China Promotes Development of Non-petroleum Based Olefin

By Li Fenming, China National Petroleum & Chemical Planning Institute

In recent years, the demand for petrochemicals in the Chinese market has continued to be brisk and the raw materials like ethylene and propylene have been in short supply. In order to meet the market needs of olefins, China not only accelerates the construction of ethylene and propylene units using the traditional naphtha process route, but also accelerates the development and introduction of the production technology for olefins using non-naphtha process route.

1. National policy to guide the development of CTO

China is poor in oil and natural gas but rich in coal. The production of the substitutes for petroleum in China has become an important issue. Taking full advantage of coal resources and using the clean coal technology to produce the substitutes for petroleum in urgent need is also an inevitable choice in China in the long term.
   According to the 12th Five-Year Plan for the Chinese petrochemical industry, during the 12th Five-Year Plan period (2011-2015), China will encourage the petrochemical enterprises to cooperate with the coal and power enterprises and form several coal-power-chemical-heat integrated clusters with large enterprises as the main body and large-scale coal chemical production bases.
The 12th Five-Year Plan for the Chinese olefin sector defines that by the end of 2015, China’s output of non-petroleum based olefins will account for 20% of the national total olefins production, of which the output growth of coal based olefins is expected to be around 6.0 million-8.0 million tons. According to the production of ethylene using the traditional naphtha process route, producing 1 ton of ethylene needs around 10 tons of petroleum. So the coal-to-olefins (CTO) process in China can replace 60.0 million-80.0 million tons of petroleum by the end of 2015.
   The 12th Five-Year Plan for Coal Deep-processing Demonstration Projects highlights the coal-power-chemical-heat integrated project as the key and includes many olefin projects in the regions including Shaanxi province, Inner Mongolia, Xinjiang and Guizhou province. DMTO technical innovation and DMTO-II as well as SMTO will be regarded as the demonstration focuses of the CTO in the near future. The 12th Five-Year Plan for Coal Deep-processing Demonstration Projects bring forward the index of energy consumption, water consumption and coal consumption in major demonstration projects.

