The Biomass Power Plants Environmental Sciences Essay

The Biomass Power Plants Environmental Sciences Essay Biomass is claimed to be the fourth largest energy resource in the world after oil, coal and gas and biomass power plants are becoming one of the most promising alternatives to the established power generation technologies based on fossil fuels. Biomass is defined as any organic material derived from plants, available on a sustainable basis. Generally identified as feedstocks, these materials include: wood, from forestry trimmings or wood processing systems; energy crops, which are crops grown exclusively for energy purposes; agricultural residues; municipal waste such as waste paper, cardboard or food waste; and also animal waste from farms and animal processing industries. The production of electricity from biomass is described as a carbon neutral technology because the carbon dioxide released into the atmosphere when plant material is burnt or decomposed during the electricity generation process, is then absorbed again by new growing plant material. This process maintains the atmospheric CO2 levels and is known as carbon cycle. There are currently two main processes used in power plants for the production of electricity from biomass: and they are direct combustion and gasification [2]. Direct combustion is essentially the incineration of dry biomass in the presence of air to produce heat. Gasification is the thermo-chemical transformation of biomass into a combustible gas which is called syngas (synthesis gas) and is a combination of principally carbon monoxide and hydrogen. This process occurs at high temperature (700Â °C to 1000Â °C) in the presence of a limited amount of oxygen [3]. The heat produced by direct biomass combustion can be used to generate electricity using a steam turbine in the same way as in a coal-fired power plant. The biomass material is collected, taken to the power station and then burnt in the boiler. The heat from burning the biomass is used to boil water which generates steam that rotates the turbines. The turbines are connected to generators where the mechanical energy is converted to electrical energy. Plants designed for working just with biomass are called dedicated biomass power plants. However, biomass combustion can be combined with coal combustion in existing coal-fired power plants. This process is called co-firing and is one of the most profitable ways of transforming biomass into electricity because it makes use of the infrastructure of the coal plant and therefore it reduces the total investment. Co-firing power plants can be designed under three concepts: direct, where biomass and coal are mixed and burnt in the same boiler; indirect, where biomass is first gasified before the combustion with coal in the boiler; or parallel, where biomass and coal are burnt in separate boilers and the processes are connected on the steam side [4]. In efficiency calculations, the scale of operation is a very important factor. In systems producing from 10MW to 50 MW, the efficiency is in the range of 18% to 33% [5]. The maximum efficiencies could reach about 45% in large scale plants producing more than 100 MW [6][7]. In co-firing plants, efficiency of 39% can be reached [8]. Biomass gasification process can be couple with a conventional combined-cycle gas turbine (CCGT) power plant to produce electricity. Biomass feedstock is first dried and then injected into the gasifier. The resulting biogas is purified in a cleaning system and from there the procedure is the same as in a natural gas power plant [9]. To produce from 10 kW to 10 MW, biogas produced in the gasification process can also be used in combustion engines with efficiency of 30% 35% [10]. At larger scales (>20 MW), where gasification-based systems are coupled with combined cycle gas turbines the efficiency increases up to about 45% [11]. There are two others processes which can be used to produce electricity from biomass but they are not commercially developed: pyrolysis and anaerobic digestion. Pyrolysis is a thermo-chemical decomposition of organic material at high temperatures (325Â °C to 500Â °C) similar to gasification but in this case there is no presence of oxygen. This process generates combustible gas and liquid products that could be used in power generation units or upgraded to transport fuel [12]. A carbon-rich residue called biochar is also produced from pyrolysis, and one of the important aspects of biochar is that it is a natural fertiliser that can be used to improve soils quality, which can potentially increase energy crop productivity. The second one, anaerobic digestion, is a natural biochemical process in which the biomass material is broken down by microorganisms in a environment with no air, to produce biogas, which is mainly a mixture of around 60% methane and 40% carbon dioxide. This process can be applied to wet biomass, municipal or animal waste to produce power generation on site [13]. There are a number of technologies that support the different methods for converting biomass material into electricity, which include: drying, pelletisation, briquetting, cleaning and lately carbon capture and storage. Drying is fundamental because in order to increase the energy density of biomass feedstocks, their moisture content needs to be reduced ( Pelletisation and briquetting are technologies to compact feedstocks mechanically, very useful for their transportation and management. Pelletisation is used