40 research outputs found
Nitrogen enriched biochar used as CO2 adsorbents: a brief review
No full textIt is widely acknowledged that the increasing CO2 concentration has led to the rise of temperature in the earth. Thus, capturing CO2 to alleviate environmental catastrophic is becoming important and urgent. Among the CO2 sorbents reported, solid adsorbents are advantageous in CO2 adsorption, CO2/N2 selectivity, easy operation and good regeneration ability. Biochar-based sorbents are promising for CO2 capture because they are self-sufficient in energy requirements, wide availability, renewability, low cost, and high porous structure. In addition, N-containing functional groups are used to improve the capability of CO2 adsorption of biochar. This review aims to evaluate the preparation and performance of nitrogen-enriched biochar for CO2 capture. Throughout this review paper, the current N-containing precursors and biomass, as well as the technologies for the preparation of N-rich biochar are discussed. It is concluded that cheaper and more sustainable ways should be proceeded to produce N-rich biochar in the field of CO2 capture research
Preparation of CO2 adsorbents and techno-economic analysis for CO2 capture and utilization
No full textIntegrated CO2 capture and utilization with CaO-alone for high purity syngas production
No full textCarbon capture and utilization (CCU) represent a promising strategy to reduce CO2 emissions and promote a sustainable economy. We report an integrated CCU (ICCU) process by integrating CO2 capture with reverse water gas shift reaction by applying simple and low-cost CaO as both sorbent and catalyst. By switching the feeding gas from CO2 source to H2 isothermally, up to 75% of captured CO2 was 100% converted into CO at 600-700 °C and the cycle performance of CaO was significantly improved under ICCU condition. In addition, the simulation confirms the significant economic advantage compared to similar traditional processes. The work could dramatically reduce the cost of materials and simplify CCU processes to advance the development and deployment of carbon neutrality technologies.One-Sentence Summary: A low-cost and widely used material, CaO, was used to not only adsorb CO2 efficiently but also in situ convert CO2 into valuable syngas with > 75% CO2 conversion to realise carbon neutrality, which is a vital target for sustainable future development
Promotion of manganese on Fe-based catalyst for the production of carbon nanotubes (CNTs) from plastics
No full textBiochar production, activation, and applications: A comprehensive technical review
No full textOur planet has been facing critical challenges since the late 20th century, including climate change, resource shortages, environmental degradation and pollution, demanding urgent and sustainable solutions. Biochar, a carbon-rich material produced from biomass pyrolysis, has gained attention for its great potentials in environmental remediation, pollutant removals, carbon neutrality, soil amendment, building materials, etc. The performance of biochar in these applications is highly related to its physicochemical properties, which are influenced by the feedstock and the preparation/activation methods. This paper reviews a wide range of biochar produced from various feedstocks and their performance in different applications. Advanced characterisations are discussed to unveil the fundamental mechanisms and provide insights for further improvement and optimization. The techno-economic analysis evaluates the feasibility, challenges, and opportunities for scaling up and adopting biochar in potential applications. By focusing on biochar's multifunctionality and sustainability, this paper provides a reference for future research on developing biochar as a green technology with environmental and economic benefits
Phenanthrenequinone-Based Hyper-Cross-Linked Polymers via a Waste-Minimizing Friedel–Crafts Alkylation
No full textAlthough hyper-cross-linked polymers (HCPs) offer significant advantages, their industrial scalability has been impeded by concerns regarding waste generation. To mitigate this challenge, we have successfully developed an efficient and cost-effective green synthesis method for phenanthrenequinone-based HCPs (PQ-HCPs). This method employs a Friedel–Crafts alkylation reaction, utilizing trifluoromethanesulfonic acid as a catalyst and PQ as the starting material. Under low catalyst concentrations, electrophilic sulfonation reactions are predominant. However, increasing the catalyst to a 2 equiv amount significantly shifts the reaction pathway toward Friedel–Crafts alkylation cross-linking. The resultant optimal sample, PQ-HCP-1:3, boasts an impressive specific surface area of up to 428 m2·g–1. Dye adsorption experiments on these samples demonstrated a marked selective affinity for Rhodamine B, with the hydrophilicity of the samples being a pivotal factor in the adsorption process. This innovative approach substantially outperforms traditional methods, which typically involve ferric chloride (FeCl3) and aluminum chloride (AlCl3), by significantly reducing the production of solid waste and effluent during the chemical reaction process
Scalable and Sustainable Chitosan/Carbon Nanotubes Composite Protective Layer for Dendrite-Free and Long-Cycling Aqueous Zinc-Metal Batteries
No full textRechargeable aqueous zinc (Zn)-metal batteries hold great promise for next-generation energy storage systems. However, their practical application is hindered by several challenges, including dendrite formation, corrosion, and the competing hydrogen evolution reaction. To address these issues, we designed and fabricated a composite protective layer for Zn anodes by integrating carbon nanotubes (CNTs) with chitosan through a simple and scalable scraping process. The CNTs ensure uniform electric field distribution due to their high electrical conductivity, while protonated chitosan regulates ion transport and suppresses dendrite formation at the anode interface. The chitosan/CNTs composite layer also facilitates smooth Zn2+ deposition, enhancing the stability and reversibility of the Zn anode. As a result, the chitosan/CNTs @ Zn anode demonstrates exceptional cycling stability, achieving over 3000 h of plating/stripping with minimal degradation. When paired with a V2O5 cathode, the composite-protected anode significantly improves the cycle stability and energy density of the full cell. Techno-economic analysis confirms that batteries incorporating the chitosan/CNTs protective layer outperform those with bare Zn anodes in terms of energy density and overall performance under optimized conditions. This work provides a scalable and sustainable strategy to overcome the critical challenges of aqueous Zn-metal batteries, paving the way for their practical application in next-generation energy storage systems
Techno-economic analysis of integrated carbon capture and utilisation compared with carbon capture and utilisation with syngas production
No full textCurrently, excessive CO2 emissions have become a global challenge due to their influence on the climate. According to the Paris Agreement, global warming should be limited to 1.5 °C by 2100. Carbon capture and utilisation (CCU) are attractive as they can both reduce CO2 content and utilise CO2 as a carbon resource. However, in conventional CCU processes, CO2 needs first to be extracted and purified for the following utilisation. In contrast, the recently reported Integrated Carbon Capture and Utilisation (ICCU) was designed to realise the overall process in one reactor, where CO2 is captured by adsorbents (e.g., CaO) and utilised in-situ with the introduction of a reducing agent (e.g., H2). This ICCU technology can promote CO2 conversion with fewer intermediate steps, leading to a reduction in overall cost. Energy and economic analysis of ICCU are thus urgently required. According to several recent research, the operational cost of ICCU has been reported to be cheaper than that of CCU. However, a comprehensive view of ICCU is still expected due to further application. This paper focuses on comparing ICCU and conventional CCU processes based on Aspen simulations covering mass balance (i.e., CaCO3 consumption, purge production, annual CO production), energy balance, the total annual cost and the CO cost, etc. Analysis shows that the ICCU process can produce more CO (1.20 Mt year−1), less purge (0.21 Mt year−1), and less consumption of CaCO3 (0.62 Mt year−1) with higher energy efficiency (37.1 %) than the CCU process. The results also show that the total annual cost of ICCU is 720.25 per tonne. In contrast, CCU has higher costs, with a total annual cost of 1004.53 per tonne. The Cost of CO2 Avoided of ICCU (317.11/ton). Therefore, ICCU was confirmed as a better choice for further industrial applications. In addition, H2 is shown to have a significant influence on economic performance, which remains a challenge for further application
