The emission of large amounts of CO₂ into the atmosphere is believed to be a major reason behind climate change, which has led to increased demand for CO₂ capture. Postcombustion CO₂ capture with chemical solvent is considered one of the most important technologies in order to reduce CO₂ emission. Amino acid salt solutions have attracted special attention in recent years due to their excellent physicochemical properties, e.g., low volatility, less toxicity, and high oxidative stability, as well as capture performance comparable with conventional amines. In this study, physicochemical properties of 20 amino acids are reported and their CO₂ absorption performance discussed. The topics covered in this review include the most relevant properties of amino acids including CO₂ loading capacity, cyclic capacity, equilibrium constant, density, viscosity, dissociation constant, CO₂ solubility, CO₂ diffusivity, reaction kinetic between CO₂ and amino acid salts, reaction rate constant, surface tension, heat of CO₂ absorption, precipitation, toxicity, solvent degradation, and corrosion rate. This review provides the most recent information available in the literature on the potential of using amino acid salts as a solvent for CO₂ capture which can help improve the performance of the CO₂ capture process from flue gas streams.

Energy need is predicted to increase by 48% in the next 30 years. Global warming resulting from the continuously increasing atmospheric CO₂ concentration is becoming a serious and pressing issue that needs to be controlled. CO₂ capture and storage/use (CCS/CCU) provide a promising route to mitigate the environmental consequences of CO₂ emission from fossil fuel combustion. In recent years, hollow fiber membrane contactors are regarded as an advanced technique with several competitive advantages over conventional technologies such as easy scale-up, independent control of flow rates, more operational flexibility, absence of flooding and foaming as well as high interfacial area per unit volume. However, many factors such as the membrane material selection, proper choice of solvent, and membrane module design are critical to success. In this regard, this paper aims at covering all areas related to hollow fiber membranes, including membrane material, membrane modification, membrane surface modification, shape, solvent characterization, operating parameters and costs, hybrid process, membrane lifetime, and energy consumption as well as commercially available systems. Current progress, future potential, and development of pilot-scale applications of this strategy are also assessed carefully. Furthermore, pore wetting as the main technical challenge in membrane contactor industrial implementation for post- and pre-combustion CO₂ capture processes is investigated in detail.

Faced with increasingly serious energy and global warming, it is critical to put forward an alternative non-carbonaceous fuel. In this regard, hydrogen appears as the ultimate clean fuel for power and heat generation, and as an important feedstock for various chemical and petrochemical industries. The chemical looping reforming (CLR) concept, is an emerging technique for the conversion of hydrocarbon fuels into high-quality hydrogen via the circulation of oxygen carriers which allows a decrease in CO₂ emissions. In this review, a comprehensive evaluation and recent progress in glycerol, ethanol and methane reforming for hydrogen production are presented. The key elements for a successful CLR process are studied and the technical challenges to achieve high-purity hydrogen along with the possible solutions are also assessed. As product quality, cost and the overall efficiency of the process can be influenced by the oxygen carrier materials used, noteworthy attention is given to the most recent development in this field. The use of Ni, Fe, Cu, Ce, Mn and Co-based material as potential oxygen carriers under different experimental conditions for hydrogen generation from different feedstock by CLR is discussed. Furthermore, the recent research conducted on the sorption-enhanced reforming process is reviewed and the performance of the various type of CO₂ sorbents such as CaO, Li₂ZrO₃ and MgO is highlighted.