Hasil untuk "Fuel"

K. Jiao, J. Xuan, Q. Du et al.

Yun Wang, D. Díaz, K. Chen et al.

Abstract PEM (Polymer Electrolyte Membrane) fuel cells have the potential to reduce our energy use, pollutant emissions, and dependence on fossil fuels. In the past decade, significant advances have been achieved for commercializing the technology. For example, several PEM fuel cell buses are currently rated at the technical readiness stage of full-scale validation in realistic driving environments and have met or closely met the ultimate 25,000-h target set by the U.S. Department of Energy. So far, Toyota has sold more than 4000 Mirai PEM fuel cell vehicles (FCVs). Over 30 hydrogen gas stations are being operated throughout the U.S. and over 60 in Germany. In this review, we cover the material, design, fundamental, and manufacturing aspects of PEM fuel cells with a focus on the portable, automobile, airplane, and space applications that require careful consideration in system design and materials. The technological status and challenges faced by PEM fuel cells toward their commercialization in these applications are described and explained. Fundamental issues that are key to fuel cell design, operational control, and material development, such as water and thermal management, dynamic operation, cold start, channel two-phase flow, and low-humidity operation, are discussed. Fuels and fuel tanks pertinent to PEM fuel cells are briefly evaluated. The objective of this review is three fold: (1) to present the latest status of PEM fuel cell technology development and applications in the portable and transportation power through an overview of the state of the art and most recent technological advances; (2) to describe materials and water/thermal transport management for fuel cell design and operational control; and (3) to outline major challenges in the technology development and the needs for fundamental research for the near future and prior to fuel cell world-wide deployment.

I. Staffell, Daniel Scamman, Anthony Velazquez Abad et al.

Hydrogen has been ‘just around the corner’ for decades, but now offers serious alternatives for decarbonising global heat, power and transport.

Z. Cano, Dustin Banham, Siyu Ye et al.

Jingguang G. Chen, Jingguang G. Chen, R. Crooks et al.

D. Cullen, K. Neyerlin, R. Ahluwalia et al.

M. Debe

Yun Wang, K. Chen, Jeffrey Mishler et al.

Polymer electrolyte membrane (PEM) fuel cells, which convert the chemical energy stored in hydrogen fuel directly and efficiently to electrical energy with water as the only byproduct, have the potential to reduce our energy use, pollutant emissions, and dependence on fossil fuels. Great deal of efforts has been made in the past, particularly during the last couple of decades or so, to advance the PEM fuel cell technology and fundamental research. Factors such as durability and cost still remain as the major barriers to fuel cell commercialization. In the past two years, more than 35% cost reduction has been achieved in fuel cell fabrication, the current status of $61/kW (2009) for transportation fuel cell is still over 50% higher than the target of the US Department of Energy (DOE), i.e. $30/kW by 2015, in order to compete with the conventional technology of internal-combustion engines. In addition, a lifetime of ~2500Â h (for transportation PEM fuel cells) was achieved in 2009, yet still needs to be doubled to meet the DOE's target, i.e. 5000Â h. Breakthroughs are urgently needed to overcome these barriers. In this regard, fundamental studies play an important and indeed critical role. Issues such as water and heat management, and new material development remain the focus of fuel-cell performance improvement and cost reduction. Previous reviews mostly focus on one aspect, either a specific fuel cell application or a particular area of fuel cell research. The objective of this review is three folds: (1) to present the latest status of PEM fuel cell technology development and applications in the transportation, stationary, and portable/micro power generation sectors through an overview of the state-of-the-art and most recent technical progress; (2) to describe the need for fundamental research in this field and fill the gap of addressing the role of fundamental research in fuel cell technology; and (3) to outline major challenges in fuel cell technology development and the needs for fundamental research for the near future and prior to fuel cell commercialization.

