An integrated process of biodiesel production from indigenous microalgae in Northern Greece: first results

For environmental, economic and competence reasons, the fuel industry has pushed for alternative fuels in the past few years. One option that is considered are biofuels, which are renewable fuels and have the characteristic of lower or zero emissions of CO2 in the lifecycle, depending on their origin, their production and use. That is done, because the carbon they contain has been committed in the development of organic matter from the atmosphere, which returns after combustion so the balance of emissions throughout the life cycle of biofuel is "theoretically zero

Multi-year interlaboratory exercises for the analysis of illicit drugs and metabolites in wastewater:development of a quality control system

Thirty-seven laboratories from 25 countries present the development of an inter-laboratory testing scheme for the analysis of seven illicit drug residues in standard solutions, tap- and wastewater. Almost 10 000 concentration values were evaluated: triplicates of up to five samples and 26 laboratories per year. The setup was substantially improved with experiences gained across the six repetitions (e.g. matrix type, sample conditions, spiking levels). From this, (pre-)analytical issues (e.g. pH adjustment, filtration) were revealed for specific analytes which resulted in formulation of best-practice protocols for inter-laboratory setup and analytical procedures. The results illustrate the effectiveness of the inter-laboratory setup to assess laboratory performance in the framework of wastewater-based epidemiology. The exercise proved that measurements of laboratories were of high quality (>80% satisfactory results for six out of seven analytes) and that analytical follow-up is important to assist laboratories in improving robustness of wastewater-based epidemiology results

Mechanical behaviour and stress corrosion cracking of super duplex stainless steel pipes in high pressure and high temperature environment

The oil and gas industry is constantly looking at ways to keep costs down in high temperature and high pressure (HPHT) well completions. The use of duplex or super duplex stainless steel (DSS or SDSS) for production tubing rather than high alloy (austenitics or nickel based) steels is one way to achieve this. An effective use of DSS or SDSS requires an understanding of the effects of environmental and metallurgical variables on the general and localised corrosion behaviour and resistance to environment assisted cracking (EAC) in HPHT well conditions. This research investigates the behaviour of small scale SDSS pipes subject to combined loads in a chloride and sulphide environment which are commonly found in the non-production annulus of oil and gas well completions. The effects of H₂S (which can sometimes leak from the production fluid) on the chloride-based fluid and ammonium bisulphite in the non-production environment is examined. This is used to provide a realistic assessment of the type of fluid that SDSS production tubing may be exposed to in service. Experimental results are presented for the failure envelope under combined internal pressure and axial tension, and mechanical properties of SDSS pipe over a range of temperatures. A standalone autoclave was designed and commissioned to study the initiation of EAC in SDSS pipes in several aqueous solutions under a range of loading conditions: internal pressure, axial load, and a combination of internal pressure and axial load. The work presented in this thesis shows that corrosion tests can be carried out using small scale pipes for better understanding of the effects of stress state on corrosion behaviour. In particular, the safe working envelope of SDSS in terms of load combination, chloride-sulphide environment and temperature is determined in this thesis. This would help the end user understand and gain better in-service performance of SDSS in oil and gas HPHT environment.EThOS - Electronic Theses Online ServiceGBUnited Kingdo