China's Shenhua Ningmei Coal Group has placed a follow-up order with Siemens Energy for four identical CO2 compressor trains for a coal liquefaction plant. The end customer is Shenhua Ningxia Coal Industry Group Co. Ltd. (SNCG), a subsidiary of the Shenhua Group, the largest coal producer in China. The compressor trains are destined for a coal liquefaction plant in Ningxia Province, which lies in the northwestern part of the People's Republic of China. The plant has a capacity of four million TPA (tons per annum) of liquefied coal. Siemens will deliver to this plant what is currently its largest CO2 compressor. The compressor trains are scheduled for delivery in the summer of 2015.
The four compressor trains each consist of one STC-GV integrally geared compressor, each of which is driven by an SST-600 condensing steam turbine via an intermediate gear. The scope of supply also includes the associated auxiliary systems. The compressors, each of which has six stages, are designed for a carbon dioxide volume flow rate of approximately 141,000 standard cubic meters (Nm3/h), allowing these new units to compress nearly twice the volume of CO2 as the predecessor model. In addition, Siemens also supplied gasification technologies and equipments for the same project.
The gas in the plant is compressed from a suction pressure of 1.25 bar to 68 bar. Each compressor has a rated output of 28 megawatts (MW). Part of the CO2 gas compressed by the Siemens compressor train is used, among other things, as process gas for internal transport within the plant, while the unneeded portion of the CO2 is vented. The compressor trains will be produced in Europe, while the Siemens joint venture in Huludao, China, will deliver the auxiliary systems and handle local project management and engineering.
"We are delighted that the Shenhua Group has chosen Siemens once again," said Lennart Nilsson, CEO of the Compression Business Unit within Siemens' Energy Sector. "With this order, we are helping enable China's largest coal producer to use this raw material for petrochemical products – and in an environmentally safe fashion in terms of CO2 emissions. At the same time, we are strengthening our position on the Chinese market, which is important to us, and helping our customers achieve their economic and ecological goals."
In 2009, Siemens delivered CO2 compressors with a volume flow rate of 83,000 Nm3/h and five coal gasifiers, each with a thermal power rating of 500 MW, for the coal chemical plant in Yinchuan, Ningxia.