Masters Thesis, KTH- Royal Institute of Technology, Stockholm Sweden Disposal of Toxic and Non-Toxic Waste through Lasers Destruction of toxic solids, liquids and gases Models and Experimental Results Author: Ali Islam Date: 30-05-2013 Supervisor :Dr. Muhammad Muddassir Silvio Gualini, Dr. Anders Eliasson, Dr. Hasse Fredriksson Masters Thesis in Materials Processing Department of Materials Science and Engineering KTH-Royal Institute of Technology, Stockholm Sweden Abstract The report discusses the destruction of toxic and non-toxic solids, liquids and gases through lasers. In order to completely understand the project first chapters describes the basics about laser and plasma separately, from definition to types, components and categories. Differences between laser and microwave system are covered in this chapter as well. Besides lasers there are different technologies that are currently being used to destroy toxic and non-toxic materials. These technologies were studied and comparison tables are made in order to discern between different destruction technologies. For the destruction of toxic and non-toxic materials through lasers two mathematical models have been developed, molecular dissociation model and plasma exploitation model, and later the experimental work was carried out on one of the toxic material. Mathematical modeling and experimental work is in accordance with each other as discussed in results and discussion. Mathematical model shows that all the materials discussed in the report can be destroyed by lasers but in order to carry further experiments on all other toxic and non- toxic materials, a proposal is made for the laser reactor using CAD model (Solid Edge) and drawing software (AutoCAD). Tables and mathematical calculations have been placed in appendix at the end of the report. Preface: This project is a portion of a big idea of Dr. Muhammad Muddassir Silvio Gualini which is to generate electrical power through solar pumped lasers. The original idea was to use solar pumped lasers to destroy toxic and non-toxic waste materials. Solid, liquid and gas toxic materials listed were supplied by AMIAT, the public company in Torino collecting house and toxic waste. The laser action on the waste materials will produce plasma and a catalyst will transform the extremely hot and high pressure plasma into a high temperature and high pressure inert gas (not-toxic, not-smelling). Generation of high temperature gas can be used to generate electricity through gas turbine. In order to obtain the optimal turbine parameters of gas temperature and pressure the inert gas is previously cooled through heat exchangers generating hot water to be supplied to for house hold purposes. The focus of this report is on the destruction of toxic and non-toxic materials through lasers. The destruction of toxic materials is studied by two mathematical models. First the molecular dissociation model is used to calculate the destruction of toxic materials and then the plasma exploitation model is used. There are different ways of destruction of toxic materials as well which are currently being employed as well but either their cost is extremely high or they produce by products which are dangerous. A solar pumped laser or a laser powered by part of the energy generated by the gas turbine (co- generation) or by a solar panel or thermal unit. In any case one of these three solutions would eliminate the running cost factor of the laser can be almost eliminated. In any case the proposed and discussed method grants the 99.5% destruction of toxic and non-toxic materials. The mathematical models prove the assertion. Contents 1. Basics about laser and plasma .............................................................................................................. 1 1.1. Laser ............................................................................................................................................. 1 1.1.1. Abbreviation .......................................................................................................................... 1 1.1.2. Definition............................................................................................................................... 1 1.1.3. How to produce laser light? .................................................................................................. 1 1.1.4. Components of lasers ........................................................................................................... 2 1.1.5. Categories of lasers ............................................................................................................... 4 1.2. Plasma ........................................................................................................................................... 4 1.2.1. Common forms of Plasma ..................................................................................................... 5 1.2.2. Degree of Ionization .............................................................................................................. 5 1.2.3. Temperature measurement of plasma ............................................................................... 6 1.2.4 Density of plasma .................................................................................................................. 6 1.2.5. Potential of Plasma ............................................................................................................... 7 1.2.6. Magnetization ...................................................................................................................... 7 1.2.7. Mathematical description of plasma .................................................................................... 7 1.3. Laser confinement of plasma ........................................................................................................ 8 1.3.1. LIBS in brief........................................................................................................................... 8 1.3.2. Life cycle of LIBS process ..................................................................................................... 10 1.3.3. Advantages of LIBS .............................................................................................................. 11 1.4. Differences between laser and microwave systems................................................................... 15 2. Overview of current technologies to treat toxic material .................................................................. 16 2.1. Thermal Energy: Incineration and pyrolysis ................................................................................ 16 2.2. Plasma Energy: ............................................................................................................................ 19 2.3. Microwave Energy: ..................................................................................................................... 21 3. Comparison tables for destruction of selected toxic materials through different technologies ....... 24 4. Molecular dissociation model ............................................................................................................. 27 4.1. Solids ........................................................................................................................................... 27 4.1.1. Zinc Sulfide, ZnS .................................................................................................................. 27 4.2. Gases ........................................................................................................................................... 31 4.2.1. NO ....................................................................................................................................... 31 4.2.2. NO2 ...................................................................................................................................... 32 4.3. Calculations for number of photons to destroy toxic materials ................................................. 32 4.4. Material destroyed rate by CO2 Gas Dynamic Laser ................................................................... 37 4.4.1. Solids ................................................................................................................................... 38 4.4.2. Gases ................................................................................................................................... 39 4.4.3. Liquids ................................................................................................................................. 40 5. Plasma exploitation ............................................................................................................................. 47 5.1. Solids ........................................................................................................................................... 50 5.2. Gases ........................................................................................................................................... 52 5.3. Liquids ......................................................................................................................................... 53 6. Proposal of laser reactor for decomposition of toxic materials ......................................................... 63 7. Experimental decomposition of NOx................................................................................................... 70 8. Results