An underfeed stoker feeds coal to a boiler at the rate of 100 kg/hr. The ultimate analysis of coal is: C = 75.2 %, H;= 3.6 %, O; = 7.4 %, N2 = 1.2 %, S = 2.1 % and the remaining is Ash. The dry refuse taken from the ash pit shows 20 % C and 80 % ash by weight. Orsat analysis of the flue gases gives the following composition, CO, = 75.2 %, O2 = 7.9 %, CO= 1 % Determine: a) m³ of air supplied per minute if the pressure is 100 kPaa and 20 °C; b) Total volume of flue gases flowing through the stack per minute if the temperature is 60 °C and pressure is 100 kPaa.

An underfeed stoker feeds coal to a boiler at the rate of 100 kg/hr. The ultimate analysis of coal is: C = 75.2 %, H;= 3.6 %, O; = 7.4 %, N2 = 1.2 %, S = 2.1 % and the remaining is Ash. The dry refuse taken from the ash pit shows 20 % C and 80 % ash by weight. Orsat analysis of the flue gases gives the following composition, CO, = 75.2 %, O2 = 7.9 %, CO= 1 % Determine: a) m³ of air supplied per minute if the pressure is 100 kPaa and 20 °C; b) Total volume of flue gases flowing through the stack per minute if the temperature is 60 °C and pressure is 100 kPaa.

