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A high demand of both electricity and heat exists in Arizona Chemical (a chemical plant dedicated to the distillation of Crude Tall Oil) for production processes. Due to the rising cost of resources and electricity, more and more companies are trying to decrease the energy expenses to increase their competitiveness in a global market, thus increasing their profit. Some companies look at their energy consumption in order to diminish it or to explore the opportunity to generate their own and cheaper energy. In companies where the production of steam already takes place, cogeneration can be a good solution to palliate the cost of the energy used. This study addresses this issue through three actions such as the characterization of the boiler, a better steam flow measurement grid and the generation of electricity. The first one addresses the state of one of the key parts of steam production, the boiler, through the calculation of its efficiency with two different methods (direct and indirect calculation). These methods require some measurements which were provided afterwards by the company supervisor. This will allow the company to identify the weaknesses of the boiler to be able to improve it in the future. The second one aims to improve the knowledge about the steam system. New flow measurement points were suggested after doing an analysis of the current controlled flows to have a better overview outline of the steam use.The third one studies the generation of electricity with a Rankine cycle. The limitations in the characteristics of the steam were identified and different configurations are proposed in accordance to the restrictions identified. An efficiency of 93% is obtained for the boiler with the direct method and 82.3 % for the indirect one. The difference between them can be explained by the use of datafrom different time frames for both methods. The main contributors to the losses are the ones related to the dry flue gas and the hydrogen in the fuel. In the current status only 40% of the steam flows are identified, a number which is expected to raise with the new measurement points. It was not possible to estimate the effect of the new points due to the desire of the company to not disturb the current production. Due to the fuel price the production of steam for only electricity was not profitable and instead the generation of both electricity and heat from the same steam is proposed. This integrated system is now possible to implement due to its low payback time (2.3 years). This solution can generate 758 kW of electricity and provide the company with 6437 MWh of electricity each year. Then, the effect of the variation of different variables over the performance of the cycle were studied: different electricity prices, steam rate production, fuel cost and the state of the condensate recovery were discussed. The variation of both the condensate recovery and fuel cost did not affect the payback time due to their costs being neutralised by the revenues obtained from them. The variation of the electricity prices and steam production affects the payback but due to the high revenue that is expected it does not hamper the good nature of the investment. The generation of electricity is recommended due to the low payback time obtained. The different variations studied in the system did not change the payback time notably and showed that the investment is highly profitable in all the scenarios considered. The use of two smaller turbines instead of the one chosen (with a maximum rated power of 6 MW while only 758 kW is generated with the proposed solution) should be studied since the turbines would work closer to their maximum efficiency.

When speaking about energy it means speaking about life, activity, economy, growth and environmental issues. The issue of energy has been the main article all over the world in recent years, this is due to the importance of energy to life and its impact on the environment. For example, Paris climate change meeting in 2015 is one of the recent global meeting which directly related to the energy use by nations. The meeting was mainly focused up on the restriction of greenhouse gas emission which implies that industries should think about other alternative energy resources rather than fossil fuel for positive impact on climatic change. This is one of the cases that led industries into greater competition in the global market. Industries must consider energy alternatives which is safe for the environment and by using such energy a competitive product with better quality and quantity should be produced. This challenge has motivated industries to look and study the energy that they are using currently. Studies and researches show that one of the main and most abundant energy resources that most of these industries can get is by improving the energy efficiency or managing the energy that they currently use. The main aim of this thesis is to provide Arizona chemical plant (Kraton) at Sandarne on the potential energy saving by managing their energy use. The first wisdom in energy utilization is managing and using the energy they possess efficiently. In Arizona plant at Sandarne, the product named “Pitch” (a natural viscoelastic polymer or rosin) is a fuel used as the primary energy supply for the production of steam by boilers. The steam may be utilized well but the energy in the condensate (after steam loses its latent heat) is not addressed well enough. Hence this paper has studied on how significant is the energy lost by the steam condensate is and how its recovery can be used to save energy and cost. The plant produces about an average of 11.42 ton of steam each hour in a year. This steam can be returned or fully recovered (100%) as condensate from the law of conservation of mass since only energy is lost from the steam. But the plant returns a maximum of about 3ton of condensate each hour. This amount is relatively low compared to the amount of condensate recovery possibility. Recovery possibility of condensate return showed that the plant at Sandarne can return at least 8.5 ton of condensate  each hour. In comparison with the current return estimated 5.5 ton of condensate is being lost simply as waste each hour leading to about 400 SEK minimum cost loss. The calculation of cost is in minimum because the charge from water supply and condensate effluent disposal charge are not considered. In this paper only recovery from the easily recoverable steam condensate is being considered (25% of the system) which resulted in payback time of the proposed investment 1.88 years without considering the above explained charges. It is much motivating study considering the generalized approach and over simplified method. If a deeper investigation is made on the potential, it can be clearly shown that how significant the potential is in securing and sustaining energy and environmental issues. Ensuring the security and sustainability of energy which addresses the environmental issue precisely will help the plant to stay on the race of global market competition.   Keywords: Energy efficiency, Boiler efficiency, Energy management, Condensate recovery,

