Coal Rankings and Maturation Exercise PDF

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Summary

Coal Ranking Lab activity for GEOL 4406. Coal Ranking charts included....

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Coal Rankings and Maturation Exercise Introduction Coal is generated from compressed or lithified remains of plants deposited in a low oxygen environment. Most coal began forming in swamps or bogs where plants grew in great abundance and accumulated in thick deposits. Because the accumulations of plant remains were so thick and the water flowing through the swamps was moving so slow, the oxygen in the water was rapidly used up and bacteria were not able to decompose the plant matter as they would on the land surface or in shallow soils. In the geologic past, coal has formed from the late Devonian when land plants evolved to present day humid environments where organic matter accumulates. Coals are ranked based on the degree of coalification, their level of organic metamorphism, and their maceral content. Macerals are the original organic sediment that makes up the coal; relative maceral composition changes with coal maturity as various maceral types are destroyed by heat and pressure. The deeper the coals are buried below the surface, the increase in coalification, and the conversion of the macerals. In more mature coals, the pieces of plant material are usually dull brown to grey in color. As the rank of coal increases, the carbon content increases and volatile content decreases. Depending on the grade or rank of coal, more or less material will need to be burned to heat the same volume of water to produce steam. As carbon content increases, the grade or rank of coal increases. Therefore coal is often graded by the amount of BTU (British Thermal Units), which is the amount of energy needed to heat one pound of water from 39°F to 40°F that it produces; which means the higher the carbon content, the higher the coal grade and the less coal that is required to heat the volume of water. Lignite produces approximately 6,200 BTU of energy from one pound of material; bituminous coal produces about 13,000 BTU of energy from one pound of material; and anthracite produces approximately 15,000 BTU of energy from one pound of material. Supplies The purpose of this module activity is to characterize the coal samples you have been provided in your activity kit, by using their relative densities to identify the samples. Then you will calculate the densities for a second set of coal samples and plot them on the coal maturation curve. For this activity you will need the following from your kit:   

Module 13 Earth’s Energy coal samples (4 samples); AWS-600 scale; and Plastic beaker

You will need to provide:

Coal Rankings and Maturation Exercise   

A copy of this worksheet; Water; and Pencil and calculator.

Part One In your Module Activity kit, you will find 4 samples of coal labeled Module 13 Earth’s Energy. Use your scale to find the mass of each sample. Then use the instructions to find the volume of an irregular object found below*. Based on the descriptions found in the module content on the “Energy from Coal” webpage and the densities of your samples, identify your samples by rank as peat, lignite, bituminous or anthracite. Fill out the table below. Density Data Chart Sample

Mass (g)

Volume (ml)

Density (g/ml)

Rank of Coal

Coal Sample A

8.9g

5ml

1.78 g/ml

Anthracite

Coal Sample B

5.0g

3ml

1.6 g/ml

Anthracite

Coal Sample C

5.0g

6ml

0.83 g/ml

Lignite

Coal Sample D

2.6g

2ml

1.3 g/ml

Bitumnious

*Some of the samples are fragile so it will probably work best to leave them in the baggies when using the scale and determining volume by the displacement method. Density for an Irregular Object  Use the scale to find mass of an object in grams. Record the mass on Density Data Chart.  Pour water into a graduated cylinder up to an easily read value. Leave room in your graduated cylinder for the water level to rise when you insert your object. Record the volume of water in your graduated cylinder in milliliters.  Drop object into graduated cylinder and record new value of water level in graduated cylinder in milliliters.  The difference between the two values is the object’s volume. One milliliter is equal to 1 cubic centimeter. Record the volume on the Density Data Chart.  Compute density of object by dividing mass value by volume value. Record density on data chart.

Part Two You are a brand new geologist at a working coal mine. Your supervisor would like for you to determine the rank of coal for a set of samples that has just been delivered. In the chart below, the mass (g) and volume (cm3) of each sample has been recorded. In order to determine the

Coal Rankings and Maturation Exercise rank of coal each sample represents, you must convert your data to density using the following formula: D = m/v. Once you have found the density, fill in the density column on your chart.

Sample

Mass (g)

Volume (cm3)

Density (g/cm3)

Rank

Energy (BTU/lb)

1

8.17

6.48

1.26 g/cm3

Anthracite

About 14,000 BTU/lb

2

7.53

9.29

0.81 g/cm3

Lignite

About 10,000 BTU/lb

3

9.43

5.27

1.78 g/cm3

Anthracite

About 15,000 BTU/lb

4

9.41

22.40

0.42 g/cm3

Peat

About 6,000 BTU/lb

5

11.28

8.61

1.31 g/cm3

Bitumnious

About 15,000 BTU/lb

6

6.73

4.10

1.64 g/cm3

Anthracite

About 14,000 BTU/lb

7

8.41

13.35

0.62 g/cm3

Lignite

About 8,000 BTU/lb

8

6.52

11.24

0.58 g/cm3

Peat

About 7,000 BTU/lb

9

6.49

8.65

0.75 g/cm3

Lignite

About 9,000 BTU/lb

10

5.96

5.09

1.17 g/cm3

Bitumnious

About 12,000 BTU/lb

After you have calculated the density of your samples, take the density for Sample 1 and find that value on the horizontal axis of the coal maturation graph on the following page. Follow that density value up to the heavy black curve – the Coal Maturation Curve – then mark and label that point on the curve as Sample 1. Follow that point to the right on the vertical axis to determine the rank of coal represented by your sample, and record in the chart above. Follow that point to the left, and determine the approximate amount of energy this coal sample would produce. Mark and label points for each sample to determine the rank of coal and amount of energy this sample would produce, and complete the chart. Example: if a coal sample had a density of 1.0 g/cm3, it would rank as bituminous coal and produce approximately 12,000 BTU/pound.

Coal Rankings and Maturation Exercise

Upload your completed worksheet and photos of work to the Module 13 – Earth’s Energy dropbox. Please use Microsoft Word for your document; if you are using other software, please convert it to a pdf so it can be read in D2L. If you are uploading photos, please be sure they are able to be converted within D2L, and not in HEIC format....