Hydrous pyrolysis of model compounds

Abstract

In pursuit of a method for the determination of the total n-alkyl content of petroleum source rocks, the reactions of model organic compounds containing a long-chain n-alkyl constituent with water have been studied in sealed tubes. At 330°C, the n-alkyl component of n-alcohols and n-ethers and the n-alcohololic components of esters are largely converted to, and release as, the corresponding n-alkanes. Some fragmentation of carbon chains accompanies this reaction. The conversion of n-alkanoic acids to n-alkanes is only partial, even at 350°C, and n-alkyl aromatics and n-alkyl hydroaromatics remain virtually unaffected under these conditions. Where significant n-alkane generation from model compounds is observed, additions of brown coal generally promote this process. In view of the stability of n-alkanoic acids and n-alkylated hydrocarbons observed under the conditions of hydrous pyrolysis used in this study, this technique is not entirely suitable for determining the total n-alkyl content of all source rocks nor, presumably, their full petroleum potential.