This diploma thesis deals with proposal of the steam boiler on combustion uncontaminated wood. For the specified parameters have been implemented stoichiometric calculations and calculations enthalpy burnt gas. In the next part have been dealt with heat balance of the boiler, the efficiency of the boiler, design of the combustion chamber and calculation of particular rating surfaces. The output parametres are temperature, pressure and the amount of steam.

The purpose of this Diploma Thesis is the construction design of the steam-boiler for the combustion of biomass – wood pellets. For the specified parameters have been defined stoichiometric calculations and calculations enthalpy burnt gas. In sequence, there is designed and solved the configuraion of the steam-boiler, so that the result design and the number of the heat-delivery surfaces can be determined, in dependence on the required inlet parametres of the air and outlet parametresof the water vapour. These parametres mean the amount, the temparature and the pressure. The aim of the thesis is to make a design of the steam.boiler burning biomass according to the set parametres. This very ecological fuel can really substitute the fossil fuel and friendly respect the environment.

The aim of the work is to design a plain wood combustion boiler of 88 t/h output. Fuelling component analysis has been added to the basic boiler parameters. For given fuel is prepared stechiometric calculations. After making the heat balance of boiler is determined the thermal efficiency. For given output of steam parametrs (temparature, pressure, volume) are designed individual convective surfaces and dimensons of the boiler. It is also made drawings.

The aim of this thesis is design a grate steam boiler for burning straw with an output of 10 tons of steam per hour. The produceds team has parameters 320 °C, 3,2 MPa. For a given fuel (fytomass) is calculated stoichiometric calculation. The following is the calculation of the heat balance of the boiler including the determinativ of thermal efficiency. The fuel used, the required parameters of steam and feed water temperature are designed individual convective surfaces and dimensions of the boiler. The boiler design includes drawings.

This thesis deals with a project of steam boiler to combustion of refused-derived fuel. With respect of required fuel and output parameters of the steam was worked out stoichiometry, energy loss and boiler efficiency, heat flows was allocate to individual heat exchange surfaces. The heat exchange surfaces was calculate and project in detail.

The thesis deals with steam boiler design of 88 tons per hour capacity and with the outlet steam parameters of 9,6 MPa and 520 °C. Fuel for boiler is wood chips. The main focus of the thesis is on heat calculation, design of dimensions and layout of heat surfaces. The thesis also include drawing of steam boiler.

