scholarly journals Principles and practice of designing microbial biocatalysts for fuel and chemical production

2021 ◽  
Author(s):  
K T Shanmugam ◽  
Lonnie O Ingram
Keyword(s):  
Fossil Fuels ◽  
Renewable Energy Sources ◽  
Liquid Fuels ◽  
Clear Understanding ◽  
Chemical Production ◽  
Basic Principles ◽  
High Productivity ◽  
Physiology And Biochemistry ◽  
Microbial Biocatalysts ◽  
Lignocellulosic Sugars

ABSTRACT The finite nature of fossil fuels and the environmental impact of its use have raised interest in alternate renewable energy sources. Specifically, non-food carbohydrates, such as lignocellulosic biomass, can be used to produce next generation biofuels, including cellulosic ethanol and other non-ethanol fuels like butanol. However, currently there is no native microorganism that can ferment all lignocellulosic sugars to fuel molecules. Thus, research is focused on engineering improved microbial biocatalysts for production of liquid fuels at high productivity, titer and yield. A clear understanding and application of the basic principles of microbial physiology and biochemistry are crucial to achieve this goal. In this review, we present and discuss the construction of microbial biocatalysts that integrate these principles with ethanol-producing Escherichia coli as an example of metabolic engineering. These principles also apply to fermentation of lignocellulosic sugars to other chemicals that are currently produced from petroleum.

Recent advances and demonstrated potentials for clean hydrogen via overall solar water splitting

MRS Advances ◽  
2019 ◽  
Vol 4 (51-52) ◽  
pp. 2771-2785 ◽  
Author(s):  
Faqrul A. Chowdhury
Keyword(s):  
Water Splitting ◽  
Large Scale ◽  
Fossil Fuels ◽  
Performance Metrics ◽  
Liquid Fuels ◽  
Energy Yield ◽  
Basic Principles ◽  
Solar Water ◽  
Solar Water Splitting ◽  
System Designs

ABSTRACTSolar water splitting can potentially play a significant role in the future, sustainable and carbon-neutral energy infrastructure - by generating hydrogen as a green fuel from renewable sources and liquid-fuels via carbon-dioxide reduction. Hydrogen has higher gravimetric energy-yield compared to most of the conventional fossil fuels, is storable and transportable on demand. With the prospective green hydrogen economy in mind, considerable efforts have been made in the quest for a stable and efficient photocatalyst/photoelectrode which can eventually lead towards the realization of large-scale hydrogen production system. This snapshot review provides a summary of the basic principles and challenges associated with unassisted overall water splitting, and highlights the recent technological advancements made on the device and system designs on lab-scale - to improve different performance metrics, i.e., efficiency, stability, scalability and large-scale prototypes with demonstrated potentials for future developments.

scholarly journals Green factories: Synthetic plant products for industry

2011 ◽  
Vol 33 (1) ◽  
pp. 26-30
Author(s):  
Rob Edwards ◽  
Tom Jenkins ◽  
Patrick Steel ◽  
Phil Roberts
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Fossil Fuels ◽  
Liquid Fuels ◽  
Fermentable Sugars ◽  
Environmental Footprint ◽  
Chemical Production ◽  
Plant Products ◽  
Fine Chemical ◽  
Industrial Sustainability

The realization that we can no longer take reserves of fossil fuels for granted, allied to issues of industrial sustainability, pollution and climate change has reawakened an interest in increasing our use of plants as a source of both chemicals and materials. Whereas plant-derived biomass, fermentable sugars and oils are now well recognized as sources of energy and liquid fuels, the use of green feedstocks for large-scale platform and fine chemical production is increasingly high on the agenda of industries wanting to reduce their environmental footprint.

scholarly journals Exergy Models and Tar Removal Techniques in Biomass Gasification

