Abstract: The relations of PAHs and PCA content were studied in order to produce environmental-friendly rubber filling oil with CA value over 12% by hydrotreating process. The rubber oils were made using different feedstock, hydrotreating catalysts under process conditions. The PAHs and PCA contents were determined for each product. The results showed that the PAHs can meet the requirements of EU environment protection laws and regulations when the PCA content is less than 3%, however, the PCA content meets the standard if and only if the content of PAHs is below 1.0 ?g/g or not detected; in addition, the operation range (reaction temperature) is wider than that of PCA when PAHs were regarded as controlling index. The relations of PAHs and PCA was established, yPAHs=0.036 3 xPCA3.186 6 with R of 0.9822 and can be used to predetermine the PAHs content from PCA data.

Key words: hydrotreating process, environmental-friendly rubber filling oil, PAHs, corresponding relations, PCA