Novel Ammonia Storage Materials for SCR Systems : Carbon Materials – Salt Composites

• Main Author: Grimaldos Osorio, Nicolas
• Format: Others
• Language: English
• Published: Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik 2019
• Subjects: magnesium chloride; ammonia; carbon materials; SCR; NOx reduction; sorption; Composite Science and Engineering; Kompositmaterial och -teknik
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-75167

The emissions of nitrogen oxides (NOx) are a serious environmental problem due to its relationship with the formation of smog, acid rain and because they are dangerous for human and animal health. These gases are produced in high quantities in diesel engines used for automotive applications, and different strategies are being used to reduce them, among which are the Selective Catalytic Reduction (SCR) systems. For its operation, it is necessary a supply of ammonia as NOx reducing agent, but the inefficiency at low temperatures of the systems used nowadays has led to the conception of the solid ammonia storage units (ASS). Unfortunately, the materials currently used, i.e. metal halides, do not meet the ammonia supply requirements at low temperatures and have problems of swelling and agglomeration. In order to find a material with better properties for its application as an ammonia sorbent material, MgCl2 composites with different carbon materials (graphite, graphene, and SWCNTs) were prepared by direct mixing and wet impregnation methods, and characterized in this work. Despite the decrease of total storage capacity, improvements were found in thermal stability and mass retention, as well as in sorption and desorption kinetics, making these materials a first result towards the improvement of the solid ammonia storage units.