CNPC's TMP (two-stage riser catalytic cracking for maximizing propylene yield) industrial test succeeded on December 4, 2008, following three years of joint efforts by Daqing Refining & Chemical Company, CPECC East-China Design Institute, China University of Petroleum (East China), and CNPC Petrochemical Research Institute in facility renovation and construction, engineering design, technical plans, basic data, and the R&D of associated catalyst.

TMP is a new heavy oil catalytic cracking technology with a high propylene yield. Growing out of two-stage riser catalytic cracking, it tackles the contradiction between the high yield of propylene and the low yield of high-hydrogen-content dry gas by using the combined feeding of light and heavy materials, a low-temperature large catalyst-oil ratio, a feed-specific reaction time, and a high fluidized density of catalyst. The result is optimized hydrogen distribution in raw materials, ensuring light oil quality with a high propylene yield. Compared with other catalytic cracking techniques at home or abroad, TMP features staged reaction, catalysts' "relay", a short dwell time, and a large catalyst-oil ratio, as well as high propylene selectivity, high total yield of LPG, gasoline and diesel, and the high octane value of gasoline. Tests on the 120kt/a industrial unit at Daqing Refining & Chemical Company have delivered a 20.38% propylene yield, a 14.46% yield and loss of dry gas and coke, 83.0% total yield of LPG, gasoline and diesel, and 95.6 gasoline octane value, as well as better diesel quality than that by ARGG.

Achievements were also made with regard to associated techniques, special equipment and catalysts of this successful and patented TMP. Three invention patents are pending. These patented core technologies form a complete, integrated set of new and world-leading refining technologies with CNPC's independent intellectual property rights, helping to improve the company's competitiveness in refining and petrochemical technologies.