Coal-to-Hydrogen: Next Wind Gap with Unlimited Potentials
Year:2019 ISSUE:12
COLUMN:ENERGY
Click:201    DateTime:Jun.22,2019


By Chen Danjiang


In the tide of the global energy revolution, hydrogen energy is one of the clean energies with the brightest application prospects and the highest practical values. With the large-scale promotion of fuel cell vehicles and the gradual maturing of hydrogen energy vehicle technologies, mankind is seeing the approach of a hydrogen energy era. In multiple hydrogen production methods, coal-to-hydrogen is a method with the most mature technology, the most convenient source, and the lowest cost. 


The hydrogen energy market in China has bright prospects

   On February 11, 2018, China Hydrogen Energy and Fuel Cell Industry Innovation Strategic Alliance was established in Beijing. This event kicked off the scaling up and commercialization of the hydrogen energy industry in China. On January 19, 2018, Wuhan of Hubei released a program to create a world-class new hydrogen energy city for the development of the hydrogen energy industry. On April 16, 2018, the Xiongtao Hydrogen Energy Industry Park and the Huashang Hydrogen Energy Industry Park were settled in Datong, Shanxi. On April 28, 2018, the construction of the “Hydrogen Corridor” in the Yangtze River Delta was launched to create a hydrogen energy and fuel cell vehicle industry economic belt. On October 22, 2018, six hydrogen energy industry projects, including Jiangsu Rugao hydrogen energy town and hydrogen energy industry parks, started construction and the development of hydrogen energy boomed. It is therefore imperative to achieve a large-scale production of hydrogen. 

   Routes for the commercial production of hydrogen mainly include hydrogen production through water electrolysis, hydrogen production through coal gasification, hydrogen production from natural gas, hydrogen production through biomass gasification, and hydrogen production from renewable energies. Judging from factors such as the present energy utilization status in China, hydrogen production through coal gasification and hydrogen production from renewable energies have a bright prospect. Hydrogen production through coal gasification is the most favored. According to the long-term program for the development of hydrogen energy formulated by the state, China will see the arrival of a hydrogen energy era in 2050 and hydrogen production through coal gasification will have wide development prospects. 


The use of hydrogen energy is already included in the national strategy

   In the “Report on the Work of the Government” this year, the Chinese Government clearly points out for the first time in history that the construction of facilities such as those for power charging and hydrogen refueling will be accelerated. In addition to favorable policies, the present shift of the “identity” of high-pressure hydrogen from a hazardous chemical to energy will also boost the construction of hydrogen refueling stations. The “Routes for Energy-Saving and New Energy Vehicles” formulated by the China Society of Automotive Engineers shows that by 2020, China will complete the construction of 100 hydrogen refueling stations, and by 2030 the number will be increased to 1 000. 

   The “Report on the Analysis to the Present Market Status of Hydrogen Refueling Stations and the Research on the Prospect of Investments in China” issued in 2018 also points out that, according to the program for the development of fuel cell vehicle industry as required by China Made 2025, the goal for 2025 is to “achieve the perfection of matched infrastructures such as hydrogen refueling stations”. The “Report” forecasts that after 2025, the fuel cell vehicle industry in China will enter a stage of rapid development. By 2030, the annual sales of fuel cell vehicles in China may exceed 1.0 million units. The number of matched hydrogen refueling stations will exceed 4 500 at that time. The investment in hydrogen refueling stations will reach RMB80.0 billion and the investment in related equipment will also reach RMB50.0 billion. 


Coal-to-hydrogen has prominent comparative advantages

   The resource endowment of “being rich in coal and lean in oil and gas” in China remains unchanged today. The import dependence of natural gas has already reached as high as 30%. Nuclear energy and renewable energies are still in the developing stage. They account for only small yields and fail to satisfy the huge demand for energy in economic development. From the practical perspective of energy safety, economic development stability, and green environmental protection, it is essential to achieve clean utilization of coal. Coal-to-hydrogen is an excellent breakthrough for the clean use of coal. 

   Coal-to-hydrogen has the most optimal economic potential. Major manifestations are the following: (1) Rich raw material: Coal constitutes 60% of primary energy sources. Coal resources are rich and easily available. (2) Low cost: Compared with energies such as natural gas, coal has a significant price advantage. The cost of gas-to-hydrogen is around RMB2.0/m3, whereas the cost of coal-to-hydrogen is around RMB0.8/m3. Nearly 20% of the cost can be reduced. (3) Mature technology: The product generated in the first step of the clean coal chemical reaction is hydrogen. Coal-to-hydrogen technology in China already started having large-scale application in the 1980s and the 1990s. Leading enterprises in the refining/chemical sector and the coal chemical sector, such as Maoming Petrochemical Co., Ltd., Qilu Petrochemical Co., Ltd., and Shenhua Group, compete with each other in making outlays for the coal-to-hydrogen business. In terms of manufacturing equipment, China has achieved localization in key technologies such as carbon monoxide shift, hydrogen separation/purification, and large-scale air separation. The coal-to-hydrogen technology is already quite well-developed. The output of coal-to-hydrogen is also high and has already reached 10.0 million tons a year. Commercialization and large-scale application have already been achieved. 

   With more stringent requirements on environmental protection and the accelerated upgrading of oil product quality, coal-to-hydrogen has started extensive applications in refineries. Six large coal-to-hydrogen and petro coke-to-hydrogen projects have been constructed in refineries since 2010 and the total coal-to-hydrogen scale is around 805 000 Nm3/h. Fifteen refining/chemical-integrated projects are also planned for construction, and 11 of them will use the process for hydrogen production through coal gasification.


