CONTINUOUS LIQUID INTERFACE PRODUCTION SYSTEM.
PRINCIPLE OF CLIP TECHNOLOGY
THE TRUE ELASTOMERIC PROPERTY WHICH CANT BE ACHIEVED IN TRADITIONAL 3D PRINTING PROCESS.
CARBON 3D FOUNDER LIVE DEMONSTRATION ON TED TALK SHOW
Wednesday, 22 February 2017
Tuesday, 26 April 2016
Wednesday, 14 October 2015
Carbon dioxide in present Earth's atmosphere
Carbon dioxide in Earth's atmosphere
Carbon dioxide is an important trace gas in Earth's atmosphere currently constituting about 0.04% (400 parts per million) of the atmosphere. Despite its relatively small concentration, CO2 is a potent greenhouse gas and plays a vital role in regulating Earth's surface temperature through radiative forcing and the greenhouse effect.Reconstructions show that concentrations of CO2 in the atmosphere have varied, ranging from as high as 7,000 parts per million during the Cambrian period about 500 million years ago to as low as 180 parts per million during the Quaternary glaciation of the last two million years.
Carbon dioxide is an integral part of the carbon cycle, a biogeochemical cycle in which carbon is exchanged between the Earth's oceans, soil, rocks and biosphere. The present biosphere of Earth is dependent on atmospheric CO2 for its existence. Plants and other photoautotrophs use solar energy to synthesize carbohydrate from atmospheric carbon dioxide and water by photosynthesis. Carbohydrate derived from consumption of plants as food is the primary source of energy and carbon compounds in almost all other organisms.
The current episode of global warming is attributed primarily to increasing industrial CO2 emissions into Earth's atmosphere. The global annual mean concentration of CO2 in the atmosphere has increased markedly since the Industrial Revolution, from 280 ppm to 400 ppm as of 2015.The present concentration is the highest in the past 800,000 years and likely the highest in the past 20 million years.The increase has been caused by anthropogenic sources, particularly the burning of fossil fuels and deforestation. The daily average concentration of atmospheric CO2 at Mauna Loa first exceeded 400 ppm on 10 May 2013. It is currently rising at a rate of approximately 2 ppm/year and accelerating. An estimated 30–40% of the CO2 released by humans into the atmosphere dissolves into oceans, rivers and lakes. which contributes to ocean acidification.
Current concentration
Over the past 400,000 years, CO2 concentrations have shown several cycles of variation from about 180 parts per million during the deep glaciations of the Holocene and Pleistocene to 280 parts permillion during the interglacial periods. Following the start of the Industrial Revolution, atmospheric CO2 concentration has increased to 400 parts per million and continues to increase. This has caused the phenomenon of global warming which is mostly attributed to human CO2 emissions.
The global average concentration of CO2 in Earth's atmosphere is currently about 0.04% or 400 parts per million by volume (ppm)There is an annual fluctuation of about 3–9 ppm which is negatively correlated with the Northern Hemisphere's growing season. The Northern Hemisphere dominates the annual cycle of CO2 concentration because it has much greater land area and plant biomass than the Southern Hemisphere. Concentrations reach a peak in May as the Northern Hemisphere spring greenup begins and decline to a minimum in October when the quantity of biomass undergoing photosynthesis is greatest.
Because global warming is attributed primarily to increasing atmospheric CO2 concentrations, scientists closely monitor atmospheric CO2 concentrations and their impact on the present-day biosphere. At the scientific recording station in Mauna Loa, the concentration reached 400 ppm for the first time in May 2013, although this concentration had already been reached in the Arctic in June 2012. Sir Brian Hoskins of the Royal Society said that the 400 ppm milestone should "jolt governments into action."The National Geographic noted that the concentration of carbon dioxide in the atmosphere is this high "for the first time in 55 years of measurement—and probably more than 3 million years of Earth history," and according to the global monitoring director at the National Oceanic and Atmospheric Administration's Earth System Research Lab, "it's just a reminder to everybody that we haven't fixed this, and we're still in trouble." The current concentration may be the highest in 20 million years.
Past concentration
Carbon dioxide concentrations have varied widely over the Earth's 4.7 billion year history. Carbon dioxide is believed to have been present in Earth's first atmosphere, shortly after Earth's formation. Earth's second atmosphere emerged after the lighter gases, hydrogen and helium, escaped to space or like oxygen were bound up in molecules and is thought to have consisted largely of nitrogen, carbon dioxide and inert gases produced by outgassing from volcanism, supplemented by gases produced during the late heavy bombardment of Earth by asteroids. The production of free oxygen by cyanobacterial photosynthesis eventually led to the oxygen catastrophe that ended Earth's second atmosphere and brought about the Earth's third atmosphere (the modern atmosphere) 2.4 billion years before the present. Carbon dioxide concentrations dropped from 7,000 parts per million during the Cambrian period about 500 million years ago to as low as 180 parts per million during the Quaternary glaciation of the last two million years.
Drivers of ancient-Earth carbon dioxide concentration
On long timescales, atmospheric CO2 concentration is determined by the balance among geochemical processes including organic carbon burial in sediments, silicate rock weathering, and volcanism. The net effect of slight imbalances in the carbon cycle over tens to hundreds of millions of years has been to reduce atmospheric CO2. On a timescale of billions of years, such downward trend appears bound to continue indefinitely as occasional massive historical releases of buried carbon due to volcanism will become less frequent (as earth mantle cooling and progressive exhaustion of internal radioactive heat proceeds further). The rates of these processes are extremely slow; hence they are of no relevance to the atmospheric CO2 concentration over the next hundreds or thousands of years.
