The modern coal chemical industry is a typical high carbon emission industry, which has formed a large-scale development in China. In the context of carbon neutrality, it is considered to be an ideal combination mode that captures high-concentration CO2 emitted by the modern coal chemical plants and transports it to oilfields through pipelines, which can both realize the low-carbon development goals of the modern coal chemical industry and reduce the cost of the whole process of Carbon Capture and Storage (CCS), as well as promote the development of CCS in China. Based on the data from modern coal chemical projects and depleted oil basins across China, a model of a pipeline network with optimal layout design was constructed, aiming to achieve specific emission reduction targets. Meanwhile, its economic effects will be analyzed. It turns out that this layout can help achieve an annual emission reduction of 280 million tons of CO2, with an average annual net income of USD 2.20 billion, and a unit net income of USD 7.85 per ton of CO2. A total of 166 pipelines up to 15,783 km in total length need to be built across China. Suitable storage sites can be found within an average radius of 94 km for emission sources. A total of 11,115 km of pipelines needs to be built in the “Three North” areas, accounting for 70.4% of the total pipeline length.
The content of the China-US CCUS technology development roadmap is summarized based on the roadmap update in 2019. Qualitative analysis and evaluation were conducted from the perspectives of running CCUS demonstrations or industrial projects, CO2 pipeline infrastructure, established regulatory frameworks, policy support, research and development capabilities, and geological storage resources. A simple analysis of the development status of carbon capture, storage, and utilization technology through relevant patent data is provided. Future planning by China and the United States in terms of planning volume, investment funds, related industries, transportation methods, geological storage, geological utilization, other utilization methods, and incentive policies is compared. Overall, US CCUS technology development is in the leading position in the world; it has entered the stage of small-scale commercial promotion, while the overall development level of China’s CCUS technology is still behind the international advanced level in a small-scale experimental demonstration period, and is still in the catch-up stage. However, as the Chinese government has put forward the strategy of “carbon peaking and carbon neutralization”, CCUS has ushered in a golden opportunity for development in China, and some large-scale industrial demonstration projects have been carried out. This study analyzes China’s advantages and challenges in developing CCUS and gives some suggestions on the direction that China’s CCUS development should take in the future.
In underground coal mines, the stability of the retracement channel in the surrounding rock is crucial for the safe and efficient retracement of the equipment and to guarantee the continuity of the retracement work. To reveal the deformation and damage mechanism of the surrounding rock of an auxiliary retracement channel (ARC) and the determination method for the reasonable spacing of two retracement channels during the end of the mining period, the deviatoric stress field in front of the working face and the change in the shape characteristics of the plastic zone in the ARC are investigated in this paper. The formation of ultimate stress equilibrium, high deviatoric stress, decreasing deviatoric stress, and low deviatoric stress environments in front of the working face during the end of mining occur successively, and the different deviatoric stress environments are the main reasons for the different shape characteristics of the plastic zone in the surrounding rock. The changes in the shape characteristics of the plastic zone correspond to the changes in the shape characteristics in the zone with deviatoric stress and exhibit the following order: full plastic deformation zone, butterfly-shaped zone, elliptical zone, and circular plastic zone. A reasonable spacing determination method for the two retracement channels is proposed: the ARC is arranged in the decreasing deviatoric stress environment, where the surrounding rock plastic zone shape is elliptical, and the ARC is relatively stable. Based on this research result, the spacing of the double retracement channels at the Lijiahao 22-116 working face was determined to be 25 m, which achieved a positive application effect and allowed the safe and efficient retracement of the working face equipment.
Coal-to-oil (CTL) combined with carbon capture, utilization and storage (CCUS) can significantly reduce the CO2 emissions generated in the production process to achieve clean coal utilization. Taking CTL enterprises as sources and deep saline aquifers and oil fields as sinks, this paper establishes a source–sink matching model, which is combined with a trinomial tree real-option model of carbon price fluctuation, and evaluates the investment decisions of CTL. The results show that 36 pipelines with an average transportation distance of 319.13 km and predominantly small diameters must be constructed for CO2 capture and storage combined with enhanced oil recovery (EOR). Under the current carbon price, 83.33% of enterprises can invest immediately when adopting EOR; when utilizing storage in a deep saline aquifer (DSF), even with a 50% subsidy and a decrease in costs due to the learning rate, enterprises still need to execute the deferred option investment. Government subsidies and technological advances can greatly increase the value of investment. The critical carbon price of CTL-CCUS projects is sensitive to government subsidies, technological advances, and CO2 transportation distances. Therefore, China should reasonably guide the development of the carbon market and give play to the role of the carbon market in emission reduction incentives. In addition, the Chinese government can provide direct financial support for the CTL-CCUS project to increase the enthusiasm of CTL enterprises for CCUS transformation and promote technological progress.