2018 ◽  
Vol 5 (1) ◽  
pp. 16-23
Author(s):  
Ahsan Ayub ◽  
Uzair Ibrahim
Keyword(s):  
Process Design ◽  
Energy Production ◽  
Fossil Fuels ◽  
Renewable Energy Sources ◽  
Biomass Gasification ◽  
Liquid Fuels ◽  
Process Variables ◽  
Tar Removal ◽  
Bubbling Fluidized Bed ◽  
Fluidized Bed Gasifier

Quest for higher conversion efficiency and reduced environmental impact has increased the focus on renewable energy sources. Biomass is a sustainable form of energy that can be used as an alternate of fossil fuels through biomass gasification. Gasification is one of the most used methods for converting biomass into syngas that is a usable form of energy. The biomass gasification serves as a promising process for energy production. However, uncertainty in process variables and formation of tar has been a challenge in efficient process design and operation. This paper contains literature review of different models used for gasification, tar removal techniques along with Fischer Tropsch reactions for conversion of biomass to liquid fuels. The paper shows circulating and bubbling fluidized bed gasifier as the most efficient model for tar removal and greater exergy efficiency.

scholarly journals Biogas utilization in an internal combustion engine working in a serial hybrid propulsion system

2012 ◽  
Vol 148 (1) ◽  
pp. 17-24
Author(s):  
Viktoria KOVACS ◽  
Adam TOROK ◽  
Akos BERECZKY ◽  
Stanislaw SZWAJA
Keyword(s):  
Renewable Energy ◽  
Fossil Fuels ◽  
Combustion Engine ◽  
Renewable Energy Sources ◽  
Internal Combustion ◽  
Liquid Fuels ◽  
Heating Value ◽  
Hybrid Propulsion ◽  
Gaseous Fuels ◽  
Reciprocating Engine

Due to increase in demand for fossil fuels and aspects of natural environment protection, there is a major need to utilize alternative and renewable energy sources in order to promote sustainable development. The use of biogas as a source of renewable energy could provide effective and alternative way to satisfy a remarkable part of this demand for the transportation sector. As biogas has high inert content of carbon dioxide, its heating value is lower compared to CNG. Applying these low heating value renewable gaseous fuels for means of transport is not fully worked out yet because their combustion characteristics significantly differ from liquid fuels that are currently used or propane, or natural gas based systems that are becoming more and more popular in transportation. Biogas is not in common use, thus its utilization is recently limited for engines with conventional equipment burning other fuels. Thus, theoretical and experimental analysis was made to investigate the usability of biogas. On the basis of conducted investigation, it was found that effective biogas utilization as a fuel for means of transport can be achieved in a serial hybrid system consisted of internal combustion reciprocating engine.

Changing the face of short fiber –a review of the eucalyptus revolution

TAPPI Journal ◽  
2015 ◽  
Vol 14 (6) ◽  
pp. 353-359 ◽  
Author(s):  
PETER W. HART ◽  
RICARDO B. SANTOS
Keyword(s):  
Fossil Fuels ◽  
Wood Quality ◽  
Short Fiber ◽  
Fiber Volume ◽  
Private Industry ◽  
High Productivity ◽  
Paper Manufacturing ◽  
Short Rotation ◽  
Eucalypt Plantations ◽  
Eucalyptus Plantations

Eucalyptus plantations have been used as a source of short fiber for papermaking for more than 40 years. The development in genetic improvement and clonal programs has produced improved density plantations that have resulted in fast growing, increased fiber volume eucalypts becoming the most widely used source of short fibers in the world. High productivity and short rotation times, along with the uniformity and improved wood quality of clonal plantations have attracted private industry investment in eucalypt plantations. Currently, only a handful of species or hybrids are used in plantation efforts. Many more species are being evaluated to either enhance fiber properties or expand the range of eucalypt plantations. Eucalyptus plantations are frequently planted on nonforested land and may be used, in part, as a means of conserving native forests while allowing the production of high quality fiber for economic uses. Finally, eucalypt plantations can provide significant carbon sinks, which may be used to help offset the carbon released from burning fossil fuels. The development and expansion of eucalypt plantations represents a substantial revolution in pulp and paper manufacturing.

