In this sense, a research group of the Department of Inorganic Chemistry of the University of Granada works on a project subsidized by the Spanish Ministry of Environmental Issues to obtain activated coal from polymeric waste as raw materials.
Activated coal is a solid with a big specific area, as it presents numerous pores of the order of the nanometres which make that a surface area of a small quantity of coal ranks equally with the area of a football pitch, as points out the coordinator of the group Francisco Javier López Garzón.
It is used to manufacture filters for cigarettes, in catalysis processes, or in the decontamination of the atmosphere, among other applications. This is, precisely, in the ambit of gaseous effluents depuration, where the research group has been working for four years to obtain activated coal with a developed and homogeneous porosity and lower production expenses at the same time. In general, commercial activated coal are obtained from precursors like olive pits, almond shells or coconut shell, natural and heterogeneous products that produce heterogeneous coal, unselective as regards the absorption of pollutant substances.
Scientists have found an alternative to the use of organic polymers as precursors. However, such precursors are very expensive. That is why they have selected a waste polymer like terephthalate of polyethylene, commonly known as PET, a plastic material used in the production of drink containers. Taking into account that such waste is calculated in millions of tons in all Europe, it is an abundant raw material, easily available, because at best, these containers end up in controlled garbage dumps, whose salvage would involve the compliance of the European regulation currently in force.
The transformation of the PET into active coal is carried out by means of a process of pyrolysis, this is, the material is burnt in a special oven and in the absence of oxygen, in such a way that it does not react with coal, which is the desired product. The researchers have obtained a highly porous, selective and uniform active coal, as they have proved through absorption tests carried out with molecules of different sizes, from nitrogen to organic vapours. Faced with the obtained results, the team is experimenting with other polymeric materials, at the same time that they optimize the production process to obtain a performance of 60%, as an important fraction of the PET volatilizes during the process, and it is necessary to recover it and turn it into coal.
Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen
A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
25.09.2017 | Power and Electrical Engineering
25.09.2017 | Health and Medicine
25.09.2017 | Physics and Astronomy