2. Technology is the key to the industrialization of CTO

At present, the commercialized CTO technology mainly includes methanol-to-ethylene and propylene (DMTO, SMTO and MTO) and methanol-to-propylene (MTP or FMTP). MTO technology is mainly successfully developed by UOP/Hydro and ExxonMobil. The processes of ExxonMobil and UOP/Hydro all use fluidized bed reactors. MTP technology successfully developed by Lurgi has been applied in olefin projects in Datang Duolun and Shenhua Ningmei.
   China’s new DMTO technology was earlier developed by Dalian Institute of Chemical Physics CAS. In 2007, Dalian Institute of Chemical Physics CAS, SYN Energy Technology Co Ltd, Sinopec Luoyang Petrochemical Engineering Corporation and Shenhua Baotou Coal Chemical Co Ltd signed a 600 thousand t/a MTO technology licensing contract in Beijing. On the basis of the original DMTO technology, Dalian Institute of Chemical Physics CAS and Shaanxi Coal Chemical Engineering Technology Center has subsequently conducted the development test of combining C4 recycle with DMTO, further increased the methanol conversion rate and developed the second-generation DMTO technology.
   In 2007, Sinopec Group implemented a 100 t/d SMTO industrial test in Sinopec Beijing Yanhua Petrochemical Co Ltd. The refinery gas is directly sent to the company’s original ethylene unit to conduct post-treatment and polymerization, and the continuous operation has been realized.
   In December 2009, the R & D team, which consisted of Tsinghua University, China National Chemical Engineering Group Corporation, China Tianchen Engineering Corporation, East China Engineering Science and Technology Co Ltd and Anhui Huaihua Group Co Ltd, officially announced the completion of the fluidized bed FMTP industrial experiment and the industrial experiment passed the appraisal of the expert committee. The industrial experiment unit could process 30 thousand tons of methanol a year and produce around 10 thousand tons of propylene a year.
   At present, China has built four large-scale industrialized CTO projects. First, China Datang Corporation has constructed a 460 thousand t/a MTP project in Duolun county, Xilinguole, Inner Mongolia and the major units of the project include 1.67 million t/a methanol, 460 thousand t/a propylene and 460 thousand t/a polypropylene. Second, Shenhua Group Corporation Limited has built a 600 thousand t/a DMTO project in Baotou, Inner Mongolia and the major units in the project consist of 1.8 million t/a methanol, 300 thousand t/a polypropylene and 300 thousand t/a polyethylene. Third, Shenhua Ningmei Group has constructed 500 thousand t/a MTP and 500 thousand t/a polypropylene project and the main units of the project include 1.67 million t/a methanol, 500 thousand t/a propylene and 500 thousand t/a polypropylene. Fourth, Sinopec Group has built 200 thousand t/a SMTO project in Sinopec Zhongyuan Petrochemical Co Ltd in Puyang of Henan province.
   Except the SMTO project in Sinopec Zhongyuan Petrochemical Co Ltd, other three CTO projects all include the technology combination of coal gasification, methanol synthesis, olefin synthesis as well as the production of olefin polymers. Of which, the coal gasification and olefin synthesis process technology is the most important. Except Shenhua Baotou project that uses the water-coal-slurry gasification process technology licensed from GE and the DMTO industrial test technology independently developed by China itself, Datang Duolun and Shenhua Ningmei projects introduce Shell’s coal gasification technology and GSP gasification technology, respectively. From 2010, the four CTO projects mentioned above were put into trial operation or commercial operation in secession. Datang Duolun project was put into an overall trial production in the second half of 2011.
   Shenhua Ningmei projects conducted the linkage commissioning of the completed olefin system and was put into an overall trial production in the first half of 2011.
   Shenhua Baotou project was put into commercial operation on January 1, 2011. Major units of the project have been operated at a high load of over 85%, and can meet the design requirements. The output of polyolefin in the project was 500 thousand tons in 2011 and the operating rate reached more than 83%.
Sinopec Group has built 200 thousand t/a SMTO project in Sinopec Zhongyuan Petrochemical Co Ltd in Puyang of Henan province. Except methanol-to- olefin process, the project was completed mainly through the technical innovation on the original naphtha based ethylene project, successfully put into trial production in October 2010 and put into the commercial operation in 2011. SMTO process not only expands the more extensive technical routes for the development of CTO, but also creates a good condition for the future technical innovation of petroleum based olefin production.
   In addition, amid the construction of CTO project, more and more independent R & D technologies and imported technologies being successfully digested and absorbed are available for selection in China. These technologies include the key coal gasification and olefin synthesis technologies that all can be used for the new olefin projects. However, China has a vast region, and the location circumstances in the project and the supply of raw materials are different. CTO is a project with long process and the combination of various technologies, and need more innovative combination in the practical applications.
   Moreover, Sinopec has completed the technology development for the combination of CTO and traditional petroleum based olefin production. Through taking full advantage of the post-treatment in matured petroleum based olefin, the investment can be further reduced. In the near future, some companies will conduct the technology development and preliminary work for the combination of the IGCC (integrated gasification combined cycle) power generation technology and CTO project. Not only can fuel gas (by product in the olefin production) be recovered for power generation, but also the steam power of the different processes can be integrated in the entire production of olefins to further improve the quality and cascade utilization efficiency as well as the comprehensive energy efficiency of material and energy, and reduce the consumption of resources like coal. According to the preliminary estimates, if a 600 thousand t/a CTO project conducts coupled cogeneration through the IGCC thermoelectric center, the total energy efficiency will raise more than 3%. If the synthesis gas is utilized by quality and form IGCC-chemical polygeneration system, the total energy efficiency of the system will increase over 5%.