Eco-friendly Transformation of Waste Biomass to Biofuels

2020 ◽  
Vol 6 (2) ◽  
pp. 120-134 ◽  
Author(s):  
Pranav D. Parakh ◽  
Sonil Nanda ◽  
Janusz A. Kozinski

Background: The development of viable alternative fuel sources is assuming a new urgency in the face of climate change and environmental degradation linked to the escalating consumption of fossil fuels. Lignocellulosic biomass is composed primarily of high-energy structural components such as cellulose, hemicellulose and lignin. The transformation of lignocellulosic biomass to biofuels requires the application of both pretreatment and conversion technologies. Methods: Several pretreatment technologies (e.g. physical, chemical and biological) are used to recover cellulose, hemicellulose and lignin from biomass and begin the transformation into biofuels. This paper reviews the thermochemical (e.g. pyrolysis, gasification and liquefaction), hydrothermal (e.g. subcritical and supercritical water gasification and hydrothermal liquefaction), and biological (e.g. fermentation) conversion pathways that are used to further transform biomass feedstocks into fuel products. Results: Through several thermochemical and biological conversion technologies, lignocellulosic biomass and other organic residues can produce biofuels such as bio-oils, biochar, syngas, biohydrogen, bioethanol and biobutanol, all of which have the potential to replace hydrocarbon-based fossil fuels. Conclusions: This review paper describes the conversion technologies used in the transformation of biomass into viable biofuels. Biofuels produced from lignocellulosic biomass and organic wastes are a promising potential clean energy source with the potential to be carbon-neutral or even carbonnegative.

Author(s):  
J G Collier

Nuclear power is a young technology that has developed within a political environment of ever-changing priorities. In the United Kingdom, Government-led central planning of electricity supply has given way to market forces and the future of nuclear power depends on its ability to compete in this competitive environment as well as its wider public acceptance. In only three years, the disciplines of private sector competition have transformed the economics of United Kingdom nuclear operations and the new generation of pressurized water reactor (PWR) at Sizewell is set to lead the world in safety and performance. Taken together with the growing recognition of the need to protect the local and global environment from the products of the combustion of fossil fuels, the prospects for the future of nuclear power as the major clean energy source for the twenty-first century have never been better.


2022 ◽  
Vol 8 (2) ◽  
pp. 49-58
Author(s):  
Grazielle Cristina de Araujo ◽  
Jair Antonio Cruz Siqueira ◽  
Loreci Zanardini ◽  
João Felipe Peixoto Marques ◽  
Rafaela Lazzarin ◽  
...  

There was a significant increase in the concern with climate issues, among them highlighted as the derivation of greenhouse gases from the burning fossil fuels, leading several research centers and researchers to seek new sources of less polluting energy, independent of the burn-based matrix of fuels. In this context, the present work has as main presenter a literature review, perspective and comparisons regarding the use of hydrogen as a clean energy source, presenting three main ways of obtaining it: a) through electrolysis using renewable sources; b) biohydrogen production, based on the photosynthesis of plants and algae; c) production through biodigesters.


Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2947 ◽  
Author(s):  
Shu-Na Zhao ◽  
Guangbo Wang ◽  
Dirk Poelman ◽  
Pascal Van Der Voort

The increase in environmental pollution due to the excessive use of fossil fuels has prompted the development of alternative and sustainable energy sources. As an abundant and sustainable energy, solar energy represents the most attractive and promising clean energy source for replacing fossil fuels. Metal organic frameworks (MOFs) are easily constructed and can be tailored towards favorable photocatalytic properties in pollution degradation, organic transformations, CO2 reduction and water splitting. In this review, we first summarize the different roles of MOF materials in the photoredox chemical systems. Then, the typical applications of MOF materials in heterogeneous photocatalysis are discussed in detail. Finally, the challenges and opportunities in this promising field are evaluated.


Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 95 ◽  
Author(s):  
Ahmad Tabish ◽  
Anish Mathai Varghese ◽  
Md A. Wahab ◽  
Georgios N. Karanikolos

CO2 emissions from the consumption of fossil fuels are continuously increasing, thus impacting Earth’s climate. In this context, intensive research efforts are being dedicated to develop materials that can effectively reduce CO2 levels in the atmosphere and convert CO2 into value-added chemicals and fuels, thus contributing to sustainable energy and meeting the increase in energy demand. The development of clean energy by conversion technologies is of high priority to circumvent these challenges. Among the various methods that include photoelectrochemical, high-temperature conversion, electrocatalytic, biocatalytic, and organocatalytic reactions, photocatalytic CO2 reduction has received great attention because of its potential to efficiently reduce the level of CO2 in the atmosphere by converting it into fuels and value-added chemicals. Among the reported CO2 conversion catalysts, perovskite oxides catalyze redox reactions and exhibit high catalytic activity, stability, long charge diffusion lengths, compositional flexibility, and tunable band gap and band edge. This review focuses on recent advances and future prospects in the design and performance of perovskites for CO2 conversion, particularly emphasizing on the structure of the catalysts, defect engineering and interface tuning at the nanoscale, and conversion technologies and rational approaches for enhancing CO2 transformation to value-added chemicals and chemical feedstocks.


Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 786 ◽  
Author(s):  
Rehman Javaid ◽  
Aqsa Sabir ◽  
Nadeem Sheikh ◽  
Muhammad Ferhan

Processing of fossil fuels is the major environmental issue today. Biomass utilization for the production of chemicals presents an alternative to simple energy generation by burning. Lignocellulosic biomass (cellulose, hemicellulose and lignin) is abundant and has been used for variety of purposes. Among them, lignin polymer having phenyl-propanoid subunits linked together either through C-C bonds or ether linkages can produce chemicals. It can be depolymerized by fungi using their enzyme machinery (laccases and peroxidases). Both acetic acid and formic acid production by certain fungi contribute significantly to lignin depolymerization. Fungal natural organic acids production is thought to have many key roles in nature depending upon the type of fungi producing them. Biological conversion of lignocellulosic biomass is beneficial over physiochemical processes. Laccases, copper containing proteins oxidize a broad spectrum of inorganic as well as organic compounds but most specifically phenolic compounds by radical catalyzed mechanism. Similarly, lignin peroxidases (LiP), heme containing proteins perform a vital part in oxidizing a wide variety of aromatic compounds with H2O2. Lignin depolymerization yields value-added compounds, the important ones are aromatics and phenols as well as certain polymers like polyurethane and carbon fibers. Thus, this review will provide a concept that biological modifications of lignin using acidophilic fungi can generate certain value added and environmentally friendly chemicals.


2019 ◽  
Vol 4 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Phuoc Quy Phong Nguyen ◽  
Van Huong Dong

The world is constantly seeking new sources of energy to replace the use of coal and fossil fuels to generate electricity. And a strong source of energy from the ocean is one of the hopes of scientists around the world. Ocean energy is an endless renewable energy source for making electricity used for the world. Marine technology was once considered too expensive to be a viable source of alternative clean energy, especially compared to already developed products such as wind and solar. However, with the increased price of oil and the issues of global warming and national security, U.S. coastal sites are looking to add ocean energy to their renewable energy portfolios. This paper gives an overview of ocean energy technologies, focusing on two different types: wave, tidal. It outlines the operating principles, the status, and the efficiency and cost of generating energy associated with each technology.


2012 ◽  
Vol 174-177 ◽  
pp. 1339-1343 ◽  
Author(s):  
Hong Min Kan ◽  
Ning Zhang ◽  
Xiao Yang Wang ◽  
Hong Sun

Hydrogen is considered a promising alternative energy carrier that can potentially facilitate the transition from fossil fuels to sources of clean energy because of its prominent advantages such as high energy density, great variety of potential sources, light weight and low environmental impact (water is the sole combustion product). Due to low price and abundance magnesium should be considered as a potential candidate for hydrogen storage. Recent progress in the application of Magnesium-based nanostructured and composite materials in hydrogen storage is presented in this review. The main focus is on the synthesis of composite material, the design of nanocomposite material, the improvement of the thermodynamical properties and kinetics of hydrogenation/dehydrogenation and the improvement of resistance towards oxygen contamination.