The commercialization of coal-to-hydrogen in China is surging 

   With the constant increase of market demand and the issuance of a series of favorable policies, coal-to-hydrogen in China displays a trend of booming development today. 

   On January 31, 2019, the hydrogen production project constructed by Sinopec Zhenhai Refining/Chemical Co., Ltd., by using the SE coal slurry gasification technology successfully produced qualified products. The project can produce 120 000 m3 of hydrogen per hour and the approved investment is RMB1.5 billion. By February 14, the coal-to-hydrogen unit in the company already made a continuous running for over 15 days and the supply of hydrogen was stable. On February 20, the No. 1 gasification furnace in the coal coke-to-hydrogen unit conducted successful wet commissioning. The qualified hydrogen produced was transmitted to pipe networks and the mode of dual-furnace operation was started. 

   Maoming Petrochemical Co., Ltd. uses the coal slurry gasification technology from GE of the United States. The scale of the unit is Two handred thousand m3/h and production was started in March 2014. Coal, high-sulfur petro coke co-produced in refineries and pure oxygen are used as raw materials. Two handred thousand m3 of industrial hydrogen with a purity of over 97.5% and a pressure of 4.8MPa can be produced per hour. 

   Shenhua Group has already constructed a 1.0 million t/a coal direct liquefaction demonstrative plant. Two production lines using the SCGP powdered coal pressurized gasification process from Shell are used to provide raw hydrogen to related units such as the coal liquefaction unit, the hydrogenation stabilization unit, and the hydrogenation modification unit. The hydrogen production capacity per production line is 313 tons/d and the purity of hydrogen is 99.5% (mole). 

   Jingmen Yingde Gases Co., Ltd. uses the Yingde coal-to-hydrogen technology and the design scale is 53 000 m3/h. In January 2019, a boiler that was one of the 7 core units in the Jingmen Yingde coal-to-hydrogen comprehensive utilization project achieved ignition and some units conducted a trial run. By the end of April 2019, hydrogen could be supplied to Jingmen Petrochemical Co., Ltd. The total investment of the Jingmen Yingde coal-to-hydrogen comprehensive utilization project is RMB4.0 billion and the project is funded by Yingde Gases Group, the biggest gas company in China. 

   Hengli Petrochemical Co., Ltd. uses the multi-nozzle opposed coal slurry gasification technology developed by East China University of Science and Technology. The design scale of the coal-to-hydrogen unit is 500 000 m3/h. The project is a 20.0 million t/a refining/chemical-integrated project. A 730 000 m3/h PSA unit and a 500 000 m3/h coal-to-hydrogen unit have been constructed for the project. Production was started at the end of 2018.

   By now 21 large-scale coal-to-hydrogen projects have already started commercial operation or are under full-swing construction in China. 


Problems needing to be solved in the development of coal-to-hydrogen

   For coal-to-hydrogen to become a top factor in the hydrogen energy market, a series of bottleneck problems still need to be solved. 

   First, constraints on the storage/transportation link need to be removed. Progress in the construction of hydrogen energy infrastructures, and especially the construction of hydrogen refueling stations, is extremely slow in China. The development of fuel cell vehicles is already seriously affected. Judging from the present status, hydrogen produced from coal is mostly used in enterprises themselves or in local areas with no need for long-distance transportation. If such hydrogen is to be used in fuel cells, the need of storage/transportation will arise. On the one hand, fuel cell vehicles have not yet been used in great quantities, matched facilities are not complete, and not many enterprises participate in the storage/transportation of hydrogen. On the other, whether coal-to-hydrogen storage/transportation technologies and equipment can meet requirements still needs to be tested in practice. 

   Second, the cost problem in the entire industrial chain needs to be solved. Although coal-to-hydrogen has an advantage in cost, storage/transportation charges are quite high. China has to vigorously develop liquid hydrogen storage/transportation technologies today and start the larger-scale application of hydrogen fuel cells in the communication sector at an earlier date. Consider the transportation link, for instance. Although the pipeline transmission cost is low, requirements for facilities are stringent and large investments are necessary for construction and operation. The freight volume of trucks for bottled hydrogen is restricted and the cost is on the high side. As some core materials used in the manufacturing of hydrogen bottles themselves still depend on imports, the cost burden is increased.

   Third, China still lacks uniform standards for hydrogen refueling stations as a key link in the hydrogen production industrial chain. It has become a knotty problem inhibiting the development of hydrogen refueling stations. Only about 10 hydrogen refueling stations can be put into use today. Such a small number of hydrogen refueling stations can hardly catch up with the rapid development of hydrogen fuel cell vehicles. It is therefore imperative to strengthen the construction of hydrogen energy infrastructures, and especially the construction of hydrogen refueling stations, so as to promote a sound and rapid development of the hydrogen fuel cell vehicle industry. 

   Fourth, special attention has to be paid to the problems of environmental protection in coal-to-hydrogen. Coal-to-hydrogen can produce the cleanest hydrogen energy, but at the same time has the problem of discharging excess carbon dioxide during production. For example, in a 100 000 m3/h hydrogen production unit constructed in refineries by using the coal-to-hydrogen route, the amount of carbon dioxide discharged reaches around 900 000 tons a year. The key to the solution of the problem lies in breakthroughs in carbon dioxide utilization technology and the extensive application of carbon capture technology in coal-to-hydrogen.