for example to compress low quality wood, and agricultural residues are compacted through briquetting process [14]. The gas obtained from gasification contains impurities and particulates that need to be removed before using it in power plants, because these contaminants can cause erosion and corrosion in the gas turbine components, and decrease the strength of the system. Conventional methods for removing contaminants from biogas are typically based on physical cleaning processes at low temperatures ( Combining biomass power plants with carbon capture and storage processes (BECCS) to provide negatives emissions [15] is a new approach. When the CO2 emitted during biomass electricity generation is captured and stored, new growing plant material will absorb CO2 from the atmosphere reducing the current high level concentrations. The key advantage of power generation from biomass is that it is based on a CO2 neutral process and it can be a clean and reliable power source if sufficient feedstocks are available. It is also a way to utilise waste materials that otherwise would represent environmental risks. Biomass electricity deployment has also a significant social and economic impact because it can create employment in the agricultural and forestry sector, benefiting rural communities and in general developing countries which economies are based on agriculture [16]. The expansion of biomass power generation faces several challenges such as high costs, low conversion efficiency and availability of biomass material [17]. As any new technology, biomass power generation currently requires financial support which make it less commercially competitive compared to fossil fuel based electricity. Biomass electricity production will depend also on technology improvements in order to increase efficiencies at small and large scale. Major concerns are associated to biomass production (intensive farming, biodiversity conservation) and competition for land with food production. Energy from biomass has been used since fire was discovered from the combustion of wood, and before the industrial revolution wood was used for all of our energy needs. However In 1890 coal began to displace wood used in steam power generation. During the 1980s decades, high prices of oil and the instability caused by the dependence on foreign fossil fuels created new interest in biomass energy in several countries, especially in North America. A large biomass power industry rapidly developed in California, who had 850 MW of installed biomass power capacity by 1985. Due to concerns about greenhouse gases emissions and global warming, governments took a greater interest in using biomass as a renewable and clean alternative to produce electricity. Currently most biomass electricity generation is based on direct combustion in dedicated and co-firing steam power plants. Electricity supply from biomass has augmented gradually since 2000, and in 2010 biomass provided 1.5% of world electricity production approximately. Although biomass power generation is still stronger in developed countries, China and Brazil are also becoming important electricity producers in particular from agricultural residues thanks to support programmes. The models established in these China and Brazil could become a viable way to encourage electricity generation from biomass in other developing countries with similar conditions [18]. According to the International Energy Agency [19], world electricity generation from biomass will multiply by more than 10 times from around 280 TWh in 2010 to 3100 TWh in 2050 and could provide around 7.5% of world electricity generation. China will become the major producer of bioenergy electricity with 920 TWh, above OECD Americas (520 TWh) and OEDC Europe (370 TWh) which will also increase their generation levels.

Dreams of Gilgamesh

Dreams of Gilgamesh When looking into the meanings of dreams, a variation of things can be found. Most people believe that dreams are a reflection of people’s inner thoughts and feelings. Most of these feelings are too private to be expressed in the real world and that is why they are expressed in a fantasy type way through dreams. In Gilgamesh, dreams are used as a form of communication between the Gods and humans. Major events are seen through these dreams and fantasies are foretold. In the ancient Mesopotamian culture, dreams play a major role.Dreams foretold the coming of Enkidu, the death of Enkidu, the protection of Shamhat during the battle with Humbaba, and much more. The fact that dreams play such an important role in this story, would lead you to believe that dreams have a significant place in society. The first mention of dreams in Gilgamesh come with Enkidu and the harlot in the wilderness. The purpose of this scene is to show that dreams tell the future. It is imp ortant for Gilgamesh to know that Enkidu is coming because he needs to know that Enkidu is there to bring him no harm.Enkidu was created to be on Gilgamesh’s side, not to challenge him. In the next scene Gilgamesh has a dream but he did not understand the dream so he asks his mother its meaning. â€Å"Mother, I had a dream last night: There were stars of heaven around me, Like the force of heaven, something kept falling upon me! I tried to carry it but it was too strong for me, I tried to move it but I could not budge it. The whole of Uruk was standing by it, The people formed a crowd around it, A throng was jostling towards it, Young men were