Hasil untuk "Electricity"

Gerda Gahleitner

S. Chaudhuri, D. Lovley

J. Khan, M. Arsalan

Hunt Allcott, Allan Collard-Wexler, Stephen D. O’Connell

J. Bento, V. Moutinho

C. Kost, J. Mayer

F. D. Sisternes, J. Jenkins, A. Botterud

Verena Jülch

Linquan Bai, F. Li, Hantao Cui et al.

Suman Bajracharya, Mohita Sharma, Mohita Sharma et al.

M. Muratori, G. Rizzoni

Y. Chae, R. Horesh, Y. Hwang et al.

B. Ang, B. Su

A. MacDonald, C. Clack, A. Alexander et al.

Ying He, Rongji Li, Mingyang Hu et al.

Transforming lignin into valuable aromatic compounds is a critical objective for sustainable biorefining. While oxidative depolymerization has been proven effective in breaks down lignin's macromolecule, its practical application has been limited by low selectivity. This review presents a paradigm shift in the field, moving from broad, non-selective oxidative degradation methods to highly targeted catalytic processes driven by controlled reactive oxygen species (ROS). It offers a comprehensive analysis of how various catalytic systems—utilizing O2, H2O2, metals oxides, electricity, light, and organic oxidants—generate distinct ROS profiles, ranging from non-specific hydroxyl radicals to more selective superoxide anions or high-valent metal-oxo complexes. These ROS serve as ''molecular scissors'', directly influencing the efficiency of C–O and C–C bond cleavage, thereby determining the yields of key products such as aldehydes, ketones, and acids. This review also explores emerging strategies, including single-atom catalysis and external field activation, which provide unparalleled precision in managing these reactive intermediates. Finally, it addresses ongoing challenges related to catalyst stability and the heterogeneity of lignin, while outlining promising future research directions focused on tandem processes and real-time mechanistic studies, to further unlock lignin's potential as a renewable source of aromatic feedstocks.

Rafał Wyszomierski, Piotr Bórawski, Aneta Bełdycka-Bórawska

Plant biomass is playing a key role in the development of renewable energy sources. The share of biomass in renewable energy sources is about 70% in Poland and more than 40% in the European Union (EU). To assess the competitive position of farms selling plant biomass including straw and wood, including both future opportunities and threats, we conducted research on 185 farms in 2022. The aim of the research was to assess the usage of plant biomass, with the aim of increasing its position compared to other renewable energy sources. We used tabular, graph and descriptive methods to present the research results. Moreover, the Dornik–Hansen test (<i>p</i> = 0.003), Shapiro–Wilk test (<i>p</i> = 0.0017), Lilliefors test (<i>p</i> = 0.000) and Jargue–Berra test (<i>p</i> = 0.008) results show the significance of the research. The most important factors shaping the increased prices of biomass were the availability of raw materials on the market, totaling 41.1%, and calorific value, totaling 17.6%. Looking at the data, it can be seen that the most popular renewable energy technologies in which respondents plan to invest is photovoltaics (57.8%) and biomass (17.6%). According to the respondents, the most profitable renewable energy sources are photovoltaics (38.4%), wind energy (23%) and biogas (16.2%). Farmers also pointed out the most ecologically friendly, renewable energy sources. According to the respondents, the most ecologically friendly, renewable energy sources were wind energy (32.2%), photovoltaics (25.3%) and water energy plants (20.7%). The most frequently indicated limitations of biomass production were the long payback period (19.2%) and high investment costs (18.9%). The most important threat to biomass production was the shortage of arable land (32.5%) and poor farmland (23.5%). These results show that policymakers should adjust laws to encourage farmers to invest in biomass as a renewable energy source. Photovoltaics, which is considered a very clean renewable energy source, faces a big task in cleaning rural areas.

Timothy King Avordeh, Adam Salifu, Christopher Quaidoo et al.