2020 ◽  
Vol 15 (7) ◽  
pp. 1007-1015
Author(s):  
Louiza Haddad ◽  
Zeroual Aouachria ◽  
Djamel Haddad

If transport is an essential means for the development of the economy, society and its mobility, it has the drawback of leading to significant atmospheric pollution. As traffic density is very high in large cities, air pollution is amplified by the various means of transport resulting from the combustion of fossil fuels. Urban air pollution is mainly caused by vehicles generating emissions harmful to human health. Our objective of this work is to analyze a strategy to eliminate or reduce the emission of these pollutants (NOx, CO, CO2) during combustion. This strategy aims to explore a clean energy source alternative to fossil fuels. This approach consists of completely replacing the internal combustion scalar with the engine powered by fuel cells using hydrogen. This motivates decision makers to choose hydrogen as an alternative fuel to protect the urban environment and the health human from air pollution. This study shows that it is possible to perfectly mitigate pollutants from urban transport systems by using a PEMFC as an alternative clean energy source. Analyze a strategy to eliminate or reduce the emissions of these pollutants (NOx, CO, CO2) during the combustion of full fossil fuel in vehicle engines. This strategy aims to exploit the energy vector represented by hydrogen in order to save human life in more populated areas and protect the environment. The pressure, temperature and concentration of each species (O2, H2 and H2O) are obtained from the resolution of the electrochemical model coupled to the dynamic model, which we do not present here.


Author(s):  
Kyle Chavez ◽  
Evan Sproul ◽  
Joshua Christian ◽  
Kendra Valdez ◽  
Ian Luders ◽  
...  

The limited supply and environmental impact of fossil fuels has become an urgent problem. To aid in overcoming this problem a team from New Mexico Tech (NMT) is improving existing heliostat technology to create a more cost-effective and mobile heliostat design. The team has devised an innovative patent pending liquid-ballast heliostat drive system which reduces the cost of heliostat drive mechanics, utilizes a cost-effective mirror design, and eliminates an unnecessary support pedestal. By implementing this new design the team will help to create a more economically viable, clean energy source that will benefit all energy consumers as well as the environment. The team’s goal is to create a heliostat that reduces the cost of production and operation by thirty percent. In doing so, the team must also meet strict accuracy and lifetime specifications created by Sandia National Labs (SNL) and NMT. In pursuit of meeting these specifications the team is currently completing fabrication of a prototype. Using this prototype the team will evaluate drive system performance through semi-automated testing. After testing, the team will continue the design process with the ultimate goal of creating multiple improved prototypes.


2020 ◽  
Vol 9 (5) ◽  
pp. e126953070
Author(s):  
Marcos Lapa Brito ◽  
José Mário Ferreira Júnior ◽  
Luiz Carlos Lobato dos Santos ◽  
George Simonelli

Concern about global warming and the high consumption of fossil fuels has led some countries to seek and invest in new energy sources that are efficient and less polluting. Among these alternatives, hydrogen fuel cells are a potential solution that can generate clean energy. Due to the industrial production of hydrogen being carried out by steam reforming of methane, which uses non-renewable raw material and is endothermic (resulting in high energy costs), the autothermal reform of ethanol has been presenting itself as an interesting technology, as it combines a renewable raw material with the reactions of reform (endothermic) and partial oxidation (exothermic), thus achieving energy self-sufficiency in the process of converting ethanol to hydrogen. Despite the various studies referring to the autothermal reform of ethanol, to our knowledge, no article has presented a detailed review of the main advances made in recent years for this process. Thus, this review presents the main results for the autothermal reform of ethanol, in recent years, in three main areas: Catalysts, Reactor Design and Modeling / Simulation. This work identified that the greatest advances have been made in the development of new catalysts and the design of reactors, while the modeling/simulation area still has few studies to efficiently describe the thermodynamics of the autothermal reform of ethanol.


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