In 2016 the Paris agreement was adopted by 196 parties. The main goal of this agreement is to obtain a climate-neutral world in 2050. The CO2 emissions should decrease as soon as possible to achieve this goal. Concrete is the world's most used building material, and with good reason, it provides cheap, solid and reliable products used for over 200 years. However, concrete is responsible for 5-10 % of the yearly CO2 emissions worldwide. These emissions are mainly because of cement production, the binding agent of concrete. Therefore, to lower the CO2 emissions from concrete, it is most effective to opt for an alternative binder. This research focuses on alkali-activated materials (AAMs), where an alkali-activated binder has replaced cement. This binder consists of a precursor and an alkaline activator. The materials most commonly used as precursors are blast furnace slag and fly ash, waste products. The production of these materials is not nearly enough to replace cement. Therefore, there is a need for alternative precursors. Volcanic materials can be an alternative precursor, and some have been successfully applied in AAMs before. However, since volcanic materials come in different forms, validation of a wide range of volcanic materials.

This research has investigated four European aluminosilicate volcanic materials: trass, phonolite, perlite and pumice. Each of these materials has been assessed on their particle size, chemical composition and microstructure to determine whether they exhibit (pozzolanic or latent hydraulic) reactivity. All four materials classify as inert. For trass and phonolite, the lack of reactivity is most likely because of their lack of amorphous phases (around 30% and 5%, respectively). For perlite and pumice, it is because of the too coarse particles.
The reactivity of trass and phonolite is enhanced by calcination, and the reactivity of perlite and pumice is enhanced by grinding. Determination of the reactivity shows that calcination had no or a negative effect on the reactivity of trass and phonolite. Most likely because of the lack of calcium and magnesium in these materials. Ground pumice does show an increase in reactivity. However, not sufficient to be classified as reactive. Ground perlite does show reactive behaviour and is classified as pozzolanic, less reactive.

Ground perlite and BFS are used as precursors in mortar to assess the contribution of perlite to compressive strength development. It shows that perlite contributes to the strength of mortar when combined with a sodium silicate and sodium hydroxide activator. Likely, the sodium silicate is necessary to delay the alkalinity of the mixture. This alkaline delay makes that perlite does not form a layer of hydration products over the particles, making it impossible for perlite to react further and contribute to the compressive strength. TGA measurements found that because of the silicates that perlite contributes to the mixture, the hydration products become denser, which seem to cause higher strength. However, it is also found that silicates from sodium silicate solution are more effective in providing silicates than perlite is.

Of all four materials, only perlite seems to be reactive enough to contribute to the strength of alkali-activated binders as precursors. Volcanic materials cannot be considered to be one material, and each one has to be assessed individually.

Transition to renewable and alternative energy sources has become one of the most important subject of the decade. In The Netherlands today, 11.1% of the primary energy demand is obtained from renewable energy and the biomass accounts for 54% [1]. Another promising material for value added chemical synthesis is carbon dioxide. By utilization of CO2, the production of valuable chemical materials such as methanol, formic acid that can be used as a fuel, heat or power source and reducing the greenhouse gas effect by lowering emission levels will provide industrial and environmental advantages at the same time. Formic acid, used in the agriculture, pharmaceuticals and textile, is a key chemical that can also be used in energy conversion processes. In the current industrial practice, formic acid is produced by carbonylation of methanol with carbon monoxide. However, methanol is another value added chemical that is used in energy production, hence expensive for the process. Therefore, researchers started looking into alternative methods. Biomass and carbon dioxide utilization methods are two of them. In this thesis study, 10 kton and 100 kton annual production of 85 wt.% formic acid from wet oxidation of glucose and catalytic reduction of carbon dioxide, have been modeled and a techno-economic analysis is carried out. Additionally, the processes of obtaining glucose from lignocellulosic biomass and carbon dioxide from syngas by pre-combustion capture are also simulated. ASPEN Plus V8.8 process flowsheeting package program has been used for the simulations. From the results, in energy analysis biomass based formic acid synthesis process showed higher efficiency than CO2 based production. When the hydrogen peroxide and oxygen based biomass wet oxidation routes are compared, it is observed that oxygen based operation is more efficient than hydrogen peroxide based conversion because of lower utility requirements. It was determined that biomass based formic acid production can be economically profitable, but only for large scale wet oxidation via oxygen together with the sale of by-products obtained in pre-treatment process. On the contrary, no profit was obtained by the hydrogen peroxide route. In carbon dioxide utilization route, the breakeven selling price (BSP) of the formic acid was computed to be 7% more than the current market price. In order to improve the process, two case studies were created. In the first case, economically the most suitable reactor amount configuration is determined. However, the process was still not profitable. In the second case study, two times more active catalyst, Au=Al2O3, has been utilized. The process took half the residence time of the previous case and BSP value determined to be 2.6% lower than the current market price. Also, slight increase in efficiency is observed. In conclusion, more research should be done and experiments regarding reaction and intermediate substance performances should be conducted, in order to simulate the process more in detail. However, despite the uncertainties, in this era where the transition to greener energy production through the use of biomass and the reduction of carbon dioxide emissions have been made a definite target by the governments, the synthesis methods studied, will gain importance as the purposes of formic acid use increase.

