Kerogen Pyrolysis in the Presence and Absence of Water and Minerals. 1. Gas Components

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• 作者：Changchun Pan ; Ansong Geng ; Ningning Zhong ; Jingzhong Liu ; Linping Yu
• 刊名：Energy & Fuels
• 出版年：2008
• 出版时间：January 2008
• 年：2008
• 卷：22
• 期：1
• 页码：416 - 427
• 全文大小：359K
• 年卷期：v.22,no.1(January 2008)
• ISSN：1520-5029

文摘

Pyrolysis experiments on kerogen (Estonian Kukersite) were conducted in a confined system (gold capsules) in the presence and absence of water and various minerals, i.e., kaolinite, montmorillonite, calcite, and dolomite, respectively, at a fixed pressure of 50 MPa and in the temperature range 240–400 °C. For the four experiments in the presence of minerals and a large amount of deionized water (OC/mineral/water 1:24:7–10), the ratios of isobutane/n-butane and isopentane/n-pentane generally increase with temperature and mineral acidity. As to the two experiments for kerogen alone and kerogen plus a small amount of water (OC/water 1:1.5), these two ratios are relatively high at low temperature (280–320 °C) and substantially low at high temperature (320–400 °C) in comparison with the experiments in the presence of minerals and a large amount of deionized water. The ratios of ethene/ethane and propene/propane generally decrease with increasing temperature. At the same temperature, these two ratios increase with an increasing amount of water and decrease with increasing mineral acidity. Pyrolysis experiments on this Kukersite kerogen with various OC/water ratios (0–15) further demonstrated that the ratios of ethene/ethane, propene/propane, isobutane/n-butane, and isopentane/n-pentane increased with increasing water/OC ratio. In addition, the amount of the gas hydrocarbons varied significantly with water/OC ratio, i.e., from 83.20 to 109.70 mg/g of OC at 350 °C and from 271.50 to 340.07 mg/g of OC at 450 °C, with the water/OC ratio increasing from 0 to 15. The amount of CO₂ produced also increases substantially and consistently with that of gas hydrocarbons with water/OC ratio. The amount of oxygen in the generated CO₂ exceeds the oxygen in the initial kerogen in the experiments with water/OC ratios of 10 and 14.5 at 450 °C, indicating that water derived hydrogen and oxygen have been incorporated into gas hydrocarbons and CO₂.