The paper explores the review on the impact of electricity outages on MSMEs in Sub-Saharan Africa, analyzing their effects on productivity and poverty levels based on a review of 102 studies spanning from 2010 to 2023. The review organizes the studies by subject, theme, and major research findings to analyze the impact of power outages in Sub-Saharan Africa on poverty reduction. Power outages in the region hinder income generation and employment, perpetuating the cycle of poverty. The key findings emphasize the importance of proactive action to minimize the negative consequences of power outages on small businesses and poverty. MSMEs face disruptions that lead to reduced productivity, operational inefficiencies, higher production costs, and supply chain disruptions. Strategies to lessen power outage effects on MSMEs, the review proposed promoting energy source diversification, such as renewables. The research review concludes that power outages are a major challenge for MSMEs and energy diversification is a key solution to reduce poverty in the region.

Chi Zhang, Kaile Zhou, Shanlin Yang et al.

Sainan Xue, Xin Zhang, Jianlu Yang et al.

A direct connection test of a rotating detonation engine was conducted. The outer and inner diameters of the annular combustors were 206 and 166 mm, respectively. High enthalpy air was used as an oxidizer, and a mixture of hydrogen, carbon monoxide, and methane was used as fuel with a volume fraction of 5/4/1. The mixture was injected through small holes, and air was injected through annular slots. The effects of combustor length, width of annular slots, and the equivalent ratio on formation, development, propagation, and flameout of rotating detonation waves were analyzed, and several modes of rotating detonation were observed. It was found that when the width of the air annular slot was within the range of 3–5 mm, the pressure of the detonation wave was augmented with an increased slot width. As width increased, detonation waves became unstable. In study test conditions, an annular slot width of 6 mm was the critical condition for the formation of stable detonation. When the slot width was 4 mm and combustor length 160 mm, the phenomena of the conversion between single and double waves, double-wave collision, and conversion of the propagation direction occurred at different equivalent ratios. When the equivalent ratio was 1.2/1 and the slot width was within the range of 3–6 mm, the slot width was inversely related to the detonation wave velocity. When the slot width was 4 mm and the equivalent ratio was 1.0/1–1.2/1, the slot width was positively correlated with the detonation wave velocity. When the combustor length was shortened to 80 mm, the propagation mode of the detonation wave was changed to a single wave first and then to a double wave in the same direction, and the velocity reduced from 1130.69 to 1024.16 m/s. The injector used in the test inhibited the propagation of back pressure from the combustor.

Yacouba Telly, Xuezhi Liu, Tadagbe Roger Sylvanus Gbenou

Despite its immense natural resources, Angola struggles to significantly improve its economy to reduce poverty. Carbon emissions have been increasing over the years, even though the country plans to reduce them by 35% by 2030. This paper attempts to assess the carbon emissions of several sectors (industries, transport, services, and residences) on economic growth, intending to find a balance between environmental protection that requires carbon emissions reduction and economic development that may add to environmental degradation. The study employed time series data on GDP, CO₂, CH₄, and N₂O covering 1971 to 2021 and ARDL and ECM models. This is the first study at the state level in Angola on the relationship between economic development and environmental sustainability considering methane and nitrous oxide emissions. Additionally, the paper assesses the responses of GDP to deviation shock of GDP, CO₂, CH₄, and N₂O by 2032. Phillip Perron and Augmented Dickey-Fuller tests showed that all the data are stationary at the first difference, favoring the application of the ARDL model to explore the short and long-run relationships. The result reveals that methane from agricultural activities and carbon emissions from the building sector and public services contribute to economic growth, whereas carbon emissions from industrial heat systems, non-renewable electricity production, and manufacturing industries harm economic growth. However, no relationship exists between nitrous oxide emissions and economic development. In addition, impulse response function estimates show that appropriate investments can sustain economic development over the years. Therefore, the country should diversify its economy and avoid polluting fuel sources, such as coal. Raising renewable energy’s proportion in the total energy mix can support growth while considering the environmental quality. Investments in skills training, academic projects in renewable energy technologies development, agriculture mechanization, and sustainable job creation are recommended. Additionally, investing in quality seeds adapted to climate realities might help lessen climate change’s adverse effects and promote growth. Manure manufacturing processes must be improved to reduce agriculture and livestock’s methane and nitrous oxide emissions. The country’s leaders are encouraged to promote raw material processing industries while insisting on reducing carbon emissions.