54

Chapter 5

SUMMARY OF FINDINGS AND ANALYSIS

Water softening remains an area of concern among manufacturing plants

considering that the hard water used as feed water to boilers and which, are also

transported by pipes can eventually clog pipes and can cause scale formation on boiler

heating surfaces, thereby lowering its efficiency. The use of coconut husk fiber as

softening medium can potentially reduce the cost of soft water production while

minimizing organic and inorganic solid waste. Thus, the need to study the feasibility of

this material as organic cation exchanger becomes an important concern.

This study aims to evaluate the parameters of coconut husk fiber that define and

characterize its adsorbing properties. These parameters include the moisture content,

adsorption isotherm, hardness-removal capacity, minimum effective contact time, and

breakthrough time of the coconut husk fiber. The study will then try to describe the

comparability of CHF to commercial ion-exchangers.

Findings

Enumerated below are the major observations and discoveries noted by the

researchers along the course of the study:

1. Coconut husk fiber has an equilibrium moisture content of about 32.5% and when

wet but completely drained has a moisture content of 63.1 %.

2. The adsorption behavior of coconut husk follows that of the Langmuir isotherm.

Its hardness removal capacity is about 10 mg Ca2+/g CHF. This capacity is three times

less than that of commercial zeolite (and 8.5 times less than that of commercial

synthetic resins).

3. Most of the adsorption that take place during softening using CHF as medium had

occurred within 30 minutes of contact with hard water.

4. The breakthrough time of CHF is 11.90 minutes using a height of 30.5 cm, a flow

rate of 2.76 mL/s, and an initial concentration and breakthrough concentration of 27

55

and 4 mg Ca2+/L, respectively. The predicted breakthrough time using BDST model is

12.24 minutes.

5. A gram of CHF increases the apparent color of 200-ml of hard water by more

than 40% (25 PCU) from the apparent color of 60 PCU after the minimum contact

time (30 minutes). The changes in apparent color using equivalent and height-

equivalent masses of synthetic resin are 60 PCU (100%) and 840 PCU (1400%),

respectively.

6. A gram of CHF decreases the pH of hard water to 7.41 from 8.08 after 30 minutes

of contact. This corresponds to a pH change of 0.67. The changes in pH using

equivalent and height-equivalent masses of synthetic resin are 0.70 and 1.08,

respectively.

7. The pre-regeneration, material cost in the removal of 1 gram of hardness using

coconut husk fiber is P2.71 while the cost using synthetic resin is P3.31. If CHF is

employed in a softening facility, the adsorbent material cost annual savings is about

P3,000.00, while the equipment cost deficit is P 32, 676.00.

Conclusion and Implication

Based on the experiments conducted, it appears that the bed depth service time (BDST)

model can satisfactorily be used to estimate the breakthrough curve time for the CHF

calcium-adsorption for most of the concentrations higher than C/Co = 0.10. It also

appears that CHF is not better than synthetic resins in the pH comparison, nor

comparable in terms of hardness-removal capacity. However, CHF is significantly better

than synthetic resin in the effluent color comparison and in the cost per amount of

hardness removed but not in the total material and equipment costs.

In sum, coconut husk fiber is not comparable to synthetic resins in terms of performance

and over-all cost of soft water production. Employing CHF as synthetic resin- alternative

would only incur additional costs than savings, contrary to what was first expected.

56

Recommendations

In real-world applications, competitive adsorption is likely to take place. The presence of

other cations in hard water, especially magnesium, will decrease the calcium-removal

capacity of the coconut husk fiber. This in turn decreases the service life of the media.

Thus, for future works and studies, the researchers recommend that this area of the

adsorption using CHF be explored. A multi-component isotherm test and multi-

component kinetic experiment could be done to measure the effect of other ions on the

adsorption calcium hardness. Future researchers can also investigate the subsequent

effects of the presence of other cations on the breakthrough time of a CHF bed.

Interested individuals may also want to develop a high-adsorbance coconut husk (HACH)

fiber that has comparable hardness-removal capacity to commercial resins. Sulfonation

with sulfuric acid at elevated temperature to produce cross-linked CHF sulfonate (CCS)

is perhaps a good starting point. Cellulosic fibers are natural polymers and they can be

cross-linked to increase the porosity of the husk fiber material. This process is similar to

vulcanization and synthetic plastic-formation.

57

BIBLIOGRAPHY

Abroguena, Honeylee A., et. al. “CHF in Cation Exchange for the Production of Soft Water”. Xavier University: 2004.

Baes, A. U., et. al. “Ion Exchange and Adsorption of Some Heavy Metals in Modified Coconut Coir (Fiber) Cation Exchanger”. 12 January 2007. http://www.iwaponline.com

Brown, Pauline, et. al. (2001). “Wastewater Treatment Using Low-Cost Adsorbents and Waste Materials”. 21 February 2007. http://www.dpo.uab.edu

Chen, Zhen, et al. “Recover and Recycle Rhodium from Spent Partial Oxidation Catalyst”. 21 February 2007. http://www.remco.com

Cooney, D.O. Adsorption Design for Wastewater Treatment. Lewis Publishers: Boca Raton, 1999.

Davis, Arden D. and Webb, Cathleen J. “Arsenic Remediation of Drinking Water.” 24 February 2007. http://water.usgs.gov

“Designing a System with Both Reverse Osmosis and Ion Exchange Resins”. 21 February 2007. http://www.dow.com

Geankoplis, Christie J. Transport Processes and Unit Operations. 3rd Edition. Prentice-Hall, 1993.