In billion-year timescales, it is predicted that plant, and therefore animal, life on land will die off altogether, since by that time most of the remaining carbon in the atmosphere will be sequestered underground, and natural releases of CO2 by radioactivity-driven tectonic activity will have continued to slow down.[25] The loss of plant life would also result in the eventual loss of oxygen. Some microbes are capable of photosynthesis at concentrations of CO2 of a few parts per million and so the last life forms would probably disappear finally due to the rising temperatures and loss of the atmosphere when the sun becomes a red giant some four-billion years from now
Measuring ancient-Earth carbon dioxide concentration
The most direct method for measuring atmospheric carbon dioxide concentrations for periods before instrumental sampling is to measure bubbles of air (fluid or gas inclusions) trapped in the Antarctic or Greenland ice sheets. The most widely accepted of such studies come from a variety of Antarctic cores and indicate that atmospheric CO2 concentrations were about 260–280 ppmv immediately before industrial emissions began and did not vary much from this level during the preceding 10,000 years.[27] The longest ice core record comes from East Antarctica, where ice has been sampled to an age of 800,000 years.[5] During this time, the atmospheric carbon dioxide concentration has varied between 180–210 ppm during ice ages, increasing to 280–300 ppm during warmer interglacials.[28][29] The beginning of human agriculture during the current Holocene epoch may have been strongly connected to the atmospheric CO2 increase after the last ice age ended, a fertilization effect raising plant biomass growth and reducing stomatal conductance requirements for CO2 intake, consequently reducing transpiration water losses and increasing water usage efficiency.[30]
Various proxy measurements have been used to attempt to determine atmospheric carbon dioxide concentrations millions of years in the past. These include boron and carbon isotope ratios in certain types of marine sediments, and the number of stomata observed on fossil plant leaves. While these measurements give much less precise estimates of carbon dioxide concentration than ice cores, there is evidence for very high CO2 volume concentrations between 200 and 150 million years ago of over 3,000 ppm, and between 600 and 400 million years ago of over 6,000 ppm.[6] In more recent times, atmospheric CO2 concentration continued to fall after about 60 million years ago. About 34 million years ago, the time of the Eocene–Oligocene extinction event and when the Antarctic ice sheet started to take its current form, CO2 is found to have been about 760 ppm,[31] and there is geochemical evidence that concentrations were less than 300 ppm by about 20 million years ago. Carbon dioxide decrease, with a tipping point of 600 ppm, was the primary agent forcing Antarctic glaciation.[32] Low CO2 concentrations may have been the stimulus that favored the evolution of C4 plants, which increased greatly in abundance between 7 and 5 million years ago.[33]
Ancient-Earth climate reconstruction is a vibrant field with numerous studies and reconstructions that sometimes reinforce one another and sometimes disagree with each other. Academically, one study disputed the claim of stable CO2 concentrations during the present interglacial of the last 10,000 years. Based on an analysis of fossil leaves, Wagner et al.[34] argued that CO2 levels during the last 7,000–10,000 year period were significantly higher (~300 ppm) and contained substantial variations that may be correlated to climate variations. Others have disputed such claims, suggesting they are more likely to reflect calibration problems than actual changes in CO2.[35] Relevant to this dispute is the observation that Greenland ice cores often report higher and more variable CO2 values than similar measurements in Antarctica. However, the groups responsible for such measurements (e.g. H. J Smith et al.[36]) believe the variations in Greenland cores result from in situ decomposition of calcium carbonate dust found in the ice. When dust concentrations in Greenland cores are low, as they nearly always are in Antarctic cores, the researchers report good agreement between measurements of Antarctic and Greenland CO2 concentrations.
Atmospheric carbon dioxide and the greenhouse effect
Earth’s natural greenhouse effect makes life as we know it possible and carbon dioxide plays a significant role in providing for the relatively warm temperature that the planet enjoys. The greenhouse effect is a process by which thermal radiation from a planetary atmosphere warms the planet's surface beyond what it would be in the absence of its atmosphere.[37][38]
Carbon dioxide is believed to have played an important effect in regulating Earth's temperature throughout its 4.7 billion year history. Early in the Earth's life, scientists have found evidence of liquid water indicating a warm world even though the Sun's output is believed to have only been 70% of what it is today. It has been suggested by scientists that higher carbon dioxide concentrations in the early Earth atmosphere might help explain this faint young sun paradox. When Earth first formed, Earth's atmosphere may have contained more greenhouse gases and CO2 concentrations may have been higher, with estimated partial pressure as large as 1,000 kPa (10 bar), because there was no bacterial photosynthesis to reduce the gas to carbon compounds and oxygen. Methane, a very active greenhouse gas which reacts with oxygen to produce CO2 and water vapor, may have been more prevalent as well, with a mixing ratio of 10−4 (100 parts per million by volume).[39][40]
Today's contribution to the greenhouse effect on Earth by the four major gases are:[41][42]
Atmospheric carbon dioxide and the carbon cycle
Atmospheric carbon dioxide plays an integral role in the Earth's carbon cycle whereby carbon dioxide is removed from the atmosphere by some natural processes and added back to the atmosphere by other natural processes. There are two broad carbon cycles on earth: the fast carbon cycle and the slow carbon cycle. The fast carbon cycle refers to movements of carbon between the environment and living things in the biosphere whereas the slow carbon cycle involves the movement of carbon between the atmosphere, oceans, soil, rocks and volcanism. Both carbon cycles are intrinsically interconnected and atmospheric gaseous carbon dioxide facilitates the carbon cycle.
Natural sources of atmospheric carbon dioxide include volcanic outgassing, the combustion of organic matter, wildfires and the respiration processes of living aerobic organisms. Man-made sources of carbon dioxide include the burning of fossil fuels for heating, power generation and transport, as well as some industrial processes such as cement making. It is also produced by various microorganisms from fermentation and cellular respiration. Plants, algae and cyanobacteria convert carbon dioxide to carbohydrates by a process called photosynthesis. They gain the energy needed for this reaction from absorption of sunlight by chlorophyll and other pigments. Oxygen, produced as a by-product of photosynthesis, is released into the atmosphere and subsequently used for respiration by heterotrophic organisms and other plants, forming a cycle.
Most sources of CO2 emissions are natural, and are balanced to various degrees by natural CO2 sinks. For example, the natural decay of organic material in forests and grasslands and the action of forest fires results in the release of about 439 gigatonnes of carbon dioxide every year, while new growth entirely counteracts this effect, absorbing 450 gigatonnes per year.[47] Although the initial carbon dioxide in the atmosphere of the young Earth was produced by volcanic activity, modern volcanic activity releases only 130 to 230 megatonnes of carbon dioxide each year.[48] These natural sources are nearly balanced by natural sinks, physical and biological processes which remove carbon dioxide from the atmosphere. For example, some is directly removed from the atmosphere by land plants for photosynthesis and it is soluble in water forming carbonic acid. There is a large natural flux of CO2 into and out of the biosphere and oceans.[49] In the pre-industrial era these fluxes were largely in balance. Currently about 57% of human-emitted CO2 is removed by the biosphere and oceans.[50][51] From pre-industrial era to 2010, the terrestrial biosphere represented a net source of atmospheric CO2 prior to 1940, switching subsequently to a net sink.[51] The ratio of the increase in atmospheric CO2 to emitted CO2 is known as the airborne fraction (Keeling et al., 1995); this varies for short-term averages and is typically about 45% over longer (5 year) periods.[51] Estimated carbon in global terrestrial vegetation increased from approximately 740 billion tons in 1910 to 780 billion tons in 1990.
