As our high dependence on the supply of diminishing fossil fuel reserves raise great concerns in its environmental, political and economic consequences, utilization of renewable biomass as an ...alternative resource has become increasingly important. Along this background, furfural as a building block, offers a promising, rich platform for lignocellulosic biofuels and value-added chemicals. These include 2-methylfuran and 2-methyltetrahydrofuran, furfuryl alcohol, tetrahydrofurfuryl alcohol, furan, tetrahydrofuran as well as various cyclo-products (e.g., cyclopentanol, cyclopentanone). The various production routes started from furfural to various fuel additives and chemicals are critically reviewed, and the current technologies for efficient production are identified. Their potential applications as well as the fuel properties of these products are discussed. Challenges and areas that need improvement are also highlighted in the corresponding area. In short, we conduct a comprehensive review of the strategies to produce furfural, new approaches and numerous possibilities to utilize furfural in industrial and laboratory sector for the production of fuel additives and value-added chemicals.
Crude volatility McNally, Robert
2017., 20170117, 2017, 2017-01-17
eBook
As OPEC has loosened its grip over the past ten years, the oil market has been rocked by wild price swings, the likes of which haven't been seen for eight decades. Crafting an engrossing journey from ...the gushing Pennsylvania oil fields of the 1860s to today's fraught and fractious Middle East,Crude Volatilityexplains how past periods of stability and volatility in oil prices help us understand the new boom-bust era. Oil's notorious volatility has always been considered a scourge afflicting not only the oil industry but also the broader economy and geopolitical landscape; Robert McNally makes sense of how oil became so central to our world and why it is subject to such extreme price fluctuations.
Tracing a history marked by conflict, intrigue, and extreme uncertainty, McNally shows how-even from the oil industry's first years-wild and harmful price volatility prompted industry leaders and officials to undertake extraordinary efforts to stabilize oil prices by controlling production. Herculean market interventions-first, by Rockefeller's Standard Oil, then, by U.S. state regulators in partnership with major international oil companies, and, finally, by OPEC-succeeded to varying degrees in taming the beast. McNally, a veteran oil market and policy expert, explains the consequences of the ebbing of OPEC's power, debunking myths and offering recommendations-including mistakes to avoid-as we confront the unwelcome return of boom and bust oil prices.
This paper presents information on global energy consumption by fuel type (liquid fuels, coal, natural gas, renewables and nuclear) and sectors (buildings, industrial, transportation and ...electricity), and environmental impact of global energy consumption (SOx, NOx and CO2 emissions). There is a strong relationship between energy consumption and economic growth. The Global Financial Crisis has affected the global economic growth violently. The governments have recently adopted some effective measures to fight against the Global Financial Crisis. The structure of energy consumption and the conditions of SOx, NOx, and CO2 emissions affect the global changes (acid rain and greenhouse effect). Today, considerable effort is being devoted to reduce CO2 emissions because of the Kyoto Protocol on climate change. This publication presents multidisciplinary perspectives on the interrelated topics of energy consumption, energy security and energy policy. Additionally, the present study examines the relationship between energy consumption and greenhouse gas emission.
In this paper, the characteristics of physical and chemical composition of municipal solid waste (MSW) in China were reviewed and the statistical indexes, namely mean value, standard deviation, ...coefficient of variation, and t-test, were applied to analyze the physical composition, proximate, ultimate analysis, and heating value. Listed in decreasing sequence, the physical components of Chinese MSW are in food residue, non-combustibles, plastics, paper, textiles, wood waste, and rubber. In food residue, the average elementary hydrogen (H), oxygen (O) and nitrogen (N) content varied greatly with samples and the chlorine (Cl) and moisture contents were extraordinarily high. While conversely, the components of wood waste were simple and different components displayed little disparity in characteristics. The elemental compositions of paper and textiles were also simple. The properties of chlorine-free plastics (polyethylene, polypropylene and polystyrene) were consistent, with high volatile matter, carbon (C) and H content. The mean higher heating value (HHV) of polrvinyl chloride (PVC) was about a half of that of chlorine-free plastics, because the Cl content of PVC was approximate 50%. It suggested that plastics with or without chlorine should be separated as possible. The HHV of different rubbers varied sharply, from 21,812 to 38,868kJ/kg. A model was proposed to predict the proximate and ultimate analysis and heating value from physical composition, in which the PVC fraction in plastics and the supplementary moisture coefficient were introduced. The results showed that the predicted results fitted well with the measured ones.
The discovery of abundant natural gas resources has greatly increased the study of using methane as a feedstock to produce transportation fuels. Biogas (primarily containing methane and CO2), which ...is generated from waste biomass via anaerobic digestion or landfills, is regarded as a renewable source of methane, and has the potential to achieve sustainable production of transportation fuels. Since biogas also contains a significant amount of impurities (e.g., H2S, NH3, and siloxane), a cleaning procedure is generally required prior to conversion to transportation fuels. Physical approaches, mainly compression and liquefaction, have been commercially applied to upgrade biogas to bio-compressed natural gas (CNG) and liquefied biogas (LBG). For chemical approaches, catalytic reforming is the dominant method for converting methane to syngas, followed by Fischer–Tropsch synthesis (FTS) or fermentation of syngas to a variety of alcohols (e.g., methanol, ethanol, and butanol) and liquid hydrocarbon fuels (e.g., gasoline, diesel, and jet fuels). High purity hydrogen, a clean fuel, can also be produced via reforming. Methanol can be produced by direct oxidation of methane, while interest in the biological conversion of methane to methanol has grown recently due to its mild operating conditions, high conversion efficiency, and potential for using raw biogas. The derived methanol can be further converted to gasoline via a methanol to gasoline (MTG) process. This paper provides a comprehensive review of major research progress on technologies for converting biogas/methane into transportation fuels, and discusses the principles, kinetics, operating conditions, and performance of each technology. Efficient direct conversion of biogas into ethanol and higher alcohol fuels (e.g. butanol), which is envisaged to be the focus of research pursuits in the near future, is also discussed, with emphasis on the development of methane-utilizing microbes through genetic engineering.