mobbed around it, Infantile, they were groveling before it!I fell in love with it, like a woman I caressed it, I carried it off and laid it down before you, Then you were making it my partner. †(page 19, tablet I, lines 246-258). This dream is very significant because it foretells the first confrontation of Gilgamesh and Enkidu. The introduction of Enkidu in Gilgamesh’s life is symbolic of someone finding a companion. In another scene, we are given a view into Humbaba. â€Å"Humbaba’s cry is the roar of a deluge, His maw is fire, his breath is death, He can hear rustling in the forest for sixty double leagues. Who can go into his forest?Adad is first and Humbaba is second. Who, even among the gods, could attack him? In order to safeguard the forest of cedars, Enlil has appointed him to terrify the people, Enlil has destined him seven fearsome glories, Besides, whosoever enters his forest is struck down by disease. † (page 25, tablet II, lines 171-180). This is very significant in that it lets us know the nature of who Humbaba is. It’s clear that Humbaba is quite evil according to this passage. Gilgamesh’s dreams make him supremely confident during his attempts to overcome Humbaba.Gilgamesh believes he can prevail against Humbaba. Due to his focus and heroism, Gilgamesh is capable of slaying a horrifying, evil monster like Humbaba. Dreams are a constant motivation for Gilgamesh, and although at times he feels physically incapable of continuing on his quest for everlasting life, his focus on achieving his goal, drives him past any conceivable ability. The dreams all play the same role in this story. They foreshadow what is to come, motivation for Gilgamesh, and they assist in the strengthening of the relationship between Gilgamesh and Enkidu.Most importantly, Gilgamesh makes his journey not for fortune or fame, but purely for spiritual knowledge. Often the purpose of his journey is not really what he thinks it is, and the knowledge he’s looking for is not the knowledge he ultimately gains. By killing Humbaba, Gilgamesh discovers that the fame he finds only opens him up to new responsibilities, challenges and psychic wounds. He learns why the goal of the journey of life isn't what he thought it was. He has to go on a second and much more difficul t journey, one with a more spiritual goal.But even though this journey is more spiritual in character, it's still not spiritual enough. His goals are still selfish. Gilgamesh isn't ready to be a king until he wants something not just for himself or for Enkidu but for the whole of Uruk. He also isn't ready to be king until he accepts human limits, embraces his humanity, and decides to seek a goal that makes sense for human beings. The importance of knowing what is going to happen before it actually happens is to build dramatic tension.Even though you may know what’s going to happen next, it doesn’t ruin the story. You may know who Gilgamesh will encounter next, but there will still be questions as to when and why. Also, by knowing a preview of what happens in advance, it helps prevent confusion and makes it more likely you will believe fantastic events in the story if you prepare for such events. It also helps prepare you for outlandish occurrences in the story. Works C ited Stephen, Owen. The Norton Anthology of World Literature. Shorter 2nd. New York: W. W Norton & Company,INC, 2009. 9-33. Print.

What Causes Gemstones to Get Their Color

Industrial Workers of the World (IWW) History

The Industrial Workers of the World (IWW) is an industrial labor union, founded in 1905 as a more radical alternative to craft unions. An industrial union organizes by industry, rather than by craft. The IWW is also intended to be a radical and socialist union, with an anti-capitalist agenda, not just reformist agenda within an overall capitalist system. The current constitution of the IWW makes clear its class struggle orientation: The working class and the employing class have nothing in common. There can be no peace so long as hunger and want are found among millions of the working people and the few, who make up the employing class, have all the good things of life.Between these two classes a struggle must go on until the workers of the world organize as a class, take possession of the means of production, abolish the wage system, and live in harmony with the Earth.†¦.It is the historic mission of the working class to do away with capitalism. The army of production must be organized, not only for everyday struggle with capitalists, but also to carry on production when capitalism shall have been overthrown. By organizing industrially we are forming the structure of the new society within the shell of the old. Informally called the â€Å"Wobblies,† the IWW originally brought together 43 labor organizations into â€Å"one big union.† The Western Federation of Miners (WFM) was one of the larger groups that inspired the founding. The organization also brought together Marxists, democratic socialists, anarchists, and others. The union was also committed to organizing workers regardless of sex, race, ethnicity, or immigrant status. Founding Convention The Industrial Workers of the World was founded at a convention in Chicago called on June 27, 1905, which â€Å"Big Bill† Haywood called â€Å"the Continental Congress of the working class.† The convention set the direction of the IWW as a confederation of workers for â€Å"the emancipation of the working class from the slave bondage of capitalism.