Atmospheric carbon dioxide and photosynthesis
Carbon dioxide in the Earth's atmosphere is essential to life and to the present planetary biosphere. Over the course of Earth's geologic history CO2 concentrations have played a role in biological evolution. The first photosynthetic organisms probably evolved early in the evolutionary history of life and most likely used reducing agents such as hydrogen or hydrogen sulfide as sources of electrons, rather than water.[53] Cyanobacteria appeared later, and the excess oxygen they produced contributed to the oxygen catastrophe,[54] which rendered the evolution of complex life possible. In recent geologic times, low CO2 concentrations below 600 parts per million might have been the stimulus that favored the evolution of C4 plants which increased greatly in abundance between 7 and 5 million years ago over plants that use the less efficient C3 metabolic pathway.[33] At current atmospheric pressures photosynthesis shuts down when atmospheric CO2 concentrations fall below 150 ppm and 200 ppm although some microbes can extract carbon from the air at much lower concentrations.[55][56] Today, the average rate of energy capture by photosynthesis globally is approximately 130 terawatts,[57][58][59] which is about six times larger than the current power consumption of human civilization.[60] Photosynthetic organisms also convert around 100–115 thousand million metric tonnes of carbon into biomass per year.[61][62]
Photosynthetic organisms are photoautotrophs, which means that they are able to synthesize food directly from CO2 and water using energy from light. However, not all organisms that use light as a source of energy carry out photosynthesis, since photoheterotrophs use organic compounds, rather than CO2, as a source of carbon.[63] In plants, algae and cyanobacteria, photosynthesis releases oxygen. This is called oxygenic photosynthesis. Although there are some differences between oxygenic photosynthesis in plants, algae, and cyanobacteria, the overall process is quite similar in these organisms. However, there are some types of bacteria that carry out anoxygenic photosynthesis, which consumes CO2 but does not release oxygen.
Carbon dioxide is converted into sugars in a process called carbon fixation. Carbon fixation is an endothermic redox reaction, so photosynthesis needs to supply both a source of energy to drive this process, and the electrons needed to convert CO2 into a carbohydrate. This addition of the electrons is a reduction reaction. In general outline and in effect, photosynthesis is the opposite of cellular respiration, in which glucose and other compounds are oxidized to produce CO2 and water, and to release exothermic chemical energy to drive the organism's metabolism. However, the two processes take place through a different sequence of chemical reactions and in different cellular compartments.
Most organisms that utilize photosynthesis to produce oxygen use visible light to do so, although at least three use shortwave infrared or, more specifically, far-red radiation
Atmospheric carbon dioxide and the oceanic carbon cycle
The Earth's oceans contain a large amount of CO2 in the form of bicarbonate and carbonate ions — much more than the amount in the atmosphere. The bicarbonate is produced in reactions between rock, water, and carbon dioxide. One example is the dissolution of calcium carbonate:
Ultimately, most of the CO2 emitted by human activities will dissolve in the ocean;[65] however, the rate at which the ocean will take it up in the future is less certain. Even if equilibrium is reached, including dissolution of carbonate minerals, the increased concentration of bicarbonate and decreased or unchanged concentration of carbonate ion will give rise to a higher concentration of un-ionized carbonic acid and dissolved CO2. This, along with higher temperatures, would mean a higher equilibrium concentration of CO2 in the air.
Atmospheric carbon dioxide and global warming
The recent phenomenon of global warming has been attributed primarily to increasing atmospheric carbon dioxide concentrations in Earth's atmosphere. While CO2 absorption and release is always happening as a result of natural processes, the recent rise in CO2 levels in the atmosphere is known to be mainly due to human activity.[68] Researchers know this both by calculating the amount released based on various national statistics, and by examining the ratio of various carbon isotopes in the atmosphere,[68] as the burning of long-buried fossil fuels releases CO2 containing carbon of different isotopic ratios to those of living plants, enabling them to distinguish between natural and human-caused contributions to CO2 concentration.
Burning fossil fuels such as coal and petroleum is the leading cause of increased anthropogenic CO2; deforestation is the second major cause. In 2010, 9.14 gigatonnes of carbon (33.5 gigatonnes of CO2) were released from fossil fuels and cement production worldwide, compared to 6.15 gigatonnes in 1990.[69] In addition, land use change contributed 0.87 gigatonnes in 2010, compared to 1.45 gigatonnes in 1990.[69] In 1997, human-caused Indonesian peat fires were estimated to have released between 13% and 40% of the average carbon emissions caused by the burning of fossil fuels around the world in a single year.[70][71][72] In the period 1751 to 1900, about 12 gigatonnes of carbon were released as carbon dioxide to the atmosphere from burning of fossil fuels, whereas from 1901 to 2008 the figure was about 334 gigatonnes.[73]
This addition, about 3% of annual natural emissions, as of 1997[update], is sufficient to exceed the balancing effect of sinks.[74] As a result, carbon dioxide has gradually accumulated in the atmosphere, and as of 2013[update], its concentration is almost 43% above pre-industrial levels.[8][17] Various techniques have been proposed for removing excess carbon dioxide from the atmosphere in carbon dioxide sinks.
Carbon dioxide has unique long-term effects on climate change that are largely "irreversible" for one thousand years after emissions stop (zero further emissions) even though carbon dioxide tends toward equilibrium with the ocean on a scale of 100 years. The greenhouse gases methane and nitrous oxide do not persist over time in the same way as carbon dioxide. Even if human carbon dioxide emissions were to completely cease, atmospheric temperatures are not expected to decrease significantly in the short term.
Carbon dioxide is an important trace gas in Earth's atmosphere currently constituting about 0.04% (400 parts per million) of the atmosphere. Despite its relatively small concentration, CO2 is a potent greenhouse gas and plays a vital role in regulating Earth's surface temperature through radiative forcing and the greenhouse effect.Reconstructions show that concentrations of CO2 in the atmosphere have varied, ranging from as high as 7,000 parts per million during the Cambrian period about 500 million years ago to as low as 180 parts per million during the Quaternary glaciation of the last two million years.
