# Special Issue on \"CCUS: Paving the Way to Net Zero Emissions Technologies\"
###### Abstract  
Dractic measures must be taken in order to reduce carbon dioxide (CO\({}_{2}\)) emissions due to the acceleration of climate change and global warming, and for which there was a value of 37.79 billion tons in 2023 [1]. Both phenomena are precipitating widespread environmental degradation. The aim specified in international agreements is to limit global temperature rise to well below 1.5/2 \({}^{\circ}\)C above the pre-industrial level [2]. Against this backdrop, carbon capture, utilization, and storage (CCUS) technologies have been recognised as critical tools for fighting the increase in CO\({}_{2}\) emissions. In a capture system, CO\({}_{2}\) can be captured directly from emission sources (e.g., power plants and industrial facilities), preventing its release into the atmosphere [3]. Alternatively, CO\({}_{2}\) can be captured directly from the air via direct air capture (DAC) technologies [4, 5]. The captured CO\({}_{2}\) can either be stored or utilized in either chemical or fuel production. The CO\({}_{2}\) capture processes from flue gas that have been investigated are physical absorption, chemical absorption, adsorption, membrane, cryogenic distillation, calcium looping, and chemical looping combustion [6]. Absorption and adsorption are the most mature and investigated options for capturing CO\({}_{2}\) from the air [4]. Currently, CO\({}_{2}\) can be stored geologically, through mineral carbonation, or via ocean storage methods [7, 8]. The CO\({}_{2}\) conversion routes that have been investigated in the literature are homogeneous catalytic conversion, heterogeneous catalytic conversion, photocatalytic conversion, electrocatalytic conversion, photo-thermal catalytic conversion, plasma-chemical/plasma-catalytic conversion, and bio-catalytic conversion [6, 9, 10]. CO\({}_{2}\) can be converted into methane, methanol, ethanol, polymers, urea, etc., in addition to cement and concrete, or it can be used directly (for yield boosting and enhanced oil recovery, as a solvent or heat transfer fluid, etc.) [11]. Recent advancements and challenges in carbon capture, utilization, and storage technologies are discussed in [6] and in the papers discussed in this Special Issue. 20 February 2025 13 March 2025 17 March 2  
that membranes can allow 90% capture with high-purity CO2 as the final product, but process configuration and the polymeric material used affect the costs and techno-economic feasibility of this process. In [PERSON] et al. 's study (Contribution 3), the quantity of amine-based sorbents required to capture total CO2 emissions (51.7 Mton in 2022 due to electricity consumption) for Bitcoin mining is evaluated and determined to be equal to almost 12 Bton. The Life Cycle Assessment (LCA) methodology was utilized toward this aim. Regarding advancement in CO2 storage, in [PERSON] et al. 's study (Contribution 4), the reservoir capacity for effective CO2 storage, considering porosity and permeability, was measured for Lithuanian deep saline aquifers (Syderiai and Vaskai), providing interesting experimental hitherto absent in the literature for the region analysed. [PERSON] et al. (Contribution 5) showed that although biological carbon fixation is an interesting topic, it currently has marginal relevance for application at scale owing to its low efficiency and ineffective rate of photosynthesis. In fact, through a small pilot study, they highlighted that this option is not actually a carbon removal technology due to the substantial emissions generated compared to the actual removal capacity. In the same context, [PERSON] et al. (Contribution 6) investigated cyanobacteria grown in bicarbonate buffer solution for the bio-fixation of CO2. The authors focused more on productivity.