The problem of global warming and climate change has attracted global attention, and reducing the concentration of CO₂ in the atmosphere is an important step towards solving the problem. This paper mainly introduces the current development status, research hotspots, challenges and some emerging technologies of carbon capture, utilization and storage (CCUS). Among CO₂ capture technologies, solvent absorption technology is currently the most mature and widely used technology, among which ionic liquid technology has great application prospects because its molecular structure can be designed and different functional groups can be connected. The surface functionalization of metal–organic frameworks in the adsorption method endows them with excellent CO₂ adsorption capacity. In CO₂ transportation, temperature and pressure must be considered in pipeline transportation, because they will affect the phase state of CO₂ transportation. The impact of impurities on CO₂ pipeline transportation is a challenge that affects pipeline design and transportation safety. In CO₂ utilization, the key to enhanced oil recovery, gas recovery and displacement of coalbed methane is to increase the recovery rate and increase the storage capacity at the same time. Only by strengthening the research on the adsorption behavior between CO₂ and CH₄ and revealing the relevant mechanism can innovative technologies be developed. The chemical utilization of CO₂ has formed many routes, but they all lack certain advantages. Most scholars are working on catalysts for CO₂ conversion, especially copper-based catalysts that can convert CO₂ into methanol. The conversion rate of CO₂ can be effectively increased through doping or process improvement. The coupling of electrocatalytic technology and renewable energy is an important development direction in the future. In CO₂ storage, geological storage is currently the most important method, especially in saline aquifers. There are currently critical issues concerning reservoir integrity and leakage potential that should be further investigated. CO₂ leakage will cause serious environmental problems, and the common monitoring methods are reviewed and discussed in this paper. Finally, the research status, hotspots and cooperation networks of CCUS are summarized by using CiteSpace software in order to help the development of CCUS technology. In addition, through the review and analysis, it is found that CCUS is faced with challenges such as low capture efficiency, difficulties in transformation and utilization, high operating costs, lack of strong support policies, and lack of international cooperation, which restrict the further development of CCUS.

Based on the mutual coupling effect among the compressor, the air cooler and pipes in the system of natural gas pipeline, innovatively with the goal of minimum energy consumption, this paper established a combined operation optimization model of the air cooler and compressor through the optimization of the switching scheme of compressors and air coolers, which can greatly reduce the production energy consumption of pipeline system. Moreover, when the air temperature is taken as an optimization variable, the most proper temperature to start the air cooler of each compressor station can be worked out to guide the optimized operation of the pipeline, which is of high value for promotion and application. The case analysis of West-East Natural Gas Pipeline II showed that among genetic algorithm(GA), particle swarm optimization(PSO) and simulated annealing algorithm(SA) that are used to solve the optimization model, the genetic algorithm is the fastest, and the simulated annealing algorithm the slowest, but the optimization results of simulated annealing algorithm is the best, in which the reduced production energy consumption accounted for 33.77%, testifying the practicability and creativity of the optimization model.