Solid Waste Engineering
Solid Waste Engineering
3rd Edition
ISBN: 9781305635203
Author: Worrell, William A.
Publisher: Cengage Learning,
bartleby

Concept explainers

Question
Book Icon
Chapter 7, Problem 7.12P
To determine

(a)

The high heat value in terms of moisture free.

Expert Solution
Check Mark

Answer to Problem 7.12P

The high heat value in terms of moisture free is 7506.6Btu/lb .

Explanation of Solution

Given:

Moisture content is 20% .

Weight of sample placed in calorimeter is 1.2g .

Gross calorific value is 6200Btu/lb .

Weight of ash that remains in the bomb calorimeter after combustion is 0.3g .

Concept Used:

The moisture heat is subtracted from the original heat energy in case of moisture free condition.

Calculation:

Write the expression for high heat value in moisture free condition.

  HHV1=(HHV0×M0)(HV water×M water)M0Mwater   ...... (I)

Here, high heat value in moisture free condition is HHV1 , original mass is M0 , original heat value is HHV0 , mass of water content is

  Mwater and latent heat of evaporation for water is HVwater .

Convert the mass of the sample to pounds.

  1.2g=(1.2g)( 0.0022046lb 1g)=2.65×103lb

Substitute, 2.65×103lb for M0 , 6200Btu/lb for HHV0 , 20% of M0 for HVwater and 974Btu/lb for HVwater in Equation (I).

  HHV1=( 6200 Btu/ lb ×2.65× 10 3 lb)( 974 Btu/ lb ×( 0.20×2.65× 10 3 lb ))2.65× 10 3lb( 0.20×2.65× 10 3 lb)=15.914Btu2.12× 10 3lb=7506.6Btu/lb

Conclusion:

Thus, the high heat value in moisture free condition is 7506.6Btu/lb .

To determine

(b)

The high heat value in moisture free and ash free conditions.

Expert Solution
Check Mark

Answer to Problem 7.12P

The high heat value in moisture free and ash free condition is 9543.8Btu/lb .

Explanation of Solution

Concept Used:

The moisture heat and the ash heat is subtracted from the original heat energy in case of moisture free and ash free condition.

Calculation:

Write the expression for the high heat value in moisture free and ash free condition.

  HHV2=(HHV0×M0)(HV water×M water)(HV ash×M ash)M0MwaterMash   ...... (II)

Here, high heat value in moisture free and ash free condition is HHV2 , original mass is M0 , original heat value is HHV0 , mass of water content is Mwater , latent heat of evaporation for water is HVwater , mass of ash content is Mash and value of heat for ash is HVash .

Convert the mass of ash to pounds.

  0.3g=(0.3g)( 0.0022046lb 1g)=6.6×104lb

Substitute, 2.65×103lb for M0 , 6200Btu/lb for HHV0 , 20% of M0 for HVwater , 974Btu/lb for HVwater , 6.6×104lb for Mash and 3000Btu/lb for HVash in Equation (II).

  HHV2=[ ( 6200 Btu/ lb ×2.65× 10 3 lb )( 974 Btu/ lb ×( 0.20×2.65× 10 3 lb ) ) ( 3000 Btu/ lb ×6.6× 10 4 lb ) ]2.65× 10 3lb( 0.20×2.65× 10 3 lb)6.6× 10 4lb=13.934Btu1.46× 10 3lb=9543.8Btu/lb

Conclusion:

The value of the high temperature of heat in moisture free and ash free condition is calculated using the concept of subtracting moisture free and ash heat from original energy.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
A sample of refuse has a moisture content of 20%. A 1.2 g sample is placed in a calorimeter, and a gross calorific value of 14,400 kJ/kg is measured based on the temperature rise. Further analysis shows that .3 g of ash remains in the bomb calorimeter after combustion. Calculate the HHV in terms of (a) moisture-free and (b) moisture- and ash-free
In a laboratory we are doing a series of tests on a sample of aggregate. This sample has the wet weight of 586.3 gr and dry weight of 513.9 gr. If the absorption of this aggregate is measured as 2.23%. Calculate the percent of free water in the original wet sample.
A sample of wet aggregate 297.2 N. After drying in an oven, this sample weighed 281.5. The absorption of this aggregates is 2.5%. Calculate the percent of free water in the original wet sample.   Weight of the wet aggregates (Wwet) = 297.2 N Weight of the dry aggregates (Wdry) = 281.5 N
Knowledge Booster
Background pattern image
Civil Engineering
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, civil-engineering and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Solid Waste Engineering
Civil Engineering
ISBN:9781305635203
Author:Worrell, William A.
Publisher:Cengage Learning,