Abstract

The dissertation presents results of the experimental research on asphaltene-based adsorbents (support coated with asphaltene layer) for gas-solid adsorption systems, with special reference to volatile organic compounds (VOCs) removal from gas streams. Analysis of gas adsorption properties revealed that asphaltenes isolated from oxidized bitumen have strong affinity toward VOCs. Interactions with target gas molecules, and selectivity were further enhanced by chemical modifications, of which nitration was the most beneficial for adsorption properties. Investigation of nitrated asphaltenes interaction with VOCs molecules revealed that the adsorption mechanism was driven by both physisorption and chemisorption. The strength of interactions with VOCs exceeds values reported for standard adsorbents. Fixed-bed adsorption studies revealed that facile coating of nitrated asphaltenes can significantly enhance adsorption capacity of a support material. Multiple adsorption-desorption cycles confirmed the durability of chemical modification and thermal resistance of asphaltene-based adsorbent. Utilization of asphaltenes and low cost supports, easily available in the target destination (e.g. diatomaceous earth or clays) can be an effective procedure for risk mitigation of hazardous VOCs, accompanied by effective waste management and low-value materials valorization.

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