The term cryogenics derives from the Greek kryos, for icy cold. The upper limit that characterizes the cryogenic region of the temperature scale is subjective. If the delimitation criterion takes into consideration practical reasons, then this upper limit can be established at a higher than usually declared value (120 K) in order to include natural gas fuel liquefaction. The cryogenics region of the temperature scale 0–120 K can be divided into sub regions according to the criteria of the cryogenic method and refrigerant (known as crycoolers) as follows: (more…)
The idea of using an absorption fluid as a refrigerant carrier derived from the drawback of VCR (vapor–compression refrigeration) s ...
Micro technology can be employed to produce miniaturized refrigeration and cryocooling systems. Although process intensificat ...
The issues of hydrogen storage run through the hydrogen production, hydrogen transport, supply and demand for end use of hydrog ...
n fabricating microscale energy systems, a number of operating conditions must first be taken into account. Foremost are the op ...
Many small-scale energy systems require effective miniaturized pumps and expanders. These devices are responsible for conveying ...
More than 48% of the raw material fiber used for paper production (chemical pulp or mechanical pulp) in the United States in 2002 was recovered or reclaimed, with recovered paper contributing 37.7% and wood residues 10.6%. The total has been more or less constant, with the percentage of recovered paper increasing and that of wood residues declining recently due to their increased use in oriented strand board and composite panels. Primary fibers are a renewable, domestic resource, much of which is currently supplied by tree plantations. Short-rotation forestry can be used to further increase the productivity of these plantations. (more…)
Most discussions of energy use in paper production and papermaking are confusing because of a failure to define exactly what is mea ...
Agricultural and forestry residues provide the largest proportion of biomass used for the production of biomas bioenergy. Some esti ...
The evidence on the environmental Kuznets curve indicates that national environmental policies differ between high-income and low-i ...
Another large source of renewable carbon supplies is waste biomass. It consists of a wide range of materials and includes munic ...
Another large source of renewable carbon supplies is waste biomass. It consists of a wide range of materials and includes munic ...
In this new century, there is considerable pressure on the top six automakers to reduce their environmental and ecological footprint calculation. The automaker that wins the race to build and sell the superior car will shape consumer preferences, thereby boosting sales and profits. The winning firm will fashion a corporate strategy that drives automobile emissions to near zero while simultaneously providing high levels of performance, safety, and comfort. (more…)
Corporate environmental strategy (CES) involves the tools, management programs, processes, and product development choices that all ...
In the pursuit of superior cars, electronic products, and computing, several leading multinational corporations began in the last q ...
Although it is significant that many of the above four imperatives are qualitative, not quantitative, such new efforts have begun t ...
This latter form of new car taxes can actually serve as an impediment to higher fuel economy to the extent that increased energ ...
There are several options that, ultimately, must be integrated when attempting to realize a change in corporate culture: the legal ...
Reductions in carbon intensity, C/E, the carbon emitted per unit of energy generated, reflect the degree to which societies decarbonize their energy sources. The long-term trend has been a shift from coal to oil to natural gas––hydrocarbons with decreasing C/H ratios emitting progressively less CO2 per joule. However, the increasing use of clean low-carbon fuels is not sustainable without somehow disposing of excess carbon because it opposes the trend in the abundance of fossil fuels, with coal resources being the most abundant followed by oil and gas. (more…)
The global cycling of carbon involves both biological and physical processes. Only the biological components are discussed here. Pl ...
The flux of carbon among terrestrial, aquatic, and atmospheric pools is at least partially controlled by photosynthetic process ...
It is of interest to examine potential sources of greenhouse gases sources or atmospheric CO2 by analysis of the global distrib ...
Climate change caused by the enhanced greenhouse effect is one of the most significant global environmental issues. Increased emiss ...
The global carbon cycle involves both biological and physical processes. Only the biological components are discussed here. Pla ...
Approximately 40% of Earth’s population is ‘‘off the grid,’’ mainly in developing countries. Wireless power transmission envisioned by Nikola Tesla a century ago is feasible today. Microwave beams can propagate power efficiently along lines-of-sight over long distances. Orbiting microwave reflectors could form the basis of a global electric grid.
An advanced technology path to electrification is the solar power satellite (SPS) proposed by Peter Glaser. Solar flux is about 10 times higher in space outside Earth’s shadow cone than the long- term average at the surface of spinning, cloudy Earth, and power from space can be beamed by microwave efficiently through cloudy skies to the surface where it is needed. (more…)
Advanced technology global electrical grids may be more promising for renewables energy. With current transmission lines, even if c ...
So you're finally tired of those exorbitant electricity bills, or, you're catching onto a "greener" way of life. Either way, solar ...
In today's tough economic times and with the increasing prices of gas and oil, finding alternative sources of energy should be ...
So-called thin-film photovoltaic devices are usually based on mixtures of elements other than silicon — most notably copper ind ...
The Home Solar Power System made its debut about two decades ago and has since flourished with the many advertisements touting ...