Principles of Modern Chemistry

8th Edition

ISBN:9781305079113

Author:David W. Oxtoby, H. Pat Gillis, Laurie J. Butler

Publisher:David W. Oxtoby, H. Pat Gillis, Laurie J. Butler

Chapter17: Electrochemistry

Section: Chapter Questions

Problem 80AP

See similar textbooks

Similar questions

In a combustion operation, anthracite used showed 92.8% C and 1.3% ash. If this coal is burned in dry air at 28°C, 1 atm abs, combustion gases with the following Orsat analysis results: 14.15% CO2, 5.77% 02, 79.97% N2, 0.03% SO2, and 0.08% NO. The combustion gases leave at 600°C and 800 mmHg. a) What is the ultimate analysis of the anthracite coal? b) What is the calorific value of the solid fuel in MJ for every kg of anthracite coal? c) What is the Orsat analysis of the flue gas?
1. A boiler burns fuel oil with the following analysis by mass : 80% C 18% H2 2%S 30% excess air is supplied to the process. Calculate the stoichiometric ratio by mass and the % Carbon Dioxide present in the dry products. (15.62/1 14.9% CO2) 2. A boiler burns coal with the following analysis by mass : 75% C 15% H2 7%S remainder ash Calculate the % Carbon Dioxide present in the dry products if 20% excess air is supplied. (16.5% CO2) 3. Calculate the % of each dry product when coal is burned stoichiometrically in air. The analysis of the coal is: 80% C 10% H2 5% S and 5% ash. (76.7%N, 22.5% CO2 0.8% SO2)
In the common process for the manufacture of nitric acid, sodium nitrate is treated with aq. sulphuric acid containing 95% H2SO4. In order that the resulting "niter cake" may be fluid; it is desirable to use sufficient acid so that there will be 34% H2SO4 by wt in the final cake. This excess H2SO4 will actually be in combination with the Na2SO4 in the cake, forming NaHSO4, although for purposes of computation it may be assumed to be free acid. The cake will contain 1.5% water and the reaction will go to completion, but 2% of the HNO3 formed will remain in the cake. Assume that the NaNO3 used is dry and pure. Calculate per 100 kg of NaNO3 charged: (a) wt and % composition of the niter cake (b) wt of aqueous acid to be used (c) wt of water vapor and nitric acid distilled from the niter cake.
Six iron tablets containing FESO4-7H,0 were dissolved in 100-ml of 0.1 M HNO; with gentle heating. All of the Fe- is converted to Fe by the strong oxidizıng conditions. After the solution had cooled to room temperature 2.5-ml of 35wt% NH4OH was added. The precipitate Fe;O3-xH,O that was filtered weighed 0.345 g. Thermogravimetric analysis of the crude product showed a 10.5% weight loss below 150 C How much iron was in each of the tablets? Report the average mg-Fe per tablet?
A sample of steel (0.506 g) was digested in acid and the solution made up to 100 cm3 with deionised water. Aliquots (25.0 cm3) of this solution were transferred into two volumetric flasks (100 cm3) labelled A and B. Flask A was made up to volume with deionised water. To flask B was added 10.0 cm3 of a 260 ppm standard solution of Mn2+ which was then also made up to volume with deionised water. The following absorbance results were obtained: Solution A = 0.356, Solution B = 0.578. Use these results to calculate the percentage (% w/w) of manganese in the steel sample.
Zinc may be directly leached from zinc-lead sulphide concentrates by reaction with sulphuricPbS(s) + H2SO4 + 1 O2(g) → PbSO4(solid) + SÂ° + H2O 21ZnS(s) + H2SO4 + 2 O2(g) → ZnSO4(aq) + SÂ° + H2Oacid and oxygen. In addition, lead sulphide will be oxidized to give insoluble lead sulphate:Assume that a plant is to treat 400 t/day of concentrate containing 20.0 weight % Zn as ZnS and 110.0 weight % Pb and PbS. The concentrate and leach solution enters the leaching vessel at 32.0% solids. During the leach, 85.0% of the zinc is extracted and all the lead sulphide is oxidized. After the leaching step, the slurry passes to a thickener.(a) Calculate the concentration of Zn (in g/L) in the solution passing to metal recovery. Assume a solution density of 1.11 g/mL.(b) Calculate the tonnes per day of elemental sulphur produced.NOTE: â€œ% solidsâ€ is the solids content of a slurry (consisting of particles and solution) and is defined as…
Tungsten is extracted from the mineral scheelite (CaWO4) by roasting it with natrite (Na2CO3) at a temperature of about 700 °C. This converts the CaWO4 to water soluble sodium tungstate (NazWO4). The solid product from the roaster (called "calcine") is transferred to a leacher. In the leacher chilled water is added to dissolve the NazWO4. The chilled water dissolves only the NazWO4 in the solid calcine. The scheelite that enters the roast is mixed with gypsum (CaSO4-2H2O). This stream is 85.2%w CaWO4 and 14.8%w CaSO4-2H2O. (%w means “percent-by-weight.") Four reactions take place during this process. In the roaster: 1: CaWO4 + Na2CO3 - NazWO4 + CaO + CO2 2: CaSO4•2H2O - CaSO4 + 2H2O In the leacher: 3: СаО + H2О —- Са(ОН)2 4: CaSO4 + 2H2O - CaSO4 2H2O The first reaction does not go to completion, all the other reactions do go to completion. For the conditions shown in the process diagram on the next page calculate the conversion of the CaWO4 in the roaster.
The Nernst-Planck equation (shown below) describes the motion of a charged chemical species in a fluid. dC; z,FC; dv J; = - D; dx RT dx' What are the units for the ion flux J, where: zis the valence state of the ion (unitless) C is the concentration (mol/m³) Fis the Faraday constant (Coulomb/mol) Ris the ideal gas constant (kg m²/(s² mol °K)) Tis the temperature (K) dCi/dx is the concentration gradient (mol/m*) dV/dx is the electric potential gradient (V/m) D; is the diffusion coefficient (m²/s) Note that Coulomb is a unit of charge and V is volts where 1 V= 1 Joule/Coulomb)
Pure CO2 may be prepared by treating limestone with sulfuric acid. The limestone used in the process contains CaCO3, MgCO3 and inert. The acid used contains 12% H2SO4 by weight The residue from the process had the following composition. CaSO4 – 8.56%; MgSO4 – 5.23%; H2SO4 – 1.05%; Inert – 0.53%; CO2 – 0.12%; H2O – 84.51%; During the process, the mass was warmed where CO2 and H2O were removed. Calculate the following.a) The analysis of lime stone and b) The % excess acid used.
Suppose you have a soil that is made up of 10% organic matter with CEC = 200 cmol/kg, 40% kaolinitewith CEC = 10 cmol/kg, and 50% vermiculite with CEC = 100 cmol/kg.1- Calculate the overall CEC of the soil by taking a weighted average of the three soil components.2- What percentage of the overall CEC is contributed by the organic matter? How does that numbercompare to the 10% of the soil itself that is organic?
A (3.6500 g) of impure ammonium aluminium sulfate (NH4Al(SO4)2)) was treated with ammonia (NH3(aq)) producing hydrous alumina Al2O3.xH2O. The collected precipitate was filtered, washed, and ignited at 1000 °C to give 0.4935 g Al2O3 (Mw 101.9635 g/mol). Determine: a. % Al2O3 b. %Al c. Express concentration of Al in ppm.
2. A furnace is fired with fuel oil with a partial analysis of 7.6% S and 2.8% N. Orsat analysis of the stack gas shows 9.44% CO2, 1.19% CO, 0.4% SO2, 0.47% H2, 6.8% O2 and 81.7% N2. Air supplied is at 23 deg Celsius, 755 mmHg and 85% RH. Calculate the percent excess air. a. 55% b. 78% c. 23% d. 38%