Catalytic upgrading evaluation under steam injection conditions with spectroscopy 1H-NMR

Abstract

Steam injection has mainly been applied due to its physical recovery mechanisms. However, a chemical process could arise and is called aquathermolysis. These reactions could be favored by the addition of a catalyst, which acts on cracking reactions of some heavy compounds. Therefore, an experimental evaluation of catalytic aquathermolysis of heavy oil was carried out in a microreactor batch. The experiments were performed at three different reaction times (24 h–62 h) and temperatures between 240 °C–300 °C. Iron naphthenate, molybdenum naphthenate, and nickel naphthenate were the catalysts used. Oil upgrading was measured by changes in the physical property, and the identification of reactive molecules by nuclear magnetic resonance 1H-NMR technique to obtain average molecular parameters. The average number of carbons in alkyl chains was determined to simplify the samples’ compositional analysis, as well as the number of substituted rings and the aromaticity factor. The experimental results showed an increase in the viscosity reduction efficiency as Mo < Ni < Fe. In addition, the catalysts increased the API° gravity and decreased the viscosity by 10° and 79%, respectively. Furthermore, naphtha and kerosene production increased the conversion of the 300 °C + fraction up to 8%. Finally, upgraded oils showed a smaller difference in alkyl chains length.