An Efficient Hybrid Forecasting Approach for Wind Speed Time Series

2017 ◽  
Vol 7 (9) ◽  
pp. 13
Author(s):  
Bhargavi Munnaluri ◽  
K. Ganesh Reddy
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Wind Speed ◽  
Fossil Fuels ◽  
Renewable Energy Sources ◽  
Support Vector ◽  
Hybrid Forecasting ◽  
Artificial Neural ◽  
Future Utilization

Wind forecasting is one of the best efficient ways to deal with the challenges of wind power generation. Due to the depletion of fossil fuels renewable energy sources plays a major role for the generation of power. For future management and for future utilization of power, we need to predict the wind speed.  In this paper, an efficient hybrid forecasting approach with the combination of Support Vector Machine (SVM) and Artificial Neural Networks(ANN) are proposed to improve the quality of prediction of wind speed. Due to the different parameters of wind, it is difficult to find the accurate prediction value of the wind speed. The proposed hybrid model of forecasting is examined by taking the hourly wind speed of past years data by reducing the prediction error with the help of Mean Square Error by 0.019. The result obtained from the Artificial Neural Networks improves the forecasting quality.

Smart Cities and Smart Regulation

2018 ◽  
Author(s):  
Anita Rønne
Keyword(s):  
Climate Change ◽  
Urban Areas ◽  
Fossil Fuels ◽  
System Analysis ◽  
New Technologies ◽  
Smart Cities ◽  
Renewable Energy Sources ◽  
Energy System ◽  
Political Agenda ◽  
Smart Regulation

Increasing focus on sustainable societies and ‘smart cities’ due to emphasis on mitigation of climate change is simultaneous with ‘smart regulation’ reaching the forefront of the political agenda. Consequently, the energy sector and its regulation are undergoing significant innovation and change. Energy innovations include transition from fossil fuels to more renewable energy sources and application of new computer technology, interactively matching production with consumer demand. Smart cities are growing and projects are being initiated for development of urban areas and energy systems. Analysis from ‘Smart Cities Accelerator’, developed under the EU Interreg funding programme that includes Climate-KIC,——provides background for the focus on a smart energy system. Analysis ensures the energy supply systems support the integration of renewables with the need for new technologies and investments. ‘Smart’ is trendy, but when becoming ‘smart’ leads to motivation that is an important step towards mitigating climate change.

scholarly journals Emissions of an agricultural engine using blends of diesel and hydrous ethanol

2019 ◽  
Vol 40 (1) ◽  
pp. 7
Author(s):  
Marcelo Silveira de Farias ◽  
José Fernando Schlosser ◽  
Javier Solis Estrada ◽  
Gismael Francisco Perin ◽  
Alfran Tellechea Martini
Keyword(s):  
Internal Combustion Engines ◽  
Fossil Fuels ◽  
Renewable Energy Sources ◽  
Standard Procedure ◽  
Diesel Oil ◽  
K Value ◽  
Operating Modes ◽  
Diesel Cycle ◽  
Reduce Emissions ◽  
Hydrous Ethanol

The growing global demand of energy, the decrease of petroleum reserves and the current of environmental contamination problems, make it imperative to study renewable energy sources for use in internal combustion engines, in order to decrease the dependence on fossil fuels and reduce emissions of pollutant gases. This study aimed to evaluate the emissions of a diesel-cycle engine of an agricultural tractor that uses diesel S500 (B5) mixed with 3, 6, 9, 12 and 15% of hydrous ethanol. It determined emissions of CO2 (ppm), NOx (ppm), and opacity (k value) of gases. A standard procedure was applied considering eight operating modes (M1, M2, M3, M4, M5, M6, M7, and M8) by breaking with an electric dynamometer in a laboratory. The experimental design was completely randomized, with 60 replicates and a 6 x 8 factorial design. Greater opacity and gas emissions were observed when the engine operated with 3% ethanol, while lower emissions occurred with 12 and 15%. With these fuels, the reduction of opacity, CO2, and NOx, in relation to diesel oil, was 24.49 and 26.53%, 4.96 and 5.15%, and 6.59 and 9.70%, respectively. In conclusion, the addition of 12 and 15% ethanol in diesel oil significantly reduces engine emissions.

