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5963 Uppsatser om Small scale biogas production - Sida 14 av 398

Pellets - en framtidsmarknad?

With higher prices for oil and increased focus on fossil fuels impact on the environment the heating sector are searching for alternative fuels. Pellets are a quite new product whose production has risen exponential in recent years. Today there are small-, medium-and large-scale users, where the large-scale consumers are the heating sector. The heating sector is mainly using oil to cover the increased demand during cold periods. The purpose of this study is to analyze the potential of pellets if it would replace thermal power plants oil and coal. The study will also analyze the economic impact a conversion would mean for a heating plant and if the pellet is a reasonable substitute. 2008 statistics from the Swedish district heating association were analyzed and a calculation was performed to determine how many tons of pellets is needed to replace coal and oil.

Teknik för biogasanvändning

This thesis is made by Carl Persson and Alejandro Saavedra for Gryaab. Gryaab is Gothenburg?s water processing plant and produces about 60 GWh biogas annually with a flow around 1150 Nm3/h. Gryaab wants to research their possibilities to become independent with electrical energy and the possibilities to enrich, upgrade biogas. The use of methane rich gases like biogas and natural gas is today low in Sweden compared to major parts of the world.

EU:s omställning till en hållbar jordbruksnäring

Cultivable land is a limited resource and agriculture contributes to some of the most serious environmental problems facing the planet like, global warming, eutrophication and loss of biodiversity. The specialized, industrial agriculture with monoculture and extensive input of external energy, commercial fertilizer, and chemical pesticides are all essentially unsustainable. An adaptation to other methods of production is necessary to preserve the environment for future generations. The aim of this study is to describe the factors that distinguish sustainable from unsustainable agriculture. The results will be used to examine if and how the European Union (EU) works in order to create a more sustainable agricultural industry and to analyze the preconditions for such development.

Utredning om en ökad biologisk behandling av matavfall i Halmstads kommun

Environment and sustainable development are very current topics in today's society, bothnational and international. The government's bill 2004/05:150 ?Swedish environment objectives - a common commission? contains several environmental quality objectives, that in turn is divided up in smaller secondary objectives. One of the secondary objectives says: ?Latest year 2010 shall at least 35% of the food waste from households, restaurants, largescale kitchens and shops be recycled through biological treatment.

Förmåga till njutning - validering av en svensk version av Snaith-Hamilton Pleasure Scale

Studiens syfte var att validera en modifierad svensk översättningav självskattningsskalan som mäter anhedoni, Snaith-Hamilton PleasureScale. Syftet var också att utforska relationen mellan anhedoni och fatigue,stress, mental trötthet respektive dagtrötthet. Studiens deltagare, 60universitetsstudenter, utgjorde en icke-klinisk grupp som rekryterades medbekvämlighetsurval. Den modifierade svenska översättningen av Snaith-Hamilton Pleasure Scale uppvisade god intern konsistens, samt god konvergentvaliditet vid korrelation med anhedonirelaterade subskalor i Beck DepressionInventory. Vidare uppvisade Snaith-Hamilton Pleasure Scale starkapositiva samband med Fatigue Impact Scale respektive Mental FatigueScale, men inte med The Perceived Stress Scale respektive Epworth SleepinessScale.

Identifiering av slöserier på Lundbergs Plåt AB

Lundbergs Plåt AB is a small company situated in Jönköping. Their main task is to process different kinds of steel such as stainless steel. Lately, they have shown an interest in Lean production.On the basis of the situation mentioned above, we developed the purpose to find and decrease the non value-added wastes in the production at Lundbergs Plåt AB. Out of this, we also developed and answered two questions: Which wastes can be found with help from a value stream mapping (VSM)? In what way can these wastes be reduced and how can these reductions contribute to an improved production? VSM is the method used to find the non value-added wastes.

En jämförelse av sitkagranens (Picea sitchensis) och den vanliga granens (P. abies) produktion :

Sitka spruce (Picea sitchensis) is a tree species that have its natural distribution along the West Coast of North America, from Alaska in the north to northern California in the south. Sitka spruce is a typical coastal tree species that can reach heights up to 85 meters and occurs in single pure as well as in mixed stands. The main purposes of this study were to describe the Sitka spruce growing characteristics and the volume production in comparison to spruce (Picea abies). The possibility to predict future volume production by using prognosis tools designed to be used on spruce were also studied. The material that has been used in this study are permanent sitka trials established by the Faculty of Forestry fixed Sitka trials and also material gathered in this study. A literature study was also carried out in order to determine the Sitka spruce growing characteristics. Sitka spruce has a high adaptation and a high volume production on a broad scale of soil types. The tree species is a pioneer species that has a fast early growth and in combination with sharp needles it is less susceptible to animal browsing than spruce. The factor that is the single most limiting factor for where the Sitka spruce can be planted is frost. This factor can be limited by using plant material with a well-suited provenance. According to the literature, the Sitka spruce has an average total volume production that is between 20-40% higher than spruce.