Carbon dioxide is an integral part of the carbon cycle, a biogeochemical cycle in which carbon is exchanged between the Earth's oceans, soil, rocks and biosphere. The present biosphere of Earth is dependent on atmospheric CO2 for its existence. Plants and other photoautotrophs use solar energy to synthesize carbohydrate from atmospheric carbon dioxide and water by photosynthesis. Carbohydrate derived from consumption of plants as food is the primary source of energy and carbon compounds in almost all other organisms.
The current episode of global warming is attributed primarily to increasing industrial CO2 emissions into Earth's atmosphere. The global annual mean concentration of CO2 in the atmosphere has increased markedly since the Industrial Revolution, from 280 ppm to 400 ppm as of 2015.The present concentration is the highest in the past 800,000 years and likely the highest in the past 20 million years.The increase has been caused by anthropogenic sources, particularly the burning of fossil fuels and deforestation. The daily average concentration of atmospheric CO2 at Mauna Loa first exceeded 400 ppm on 10 May 2013. It is currently rising at a rate of approximately 2 ppm/year and accelerating. An estimated 30–40% of the CO2 released by humans into the atmosphere dissolves into oceans, rivers and lakes. which contributes to ocean acidification.
Current concentration
Over the past 400,000 years, CO2 concentrations have shown several cycles of variation from about 180 parts per million during the deep glaciations of the Holocene and Pleistocene to 280 parts permillion during the interglacial periods. Following the start of the Industrial Revolution, atmospheric CO2 concentration has increased to 400 parts per million and continues to increase. This has caused the phenomenon of global warming which is mostly attributed to human CO2 emissions.
The global average concentration of CO2 in Earth's atmosphere is currently about 0.04% or 400 parts per million by volume (ppm)There is an annual fluctuation of about 3–9 ppm which is negatively correlated with the Northern Hemisphere's growing season. The Northern Hemisphere dominates the annual cycle of CO2 concentration because it has much greater land area and plant biomass than the Southern Hemisphere. Concentrations reach a peak in May as the Northern Hemisphere spring greenup begins and decline to a minimum in October when the quantity of biomass undergoing photosynthesis is greatest.
Because global warming is attributed primarily to increasing atmospheric CO2 concentrations, scientists closely monitor atmospheric CO2 concentrations and their impact on the present-day biosphere. At the scientific recording station in Mauna Loa, the concentration reached 400 ppm for the first time in May 2013, although this concentration had already been reached in the Arctic in June 2012. Sir Brian Hoskins of the Royal Society said that the 400 ppm milestone should "jolt governments into action."The National Geographic noted that the concentration of carbon dioxide in the atmosphere is this high "for the first time in 55 years of measurement—and probably more than 3 million years of Earth history," and according to the global monitoring director at the National Oceanic and Atmospheric Administration's Earth System Research Lab, "it's just a reminder to everybody that we haven't fixed this, and we're still in trouble." The current concentration may be the highest in 20 million years.
Past concentration
Carbon dioxide concentrations have varied widely over the Earth's 4.7 billion year history. Carbon dioxide is believed to have been present in Earth's first atmosphere, shortly after Earth's formation. Earth's second atmosphere emerged after the lighter gases, hydrogen and helium, escaped to space or like oxygen were bound up in molecules and is thought to have consisted largely of nitrogen, carbon dioxide and inert gases produced by outgassing from volcanism, supplemented by gases produced during the late heavy bombardment of Earth by asteroids. The production of free oxygen by cyanobacterial photosynthesis eventually led to the oxygen catastrophe that ended Earth's second atmosphere and brought about the Earth's third atmosphere (the modern atmosphere) 2.4 billion years before the present. Carbon dioxide concentrations dropped from 7,000 parts per million during the Cambrian period about 500 million years ago to as low as 180 parts per million during the Quaternary glaciation of the last two million years.
Drivers of ancient-Earth carbon dioxide concentration
On long timescales, atmospheric CO2 concentration is determined by the balance among geochemical processes including organic carbon burial in sediments, silicate rock weathering, and volcanism. The net effect of slight imbalances in the carbon cycle over tens to hundreds of millions of years has been to reduce atmospheric CO2. On a timescale of billions of years, such downward trend appears bound to continue indefinitely as occasional massive historical releases of buried carbon due to volcanism will become less frequent (as earth mantle cooling and progressive exhaustion of internal radioactive heat proceeds further). The rates of these processes are extremely slow; hence they are of no relevance to the atmospheric CO2 concentration over the next hundreds or thousands of years.
In billion-year timescales, it is predicted that plant, and therefore animal, life on land will die off altogether, since by that time most of the remaining carbon in the atmosphere will be sequestered underground, and natural releases of CO2 by radioactivity-driven tectonic activity will have continued to slow down.[25] The loss of plant life would also result in the eventual loss of oxygen. Some microbes are capable of photosynthesis at concentrations of CO2 of a few parts per million and so the last life forms would probably disappear finally due to the rising temperatures and loss of the atmosphere when the sun becomes a red giant some four-billion years from now
Measuring ancient-Earth carbon dioxide concentration
The most direct method for measuring atmospheric carbon dioxide concentrations for periods before instrumental sampling is to measure bubbles of air (fluid or gas inclusions) trapped in the Antarctic or Greenland ice sheets. The most widely accepted of such studies come from a variety of Antarctic cores and indicate that atmospheric CO2 concentrations were about 260–280 ppmv immediately before industrial emissions began and did not vary much from this level during the preceding 10,000 years.[27] The longest ice core record comes from East Antarctica, where ice has been sampled to an age of 800,000 years.[5] During this time, the atmospheric carbon dioxide concentration has varied between 180–210 ppm during ice ages, increasing to 280–300 ppm during warmer interglacials.[28][29] The beginning of human agriculture during the current Holocene epoch may have been strongly connected to the atmospheric CO2 increase after the last ice age ended, a fertilization effect raising plant biomass growth and reducing stomatal conductance requirements for CO2 intake, consequently reducing transpiration water losses and increasing water usage efficiency.[30]
Various proxy measurements have been used to attempt to determine atmospheric carbon dioxide concentrations millions of years in the past. These include boron and carbon isotope ratios in certain types of marine sediments, and the number of stomata observed on fossil plant leaves. While these measurements give much less precise estimates of carbon dioxide concentration than ice cores, there is evidence for very high CO2 volume concentrations between 200 and 150 million years ago of over 3,000 ppm, and between 600 and 400 million years ago of over 6,000 ppm.[6] In more recent times, atmospheric CO2 concentration continued to fall after about 60 million years ago. About 34 million years ago, the time of the Eocene–Oligocene extinction event and when the Antarctic ice sheet started to take its current form, CO2 is found to have been about 760 ppm,[31] and there is geochemical evidence that concentrations were less than 300 ppm by about 20 million years ago. Carbon dioxide decrease, with a tipping point of 600 ppm, was the primary agent forcing Antarctic glaciation.[32] Low CO2 concentrations may have been the stimulus that favored the evolution of C4 plants, which increased greatly in abundance between 7 and 5 million years ago.[33]
Ancient-Earth climate reconstruction is a vibrant field with numerous studies and reconstructions that sometimes reinforce one another and sometimes disagree with each other. Academically, one study disputed the claim of stable CO2 concentrations during the present interglacial of the last 10,000 years. Based on an analysis of fossil leaves, Wagner et al.[34] argued that CO2 levels during the last 7,000–10,000 year period were significantly higher (~300 ppm) and contained substantial variations that may be correlated to climate variations. Others have disputed such claims, suggesting they are more likely to reflect calibration problems than actual changes in CO2.[35] Relevant to this dispute is the observation that Greenland ice cores often report higher and more variable CO2 values than similar measurements in Antarctica. However, the groups responsible for such measurements (e.g. H. J Smith et al.[36]) believe the variations in Greenland cores result from in situ decomposition of calcium carbonate dust found in the ice. When dust concentrations in Greenland cores are low, as they nearly always are in Antarctic cores, the researchers report good agreement between measurements of Antarctic and Greenland CO2 concentrations.
