Vattenfall district Heating power plant in Uppsala produces district cooling with absorption heat pumps which leads to a large amount of waste heat that has to be cooled with evaporative cooling towers. The Environmental Court has ordered Vattenfall to survey the possibilities to recover the heat, which is the focus of this thesis.The study begins with an overview of the system, and conditions and limitations for waste heat recovery is examined. In the next step alternatives to recycle the heat is evaluated, either by direct recovering or by upgrading.First, the technical possibility of each alternative is discussed, and then the operation time and the amount of recovered heat is calculated. Those alternatives which are possible are brought further to an economic analysis.The cost of investment for each alternative constitutes the basis for a present value analysis. The results are put together in a table where the total amount of recovered heat is compared with the present value for the different alternatives.

Odling av mikroalger för framställning av biogas är ett relativt outforskat område. Den forskning som hittills utförts har påvisat lovande resultat tack vare möjligheten att utnyttja resurser som idag går till spillo, eller till och med utgör miljöproblem; mikroalgerna kan rena både näringsrikt vatten (exv. avloppsvatten) och koldioxidutsläpp (rökgaser från industrin) då de tar upp föreningar innehållande kväve, fosfor och kol från dessa källor. Den producerade biogasen kan ersätta fossila bränslen. Dessutom skapas en rötrest som kan återföras till odlingsmarker vilket sluter näringskretsloppet.

District heating covers around 80 % of the heating demand in apartment buildings and 10 % in single-family homes in Sweden. In the year 2010 the total input of energy to the Swedish district heating grids was about 70 TWh, which corresponds to 11 % of the total energy input to the whole energy system in the country. Through the combined production of heat and power the CHP-plants often reaches an efficiency of 90 % from energy in the fuel to produced heat and power. In order to keep the efficiency high it is important for the owners of the plant to have good knowledge about the plants performance at different operation points. Strängnäs Energi AB initiated this diploma work together with FVB Sverige ab in order to come up with a program for short term planning of the production of heat and power at the company´s CHP-plant.The work consists of three main parts.

District heating covers around 80 % of the heating demand in apartment buildings and 10 % in single-family homes in Sweden. In the year 2010 the total input of energy to the Swedish district heating grids was about 70 TWh, which corresponds to 11 % of the total energy input to the whole energy system in the country. Through the combined production of heat and power the CHP-plants often reaches an efficiency of 90 % from energy in the fuel to produced heat and power. In order to keep the efficiency high it is important for the owners of the plant to have good knowledge about the plants performance at different operation points. Strängnäs Energi AB initiated this diploma work together with FVB Sverige ab in order to come up with a program for short term planning of the production of heat and power at the company´s CHP-plant.The work consists of three main parts.

The aim of this thesis is to improve the control of urea injection at the combined power and heating plant Framtidens Gärstad (FTG). Tekniska Verken i Linköping AB is the owner of the plant.The FTG plant consists of a boiler where garbage combustion is done. From the combustion nitrogen oxides are emitted. These nitrogen oxides are hazardous to the environment. To reduce the nitrogen oxides, injection of urea into the boiler is used.

Soils in a metal contaminated site on Stångberget in Gusum in southeastSweden were investigated and compared to relatively unaffected soils a fewkilometres away. Pollution came from historical release of untreated flue gasesfrom a brass mill. The objective was to find information on how high the metalconcentrations are, if metals from the polluted soil affect the surroundings andif the metal contamination affects the microbial community. The soil wasinvestigated using several different methods, such as field XRF measurements,chemical analysis of metal, carbon and nitrogen content, pH, acid neutralizingcapacity, texture, soil depth, field leach tests, sequential extraction and microbialfunctional profiles. The study showed that copper and zinc concentrationswere above Swedish Environmental Protection Agency guidelines for lesssensitive land use on the entire investigated area.

Föreliggande rapport är ett resultat av ett examensarbete utfört på Lulekraft AB (LUKAB), med syftet att dimensionera en återföring av rökgas. Målen är att sänka utsläppen av NOx, att minska fluktuationerna av temperaturen i överhettarna vid bränslebyte samt att undersöka ifall verkningsgraden ökar med implementerad rökgasåterföring.Ett flertal olika sätt att reducera utsläppen av NOx finns grundligt beskrivna i litteraturen, såväl i rökgasflödet som av modifikation av brännarna. Åtgärder i rökgasflödet är t.ex. rökgasåterföring (FGR, flue gas recirculation) och selektiv katalytisk reduktion (SCR, selecive catalytic reduction). Rökgasåterföringen sänker temperaturen på flamman, vilket leder till en sänkning av bildningen av termisk NOx.

Solid waste management is one of the most essential functions in a country to achieve asustainable development. In India, it has been one of the least prioritized functions during thelast decades. The most common ways to treat waste in India today are open dumping anduncontrolled burning. These methods are causing severe environmental pollution and healthproblems. India is one of the world?s largest emitter of methane gas from waste disposal.Since methane is a strong greenhouse gas, even small emissions have large impact on theclimate.

Samhället är mer eller mindre konstant utsatt för risker. De flesta av dem är så små, och har kanske till och med så pass obetydande effekter för individen om de realiseras, att vi negligerar dem i våra dagliga beslut. Vid vissa tillfällen står vid dock inför beslut som är betydligt svårare, t.ex. i vilken mån vi ska handla kostsamma försäkringar för stora olyckor som högst osannolikt inträffar men skulle få katastrofala konsekvenser. Liknande situationer uppstår för centrala beslutsfattare där man fattar beslut att genomföra riskreducerande åtgärder i samband med potentiella katastrofer.

This report is made as a literature review, focusing on the work done to increase understanding of efficiency in the categories of substations and secondary heating systems, with respect to the deviation from the theoretically possible cooling off in the distribution network as well as the economic benefit that appear. The main purpose of a considerable part of the literature used in this report addresses the issue of identifying individual causes of reduced cooling in district heating systems. These literature resources have been compiled and summarized as part of the report.The technology of district heating is associated with benefits such as better use of the energy in a fuel. This is the case of cogeneration plants where serial generation of electricity and thermal energy increases efficiency compared with the parallel generation where heat is generated locally and electricity is generated centrally. Serial generation thus allows for lower primary energy demand.