På uppdrag från Umeå Energi AB ska två av deras rostereldade värmepannor (panna 6 och 7) undersökas med avseende på pannverkningsgraden. Umeå Energi genomför i dagsläget månadsvisa kontroller av pannverkningsgraden beräknade med den direkta metoden. Denna beräkningsmetod är dessvärre ganska otillförlitlig, vilket medför att en noggrannare undersökning av pannverkningsgraden krävs. Av denna anledning så beräknades pannverkningsgraden med den indirekta beräkningsmetoden, vilket resulterade i ett mer tillförlitligt resultat där även pannans förlustfaktorer bestämdes. Pannverkningsgraden beräknades och analyserades med hänsyn till de ingående förlustfaktorerna vid samma nyttiga effekt för båda pannorna. För att genomföra detta arbete så undersöktes först de rådande standarderna inom området, detta för att välja ut den mest lämpliga standarden för detta arbete beträffande kriterier och viktiga beräkningsfaktorer. De viktigaste provtagningarna och analyserna som dessa standarder berörde gällde bränsle, aska och rökgaser. För att genomföra alla provtagningar skapades ett provtagningsschema. Provtagningarna genomfördes på båda pannorna vid två olika provtagningstillfällen, därefter skickades proverna på analys och pannverkningsgraden kunde sedan beräknas.Resultatet som detta arbete resulterade i är att panna 6 har något högre pannverkningsgrad än panna 7, 89,3 respektive 82,8 %. Detta medför att förlustfaktorerna står för 10,7 samt 17,2 % för panna 6 respektive panna 7, där den överlägset största förlustfaktorn är rökgasförlusterna. Denna förlustfaktor beror till stor del på rökgasernas temperatur och fukthalt. Rökgasförlusterna uppgår till 9,5 samt 16,3 % på panna 6 respektive panna 7. Därefter i storleksordningen kommer askförlusterna för panna 6 (0,8 %) och värmeförlusterna för panna 7 (0,5 %). Både värmeförlusterna och askförlusterna för panna 6 respektive panna 7 uppgår till en förlustfaktor på 0,3 %. Den minsta förlustfaktorn är oförbränt i gasfas (CO) som ligger mellan 0–0,1 % för panna 6 och panna 7, detta tyder på låga halter av kolmonoxid och oförbränt i rökgaserna.De effektiviseringsförslag som detta arbete ledde fram till var att minska fukthalten och temperaturen på de utgående rökgaserna, detta genom att installera en rökgaskondenseringsanläggning som sänker rökgastemperaturen ytterligare och kondenserar ut mer fukt från rökgaserna. Detta realiseras genom att sänka kondensattemperaturen i rökgaskondenseringsanläggningen antingen genom lägre returledningstemperatur på fjärrvärmen som värmeväxlas mot kondensatet eller via en värmepump placerad mellan fjärrvärmereturen och kondensatet som arbetar med en lägre drifttemperatur än fjärrvärmen. Ett annat effektiviseringsförslag är att förbättra bränslehanteringen genom att torka bränslet innan de matas in i pannan. Slutligen skulle också en mer frekvent uppföljning av bränsleparametrar såsom värmevärde vara ett möjligt effektiviseringsförslag. Alla dessa förslag kräver dessvärre en ekonomisk och tekniskt utredning för att avgöra om dessa effektiviseringsförslag är ekonomiskt försvarbara samt tekniskt genomförbara. / On behalf of Umeå Energi AB, two of their grate fired heating boilers (boiler 6 and 7) was evaluated with respect to boiler efficiency. Currently these boiler efficiency calculations is carried out monthly by the input-output method. This calculation method is unfortunately rather unreliable, which means that a more exact examination of the boiler efficiency is required. For this reason, the boiler efficiency was calculated using the energy balance method, which gives more reliable results and also evaluates the boiler losses. Boiler efficiency was calculated and analysed with respect to the boiler losses at approximately the same useful effect for both the boilers.To perform this work the leading standards in the field were examined, which was done in order to evaluate the most appropriate standard with regard to criteria and important calculation factors. The most important samples and analyses that these standards was concerned with was fuel, ash and flue gas. To conduct all sampling, a sampling plan was created. All samplings was performed on both boilers at two sampling occasions, the samples were then sent for analysis and the boiler efficiency could then be calculated.The result from this work shows that boiler 6 has slightly higher boiler efficiency than boiler 7, 89.3 and 82.8% respectively. As a result, the boiler losses total up to 10.7 and 17.2% for boiler 6 and 7 respectively, where the flue gas losses constitutes the largest losses. The flue gas losses depends largely on the temperature of the flue gases and the moisture content. Flue gas losses sums up to 9.5 and 16.3% on boiler 6 and 7 respectively. The second largest boiler loss is ash losses on boiler 6 which sums up to 0.8% and heat losses on boiler 7 which sums up to 0.5%. The heat losses on boiler 6 and the ash losses on boiler 7 both sums up to a boiler loss of 0.3 %. The smallest loss factor is unburned in gas phase (CO) and is between 0–0.1% for boiler 6 and boiler 7, this suggests low levels of carbon monoxide and unburned in flue gases.The efficiency proposals this work resulted in was to reduce the moisture content and temperature of the outgoing flue gases, this by installing a flue gas condenser, which lowers the temperature further and condenses out more moisture from the flue gases. This is realized by reducing the flue gas condensate temperature either through lowering district heating return temperature which exchange heat with the flue gas condensate or through a heat pump that is placed between the district heating return and flue gas condensate which operates at a lower temperature than the district heating. Another efficiency proposals is to improve the fuel handling by drying the fuel before being fed into the furnace. Finally, also a more frequent follow up of the fuel parameters such as calorific value would be a possible efficiency proposal. All of these proposals require unfortunately economic and technical investigation to determine whether these efficiency proposals are economically viable and technically feasible.