Hydrogen energy, as a low-carbon, clean, and high-energy-density secondary energy source, can help reduce fossil fuel usage and is crucial for achieving carbon peaking and carbon neutrality goals. Current hydrogen production methods using water, methanol, and methane effectively reduce dependence on coal, making them key for low/zero carbon hydrogen production. The hydrogen production process involves converting materials and energy, with key focus areas being energy consumption, conversion efficiency, carbon emissions, and cost. This paper reviews three low/zero carbon hydrogen production technologies, highlights progress in thermal integration management of hydrogen production systems and discusses the issues and challenges of each technology. It also outlines future development directions, offering new ideas to improve energy efficiency and reduce energy consumption in low/zero carbon hydrogen production systems.

During the operation of a data center, there is a huge amount of low-grade waste heat. Improving the energy grade of the waste heat in the data center is an important way to save energy and reduce emissions. In this paper, a traditional air-cooled data center is taken as the research object, and an operation model of an integrated energy system for improving the energy grade of the waste heat in the air-cooled data center with new energy is constructed. The performance of the integrated energy system in different periods is evaluated, and the energy consumption and economic cost of the data center without waste heat recovery are compared to verify the superiority of the integrated energy system model after waste heat recovery. The integrated energy system is optimized with the primary energy savings rate, annual cost savings rate, and CO₂ emission reduction rate as the objectives. The results show that, compared with the traditional cooling system of the data center, the annual cost of the optimized integrated energy system decreases by 4.38%, the primary energy savings rate is 23.74%, and the CO₂ emission reduction rate is 29.99%.

With the proposal of the “dual carbon” goals, the replacement and destruction of hydrofluorocarbon (HFCs) refrigerants, which have a significant impact on global warming, have become critical issues. Photothermal synergistic catalytic degradation, as a low-to-medium temperature catalytic technology, can effectively achieve low-carbon, efficient, and economical degradation of HFC refrigerants. Based on the photothermal synergistic catalytic degradation reaction kinetics model proposed by the research group, this paper conducts an energy analysis of the photothermal utilization process under set conditions. It is found that for a given amount of available light, there exists an optimal concentration ratio and cutoff wavelength that maximize the degradation amount. Additionally, the exergy losses in various stages of the system are analyzed.

The denitration system has strong nonlinearity, large hysteresis and other characteristics, and faces the problem of unsatisfactory control performance under environmental pressure. This article proposes a combined control strategy based on the Twin Delayed Deep Deterministic Policy Gradient (TD3PG) algorithm and PID for the strong nonlinearity of denitrification models. By designing the neural network structure and reward function of TD3PG algorithm, PID parameters are optimized to achieve real-time adjustment of parameters in simulation. Compared with classical PID, active disturbance rejection control and fuzzy active disturbance rejection control, the simulation results show that the proposed TD3PG-PID has the fastest tracking effect, making the system fast and stable, and also has satisfactory control effects under uncertain conditions, with strong robustness.