Provision of clean drinking water to poor can prevent a large number of deaths and illnesses amongst children around the world. In 2010, about 0.75 million child deaths were caused due to diarrhea, and a further 22.5 million years of life were lost due to ill-health, disability or early death caused by unimproved water and inadequate sanitation around the world. Most of these people live in regions with limited or no electricity, and abundance of sunshine and salt water or unclean water. Solar thermal distillation using solar stills is the most potent way of cleaning the salt water in the absence of electricity. Several products, such as the inflatable stills for life rafts, water-cone and water pyramid have been demonstrated for the purification of salt water. None of these is specifically targeting a single family. We found that simple ways of natural cooling improve the production considerably. Moreover, dripping from cleaned water from the condensing area reduced the production. A simple rule could be formulated that provides an estimate of the maximum length before dripping starts. With this a more clever design of the collection of clean water allows stills of larger scale that still produce efficiently. The work of this thesis we aim at a plastic based solar stills capable of providing at least 2.5 liters/day of drinking water, an amount put forward by the UNICEF. The results are being used by Dr Ten B.V. for the development of a simple and replicable mass manufacturing process for plastic based stills. Future projects for the use of solar stills are under consideration with several governments and organizations like UNHCR.@en

Plastics have been the preferred choice of material for the commercial production of the solar stills. However, most of the currently available solar stills are either too big or too small for satisfying drinking water needs of a single family. Furthermore, methods for increasing the production of water from a solar still are often difficult and costly to integrate in a solar still. Here, we show the effect of adding a plastic channels as passive condenser on an inflatable solar still. The still has a basin area of 1.8 m². The tests were performed in lab conditions at different water temperatures. The production of water achieved from the still at a water temperature of 73 ° C was 0.75  l/h. Furthermore, the production of water increased to more than 0.95  l/h with use of air flow over the the passive condenser to mimic wind or with use of wet tissue on the passive condenser to mimic evaporation cooling.

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The presence of water (H₂O) is essential for the adsorption of carbon dioxide (CO₂) on the serpentine particles. However, the use of H₂O in the slurry bed columns requires high energy inputs to maintain the temperature during operation above ambient temperatures. Moreover, the separation, drying, handling, and processing of the product stream will pose challenges and cost even more energy. Here, we show the proof of principle of CO₂ sequestration on mineral particles in a fluidized bed using a moist CO₂ stream. The setup allows wetting of the particles while maintaining fluidization. The results show 50% mineral conversion and 40% CO₂ conversion in 8 min at 1 bar and 90 °C.

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Cooling of the condensation surface increases the production of purified water in solar distillation devices, also known as solar stills. However, most cooling methods are costly, complex and involve regular monitoring. Simple, easily operable and cheap cooling in solar stills can make it attractive for commercial adaptation at a large number of rural locations across the world. Here we demonstrate the increase in the area of the condensation surface as an effective way of increasing the production of purified water from the stills. Experiments were conducted inside the lab and under the sun. In the lab experiments, performed at a constant energy input of 625 W/m(2), the production of water increased by more than 65% with an increase in the area of the condensation surface by 7.5 times. In the experiments conducted under the sun, the production of water increased by more than 50% by using an additional area for condensation which is 7.5 times larger when compared with a reference still without an additional area of condensation. Further, by using a higher heat input, we show that the effect of increase in the area of the condensation surface by 6.5 times can increase the production of water by more than five times. We further demonstrate the effect of external cooling by decreasing the temperature of the condensation surface to almost 0 degrees C. The amount of water produced from the still was increased by more than eight times by maximizing cooling of the condensation surface. The results suggest that a solar still device with an increased area of condensation surface can be adapted as a cheap, easy to manufacture and easily operable device for a large number of people who are in need of drinking water. (C) 2015 Elsevier Ltd. All rights reserved.@en

Abstract Glass has been the preferable choice of material for its use as a condensation surface in solar distillation as it gives higher water production than other materials. However, it is not certain which property and subsequently which phenomena are responsible for higher production of water. In this paper, we study the influence of different condensation surfaces on the total water production in solar water distillation. From our results, we conclude that the contact angle is the most important parameter for choosing the material of condensation surface inside a solar water distiller. Subsequently, we also conclude that the reflection of solar irradiation from the surface is the most important phenomenon affecting the differences in water production from solar distillation.@en