How are the 4 coal-to-natural gas projects that have been put into operation in our country performing currently?

Coal-to-natural gas: Overall losses – Contrary to the profitability of coal-to-olefins plants, of the 4 coal-to-natural gas projects that have been built and put into operation in China, aside from HuiNeng in Inner Mongolia, which remains profitable due to its associated LNG operations, the remaining projects have been operating at a loss for a long time. “Coal-to-natural gas companies are suffering heavy losses, facing immense pressure to survive and develop. ”Liu Yongjian, director of the Planning Department at Datang Group SinoNew Energy Technology Co., Ltd., admitted that although the Datang Keqi coal-to-natural gas project operates stably and its production volume has been increasing over the past three years, reaching 1.09 billion cubic meters in 2018, with its key technical parameters being close to or better than those specified in the design, the project still suffers from losses. In 2016, the loss amounted to 1.19 billion yuan; losses have gradually decreased in recent years, with a loss of 284 million yuan in 2018. In the first half of this year, the loss was reduced to 49 million yuan. Liu Yongjian believes that while there are subjective factors such as delayed project planning and layout, excessive rapid development in the early stages, low maturity of technical equipment, unscientific selection of technologies, and insufficient reserves of technical talent, objective factors including pressure on coal and gas prices are also among the main reasons.

The coal-to-natural gas project of Inner Mongolia HuiNeng Coal and Electricity Group Company is the first demonstration project of its kind in China to be invested and built by a private enterprise. The first phase of this project, with an annual production capacity of 400 million cubic meters of coal-derived gas, began operations in October 2014. The quality of the gas produced is stable, and the conversion efficiency is high; the technical equipment, process flows, environmental protection standards, and overall efficiency of this project are all at the leading level in China. It filled a technical gap in the country regarding the use of water-coal slurry gasification technology for producing coal-derived gas, and it demonstrated the feasibility of producing synthetic natural gas on a large scale using coal as raw material. This project has opened up a new path for the clean and efficient utilization of coal resources and for ensuring energy strategic security. It serves as a key project for Ordos City in its efforts to develop itself into a major hub for clean energy production, and it provides technical leadership and a model for the development of the coal chemical industry.

It is understood that the second phase of the coal-to-natural gas project undertaken by Inner Mongolia HuiNeng Coal and Electricity Group Company will require an investment of 12 billion yuan. This phase will enable an increase in the production capacity of coal-to-natural gas to 1.6 billion cubic meters, with all of this gas to be liquefied. Operation of this facility is expected to begin in 2021; once operational, it is anticipated to generate annual sales revenue of 6.5 billion yuan and tax revenues of 900 million yuan, while also creating employment opportunities for 3,000 people.

For the coal gasification technology in the HuiNeng Phase II coal-to-gas project, the multi-nozzle opposed coal gasification technology developed by Yankuang Group and East China University of Science and Technology is employed. The daily coal feeding capacity of each gasifier reaches 3,300 tons, making it the gasifier with the highest daily coal feeding capacity in the world to date. The converter is the core equipment in the carbon monoxide production section of ammonia synthesis plants, and it is also the key device in the carbon monoxide production stage of the process for producing methane, which is the main component of natural gas. In current coal-to-gas processes, coal is pressurized and gasified, after which pre-reformation and main reformation reactions are used to adjust the H/C ratio at the methanation inlet, thereby converting part of the CO in the raw gas into H2 to meet the gas requirements for methane synthesis. Finally, methane is produced through methanol washing and methanation processes.

The converter for this project has a diameter of 4600 mm, a wall thickness of 160 mm, and a height of 23611 mm. The main material used is SA387Gr22CL2, and its weight is 352 tons. The surfacing on the inner wall was carried out entirely using an automatic double-band surfacing welder with a electrode attached to the inner wall of the cylinder; the surfacing area is approximately 216 m2. During the manufacturing process, the Welding Workshop 1 of Lansi Heavy Equipment properly planned production schedules, coordinated various production steps efficiently, and assigned experienced employees to carry out welding tasks in order to increase the rate of welds passing quality checks on the first attempt. At the same time, it worked with the Production Department to arrange for the large forgings used in the construction of the skirt base to arrive at the factory earlier, which helped to shorten the production cycle and ensured that the product was completed on schedule.

The design allows one furnace to produce 245,000 Nm³ of useful gas per hour, making it the largest gasification furnace in the world at present. After 18 months of research and development efforts and meticulous manufacturing, Harbin Electric Group Co., Ltd. developed a four-nozzle gasification furnace that uses nickel-based alloy cladding on its inner walls – a technology used for the first time in China. On the afternoon of June 2, 2020, 2 units were successfully delivered to the construction site (with another unit still in transit), marking the full entry of the reconstruction project for the Inner Mongolia HuiNeng coal-to-natural gas project into a new phase.

The expansion project of HuiNeng’s coal-to-natural gas facility was fully launched in 2018, building on the experience gained from the first phase of construction and operation, as well as through further optimization of processes and innovation in technology. Completion and commissioning of this project are scheduled for July 2021. By then, the total production capacity for coal-to-natural gas is expected to reach 1.6 billion cubic meters per year, with LNG production amounting to 1.1 million tons per year. It can convert 5.5 to 6 million tons of coal per year, providing over 2,000 job opportunities for society.