scholarly journals Post COVID-19 Recovery and 2050 Climate Change Targets: Changing the Emphasis from Promotion of Renewables to Mandated Curtailment of Fossil Fuels in the EU Policies

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1347
Author(s):  
Kyriakos Maniatis ◽  
David Chiaramonti ◽  
Eric van den Heuvel
Keyword(s):  
Climate Change ◽  
European Union ◽  
Renewable Energy ◽  
Global Economy ◽  
Fossil Fuels ◽  
Global Climate ◽  
Renewable Energy Sources ◽  
Climate Change Policy ◽  
Climate Impacts ◽  
The European Union

The present work considers the dramatic changes the COVID-19 pandemic has brought to the global economy, with particular emphasis on energy. Focusing on the European Union, the article discusses the opportunities policy makers can implement to reduce the climate impacts and achieve the Paris Agreement 2050 targets. The analysis specifically looks at the fossil fuels industry and the future of the fossil sector post COVID-19 pandemic. The analysis first revises the fossil fuel sector, and then considers the need for a shift of the global climate change policy from promoting the deployment of renewable energy sources to curtailing the use of fossil fuels. This will be a change to the current global approach, from a relative passive one to a strategically dynamic and proactive one. Such a curtailment should be based on actual volumes of fossil fuels used and not on percentages. Finally, conclusions are preliminary applied to the European Union policies for net zero by 2050 based on a two-fold strategy: continuing and reinforcing the implementation of the Renewable Energy Directive to 2035, while adopting a new directive for fixed and over time increasing curtailment of fossils as of 2025 until 2050.

scholarly journals Conversion of biomass to biofuels and life cycle assessment: a review

2021 ◽  
Author(s):  
Ahmed I. Osman ◽  
Neha Mehta ◽  
Ahmed M. Elgarahy ◽  
Amer Al-Hinai ◽  
Ala’a H. Al-Muhtaseb ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Energy Demand ◽  
Fossil Fuels ◽  
Biomass Conversion ◽  
Biofuel Production ◽  
Process Efficiency ◽  
Liquid Fuels ◽  
Thermochemical Processes ◽  
Lower Temperature

AbstractThe global energy demand is projected to rise by almost 28% by 2040 compared to current levels. Biomass is a promising energy source for producing either solid or liquid fuels. Biofuels are alternatives to fossil fuels to reduce anthropogenic greenhouse gas emissions. Nonetheless, policy decisions for biofuels should be based on evidence that biofuels are produced in a sustainable manner. To this end, life cycle assessment (LCA) provides information on environmental impacts associated with biofuel production chains. Here, we review advances in biomass conversion to biofuels and their environmental impact by life cycle assessment. Processes are gasification, combustion, pyrolysis, enzymatic hydrolysis routes and fermentation. Thermochemical processes are classified into low temperature, below 300 °C, and high temperature, higher than 300 °C, i.e. gasification, combustion and pyrolysis. Pyrolysis is promising because it operates at a relatively lower temperature of up to 500 °C, compared to gasification, which operates at 800–1300 °C. We focus on 1) the drawbacks and advantages of the thermochemical and biochemical conversion routes of biomass into various fuels and the possibility of integrating these routes for better process efficiency; 2) methodological approaches and key findings from 40 LCA studies on biomass to biofuel conversion pathways published from 2019 to 2021; and 3) bibliometric trends and knowledge gaps in biomass conversion into biofuels using thermochemical and biochemical routes. The integration of hydrothermal and biochemical routes is promising for the circular economy.

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