Atmospheric carbon dioxide and the greenhouse effect
Earth’s natural greenhouse effect makes life as we know it possible and carbon dioxide plays a significant role in providing for the relatively warm temperature that the planet enjoys. The greenhouse effect is a process by which thermal radiation from a planetary atmosphere warms the planet's surface beyond what it would be in the absence of its atmosphere.[37][38]
Carbon dioxide is believed to have played an important effect in regulating Earth's temperature throughout its 4.7 billion year history. Early in the Earth's life, scientists have found evidence of liquid water indicating a warm world even though the Sun's output is believed to have only been 70% of what it is today. It has been suggested by scientists that higher carbon dioxide concentrations in the early Earth atmosphere might help explain this faint young sun paradox. When Earth first formed, Earth's atmosphere may have contained more greenhouse gases and CO2 concentrations may have been higher, with estimated partial pressure as large as 1,000 kPa (10 bar), because there was no bacterial photosynthesis to reduce the gas to carbon compounds and oxygen. Methane, a very active greenhouse gas which reacts with oxygen to produce CO2 and water vapor, may have been more prevalent as well, with a mixing ratio of 10−4 (100 parts per million by volume).[39][40]
Today's contribution to the greenhouse effect on Earth by the four major gases are:[41][42]
- water vapor, 36–70%
- carbon dioxide, 9–26%
- methane, 4–9%
- ozone, 3–7%
Atmospheric carbon dioxide and the carbon cycle
Atmospheric carbon dioxide plays an integral role in the Earth's carbon cycle whereby carbon dioxide is removed from the atmosphere by some natural processes and added back to the atmosphere by other natural processes. There are two broad carbon cycles on earth: the fast carbon cycle and the slow carbon cycle. The fast carbon cycle refers to movements of carbon between the environment and living things in the biosphere whereas the slow carbon cycle involves the movement of carbon between the atmosphere, oceans, soil, rocks and volcanism. Both carbon cycles are intrinsically interconnected and atmospheric gaseous carbon dioxide facilitates the carbon cycle.
Natural sources of atmospheric carbon dioxide include volcanic outgassing, the combustion of organic matter, wildfires and the respiration processes of living aerobic organisms. Man-made sources of carbon dioxide include the burning of fossil fuels for heating, power generation and transport, as well as some industrial processes such as cement making. It is also produced by various microorganisms from fermentation and cellular respiration. Plants, algae and cyanobacteria convert carbon dioxide to carbohydrates by a process called photosynthesis. They gain the energy needed for this reaction from absorption of sunlight by chlorophyll and other pigments. Oxygen, produced as a by-product of photosynthesis, is released into the atmosphere and subsequently used for respiration by heterotrophic organisms and other plants, forming a cycle.
Most sources of CO2 emissions are natural, and are balanced to various degrees by natural CO2 sinks. For example, the natural decay of organic material in forests and grasslands and the action of forest fires results in the release of about 439 gigatonnes of carbon dioxide every year, while new growth entirely counteracts this effect, absorbing 450 gigatonnes per year.[47] Although the initial carbon dioxide in the atmosphere of the young Earth was produced by volcanic activity, modern volcanic activity releases only 130 to 230 megatonnes of carbon dioxide each year.[48] These natural sources are nearly balanced by natural sinks, physical and biological processes which remove carbon dioxide from the atmosphere. For example, some is directly removed from the atmosphere by land plants for photosynthesis and it is soluble in water forming carbonic acid. There is a large natural flux of CO2 into and out of the biosphere and oceans.[49] In the pre-industrial era these fluxes were largely in balance. Currently about 57% of human-emitted CO2 is removed by the biosphere and oceans.[50][51] From pre-industrial era to 2010, the terrestrial biosphere represented a net source of atmospheric CO2 prior to 1940, switching subsequently to a net sink.[51] The ratio of the increase in atmospheric CO2 to emitted CO2 is known as the airborne fraction (Keeling et al., 1995); this varies for short-term averages and is typically about 45% over longer (5 year) periods.[51] Estimated carbon in global terrestrial vegetation increased from approximately 740 billion tons in 1910 to 780 billion tons in 1990.