Air-blown circulating fluidized bed gasifiers are of interest because they produce a good quality, low calorific value (LCV) gas (4–6 MJ/Nm 3 ) and possess a very high carbon conversion efficiency while allowing high capacity, good tolerance to variations in fuel quality, and reliable operation. The high and homogeneously distributed temperatures and the use of particular bed materials, such as dolomite, favor tar cracking. Successful tar cracking can also be achieved using secondary circulating fluidized bed reactors. Also, successful tests on catalytic tar cracking have been performed, for example, by introducing nickel compounds into the gasifier. Sulfur control is made easier because of the significant reduction that can be achieved by adding limestone or dolomite to the gasifier bed. (more…)
The moisture content of the feedstock affects the gas composition and the energy balance of the process since gasification is an en ...
Thermo chemical processing of biomass yields gaseous, liquid, and solid products and offers a means of producing useful gaseous ...
A combination of legislation and technology has helped clean up many of the world’s coal-burning plants. Both developed and develop ...
Biomass Storage Biomass storage is required to ensure the continuous operation of the facility. To limit the space required for ...
Gasification is a thermo chemical process that has been exploited for more than a century for converting solid feedstocks to ga ...
The product gas can be burned in boilers to generate heat and raise steam, in internal combustion engines to generate electricity and heat at small to medium scale (from a few kilowatts to a few megawatts), and in gas turbines to generate electricity (Brayton cycle) and heat at small to large scale. In large-scale systems using gas turbines, the exhaust gas from the gas turbine can be used to raise steam in a heat recovery steam generator to generate additional electricity using a steam turbine (Rankine cycle), resulting in combined cycle operation. (more…)
Gasification is a thermo chemical process that has been exploited for more than a century for converting solid feedstocks to ga ...
The moisture content of the feedstock affects the gas composition and the energy balance of the process since gasification is an en ...
Biomass Storage Biomass storage is required to ensure the continuous operation of the facility. To limit the space required for ...
Natural gas and oil are common source energy used to give electricity. How efficient is coal if we compare to these other source of ...
Many characteristics of traditional engines make them attractive for use in power generation and propulsion technology. They tend t ...
Sir Arthur Eddington’s general address on subatomic energy at the 1930 World Power Conference in Berlin stirred the imagination of every scientist and engineer present. The challenge was clear: find a practical means of accessing, controlling, and using the enormous energy locked in the atom as predicted by Einstein’s remarkable mass–energy relation, E=mc2. On December 2, 1942, Enrico Fermi transformed Eddington’s visionary challenge into reality by producing the world’s first controlled, self-sustaining nuclear reactor, Chicago Pile 1. Six decades later, nuclear energy now produces 16% of the world’s electrical power. (more…)
Nuclear fission and fusion Research and Development continues to account for nearly half of the total spending by IEA countries, al ...
ITMA Foundation, a group of researchers formed by Javier Belzunce, José Manuel Artimez, Ana Moran and Ruben Coto, has developed the ...
Geographers researching the development of nuclear power have shifted emphasis from commercialization, cost, risk, public acceptanc ...
Because a nuclear explosion in a nuclear power plant is impossible due to the low fuel enrichment, the worst conceivable accident i ...
Nuclear power plants have many different designs and shapes. Early technology restrictions in nuclear power plants make huge ...
Transport applications tend to demand rapid start-up and instant dynamic response from fuel cell systems, so a high-temperature fuel cell is unlikely to be competitive as the main engine in applications such as cars and buses. The prime candidate for these vehicle propulsion systems is the Polymer Electrolyte Fuel Cells, which exhibits both of the above characteristics while also having very high power density. This is important as it must also occupy a similar amount of space to an internal combustion engine. Of recent interest has been the development of auxiliary power units for vehicles, in which the fuel cell meets the onboard electric load of the vehicle. Both Polymer Electrolyte Fuel Cells and ITSOFCs are under development for this application. (more…)
Fuel cells are typically classified according to type of electrolyte. While many varieties of fuel cells have been demonstrated ...
Alkaline fuel cell, often known as the Bacon fuel cell following the British inventor’ name. It has become the most created fue ...
A fuel cell is an electrochemical device that combines hydrogen with oxygen to generate electricity, heat and water to produce. ...
Polymer Electrolyte Fuel Cells have high-power density, rapid startup, and low-temperature operation (around 80 to 120 C), and ...
The fuel cell can trace its roots back to the 1800s when a Welsh-born, Oxford-educated barrister, Sir William Robert Grove, realize ...
Gasification is a thermo chemical process that has been exploited for more than a century for converting solid feedstocks to gaseous energy carriers. The first gasifier patent was issued in England at the end of the 18th century and producer gas from coal gasification was mainly used as lighting fuel throughout the 19th century. At the turn of the 20th century, the main use of producer gas, obtained essentially from coal, switched to electricity generation and automotive applications via internal combustion engines. The use of producer gas was gradually supplanted by the use of higher energy density liquid fuels and as a result confined to areas with expensive or unreliable supplies of petroleum fuels. (more…)
The product gas can be burned in boilers to generate heat and raise steam, in internal combustion engines to generate electricity a ...
Thermo chemical processing of biomass yields gaseous, liquid, and solid products and offers a means of producing useful gaseous ...
Biomass Storage Biomass storage is required to ensure the continuous operation of the facility. To limit the space required for ...
Estimation of the future technical potential of biomass as an energy source is dependent on assumptions with respect to land av ...
The moisture content of the feedstock affects the gas composition and the energy balance of the process since gasification is an en ...