Nätanslutning av vindkraft : vindkraftsbranschens aktörers perspektiv på nätanslutning och tariffer

Wind power is a growing energy sector in Sweden. However, it still represents only a small part of the total electricity production, about 0.7%. In order to create good conditions and to facilitate the establishment of wind power in Sweden, the government has for example, created a national centre for wind use. The objective has been to reach the governmental goal, which is an expansion of wind power by 10 TWh by year 2015 compared to the level in 2002. The Swedish electricity market was deregulated in 1996 which refers to the introduction of a competitive market in electricity production and trade.

Methane production from dairy cows : relations between enteric production and production from faeces and urine

Methane (CH4) is a greenhouse gas (GHG) that contributes to the global warming. One of the largest sources of methane is livestock, preferably ruminants which alone counted for 30% of the total agricultural anthropogenic methane emissions in the year of 2000. The reason to why ruminants are such large contributors of methane are that the gas is produced in the rumen by enteric formation and leaves the animals by belching, exhaling or by the excreta.Diets high in concentrates can result in a lower emission of methane. Also diets with a high content of starch, such as alfalfa-grass, have a methane-decreasing. It is profitable to reduce enteric methane formation since that form of methane is unavoidably lost.

Den brasilianska nötköttsproduktionens framtida utveckling :

To value the risk and opportunity for our production in Sweden it is necessary to understand the marketing development for beef cattle production in the world. We have chosen to look at the Brazil beef cattle production. They are one of the biggest producers, have good opportunity to develop further and have a big affect at the world market. The method of our work is to gather information from experts of beef cattle production, located in Brazil. We have also gathered information through studies of literature. The factors that will have a big influence at the Brazil beef cattle production during the upcoming years is more efficient land use, lower age of slaughtering and extended use of feedlot-system. Our conclusion is that the Brazil beef cattle will have a sharp increase during the next five years. The amount of pasture will not change during that time.

Effektiv sökning med Google: en jämförelse i återvinningseffektivitet mellan enkel och avancerad sökning

The purpose with this essay is to evaluate the retrieval performance between Googles basic search and the advanced search functions. A secondary purpose is to evaluate the differences between the binary relevance scale and a 4- point scale. The basic search is defined as a search with two terms combined with the Boolean operator AND. The advanced search is based on search functions that are adequate to compare to the basic search. They are categorized as AND-searches, OR-searches, AND and OR-searches, exact phrase, and depending on where the terms occur on the page.

Integrering av pelletsfabrik med Rya kraftvärmeverk i Göteborg : en teknisk och ekonomisk utredning

Göteborg Energi has a surplus of district heating during spring, summer and fall. The heat surplus is due to a constant production of waste heat from oil refineries and heat from waste incineration over the year. It would be desirable to increase the demand for heat and the uptime for the newly built combined heat and power generation plant, Rya Kraftvärmeverk. One alternative could be to integrate Rya Kraftvärmeverk with a pellet production facility. By producing heat, electricity and pellet in a joint process the energy use can be decreased.

Optimeringsunderlag för anaerob rötning av flytgödsel från nötkreatur

Produktions- och optimeringspotentialen vid anaerob rötning av flytgödsel från nötkreatur granskades. Detta genom att, i laboratoriemiljö, undersöka förändringar i processtabilitet, gasproduktion och metanhalt vid tillsats av kycklinggödsel och pH-buffert med flytgödsel från nötkreatur som grundsubstrat. Tillsatsen av pH-buffert underlättade tillväxtfasen för mikroorganismerna, snabbare ökning i metanhalt och den totala metangasproduktionen ökade. Skillnaden var som störst under tillväxtfasen och avtog från stationärfas och framåt. Tillsats av kycklinggödsel har i detta fall inhiberat processen, möjligtvis på grund av ammoniakinhibering vid tillsats av det kväverika substratet som kycklinggödsel är..

Termofil rötning av drankvatten

Biogasprocessen är en komplex anaerob nedbrytningskedja där olika mikroorganismer är inblandade. Vanligast är att biogas produceras i mesofil rötning (cirka 38 oC), men även termofil rötning används (> 50 oC).Svensk Biogas i Norrköping använder återstoden av etanoldestillationen hos en närliggande etanolproducent (drankvatten) som substrat. Substratets höga temperatur vid leverans motiverar termofilt rötningsförsök av drankvatten.Försöket genomfördes i 55 oC med två kontinuerligt omrörda tankreaktorer (CSTR) och en termofil ymp. Biogasproduktion av drankvatten undersöktes. Sätt att hantera och motverka höga ammoniumhalter, samt effekter av näringslösningstillsats undersöktes.

Ny betygsskala- för elevernas bästa?

This essay is a study of the government bills for a new grading scale in the Swedish schools. There have been many complaints about the current grading scale and the main problem seems to be that teachers are interpreting the criteria for certificates differently. There are two major challenges for Swedish teachers, one is how to interpret the criteria for certificates, the other one is the equality problem , students can not be sure of that two different teachers would give the same grades. The main point of the essay is to try to find out whether the new grading scale will solve this problem. To my help I have made an analysis of the bills of the Swedish government for the new grading scale.

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