Atmospheric carbon dioxide and photosynthesis
Carbon dioxide in the Earth's atmosphere is essential to life and to the present planetary biosphere. Over the course of Earth's geologic history CO2 concentrations have played a role in biological evolution. The first photosynthetic organisms probably evolved early in the evolutionary history of life and most likely used reducing agents such as hydrogen or hydrogen sulfide as sources of electrons, rather than water.[53] Cyanobacteria appeared later, and the excess oxygen they produced contributed to the oxygen catastrophe,[54] which rendered the evolution of complex life possible. In recent geologic times, low CO2 concentrations below 600 parts per million might have been the stimulus that favored the evolution of C4 plants which increased greatly in abundance between 7 and 5 million years ago over plants that use the less efficient C3 metabolic pathway.[33] At current atmospheric pressures photosynthesis shuts down when atmospheric CO2 concentrations fall below 150 ppm and 200 ppm although some microbes can extract carbon from the air at much lower concentrations.[55][56] Today, the average rate of energy capture by photosynthesis globally is approximately 130 terawatts,[57][58][59] which is about six times larger than the current power consumption of human civilization.[60] Photosynthetic organisms also convert around 100–115 thousand million metric tonnes of carbon into biomass per year.[61][62]
Photosynthetic organisms are photoautotrophs, which means that they are able to synthesize food directly from CO2 and water using energy from light. However, not all organisms that use light as a source of energy carry out photosynthesis, since photoheterotrophs use organic compounds, rather than CO2, as a source of carbon.[63] In plants, algae and cyanobacteria, photosynthesis releases oxygen. This is called oxygenic photosynthesis. Although there are some differences between oxygenic photosynthesis in plants, algae, and cyanobacteria, the overall process is quite similar in these organisms. However, there are some types of bacteria that carry out anoxygenic photosynthesis, which consumes CO2 but does not release oxygen.
Carbon dioxide is converted into sugars in a process called carbon fixation. Carbon fixation is an endothermic redox reaction, so photosynthesis needs to supply both a source of energy to drive this process, and the electrons needed to convert CO2 into a carbohydrate. This addition of the electrons is a reduction reaction. In general outline and in effect, photosynthesis is the opposite of cellular respiration, in which glucose and other compounds are oxidized to produce CO2 and water, and to release exothermic chemical energy to drive the organism's metabolism. However, the two processes take place through a different sequence of chemical reactions and in different cellular compartments.
Most organisms that utilize photosynthesis to produce oxygen use visible light to do so, although at least three use shortwave infrared or, more specifically, far-red radiation
Atmospheric carbon dioxide and the oceanic carbon cycle
The Earth's oceans contain a large amount of CO2 in the form of bicarbonate and carbonate ions — much more than the amount in the atmosphere. The bicarbonate is produced in reactions between rock, water, and carbon dioxide. One example is the dissolution of calcium carbonate:
- CaCO
3 + CO2 + H
2O ⇌ Ca2+ + 2 HCO−
3
Ultimately, most of the CO2 emitted by human activities will dissolve in the ocean;[65] however, the rate at which the ocean will take it up in the future is less certain. Even if equilibrium is reached, including dissolution of carbonate minerals, the increased concentration of bicarbonate and decreased or unchanged concentration of carbonate ion will give rise to a higher concentration of un-ionized carbonic acid and dissolved CO2. This, along with higher temperatures, would mean a higher equilibrium concentration of CO2 in the air.
Atmospheric carbon dioxide and global warming
The recent phenomenon of global warming has been attributed primarily to increasing atmospheric carbon dioxide concentrations in Earth's atmosphere. While CO2 absorption and release is always happening as a result of natural processes, the recent rise in CO2 levels in the atmosphere is known to be mainly due to human activity.[68] Researchers know this both by calculating the amount released based on various national statistics, and by examining the ratio of various carbon isotopes in the atmosphere,[68] as the burning of long-buried fossil fuels releases CO2 containing carbon of different isotopic ratios to those of living plants, enabling them to distinguish between natural and human-caused contributions to CO2 concentration.
Burning fossil fuels such as coal and petroleum is the leading cause of increased anthropogenic CO2; deforestation is the second major cause. In 2010, 9.14 gigatonnes of carbon (33.5 gigatonnes of CO2) were released from fossil fuels and cement production worldwide, compared to 6.15 gigatonnes in 1990.[69] In addition, land use change contributed 0.87 gigatonnes in 2010, compared to 1.45 gigatonnes in 1990.[69] In 1997, human-caused Indonesian peat fires were estimated to have released between 13% and 40% of the average carbon emissions caused by the burning of fossil fuels around the world in a single year.[70][71][72] In the period 1751 to 1900, about 12 gigatonnes of carbon were released as carbon dioxide to the atmosphere from burning of fossil fuels, whereas from 1901 to 2008 the figure was about 334 gigatonnes.[73]
This addition, about 3% of annual natural emissions, as of 1997[update], is sufficient to exceed the balancing effect of sinks.[74] As a result, carbon dioxide has gradually accumulated in the atmosphere, and as of 2013[update], its concentration is almost 43% above pre-industrial levels.[8][17] Various techniques have been proposed for removing excess carbon dioxide from the atmosphere in carbon dioxide sinks.
Carbon dioxide has unique long-term effects on climate change that are largely "irreversible" for one thousand years after emissions stop (zero further emissions) even though carbon dioxide tends toward equilibrium with the ocean on a scale of 100 years. The greenhouse gases methane and nitrous oxide do not persist over time in the same way as carbon dioxide. Even if human carbon dioxide emissions were to completely cease, atmospheric temperatures are not expected to decrease significantly in the short term.
Saturday, 3 October 2015
“ADVANCED CARBON MANAGEMENT TECHNIQUES”
->Carbon Dioxide Emission:
“24
billion tons per year”
To stop that we have some advanced techniques those are discussed below--->
(or )carbon
capture and sequestration) is the process of capturing waste carbon (CO2) from large point sources, such
as fossil fuel power plants, transporting it to a storage site, and depositing it where
it will not enter the atmosphere, normally an underground geological formation. The aim is to prevent the release of large quantities of CO2 into the atmosphere (from
fossil fuel use in power generation and other industries). It is a potential
means of mitigating the
contribution of fossil fuel emissions to global warming[1] and ocean acidification.[2] Although CO2 has been injected into
geological formations for several decades for various purposes, including enhanced oil recovery, the long term storage of CO2 is a relatively new
concept. The first commercial example was Weyburn in 2000.[3] Other examples include SaskPower's Boundary Dam and Mississippi Power'sKemper Project. 'CCS' can
also be used to describe the scrubbing of CO2 from ambient air as a engineering technique. An integrated pilot-scale CCS power plant was to begin
operating in September 2008 in the eastern German power plant Schwarze Pumpe run by utility Vattenfall, in the hope of answering questions about
technological feasibility and economic efficiency. CCS applied to a modern
conventional power plant could reduce CO2 emissions to the atmosphere by
approximately 80–90% compared to a plant without CCS.[4] The IPCC estimates that the economic potential of
CCS could be between 10% and 55% of the total carbon mitigation effort until
year 2100.[4]
Capture
·
In post combustion capture,
the
CO2 is
removed after combustion of the fossil fuel — this is the scheme that
would be applied to fossil-fuel burning power plants. Here, carbon dioxide is
captured from flue
gases at power stations or
other large point sources. The technology is well understood and is currently
used in other industrial applications, although not at the same scale as might
be required in a commercial scale power station.