L. Qu, Y. Liu, Jong‐Beom Baek et al.

K. Vohra, A. Vodonos, Joel Schwartz et al.

The burning of fossil fuels - especially coal, petrol, and diesel - is a major source of airborne fine particulate matter (PM2.5), and a key contributor to the global burden of mortality and disease. Previous risk assessments have examined the health response to total PM2.5, not just PM2.5 from fossil fuel combustion, and have used a concentration-response function with limited support from the literature and data at both high and low concentrations. This assessment examines mortality associated with PM2.5 from only fossil fuel combustion, making use of a recent meta-analysis of newer studies with a wider range of exposure. We also estimated mortality due to lower respiratory infections (LRI) among children under the age of five in the Americas and Europe, regions for which we have reliable data on the relative risk of this health outcome from PM2.5 exposure. We used the chemical transport model GEOS-Chem to estimate global exposure levels to fossil-fuel related PM2.5 in 2012. Relative risks of mortality were modeled using functions that link long-term exposure to PM2.5 and mortality, incorporating nonlinearity in the concentration response. We estimate a global total of 10.2 (95% CI: -47.1 to 17.0) million premature deaths annually attributable to the fossil-fuel component of PM2.5. The greatest mortality impact is estimated over regions with substantial fossil fuel related PM2.5, notably China (3.9 million), India (2.5 million) and parts of eastern US, Europe and Southeast Asia. The estimate for China predates substantial decline in fossil fuel emissions and decreases to 2.4 million premature deaths due to 43.7% reduction in fossil fuel PM2.5 from 2012 to 2018 bringing the global total to 8.7 (95% CI: -1.8 to 14.0) million premature deaths. We also estimated excess annual deaths due to LRI in children (0-4 years old) of 876 in North America, 747 in South America, and 605 in Europe. This study demonstrates that the fossil fuel component of PM2.5 contributes a large mortality burden. The steeper concentration-response function slope at lower concentrations leads to larger estimates than previously found in Europe and North America, and the slower drop-off in slope at higher concentrations results in larger estimates in Asia. Fossil fuel combustion can be more readily controlled than other sources and precursors of PM2.5 such as dust or wildfire smoke, so this is a clear message to policymakers and stakeholders to further incentivize a shift to clean sources of energy.

B. Logan, B. Hamelers, R. Rozendal et al.

J. Larminie, A. Dicks

J. Nørskov, J. Rossmeisl, A. Logadottir et al.

B. Steele, A. Heinzel

M. Winter, R. Brodd

T. Springer, T. Zawodzinski, S. Gottesfeld

N. Minh

A. Pramuanjaroenkij, S. Kakaç

Transportation sector is the important sector and consumed the most fossil fuel in the world. Since COVID-19 started in 2019, this sector had become the world connector because every country relies on logistics. The transportation sector does not only deal with the human transportation but also relates to logistics. Research in every country has searched for alternative transportation to replace internal combustion engines using fossil fuel, one of the most prominent choices is fuel cells. Fuel cells can use hydrogen as fuel. Hydrogen can be fed to the fuel cells to provide electric power to drive vehicles, no greenhouse gas emission and no direct combustion required. The fuel cells have been developed widely as the 21st century energy-conservation devices for mobile, stationary, and especially vehicles. The fuel cell electric vehicles using hydrogen as fuel were also called hydrogen fuel cell vehicles or hydrogen electric vehicles. The fuel cells were misconceived by several people that they were batteries, but the fuel cells could provide electric power continuously if their fuel was provided continuously. The batteries could provide electric power as their only capacities, when all ions are released, no power could be provided. Because the fuel cell vehicles play important roles for our future transportation, the overall review for these vehicles is significantly interesting. This overall review can provide general and technical information, variety of readers;vehicle users, manufacturers, and scientists, can perceive and understand the fuel cell vehicles within this review. The readers can realize how important the fuel cell technologies are and support research around the world to drive the fuel cell vehicles to be the leading vehicles in our sustainable developing world.

M. Delis, Kathrin de Greiff, S. Ongena

Do banks price the risk of stranded fossil fuel reserves? To address this question, we hand collect global data on corporate fossil fuel reserves from 2002 to 2016, match it with syndicated loans, and subsequently compare the loan rate charged to fossil fuel firms — along their climate policy exposure — to other firms. We find that banks price climate policy exposure, especially after 2015. We also uncover that our main effect further increases for loans with longer maturity, that loan size to fossil fuel firms increases, and that ‛Green’ banks also charge higher loan rates to fossil fuel firms.

Sujeet Yadav, S. S. Mondal

Abstract Carbon capture and sequestration (CCS) technologies have emerged as a promising technique to prevent greenhouse gas emissions of fossil fuel-fired power plants. In recent years oxy-fuel combustion-based CCS technique has gained a lot of attention and consideration because of its cost-effective CO2 capture. The present review article outlines the progress made in carbon capture and sequestration (CCS) based on oxy-fuel combustion by incorporating an air separation unit (ASU) and carbon dioxide purification and compression unit (CPU). The present article discusses the major components of the oxy-fuel combustion power plant and compares various novel configurations of oxy-fuel power generation systems in terms of energy penalty, auxiliary energy consumption, CO2 purity, and CO2 capture efficiency. This review also focuses on modifications to oxy-fuel combustion power generation systems such as pressurized oxy-fuel combustion, flue gas enriched oxy-fuel combustion, and few advanced oxy-fuel configurations. This review article has addressed the techno-economic and thermodynamic aspects of the oxy-fuel combustion-based carbon capture and sequestration (CCS) method.