Search

Recent literature highlights the contributions the global energy sector has made to anthropogenic CH4 emissions, calling for immediate action. However, extant studies have failed to reveal the energy-related CH4 emissions induced by global trades of intermediate and final commodities or services. This paper traces fugitive CH4 emissions via global trade networks using the multi-regional input-output and complex network models. Results show that approximately four-fifths of global fugitive CH4 emissions in 2014 were associated with international trade, of which 83.07% and 16.93% were embodied in the intermediate and final trades, respectively. Japan, India, the USA, South Korea, and Germany were the world's five largest net importers of embodied fugitive CH4 emissions, while Indonesia, Russia, Nigeria, Qatar, and Iran were the five largest net exporters. Gas-related embodied emission transfers were the largest in both the intermediate and the final trade networks. The fugitive CH4 emissions embodied within the intermediate and final trade networks were all characterized by five trading communities. The virtual fugitive CH4 emission transfers via intermediate trade were largely determined by global energy trade patterns, especially the trade in regionally integrated crude oil and natural gas. Significant heterogeneity was revealed by the coexistence of numerous loosely linked economies and several hub economies (e.g., China, Germany, the USA, and South Africa). Interventions on the demand side of interregional and intraregional trade partners in different communities and hub economies will bring targeted opportunities for global energy-related CH4 emission reduction. [ABSTRACT FROM AUTHOR]

Toluene diisocyanate is an important chemical intermediate prepared by phosgenation reaction with two steps named cold and thermal phosgenation, respectively. The thermal phosgenation reaction is a complex reactive distillation process with high energy consumption and multiple targets of reaction and separation, so it is of great significance to optimize the step. The reactive distillation model of the thermal phosgenation was established for an industrial installation by aspen plus, and the effects of the different parameters of temperatures, residence times, etc., were investigated firstly; then a thermally coupled reactive distillation column was presented to perform the thermal phosgenation process, and the optimal operation and configuration parameters were obtained by simulation. The results showed that the proposed process can save the heat and cold energy with 7.29% and 32.78%, respectively, and reduce the total annual cost by about 17.11%. [ABSTRACT FROM AUTHOR]

This paper examines the relationship between CO2 emissions in three economic sectors of G20 member countries using the environmental IPAT model and STIRPAT model and validates the EKC hypothesis by comparing the results for developing and developed countries. The results confirm that there is a significant long-run equilibrium relationship between the three sectors (primary, secondary, and tertiary) and CO2 emissions across the panel. Furthermore, the long-run elasticities suggest that the primary sector (agriculture) positively and negatively affects the CO2 emissions of developing and developed economies, respectively. This finding proves that the development of agriculture is in line with the EKC hypothesis that a more developed economy will instead improve environmental degradation. Based on the findings, for each sector, we provide policymakers with suggestions to potentially curb CO2 emissions without significantly compromising economic growth. [ABSTRACT FROM AUTHOR]

Here we describe the diastereoselective synthesis of (5r,8r)‐1,9‐diazadispiro[4.2.48.25]tetradecatrienes via domino double spirocyclization of N‐arylamide derivatives. This reaction can serve as a fast way to synthesize diazadispirocycles, which are found in the core structures of bioactive natural products. Product diversification via Suzuki–Miyaura cross coupling and application to the synthesis of 1‐oxa‐9‐azadispiro[4.2.48.25]tetradecatrienes were also conducted. [ABSTRACT FROM AUTHOR]

Keywords: cyclization; domino reactions; cross coupling; dearomatization; natural products EN cyclization domino reactions cross coupling dearomatization natural products 4130 4130 1 12/18/20 20201214 NES 201214 B There is an Asian legend b in which a fish climbs over a waterfall and turns into a dragon. In this study, domino double spirocyclization occurred over the high energy barrier arising from the aromaticity. Cyclization, domino reactions, cross coupling, dearomatization, natural products. [Extracted from the article]