· pre-combustion
Sequestration
Tyre pyrolysis
GASIFICATION.
Gasification:
Fluidized bed reactor
Waste disposal
Heat
Electricity
Combined heat and power
Transport fuel
Renewable energy and fuels
->Carbon Dioxide Emission:
To stop that we have some advanced techniques those are discussed below--->
1)Carbon capture and storage:-
Capturing and compressing CO2 may increase the fuel needs of a coal-fired
CCS plant by 25–40%.[4] These and other system costs are estimated
to increase the cost of the energy produced by 21–91% for purpose built plants.[4]Applying
the technology to existing plants would be more expensive especially if they
are far from a sequestration site. Recent industry reports suggest that with
successful research, development and deployment (RD&D), sequestered
coal-based electricity generation in 2025 may cost less than unsequestered
coal-based electricity generation today.[5]
Storage of the CO2 is envisaged either in deep geological
formations, or in the form of mineral carbonates. Deep
ocean storage is no longer considered feasible because it greatly increases the
problem of ocean acidification.[6] Geological formations are currently
considered the most promising sequestration sites. The National Energy Technology
Laboratory (NETL)
reported that North America has enough storage capacity for more than 900 years
worth of carbon dioxide at current production rates.[7] A general problem is that long term
predictions about submarine or underground storage security are very difficult
and uncertain, and there is still the risk that CO2 might leak into the atmosphere.[8]
Capture
Capturing CO2 is probably most effective at point
sources, such as large fossil fuel or biomass energy facilities, industries
with major CO2 emissions, natural gas processing, synthetic fuel plants and
fossil fuel-based hydrogen production plants.
Extraction (recovery) from air is possible, but not very practical. The CO2 concentration drops rapidly moving away
from the point source. The lower concentration increases the amount of mass
flow that must be processed (per tonne of carbon dioxide extracted).[9]
Concentrated CO2 from the combustion of coal in oxygen is relatively pure, and could be directly
processed. Impurities in CO2 streams could have a significant effect on
their phase behaviour and could pose a significant threat of increased corrosion
of pipeline and well materials.[10] In instances where CO2 impurities exist and especially with air
capture, a scrubbing process
would be needed.[11]
Organisms that produce ethanol by fermentation generate
cool, essentially pure CO2 that can be pumped underground.[12] Fermentation produces slightly less CO2 than ethanol by weight.
Broadly, three different types
of technologies for scrubbing exist: post-combustion, pre-combustion, and
oxyfuel combustion:
·
In post combustion capture,
· pre-combustion
is widely applied in fertilizer, chemical,
gaseous fuel (H2, CH4), and power production. In these cases, the fossil fuel is
partially oxidized, for instance in a gasifier. The resulting syngas (CO and H2) is shifted into CO2 and H2. The
resulting CO2 can be
captured from a relatively pure exhaust stream. The H2 can now be used as fuel; the carbon dioxide
is removed before combustion takes place. There are several advantages and
disadvantages when compared to conventional post combustion carbon dioxide
capture. The CO2 is removed after combustion of fossil
fuels, but before the flue gas is expanded to atmospheric pressure. This scheme
is applied to new fossil fuel burning power plants, or to existing plants where
re-powering is an option. The capture before expansion, i.e. from pressurized
gas, is standard in almost all industrial CO2 capture processes, at the same scale as
will be required for utility power plants.
·
In oxy-fuel combustion
the fuel is burned in oxygen instead of
air. To limit the resulting flame temperatures to levels common during
conventional combustion, cooled flue gas is recirculated and injected into the
combustion chamber. The flue gas consists of mainly carbon dioxide and water
vapour, the latter of which is condensed through cooling. The result is an
almost pure carbon dioxide stream that can be transported to the sequestration
site and stored. Power plant processes based on oxyfuel combustion are
sometimes referred to as "zero emission" cycles, because the CO2 stored is not a fraction removed from the
flue gas stream (as in the cases of pre- and post-combustion capture) but the
flue gas stream itself. A certain fraction of the CO2 generated during combustion will inevitably
end up in the condensed water. To warrant the label "zero emission"
the water would thus have to be treated or disposed of appropriately. The
technique is promising, but the initial air separation step demands a lot of
energy.
Transport
After capture, the CO2 would have to be transported to suitable
storage sites. This is done by pipeline, which is generally the cheapest form
of transport. In 2008, there were approximately 5,800 km of CO2 pipelines in the United States, used to
transport CO2 to oil
production fields where it is then injected into older fields to extract oil.
The injection of CO2 to
produce oil is generally called Enhanced Oil Recovery or EORIn addition, there are several pilot
programs in various stages to test the long-term storage of CO2 in non-oil producing geologic formations.
According to the Congressional
Research Service, "There are important unanswered questions about pipeline
network requirements, economic regulation, utility cost recovery, regulatory
classification of CO2 itself,
and pipeline safety. Furthermore, because CO2 pipelines for enhanced oil recovery are already in use today, policy decisions
affecting CO2pipelines take on an urgency that is unrecognized by many.
Federal classification of CO2 as both a commodity (by the Bureau of Land Management) and
as a pollutant (by theEnvironmental Protection
Agency) could potentially create an immediate conflict which may need
to be addressed not only for the sake of future CCS implementation, but also to
ensure consistency of future CCS with CO2 pipeline operations today."
Ships could also be utilized
for transport where pipelines are not feasible. These methods are currently
used for transporting CO2 for other applications.
Sequestration
Various forms have been
conceived for permanent storage of CO2. These
forms include gaseous storage in various deep geological formations (including
saline formations and exhausted gas fields), and solid storage by reaction of
CO2 with
metal oxides to produce stable carbonates.
Geological storage
Also known as geo-sequestration, this method
involves injecting carbon dioxide, generally in supercritical form,
directly into underground geological formations. Oil
fields, gas
fields, saline formations, unmineable coal
seams, and saline-filled basalt formations have been suggested as
storage sites. Various physical (e.g., highly impermeable caprock) and geochemical trapping mechanisms would
prevent the CO2 from
escaping to the surface.[25]
CO2 is sometimes injected into declining oil
fields to increase oil recovery. Approximately 30 to 50
million metric tonnes of CO2 are injected annually in the United States
into declining oil fields.[26] This option is attractive because the
geology of hydrocarbon reservoirs is generally well understood and storage
costs may be partly offset by the sale of additional oil that is recovered.[27] Disadvantages of old oil fields are their
geographic distribution and their limited capacity, as well as the fact that
subsequent burning of the additional oil recovered will offset much or all of
the reduction in CO2 emissions.[28]
Unmineable coal seams can be
used to store CO2 because
the CO2 molecules
attach to the surface of coal. The technical feasibility, however, depends on
the permeability of the coal bed. In the process of absorption the coal
releases previously absorbed methane, and
the methane can be recovered (enhanced coal bed methane
recovery). The sale of the methane can be used to offset a portion of
the cost of the CO2 storage.
