulting in the deactivation of KCl and CaCO3. It could be concluded that for high K-high Ca-low Si ternary catalytic system, KCl and CaCO3 would still show a synergistic effect due to higher CaCO3 content than SiO2.

Catalytic pyrolysis of Paulownia wood and bio-oil characterization

ABSTRACT This study focused on the catalytic pyrolysis of Paulownia (P. elongota) wood. The effects of ZSM-5, Na2CO3, sepiolite, and catalyst ratio (10–80% by wood weight) on product yields and bio-oil composition were investigated. In pyrolysis experiments, 500°C pyrolysis temperature, 50°C min−1 heating rate, and 100 mL min−1 N2 flow rate were kept as constant. The catalyst type and catalyst ratio changed the product yields and bio-oil compositions. Pyrolysis conversion was increased for all catalyst types. Maximum liquid product yields were obtained as 63.26 wt%, 56.18 wt%, and 54.59 wt% with the ZSM-5, Na2CO3 and sepiolite, respectively, at 10 wt% catalyst ratio. For all catalysts, it was determined that the liquid and solid yields reduce and the gas product yield rises with the catalyst ratio. The bio-oil characterization was performed with elemental analysis, FTIR, 1HNMR, and GC-MS techniques. The bio-oil composition was determined to consist of alkanes, carboxylic acids, ketones, esters, benzenes, and phenols.

Energy Recovery from Municipal Solid Waste through Co-Gasification Using Steam or Carbon Dioxide with Olive By-Products

The valorization of untreated municipal waste (MSW) biochar for energetic uses, through its co-gasification with olive stone (OST) biochar under a steam or carbon dioxide atmosphere, was investigated. The experiments were conducted in a fixed bed unit and a thermal analysis–mass spectrometer system. The thermal behavior, reactivity, conversion, product gas composition, syngas yield and energy potential were determined, while the influence of the fuel’s internal structure, chemical functional groups and operating conditions were examined. The concentrations of H2 and CO2 in the product gas mixture under a steam atmosphere were increased with steam/biochar ratio, while that of CO was reduced. At a steam/biochar = 3 H2 yield, the higher heating value and conversion for the OST were 52.8%, 10.8 MJ/m3 and 87.5%; for the MSW, they were 44.4%, 9.9 MJ/m3 and 51.5%, whereas for their blend, they were 50%, 10.6 MJ/m3 and 76.6%, respectively. Under a carbon dioxide atmosphere, the reactivity and conversion of the OST biochar (84%) were significantly higher as compared with the MSW biochar (50%). The higher heating value of the product gas was 12.4–12.9 MJ/m3. Co-gasification of the MSW with OST (in proportions 30:70) resulted in the enhanced reactivity, conversion, syngas yield and heating value of product gas compared with gasification of solely MSW material.

Biomass gasification in rotary kiln integrated with a producer gas thermal cleaning unit: An experimental investigation

In this work, gasification of hazelnut shells grains is carried out in a bench-scale rotary kiln by using air as gasifying agent at 800 °C. The producer gas is directly treated in a thermal cleaning unit operating at 800–1100 °C with the aim to reduce the load of contaminants. The producer gas cleaning by thermal methods is usually studied by using model compounds, whilst herewith the behavior of a real producer gas is investigated. Results indicate that at high temperature CO2 reacts with tar and particulate to generate CO, thereby improving the quality of producer gas in terms of heating value, producer gas yield and contaminants content. Benzene is the most abundant organic contaminant of the producer gas, the concentration of which is significantly reduced upon thermal treatment. For the first time, a bench-scale rotary kiln gasifier with lignocellulosic biomass as feedstock is integrated with a thermal cleaning unit, providing experimental evidences about the suitability of rotary kiln for air gasification of lignocellulosic biomass and its integration with a thermal unit. The proposed approach could find application also when other types of gasifier are adopted, although a parametric study should be carried out in order to fully understand the reaction mechanism of contaminant removal and to find optimal operation conditions, also as a function of biomass feedstock features.

Cellulose pyrolysis kinetic model: Detailed description of volatile species

Lignocellulosic biomass is typically composed by a major fraction of cellulose. Its decomposition influences on large extent the biomass rate of pyrolysis and product distribution, affecting process behaviour in thermochemical conversion processes. Containing approximately 90 % of volatile matter, volatile products from cellulose pyrolysis are very important in the characteristics of flames and ignition properties. Recent developments in analytical methods allowed a detailed identification of these volatile products, giving valuable information to process development and better understanding of kinetics. Predictions of a previous kinetic model are compared with these new findings, revealing large space for improvements. In this work, we propose a multi-step kinetic model of cellulose pyrolysis, incorporating the most recent experimental findings into the detailed product description. The model consists of four main reactions for the decomposition of cellulose, with formation of gases, volatiles, char and metaplastic species. The release of metaplastic species is described by a set of six reactions. The formation and release of 13 oxygenated hydrocarbons is predicted by the model, including anhydrosugars, furans, aldehydes, alcohols, ketones and carboxylic acids. The model also describes the formation of levoglucosan in metaplastic state before its release, explaining high heating rate mass loss behaviour. The model is compared with a large variety of experiments from literature, and validated for mass loss rates and product distribution, achieving overall good agreement despite experimental uncertainties and the large simplifications characteristic of the model formulation. Besides effectively quantifying the yields of gaseous, condensable and solid products, the model accurately captures the distribution of volatiles in terms of functional groups and C-chain length.

Plasma-chemical pyrolysis of a mixture of fuel oil and methyl tert-butyl ether

NTP-pyrolysis of heavy petroleum products is a difficult task due to high viscosity, low hydrogen-to-carbon ratio and tendency to polycondensation with formation of high-molecular products. The use of oxygen-containing compounds for NTP-pyrolysis can reduce the yield of polycondensation products due to internal oxygen. In the present work, NTP pyrolysis of fuel oil in the presence of oxygen-containing additive (methyl tert-butyl ether) was carried out at a current source voltage of 700V. The influence of the content of the doping component in the range of 5-15 wt% on conversion, energy consumption and product composition was investigated. At increase in the content of methyl-tert-butyl ether up to 15 wt% in fuel oil the energy consumption decreases and the yield of gaseous products increases from 21.7 to 47.9 wt%. Carrying out NTP-pyrolysis process in the presence of oxygen-containing additive leads to an increase in the depth of processing of heavy fractions.