The increasing use of silver nanoparticles (AgNPs) in various products leads to their presence in the aquatic environment. The dissolution of AgNPs is an important property that has a direct impact on human health and the natural environment. Understanding the dissolution behaviour of nanoparticles in liquid suspensions is essential for predicting their potential toxic effect in organisms, ranging from viruses and bacteria to humans. Moreover, the dissolution rate of nanoparticles can explain some of their disinfecting properties, which are important for sanitation. The objective of this study is to determine the dissolution behaviour of AgNPs in pure water and to improve our understanding of its most fundamental principles. Dissolution constants of AgNPs found in literature span over a wide range, indicating that improvement of the measuring method is needed. AgNPs in this study were produced in a principally impurity-free way, from the gas phase, after which they were transferred into liquid solutions. The purity of the particles produced in this study is in principle higher compared to those used until now, which allows for higher precision in determining the dissolution constant. Measuring the silver ion concentration in the resulting liquid solutions (i.e., after introducing the AgNPs in the solution) with an ICP-MS at specific time intervals gave direct information on the dissolution kinetics. The experiments were repeated with particles having diameters from 7 to 12 nm and, as expected, dissolution kinetics were found to be highly dependent on particle size. The determined dissolution constants are in the same order of magnitude as the values reported in literature. To further improve the reliability of the measurements, the experiment needs to be repeated using different methods for transferring the particles into the liquid, given that the used bubbling method showed deficiencies.

Presently, the majority of the worlds energy supply is dependent on fossil fuels. As these fuels area limited resource and have significant negative side effects, the way humanity uses these is unsustainable and other sources of energy have to be found. One of these sustainable energy sources is plant-derived biomass. However, biomass cannot be efficiently used in its natural form and needs to be converted to other products through processes such as pyrolysis and gasification. Pyrolysis will be the focus of this thesis, as fast pyrolysis of Miscanthus is studied for the BRISK 2 project at Process & Energy (TU Delft). However, the current setup used for pyrolysis research does not provide a complete mass-closure of the experiments, with only 80% of the total mass accounted for in the char, tar and gaseous yields. In order to improve this closure, four different methods were developed and investigated during this thesis. All of the pyrolysis experiments were performed in a Pyroprobe 5200. The pyrolysis parameters were comparable to fast pyrolysis, with a high heating rate of 600°C/s, a low residence time of 10 s and a Final Pyrolysis Temperature between 600°C and 1000°C. The objective of the first adjustment was to improve the purge flow stability, reduce the amount of blockages in the system and increase the accuracy of the experiments. The flow meter, controlling the purge flow, was replaced with a mass-flow controller and a tube in the setup was simplified and shortened. No further blockages were observed and the total mass-closure improved on average by 7.85 wt% over the temperature range of 600-1000°C, with an increase at every temperature. The second considered element was the homogeneity of the biomass. Two biomass feedstocks were investigated, the first feedstock consisted of inhomogeneous pellets grinded down to a size less than 80μm, while the second type was homogenized biomass of a size of less than 200μm. Both biomass types performed comparably to each other and better than the previous data collected with the setup. At 600°C the inhomogeneous biomass performed better, while at 700°C the homogeneous biomass gave a higher yield. The last two experimental series both focused on gravimetrically measuring the tars collected in the condenser of the setup, which was not gravimetrically measured before. The first of these methods removed the condenser in favour of a direct capture in a quartz trap. This gave a maximum yield increase of 1.14 wt% at 700°C. However, concerns of contaminating the gas mixture with tars arose, therefore this method was not investigated at higher temperatures. In the second technique, the 2ml of isopropanol in the condenser was evaporated from a glass Petri dish, leaving the tars behind. This method was explored over a larger temperature range (600-1000°C), yet only provided a maximum increase of 1.5 wt% at 1000°C, while giving significant fluctuations between experiments. Thus proving that neither of these methods is a suitable way of gravimetrically measuring the condenser.

Our use of pharmaceuticals, pesticides and personal care products leads to an increase of organic micropollutants (OMPs) into the aquatic environment. Conventional wastewater treatment plants are not designed for the removal of OMPs and need to be upgraded to reduce OMP contamination. The adsorption of OMPs to zeolites is proposed as an alternative treatment method. Zeolites are synthesized as powders, however they need to be shaped into pellets to be used in water treatment practice. This research focussed on engineering zeolite pellets and which properties of these pellets are important for the adsorption of OMPs.
First the influence of the calcination temperature and binder content on the mechanical stability and porosity of the pellets was analysed. Second, the influence of two different preparation techniques (extrusion and high-shear granulation) and the introduction of a polymer on the mechanical stability, porosity and adsorption kinetics of the pellets was assessed. Third, the effect of the porosity on the breakthrough for an empty bed contact time (EBCT) of 20, 5 and 1 minute(s) was determined according to the linear driving force (LDF) model. It was found that an increasing binder content and calcination temperature increased the wear resistance and porosity of the pellets. However, the effect on the porosity is minimal. The introduction of the polymer had opposite effect on extruded and granulated pellets. For extruded pellets, the introduction of the polymer increased the porosity. However, the granulated pellets showed a decrease in porosity. A relation was found between the porosity and the wear resistance and between the porosity and adsorption kinetics. A larger porosity decreased the wear resistance of the pellets and increased the kinetic rate constant. The porosity was of great importance in relation to the breakthrough. First, the porosity in the zeolite pellets determined to a great extent the bulk density of the filter bed. A higher bulk density resulted in a later breakthrough point. The bulk density was also influenced by the shape of the pellet. Spherically-shaped (granulated) pellets had a higher bulk density than rod-shaped (extruded) pellets. Second, the porosity was related to the kinetic rate constant. At lower EBCTs (5 and 1 minute), the kinetic rate constant had an influence on the breakthrough point. For these EBCTs, a higher kinetic rate constant led to a later breakthrough point. It was recommended to optimize the zeolite pellets by making the extruded pellets in a more spherically-shaped form and to start column experiments to validate the LDF-model.