The optimization of ejector geometry for mixing NaOH powders with water in on-board carbon solidification system

Owing to increasing requirement of greenhouse gas emissions reductions, researchers all over the world has been investigating and developing technology applying to all different sectors. According to the report from International Maritime Organization (IMO), the international shipping has contributed 2.2% of global carbon emissions in 2012. To mitigate this situation, organizations, researchers and engineers are striving to reduce the emissions by increasing the energy efficiency or applying emission reduction regulations and techniques. Authors has investigated a chemical absorption method to absorb and solidify the carbon content in the exhaust gases from ships. In the chemical absorption method, to absorb the carbon dioxide from exhaust gases, sodium hydroxide (NaOH) solution is applied as absorbent. However, the storage of NaOH solution may cause stability and corrosion problems on ships. To eliminate these problem, this paper introduce the ejector technology to mix NaOH powders with water to supply and replenish absorbent to the system which will reduce the storage of NaOH solution and instead only NaOH powders should be stored on board. This paper also investigates the impact of swapping fluid inlets to determine a preferred design. With the application of design of experiment and computing fluid dynamic, the optimization of the preferred design is also carried out in order to determine an optimal design of the ejector geometry.