•The hydrothermal carbonization of sewage sludge process is developed.•Hydrochars are solid fuels with less nitrogen and sulfur contents.•The first order combustion reaction of hydrochars is ...derived.•Main combustion decomposition of hydrochars is easier and more stable.•Formation pathways of hydrochars during hydrothermal carbonization are proposed.
Conventional thermochemical treatment of sewage sludge (SS) is energy-intensive due to its high moisture content. To overcome this drawback, the hydrothermal carbonization (HTC) process was used to convert SS into clean solid fuel without prior drying. Different carbonization times were applied in order to produce hydrochars possessing better fuel properties. After the carbonization process, fuel characteristics and combustion behaviors of hydrochars were evaluated. Elemental analysis showed that 88% of carbon was recovered while 60% of nitrogen and sulfur was removed. Due to dehydration and decarboxylation reactions, hydrogen/carbon and oxygen/carbon atomic ratios reduced to 1.53 and 0.39, respectively. It was found that the fuel ratio increased to 0.18 by prolonging the carbonization process. Besides, longer carbonization time seemed to decrease oxygen containing functional groups while carbon aromaticity structure increased, thereby rendering hydrochars highly hydrophobic. The thermogravimetric analysis showed that the combustion decomposition was altered from a single stage for raw sludge to two stages for hydrochars. The combustion reaction was best fitted to the first order for both raw sludge and hydrochars. The combustion of hydrochars is expected to be easier and more stable than raw sludge because of lower activation energy and pre-exponential factor.
The energy sector in the global scenario faces a major challenge of providing energy at an affordable cost and simultaneously protecting the environment. The energy mix globally is primarily ...dominated by fossil fuels, coal being the major contributor. Increasing concerns on the adverse effect of the emissions arising from coal conversion technologies on the environment and the gradual depletion of the fossil fuel reserves had led to global initiatives on using renewables and other opportunity resources to meet the future energy demands in a sustainable manner. Use of coal with biomass as a supplementary fuel in the combustion or gasification based processes is a viable technological option for reducing the harmful emissions. Co-combustion of coal with biomass for electricity generation is gradually gaining ground in spite of the fact that their combustion behavior differ widely due to wide variations in their physical and chemical properties. This article deals with the technical aspects of co-combustion with emphasis on the fundamentals of devolatilization, ignition, burnout and ash deposition behavior along with the constraints and uncertainties associated with the use of different types of biomass of diverse characteristics and the likely impact of partial replacement of coal by biomass on the emission of CO2, SOx, NOx. Other issues of no less importance like sustained availability of biomass, transportation and storage, effect on biodiversity, etc., are left out in the study. The investigations reported in the study reflect the potential of biomass as co-fuel, and the scope of maximizing its proportion in the blend in the coal based power plants and the derived benefits.
The energy insecurity from oil and natural gas and increased CO2 emission from fossil fuels is driving societies to look for sustainable and renewable energy supply. The huge coal resources can serve ...as a potential source for fuels. Bio-energy from biomass has been recognized as renewable energy to reduce CO2 emission. Although fast pyrolysis has emerged as the most promising technology to convert organic materials to liquid fuels at shorter duration but it still faces some technical challenges in improving product yield, its quality and process energy efficiency. Microwave assisted pyrolysis of coal and biomass in the presence of microwave absorber provides distinctive environment to resolve these challenges. The microwave absorber can indirectly heat coal and biomass particles which are relatively microwave transparent and influence product yield and its quality by contributing as a catalytic precursor. The microwave heating of coal or biomass particles with microwave absorber shows efficient heating and sufficient contact of volatile or gas phase species with specific microwave absorber can improve fuel quality.
•Review of state-of-the-art fast pyrolysis oil combustion in burner applications.•Fast pyrolysis oil has been found to be suitable for industrial scale utilization.•Curves for NOx-emissions for ...air-assisted atomization burners are presented.•Quality control, combined with standards and specifications is recommended.
Fast pyrolysis bio-oils are completely different from petroleum fuels and other bio-fuels available in the market, as regards both to their physical properties and chemical composition. When the unusual properties of these bio-oils are carefully taken into account in system and burner design, their combustion without a pilot flame or support fuel is possible on an industrial scale. The aim of the paper is to review the work done on combustion of fast pyrolysis bio-oils and highlight the latest and most important findings of its combustion from laboratory fundamentals to industrial scale. The main focus of the paper is on the bio-oil burner applications.
In recent industrial scale bio-oil combustion tests, bio-oil has been found to be technically suitable for replacing heavy fuel oil in district heating. In addition, it has also been found out that limited possibilities for further lowering particulate emissions exist, since the majority of the particulates are typically incombustible matter. Curves for NOx-emissions of fast pyrolysis bio-oil combustion for air-assisted atomization burners are presented in the paper.
Current burner designs are quite sensitive to the changes in the quality of the bio-oil, which may cause problems in ignition, flame detection and flame stabilization. Therefore, in order to be able to create reliable bio-oil combustion systems that operate at high efficiency, bio-oil grades should be standardized for combustion applications. Careful quality control, combined with standards and specifications, all the way from feedstock harvesting through production to end-use is recommended in order to make sure that emission targets and limits in combustion applications are achieved. Also the cost-effectiveness of the total package is extremely important.
