How I made my bachelor's final report

"Preliminary Design of Hydrogen Plant Using Low Pressure Gasification of Rubber Wood"

When it came to me a time to make my bachelor’s final report (a preliminary design of a chemical plant), I had a will in my mind that I wanted to write something new. I wanted to design a new plant that had not been designed yet by my previous seniors.

Therefore, I went to a net shop almost everyday to get an idea of my plant design. I was interested in biomass technology at that time, so I always tried to search a process involving biomass. With search engine Google, I used keywords like “biomass processing chemical plant process flow diagram”. Finally, I got an excellent file (in pdf) from National Renewable Energy Laboratory, United States. It was a report file of a detailed design and economics of biomass to hydrogen production utilizing the battelle columbus laboratory indirectly heated gasifier. The files contained complete process flow diagrams divided into some plant areas, complete mass and energy streams tables, specification table for every equipment in the plant, and the economic analyses. The plant used yellow poplar as the biomass sources. It is a kind of American wood.

I was so excited and confident with this file. I decided to design such plant in Indonesia with different kind of wood. Soon, I met my advisor to discuss about it. He agreed with my title. He suggested me to use rubber wood because the source was abundant especially in South Sumatra Province.

The file I had did not contained the detailed calculation certainly, only the numbers showed. So I had to find out how they got the numbers. I used HYSYS to simulate their plant untill I got the equal results, the equal numbers, as they. It took about two weeks to deal with it. From here, I modified my simulation by changing the raw material of the plant, from yellow poplar to rubber wood. The next step was I had to calculate all the results from the HYSYS simulation manually because all calculations had to be described in my final report. This step took the time mostly because I stopped to calculate untill my calculations were equal to HYSYS’s.

The most difficult problem in my final report was to design the equipments. Some could be done by HYSYS but most could not. However I had to write down the detailed calculations in my report. More and more study of literatures were conducted by going to libraries and/or to net shop. It was a stressing moment when it was hard to find how to design an equipment correctly. After all the equipments were designed, the next step was to estimate its cost and make the economic analyses of the plant project. Thanks to Google, I found a very good file from National Energy Technology Laboratory, USA, which reported some important chemical equipments cost estimation. This file really helped me. For the economic analyses it was not too difficult because there are many references for it.

After all the things that needed detailed calculations were done (all were put in appendixes), the next step was arranging words. I had to make a good report with the format Introduction (chapter 1), Plant Overview (chapter 2), Plant Location and Layout (chapter 3), Mass and Energy Balances Summary (chapter 4), Plant Utility (chapter 5), Equipment Specifications Summary (chapter 6), Structure of Organization (chapter 7), Economic Analyses (chapter 8), and Conclusion (chapter 9). Followed by nomenclature, references, and appendixes.

The process flow diagram of the NREL plant was so long and complex. So I made it shorter by eliminating some equipments. It influenced the amount of the Hydrogen produced. Here are the processes I had modified :

· The rubber wood was crushed to chips then dried in Rotary Drier

· The chips was gasified in the Indirectly Heated Fluidized Bed Gasifier

· The syngas from the gasifier was cleaned by cylone and reformed in reformer reactor (fluidized bed)

· Gas from the reformer was cooled with some Heat Exchangers continued by scrubbing in Scrubber.

· Gas from the scrubber was then compressed to 24.7 atm in 4 step compressions

· The compressed gas was sent to the Pressure Swing Adsorber to separate Hydrogen from other gases

I learned from my experiences in finishing this report that designing a chemical plant is not an easy thing. It needs specialists from various diciplines because it is a complex problem. A chemical engineering student can only make a conceptual design not a detailed design of the plant. I believe a proverb that says “ experience is the best teacher”.

Below is a link to download my complete bachelor’s final report (in zip file). I hope it can be useful for many people especially for chemical engineering students who want to make a plant design.

http://getfilehosting.com/file/125/-s-H2_Plant.zip.html