Burning the resultant methane, however, would negate some of the benefit of
sequestering the original CO2.
Saline formations contain
highly mineralized brines, and have so far been considered of no benefit to
humans. Saline aquifers have been used for storage of chemical waste in a few
cases. The main advantage of saline aquifers is their large potential storage
volume and their common occurrence. The major disadvantage of saline aquifers
is that relatively little is known about them, especially compared to oil
fields. To keep the cost of storage acceptable, the geophysical exploration may
be limited, resulting in larger uncertainty about the aquifer structure. Unlike
storage in oil fields or coal beds, no side product will offset the storage
cost. Leakage of CO2 back
into the atmosphere may be a problem in saline aquifer storage. Current
research shows, however, that trapping
mechanisms such as structural
trapping, residual trapping, solubility trapping and mineral trapping could
immobilize the CO2 underground
and reduce the risk of leakage.
Tyre pyrolysis
The pyrolysis method for recycling used tires is a technique
which heats whole or shredded tires in a reactor vessel containing an
oxygen-free atmosphere. In the reactor the rubber is softened after which the
rubber polymers break
down into smaller molecules. These
smaller molecules vaporize and exit from the reactor. These vapors can be
burned directly to produce power or condensed into an oily type liquid,
generally used as a fuel. Some molecules are too small to condense. They remain
as a gas which can be burned as fuel. The minerals that were part of the tire,
about 40% by weight, are removed as a solid. When performed well a tire
pyrolysis process is a very clean operation and has nearly no emissions or
waste.
The properties of the gas,
liquid, and solid output are determined by the type of feedstock used and the
process conditions. For instance whole tires contain fibers and steel. Shredded
tires have most of the steel and sometimes most of the fiber removed. Processes
can be either batch or continuous. The energy required to drive the
decomposition of the rubber include using directly fired fuel (like a gas
oven), electrical induction (like an electrically heated oven) or by microwaves
(like a microwave oven). Sometimes a catalyst is used to accelerate the
decomposition. The choice of feedstock and process can affect the value of the
finished products.
The historical issue of tire
pyrolysis has been the solid mineral stream which accounts for about 40% of the
output. The steel can be removed from the solid stream with magnets for recycling.
The remaining solid material, often referred to as "char", has had
little or no value other than possibly as a low grade carbon
fuel. Char is the destroyed remains of the original carbon black
used to reinforce and provide abrasion resistance to rubber. The solid stream
also includes the minerals used in rubber manufacturing. This high volume component
of tire pyrolysis, until recently, has made the economic viability very
difficult to achieve. Over the past five years two or three companies have
discovered ways to recover the carbon in its original form.. These
companies have been commercially producing and selling recovered carbon black
based products that successfully supplement virgin carbon black in rubber and
plastics
GASIFICATION.
Gasification:
is a process that converts organic or fossil fuel based carbonaceous materials into carbon monoxide, hydrogen and carbon dioxide. This is achieved by reacting the material at high temperatures (>700 °C), without combustion, with a controlled amount of oxygen and/or steam. The resulting gas mixture is called syngas (from synthesis gas or synthetic gas) or producer gas and is itself a fuel. The power derived from gasification and combustion of the resultant gas is considered to be a source of renewable energy if the gasified compounds were obtained from biomass.
The advantage of gasification
is that using the syngas is potentially more efficient than direct combustion
of the original fuel because it can be combusted at higher temperatures or even
in fuel cells, so that the thermodynamic upper limit to the efficiency
defined by Carnot's rule is higher or (in case of fuel cells) not
applicable. Syngas may be burned directly in gas
engines
Gasification processes
Main
gasifier types
Several types of gasifiers are
currently available for commercial use: counter-current fixed bed, co-current
fixed bed, fluidized
bed, entrained flow, plasma, and free radical
Fluidized bed reactor
The fuel is fluidized in oxygen and steam or air. The ash is
removed dry or as heavy agglomerates that defluidize. The temperatures are
relatively low in dry ash gasifiers, so the fuel must be highly reactive;
low-grade coals are particularly suitable. The agglomerating gasifiers have
slightly higher temperatures, and are suitable for higher rank coals. Fuel
throughput is higher than for the fixed bed, but not as high as for the
entrained flow gasifier. The conversion efficiency can be rather low due to elutriation of carbonaceous material. Recycle or
subsequent combustion of solids can be used to increase conversion. Fluidized
bed gasifiers are most useful for fuels that form highly corrosive ash that
would damage the walls of slagging gasifiers. Biomass fuels generally contain
high levels of corrosive ash.
Waste disposal
present situation.
present situation.
HTCW
reactor, one of several proposed waste gasification processes. According to the
sales and sales management consultants KBI
Group a pilot plant in
Arnstadt implementing this process has completed initial tests.
Waste gasification has several
advantages over incineration:
·
The necessary extensive flue gas cleaning may be performed on
the syngas instead of the much larger volume of flue
gas after
combustion.
·
Electric
power may be
generated in engines and gas
turbines, which are much cheaper and more efficient than the steam
cycle used in
incineration. Even fuel cells may potentially be used, but these have rather
severe requirements regarding the purity of the gas.
·
Chemical processing (Gas to
liquids) of the syngas may produce other synthetic fuels instead of
electricity.
·
Some gasification processes treat ash containing heavy metals at
very high temperatures so that it is released in a glassy and chemically stable
form
Current applications
Syngas can be used for heat
production and for generation of mechanical and electrical power. Like other
gaseous fuels, producer gas gives greater control over power levels when
compared to solid fuels, leading to more efficient and cleaner operation.
Syngas can also be used for
further processing to liquid fuels or chemicals.
Heat
Electricity
Combined heat and power
Transport fuel
Renewable energy and fuels
IF WE MAKE THIS REAL WORLD PRACTISE……THESE TECHNOLOGIES CAN BE MADE THE NEW WORLD OF
“O%POLLUTION”
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