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Expert Opinion of the Doctoral Thesis
Opponent: prof. Mgr. Juraj Ladomerský, CSc.
PhD Student: MSc. Maw Maw Tun
Supervisor: prof. Ing. Helena Raclavská, CSc.
Title of the work: Optimization of Municipal Solid Waste Utilization Possibilities
A. Topicality of the chosen theme
The doctoral thesis MSc. Maw Maw Tun addresses the topical problems of optimization of biodegradable wastes processing in order to improve the quality of the biomass as one of the significant renewable energy sources. Problems of waste to energy and related problems are important in developed countries as well as in developing countries.
Conclusion
I consider the topic of the submitted doctoral thesis as very interesting and topical, namely especially from the point of view of real use of the obtained results.
B. Aim of the thesis
(the assessment of the set aims and the assessment how the PhD. candidate has fulfilled them) The aim of the dissertation thesis was to explore the municipal solid waste utilization opportunities for the environmental and economic benefits from wastes. This includes the possibilities of exploring a clean energy source from biodegradable wastes by optimization of their qualities for the purposes of combustion, sanitation, agricultural nutrients, refuse derived fuels, etc.
The objectives of the study were categorized as follows:
To optimize the quality of wastes by drying methods.
To analyse and evaluate the qualities of raw samples and the optimized samples by drying processes.
To make a comparative analysis of different drying methods.
To highlight the energy sources and greenhouse gas emission reduction possibilities from the utilization of optimized samples for biomass energy sources, based on Myanmar Therefore.
Conclusion
The PhD. candidate has fully met the set aims and on the professional level, his work corresponds with the character of scientific and research work of this type.
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C. The chosen methods of processing and the procedure of solving (comments on the chosen methods and the procedure of solving the problems)
The theoretical part of the work is divided into several logically arranged and related chapters.
Here, the author characterizes the present situation of the issue addressed.
The author describes the most common drying methods recently used around the world for optimization of MSW quality are as follows:
(a) Biodrying (b) Biostabilization (c) Solar Drying (d) Thermal Drying
Subsequently, the author describes the effect of moisture reduction on weight reduction, volume reduction and heating value increase, also energy sources for drying, benefits and drawbacks of drying methods.
The experimental part of the dissertation thesis is reproducible and verifiable. Experiment included: sample collection and preparation wastes, measuring moisture content and briefly chemical properties.
The optimization of the biodegradable wastes processing was done by oven drying and solar drying.
The calculation methods are very clearly described.
Conclusion
Methods addressed in the dissertation thesis are suitable for the chosen topic.
D. Assessment of the results obtained by the PhD. candidate
(comments on the results of the doctoral thesis mentioning the concrete contribution of the PhD. candidate)
The results of the experiments on moisture reduction, volume reduction and weight reduction of wastes with drying time are presented in detail in the dissertation thesis.
The research work investigated the qualities of the raw biodegradable wastes before and after drying processes. Very important results concerning how the quality of biomass after drying has changed were achieved.
The dissertation thesis dealt with optimization of biodegradable wastes processes to improve the quality of the biomass energy sources. Optimization was done by oven drying and solar drying, compared to sun drying. The results of qualities of biomass sources in tab. 12 and 13 are highly valuable. These results highlighted the possibilities of optimization of biodegradable waste quality for energy sources and agriculture sources.
As the outputs of the study work, the problem and current approach to the wastes for waste to energy areas as well as greenhouse gas emission reduction scenarios were highlighted.
The work has a complex character. Its results show possibilities of solving the whole series of problems and it brings preconditions for significant enrichment of our knowledge within the study program.
3 Conclusion
The candidate proved that he is well versed in his problem and he is able to use knowledge, experience and skills when solving professional problems of the studied program.
E. The importance for practice or the development of the branch of science
(comments on the importance for practice or for the development of the branch of science) The research work can be of great help to the environmental engineering applications and exploration of renewable energy sources due to the highlights of possibilities of optimization of biodegradable waste qualities by drying and their utilization for energy and agriculture. I agree with the author that this dissertation thesis would be the preliminary work for the future prospective of the research work for drying related to waste heat and heat supplied by solar energy and for exploring the possibilities of optimization and utilization of biodegradable wastes for a clean energy source and agriculture resource.
For the future research the benefits from utilization of improved biodegradable wastes in terms of GHG emission reductions are also important. The experimental results could be further processed by the LCA method.
Conclusion
The doctoral thesis includes the original, very interesting and topical knowledge, which can contribute to environment conservation.
F. Publication activity of the PhD. candidate
(comments on the PhD. candidate´s publication activity)
The dissertation thesis contains a list of own publication of the author. He has published four articles in database WOS, three of them with impact factors and two were published in Scopus, and many other articles and book chapters.
Conclusion
I find the publication activity of the PhD. candidate above standard.
G. Formal arrangement of the doctoral thesis and the language level
(comments on the structure of the doctoral thesis, its formal processing and the language level)
The dissertation thesis has 116 pages of the text, which is appropriately supported by 14 tables and 47 figures. The author used 162 references.
Conclusion
The doctoral thesis is worked out clearly, thoroughly, formulations are clear and factual. The graphics is on a high level.
4 H. Comments on the doctoral thesis
(concrete comments on the doctoral thesis)
You present in your dissertation thesis “the research work highlighted the future clean energy sources derived from biodegradable wastes in order to be used directly for direct combustion and co-firing of biomass and indirectly for the preparation processes of refuse-derived fuels”.
Could you explain the characteristics and differences between RDF, SRF and solid biofuels in more detail?
Among other things, you have a very nice chapter 2.1.4 Biomass Resources in Myanmar.
What is your idea of using your research results in Myanmar?
Utilization of waste heat from industries is one of the best solution. Are there any possibilities of waste heat using to drying in developing countries?
Could you explain the connections between R and R2 (Tab. 5 and Fig. 30(a)) in more detail?
I did not find the information about how you measured the volume of wastes.
Final assessment
The work can be considered as very progressive. It has a character of the scientific and developmental work and it fulfils the requirements of the doctoral thesis within the study program of "P2346 Mechanical Engineering" and field of study "2302V006 Energy Machines and Equipment". The results can also be of great importance for solving the subject tasks within the international context for both basic and applied research.
I consider the submitted work to be of good quality and I recommend to defend it and I recommend giving doctoral degree "doctor" - Ph.D.
In Zvolen on 08.07.2019
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Prof. Mgr. Juraj Ladomerský, CSc.
