Changing the structure of resin-asphaltenes molecules in cracking 5th World Congress on Petrochemistry and Chemical Engineering, Phoenix, USA Changing the structure of resin-asphaltenes molecules in cracking Yerzhan Imanbayev, Yerdos Ongarbayev, Yerbol Tileuberdi, Zulkhair Mansurov Institute of Combustion Problems, Almaty, Kazakhstan Al-Farabi Kazakh National University, Almaty, Kazakhstan

Outline of research Extraction of the organic part from oil sands; To study the products of the cracking of natural bitumen; Analysis of bitumen resin-asphaltene components; To construct the molecular structure of macromolecular compounds. 2

Oil Sands in Kazakhstan 9th Largest Oil Reserves 15th Largest Crude Oil Producer Kazakhstan On the 3 territory of Western Kazakhstan identified and registered more than 100 deposits and occurrences of bituminous minerals. According to preliminary data at depths up to 120 m and occur 15-20 billion tons of oil sands. Bituminous minerals (oil sands) of Kazakhstan have fine sand and loamy mineral part. Oil sands are primarily located in Western Kazakhstan (Near Caspian Sea)

Why Upgrade Bitumen? For the value of the bitumen to be increased so that it may compete with the conventional crude, it is absolutely necessary to increase the quality of the bitumen by upgrading. With the increase in production of bitumen, the market for syncrude will have to be increased, which requires investment by the producer in a heavy oil upgrader. Whether it is attractive to invest in an upgrader will be determined by the price differential between light and heavy crude. A steady price differential market will be required over the planning, design, and construction period, which typically takes several years.

Extraction of natural bitumen from oil sands Extracted Oil sands Natural Bitumen Asphaltenes Maltenes Precipitation of Asphaltene Extraction with Chloroform

Physical and chemical characteristics of the natural bitumen from Beke field Parameters After extraction Content of organic part, wt. % 11.0-13.0 Total sulfur content, wt. % 1.5 Density, g/cm3 1.112 Kinematic viscosity at 80 С, sSt 26.0 Carbon residue, wt. % 30.1 Ash content, wt. % 0.3 Softening temperature by Ring and Ball, С 20.0 Maltenes, wt. % 94.1 Asphaltenes, wt. % 5.9

Temperature: 450 °C Time: 60 minute Experimental scheme of cracking process and analysis of the obtained products Temperature: 450 °C Time: 60 minute

Initial Bitumen After Cracking

Elemental Analysis of resin and asphaltene components Elements Initial asphaltenes Cracking asphaltenes Initial resins Cracking resins С 77.30 81.91 79.70 81.01 Н 7.59 7.00 9.77 10.52 S 1.00 0.64 0.56 0.26 N 1.07 1.45 0.72 0.10 O 13.04 9.00 9.26 8.11 С/Н 10.18 11.69 8.16 7.69 MW, Da 2044 1304 751 499 MW – Molecular weights Da – Dalton or atomic mass unit

DISCUSSIONS At high temperatures within the molecular cyclization, recombination with benzyl and heterocyclic radicals, dehydrogenation, condensation – all these processes lead to an increase in the degree of condensation and aromaticity of system. Initally C/H ratio decreases fast due to de-alkylation and removal of Н2S and Н2O. The net concentration of aromatics in liquid product kept going higher with removal of aliphatic as fragments in the gas fraction. Aromatic in liquid product can be created either from naphthenes or side chains in aromatic compounds of bitumen. The olefins from cracked side chains can build aromatics by free-radical additions followed by rearrangements Sample Proton NMR results, wt. % Н(aromatic) Н(СН3) Н(СН2) Н(СН) Initial asphaltenes 14.28 24.97 45.94 14.81 Cracking asphaltenes 14.75 24.63 50.19 10.43 Initial tars 4.82 14.41 67.21 13.56 Cracking tars 7.45 14.88 63.29 14.38

Infrared Spectra of Resins Initial Resin’s Spectrum Ar-O C-O-C, C-OH C-O-C, C-OH Cracking Resin’s Spectrum

Infrared Spectra of Asphaltenes Initial Asphaltene’s Spectrum 3 Ar C-S-C Cracking Asphaltene’s Spectrum

CONCLUSION Based on the results of the analysis of bitumen and cracking products above, it can be concluded that in the thermal cracking process, hydrocarbon generated free radicals which leads to formation light gases and coke products. Several features of the reaction have led to the postulation that coke formation is triggered by the phase separation of asphaltene. Challenges in modeling asphaltene compositions include matching elemental mass percentage of sulfur, mass percentage of carbon and the balance between aromatic and aliphatic carbon and hydrogen. From the results there are multiple polycyclic aromatic hydrocarbons units containing 2-5 or more rings inside asphaltene molecules. Future Work: Estimation of catalysts and other additions to reactivity of bitumen

Institute of Combustion Problems Institute of Petroleum Chemistry Acknowledgments Institute of Combustion Problems Almaty, Kazakhstan Institute of Petroleum Chemistry Tomsk, Russia

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