† Second Convention The following year, 1906, with Debs and Haywood absent, Daniel DeLeon led his followers within the organization to remove the president and abolish that office, and to diminish the influence of the Western Federation of Miners, which DeLeon and his Socialist Labor Party fellows considered too conservative. Western Federation of Miners Trial At the end of 1905, after confronting the Western Federation of Miners on strike at Coeur d’Alene, someone assassinated the governor of Idaho, Frank Steunenberg.  In the first months of 1906, the Idaho authorities kidnapped Haywood, another union official Charles Moyer, and sympathizer George A. Pettibone, taking them across state lines to stand trial in Idaho.  Clarence Darrow took up the defense of the accused, winning the case at the trial from May 9 to July 27, which was widely publicized.  Darrow won an acquittal for the three men, and the union profited from the publicity. 1908 Split In 1908, a split in the party formed when Daniel DeLeon and his followers argued that the IWW should pursue political goals through the Social Labor Party (SLP). The faction which prevailed, often identified with â€Å"Big Bill† Haywood, supported strikes, boycotts, and general propaganda, and opposed political organization. The SLP faction left the IWW, forming the Workers’ International Industrial Union, which lasted until 1924. Strikes The first IWW strike of note was the Pressed Steel Car Strike, 1909, in Pennsylvania. The Lawrence textile strike of 1912 began among the workers at the Lawrence mills and then attracted IWW organizers to help out. The strikers numbered about 60% of the city’s population and were successful in their strike. In the east and Midwest, the IWW organized many strikes. Then they organized miners and lumberjacks in the west.   People Key early organizers of the IWW included Eugene Debs, â€Å"Big Bill† Haywood, â€Å"Mother† Jones, Daniel DeLeon, Lucy Parsons, Ralph Chaplin, William Trautmann, and others.  Elizabeth Gurley Flynn gave speeches for the IWW until she was expelled from high school, then she became a full-time organizer. Joe Hill (remembered in the â€Å"Ballad of Joe Hill†) was another early member who contributed his skill in writing song lyrics including parodies.  Helen Keller joined in 1918, to considerable criticism. Many workers joined the IWW when it was organizing a particular strike, and dropped membership when the strike was over.  In 1908, the union, despite its larger-than-life image, had only 3700 members. By 1912, the membership was 30,000 but was only half that the next three years.  Some have estimated that 50,000 to 100,000 workers may have belonged to the IWW at various times. Tactics The IWW used a variety of radical and conventional union tactics. The IWW supported collective bargaining, with the union and the owners negotiating over wages and working conditions. The IWW opposed the use of arbitration – settlement with negotiations run by a third party.  They organized in mills and factories, railroad yards and railroad cars. Factory owners used propaganda, strike-breaking, and police actions to break up IWW efforts. One tactic was using Salvation Army bands to drown out IWW speakers. (No wonder some IWW songs make fun of the Salvation Army, especially Pie in the Sky or Preacher and Slave.) When the IWW struck in company towns or work camps, employers responded with violent and brutal repression. Frank Little, partly of Native American heritage, was lynched in Butte, Montana, in 1917. The American Legion attacked an IWW hall in 1919 and murdered Wesley Everest. Trials of IWW organizers on trumped-up charges was another tactic. From the Haywood trial, to the trial of immigrant Joe Hill (the evidence was slim and then disappeared) for which he was convicted and the executed in 1915, to a Seattle rally where deputies fired on a boat and a dozen people died, to the 1200 Arizona strikers and family members detained, put in railroad cars, and dumped in the desert in 1917. In 1909, when Elizabeth Gurley Flynn was arrested in Spokane, Washington, under a new law against street speeches, the IWW developed a response: whenever any member was arrested for speaking, many others would also begin speaking in the same place, daring the police to arrest them, and overwhelming the local jails.  The defense of free speech brought attention to the movement, and in some places, also brought out vigilantes using force and violence to oppose street meetings.  Free speech fights continued from 1909 through 1914 in a number of cities. The IWW advocated for general strikes to oppose capitalism in general as an economic system. Songs To build solidarity, the members of IWW often used music.  Dump the Bosses Off Your Back, Pie in the Sky (Preacher and Slave), One Big Industrial Union, Popular Wobbly, Rebel Girl were among those included in the IWW’s â€Å"Little Red Songbook.† The IWW Today The IWW still exists.  But its power diminished during World War I, as sedition laws were used to put many of its leaders in prison, totaling almost 300 people. Local police and off duty military personnel forcibly closed IWW offices. Then some key IWW leaders, immediately after the Russian Revolution of 1917, left the IWW to found the Communist Party, USA.  Haywood, charged with sedition and out on bail, fled to the Soviet Union. After the war, a few strikes were won through the 1920s and 1930s, but the IWW had faded to a very small group with little national power.