Laboratory Demonstrations and Exercises

Chemistry in Combustion Processes I

Laboratory demonstrations and exercises

There are four laboratory stations

1. Bomb calorimeter for determination of fuel heating value (Axelia II, third floor, Laboratory of Process Design & Systems Engineering)

2. Single Particle Reactor (SPR) for combustion of single fuel particles (Axelia II, second floor, “Apparathallen”)

3. Thermal analysis using TGA/DTA for determination of fuel mass loss during conversion (Axelia II, second floor, Laboratory of Inorganic chemistry)

4. Elemental analyzer / fuel database for fuel characteristics (Axelia I, first floor, PC-class)

Below are tasks and question to be answered in connection with the laboratory demonstrations.

Bomb calorimeter

 Shortly review (describe for yourself) what is the working principle of the bomb calorimeter

 Which heating value (HHV or LHV) is obtained with the bomb calorimeter?

 What fuel did you examine, what was the heating value obtained, and does the value agree with existing data? (see “fuel database” further down in this document)

 Calculate what is the effective heating value of the fuel in case it contains 30 wt-% moisture? (You can neglect moisture formed from fuel-H)

1  What other approaches than calorimetry can be used for obtaining the heating value of a fuel, and why was calorimetry a good approach to use in the case of your fuel?

Single Particle Reactor and TGA/DTA

You will receive combustion video and CO2 and NO emission data, as well as TGA data for coal and wood. You task is to

 use the emission data to calculate amounts (mg) of carbon (C) and nitrogen (N) released during combustion,

 relate these to the fuel sample mass (=calculate sample C and N contents in wt-%)

 compare your calculated C and N contents with fuel analysis data (see “fuel database” further down in this document)

 Reflect (discuss) is there a difference in C and N contents between fuels (coal vs. wood), and a difference in your experimental C and N contents and database data?

 What fuel analysis (proximate or ultimate) does the TGA data provide?

 From the video, estimate times for pyrolysis and char combustion

 Identify from TGA curves the mass losses corresponding to pyrolysis and char combustion,

 Compare your TGA data with fuel analysis data (see “fuel database” further down in this document)

 Reflect (discuss)

o is there a difference in pyrolysis and char combustion times between fuels (coal vs. wood) ?

o 4.2) is there a difference between volatile/char carbon contents between the fuels (coal vs. wood) ?

2 3 Elemental analysis / fuel database

Fuel data bases are a good place to look for fuel type specific information. Your task is to have a look at two fuel databases to see what kind of information they contain, and to search for information relevant for your lab demo calculations.

Database by the Energy Research Centre of the Netherlands https://www.ecn.nl/phyllis2/

The above link points to a web page where you can enter for example “wood” as the name of the material you are looking for, or you can click the link under the green “Start browsing” text.

Both take you to a navigation page where you can choose fuel type from the “search tree” structure on the left side of the page.

After selecting material type, you need to press the “Average of selected” button at the top of the search tree to obtain the data.

Åbo Akademi fuel database https://web.abo.fi/fak/tkf/ook/bransle/

Choose ”Free Access” and follow instructions to start browsing. Select fuel type from “search tree” on left of the web page.

4 Groups and schedule for laboratory demonstrations

Group 1 Group 2 Group 3 Group 4 9.40 Fuel database Bomb TGA, Axelia II, Single Particle o’clock PC-class calorimeter, 2nd floor, Lab of Reactor, Axelia II, 3rd Inorganic Axelia II, floor chemistry “Apparathallen” 10.10 Single Particle Fuel database Bomb TGA, Axelia II, o’clock Reactor, PC-class calorimeter, 2nd floor, Lab of Axelia II, Axelia II, 3rd Inorganic “Apparathallen” floor chemistry 10.40 TGA, Axelia II, Single Particle Fuel database Bomb o’clock 2nd floor, Lab of Reactor, PC-class calorimeter, Inorganic Axelia II, Axelia II, 3rd chemistry “Apparathallen” floor 11.10 Bomb TGA, Axelia II, Single Particle Fuel database o’clock calorimeter, 2nd floor, Lab of Reactor, PC-class Axelia II, 3rd Inorganic Axelia II, floor chemistry “Apparathallen”

Group 5 Group 6 Group 7 Group 8 11.40 Fuel database Bomb TGA, Axelia II, Single Particle o’clock PC-class calorimeter, 2nd floor, Lab of Reactor, Axelia II, 3rd Inorganic Axelia II, floor chemistry “Apparathallen” 12.10 Single Particle Fuel database Bomb TGA, Axelia II, o’clock Reactor, PC-class calorimeter, 2nd floor, Lab of Axelia II, Axelia II, 3rd Inorganic “Apparathallen” floor chemistry 12.40 TGA, Axelia II, Single Particle Fuel database Bomb o’clock 2nd floor, Lab of Reactor, PC-class calorimeter, Inorganic Axelia II, Axelia II, 3rd chemistry “Apparathallen” floor 13.10 Bomb TGA, Axelia II, Single Particle Fuel database o’clock calorimeter, 2nd floor, Lab of Reactor, PC-class Axelia II, 3rd Inorganic Axelia II, floor chemistry “Apparathallen”

PC-class reserved 9-13 and 15-17. Lunch at 13