Industrialization of Coal-to-Olefins Technology in China   

The coal to olefin (CTO) process is to convert coal into olefins, which are then polymerized into PE (polyethylene) and PP (polypropylene). It includes several major processes: the coal gasification process (coal to syngas), the syngas to methanol process, the methanol to olefins (MTO) process, and the olefin polymerization processes.
   MTO is the core part of the CTO process. It also includes the MTP (methanol to propylene) process. Major MTO processes include: UOP MTO process, DICP DMTO process and Sinopec SMTO process. The DMTO process was developed by Dalian Institute of Chemical Physics (DICP), Chinese Academy of Sciences. It now dominates China's CTO/MTO market, because the world's first commercial CTO project - Shenhua Baotou CTO Project - uses it. Major MTP processes include: Lurgi MTP process and FMTP process, which was jointly developed by China National Chemical Engineering Co Ltd, Tsinghua University and Huaihua Group.

Status of CTO/MTO industrialization in China

Every year, China needs to consume millions of tons of ethylene and propylene for the production of PE, PVC, PP and other products. In 2010, China consumed nearly 30 million tons of ethylene, but it only produced 14.2 million tons of ethylene and had to import 15.8 million tons from abroad. In the same year, China also consumed nearly 22 million tons of propylene, but it only produced 13 million tons and had to import nearly 10 million tons from abroad.
   China is poor in oil and natural gas but rich in coal. Faced with so large shortage in the supply of olefins (ethylene and propylene), China has shifted its attention to the coal-to-olefins technology. In 2006, Shenhua Baotou CTO Project was approved as a CTO demonstration project and started construction. In August 2010, it successfully produced qualified PE and PP products, proving the feasibility of the coal to olefins route. Since then, the CTO/MTO industrialization has developed fast in China. Many CTO/MTO projects have been put forward.
　　In China, there are now one CTO/MTO project in commercial operation, three in trial run and nine under construction (see Table 1 and Table 2). These projects are mainly concentrated in coal-rich areas, such as Inner Mongolia, Shaanxi province's Yulin area, and Ningxia autonomous region.
Table 1  CTO/MTO projects in operation or trial run in China
Project    Location    Investor    Process    Status
Shenhua Baotou CTO Project    Baotou, Inner Mongolia    Shenhua Group    Coal to olefins    Operation
Shenhua Ningmei Group Coal-based MTP Project     Ningdong Energy Chemical Base, Ningxia region    Shenhua Ningmei Group    Coal to olefins    Trial run
Datang Coal-based MTP Project    Duolun, Inner Mongolia    Datang International Power Generation Co Ltd    Coal to olefins    Trial run
Sinopec Puyang MTO Project    Puyang, Henan province    Sinopec    Outsourcing methanol to olefins    Trial run

1) Shenhua Baotou CTO Project

Shenhua Baotou CTO Project is located at a new industrial base in Jiuyuan District of Baotou City, Inner Mongolia, having an investment of RMB18 billion. The project is a national CTO demonstration unit approved by the National Reform and Development Commission (NDRC) in 2006. It includes a coal gasification unit, a syngas cleaning unit, a 1.8 Mt/a methanol unit, a 600 kt/a MTO unit, a 300 kt/a PP unit, a 300 kt/a PE unit, a 240 000 Nm3/h (oxygen) air separation unit, 3 × 410 t/h HP steam boilers, 100 MW combined steam turbine power generation package, as well as other utilities. The project is designed to convert 4.73 million tons of coal into olefins, PP, PE and other products.
   The project was completed on May 28, 2010. Coal started to be fed to the 1.8 Mt/a coal-to-methanol unit on May 30, and qualified methanol was obtained on July 3, followed by the startup of the MTO unit on August 8. First batches of PE (polyethylene) and PP (polypropylene) products were taken off the line on August 15 and 19, respectively.
   Since January 1, 2011, the project has entered commercial operation. Up to mid-September, it achieved a cumulative polyolefin (PE and PP) output of 315 000 tons and a total sales income of RMB3.99 billion. Its profit margin was estimated to reach 25-30%.
   The project is divided into several major sections: coal gasification (coal to syngas), syngas to methanol, methanol to olefins (MTO), and olefin polymerization. The coal gasification section uses the water-coal-slurry gasification technology licensed from GE. The syngas to methanol section uses a process from DAVY Process Technology Ltd under British Jonson Mathew Plc, along with Jonson Mathews' proprietary catalyst. The MTO section uses the DTMO process package developed by Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Sinopec Luoyang Engineering Inc. was in charge of the MTO reactor manufacturing and process engineering. The olefin separation technology was provided by CB&I Lummus. The olefin polymerization section uses Unipol gaseous PE and Unipol fluidized bed PP processes provided by US Univation and Dow Chemical, respectively.

2) Shenhua Ningmei Group Coal-based MTP Project

Shenhua Ningmei Group Coal-based MTP Project is located in Ningdong Energy & Heavy Chemical Industry Base in Ningxia autonomous region, having an investment of RMB19.5 billion. Construction on the project was started in the end of 2005, and it is designed to convert 5.26 million tons of coal into chemicals a year, producing 1.67 Mt/a methanol, 520 kt/a PP, as well as by-producing 184.8 kt/a gasoline, 41.2 kt/a liquid fuel and 13.8 kt/a sulfur.
   Its coal gasification section used Siemens GSP pulverized coal gasification process. The syngas to methanol process came from Lurgi, Germany. The MTP (methanol to propylene) process was also provided by Lurgi. The propylene polymerization section used the ABB gaseous phase process.
   In October 2010, the project was put into trial operation and successfully produced qualified propylene with a purity of 99.69%. In May 2011, the project successfully produced its final product – PP.

3)  Datang Coal-based MTP Project

Datang International Coal-based MTP Project is located in Duolun County, Inner Mongolia, having an investment of RMB18 billion. It started construction in September 2009. It is designed to convert local lignite resources into methanol and PP (polypropylene), having a capacity of 1.68 Mt/a methanol and 460 kt/a PP. It uses Shell coal gasification process, Lurgi LP methanol synthesis process, Lurgi MTP process and Spheripol PP process.
   In late September 2010, the project was put into trial run. On June 21, 2011, it successfully produced methanol.
Table 2  CTO/MTO projects under construction in China
Location    Investor    Process    Status
Yulin, Shaanxi province    Shaanxi Yanchang ChinaCoal Yulin Energy Chemical Co Ltd     Coal/oil/gas  to olefins    Under construction
Yulin, Shaanxi province    ChinaCoal Yulin Energy Chemical Co Ltd    Coal to olefins    Under construction
Yan'an, Shaanxi province  &n