Considering the global scientific and industrial effort to utilize ammonia as an alternative to natural gas combustion to run power plants, it is crucial to objectively assess the literature before adjusting or proposing new and advancing techniques in ammonia plants while considering a variety of factors. As a result, this paper assesses the global effort to improve existing ammonia plants and identifies progress by evaluating the currently available dataset to identify knowledge gaps and highlight aspects that have yet to be addressed. Based on the literature reviewed in this study, it was found that the majority of the efforts to advance ammonia plants mainly focus on reducing energy consumption, implementing alternative methods to extract the necessary hydrogen and nitrogen in the process, and changing the cycle arrangement and operating conditions to make the industrial plants more compact. However, regarding carbon reduction in the ammonia production process, it is clear that the effort is less significant when compared to the global scientific and industrial progress in other areas.
As the world continues to grapple with the reality of coronavirus disease, global research communities are racing to develop practical solutions to adjust to the new challenges. One such challenge is the control of indoor air quality in the COVID-19 era and beyond. Since COVID-19 became a global pandemic, the “super spread” of the virus has continued to amaze policymakers despite measures put in place by public health officials to sensitize the general public on the need for social distancing, personal hygiene, etc. In this work, we have reviewed the literature to demonstrate, by investigating the historical and present circumstances, that indoor spread of infectious diseases may be assisted by the conditions of the HVAC systems. While little consideration has been given to the possibility of indoor airborne transmission of the virus, the available reports have demonstrated that the virus, with average aerodynamic diameter up to 80–120 nm, is viable as aerosol in indoor atmosphere for more than 3 h, and its spread may be assisted by the HVAC systems. Having reviewed the vulnerability of the conventional ventilation systems, we recommend innovative air circulation concept supported by the use of UVGI in combination with nanoporous air filter to combat the spread of SARS-CoV-2 and other harmful microbes in enclosed spaces.
16 August 2023 in Green Technology, Resilience, and Sustainability
The food security challenge continues to be one of the main issues that currently face the world despite improved economic development in many countries. The challenge is particularly unique in one of the world’s arid regions, the Gulf Cooperation Council (GCC). This paper analyses the food security strategies of Qatar (one of the six countries that make up the GCC), especially since 2017 when the blockade of the country by its neighbors began. Qatar’s current food sufficiency was made possible by the country’s swift and profound changes in its food production strategies to ensure food security for its population. In order to provide locally sourced foods to the population, private and public initiatives were activated to support small farmers to distribute and supply their farm produce to local markets. The results show that Qatar has shifted from importing some food commodities to locally producing a high proportion of its foods to the extent of becoming an exporter of some farm produce. However, this increase in the local food production was achieved at the cost of depleting the local groundwater at a rate higher than the natural recharge. This paper thus critically assesses the specific situation of food security in Qatar that could be used as an example for other countries aiming to strengthen their food security, especially during transnational crises when international food supply chains suffer from unavoidable disruption (e.g., COVID-19 crisis).
We report the unique electrochemical properties of nitrogen-containing carbon nanostructures (N-CP) grown on commercial carbon paper (CP), used as electrocatalysts in all-vanadium redox flow batteries (VRFBs). The focus is on the anode, where mitigation of the hydrogen evolution reaction and loss in redox kinetics due to cycling is considered as a challenge. The growth of bamboo-like carbon nanostructures is achieved through a catalytic chemical vapor deposition (CVD) process with a very small geometric loading of Fe (from FeCl3) as the catalyst. Anhydrous acetonitrile, used as a nitrogen/carbon precursor, is fed to the electrode sample at 900 °C for 3 hours in a stream of H2–Ar (carrier gas). The three-electrode-cell study shows enhanced kinetics and durability of the electrode for V3+/V2+ redox reactions; N-CP shows a significant suppression of the peak potential separation (ΔE ∼ 80 mV), indicating faster kinetics compared to conventional CP (ΔE ∼ 160 mV). In addition, the subscale cell performance shows good durability (about 5% and 15% loss in energy efficiency in N-CP and CP, respectively) after 50 charge–discharge cycles. The improved durability of the N-CP electrode is attributed to the presence of nitrogen–carbon nanostructures, increased active area, and improved sp2 carbon content. Such findings can contribute to the development of large scale high performance VRFB systems.