Hankins, N. P.”Removal of NH 4 + Ion from NH 4Cl Solution Using Clinoptilolite: A Dynamic Study Using a Continuous Packed-Bed Column in Up-Flow Mode.” 21 February 2007. http://taylorandfrancis.metapress.com

Harris, Daniel C. Quantitative Chemical Analysis. 5th Ed. W.H. Freeman: New York, 1998.

Klein, Elias, et al. “Ion-exchange Hollow Fibers.” 21 February 2007. http://www.freepatentsonline.com

Malej, Sonja. Structural Characteristics of New and Conventional Regenerated Cellulosic Fiber. Textile Research Journal, 2003.

McCabe, Warren L., et. al. Unit Operations of Chemical Engineering. 7th ed. USA: McGraw-Hill, 2005.

Price, R. M. (2003). “Lecture Notes: Adsorption”. 2 March 2007. http://www.cbu.edu

Smith, Robin. Chemical Process Design and Integration. England: John Wiley and Sons, 2005

Society of Chemical Industry. Ion Exchange and Its Applications. London: Society of Chemical Industry, 1985.

Stanek, Vladimir. Fixed Bed Operations: Flow Distribution. New York: Ellis Horwood, 1994.

58

About Coir. (n.d.). Retrieved February 3, 2007, from http://www.karan-carpets.com

Allen, D. T., & Shonnard, D. R. (2002). Green Engineering: Environmentally Conscious Design of Chemical Processes. New Jersey: Prentice-Hall.

Ashby, M. F. (2005). Materials Selection in Mechanical Design (Third ed.). Burlington: Butterworth-Heinemann.

Brown, P. (n.d.). Wastewater Treatment Using Low-Cost Adsorbents and Waste Materials. Retrieved February 21, 2007, from htttp://dpo.uab.edu

Harriott, P., Smith, J. C., & McCabe, W. L. (2005). Unit Operations of Chemical Engineering (McGraw-Hill International Edition ed.). Singapore: McGraw-Hill.

Hazard and Operabilty Study: Recontek Waste Recycling Facility. (n.d.). Retrieved September 5, 2007, from http://www.epa.gov

Lihou, M. (n.d.). Hazard And Operability Studies (HAZOPS). Retrieved September 5, 2007, from http://www.lihuotech.com

59

APPENDICES

Appendix A. STANDARD PROCEDURES

I. ASTM D 4456-99: Standard Test Methods for Physical and Chemical

Properties of Powdered Ion Exchange Resins

TEST METHOD B—SOLIDS CONTENT

17. Summary of Test Method

17.1 This test method consists of determining the loss of mass on drying at 104 6 2°C for 18 h.

18. Significance and Use

18.1 Powdered ion exchange resins are manufactured and shipped in a moist form. However, they are sold and used on a dry weight basis. Thus, it is important that the actual solids content of the resin be determined.

19. Sampling

19.1 Obtain a representative sample of the powdered ion exchange resin in accordance with Practices D 2687, Practice A, but substitute a 12.5-mm (1⁄2-in.) inside diameter tube

20. Procedure

20.1 Weigh three approximately 15-g representative samples of material to the nearest 1 mg into previously tared weighing vessels.

20.2 Heat the samples for 18 h at 104 6 2°C.

20.3 Remove the samples from the oven, cool at least 30 min in a desiccator to room temperature and reweigh.

21. Calculation

21.1 Calculate the solids content, in percent, as follows:

22. Report

22.1 Reject and repeat any sample analysis in which the result differs by more than 2 % from either of the other two samples.

22.2 Report the percent solids content as the average of the three values obtained.

23. Precision and Bias

23.1 The overall precision of this test method may be expressed as follows: SA 5 1.43 SC 5 0.391 where: SA = overall precision for powdered anion exchange resins in hydroxide form expressed as weight percent solids, and SC = overall precision for powdered cation exchange resins in hydrogen or ammonium forms expressed as weight percent solids.

60

23.2 For the collaborative study, completed in 1982, eight powdered IEX resin samples were sent to eight laboratories. Two samples each of hydrogen form, ammonium form, hydroxide form and hydrogen/hydroxide mixed beds with fibers, were evaluated.

23.3 Bias—Ion Exchange resins are the product of a complex, multiple step synthesis involving a polymerization reaction followed by one or more additional reactions to put functional groups on the polymeric structure. Consequently, the true value for any property of the finished product is unknown and a bias statement cannot be given.

61

II. ASTM D1293- 99: Standard Test Methods for pH of Water

1. Scope

1.1 These test methods cover the determination of pH by electrometric measurement using the glass electrode as the sensor. Two test methods are given as follows:

Sections

Test Method A —Precise Laboratory Measurement 8 to 15

Test Method B —Routine or Continuous Measurement 16 to 24

1.2 Test Method A covers the precise measurement of pH in water utilizing at least two of seven standard reference buffer solutions for instrument standardization.

1.3 Test Method B covers the routine measurement of pH in water and is especially useful for continuous monitoring. Two buffers are used to standardize the instrument under controlled parameters, but the conditions are somewhat less restrictive than those in Test Method A.

1.4 Both test methods are based on the pH scale established by NIST (formerly NBS) Standard Reference Materials.2

1.5 Neither test method is considered to be adequate for measurement of pH in water whose conductivity is less than about 5 µS/cm.

1.6 Precision and bias data were obtained using buffer solutions only. It is the user’s responsibility to assure the validity of these test methods for untested types of water.

4. Summary of Test Method

4.1 The pH meter and associated electrodes are standardized against two reference buffer solutions that closely bracket the anticipated sample pH. The sample measurement is made under strictly controlled conditions and prescribed techniques.

5. Significance and Use

5.1 The pH of water is a critical parameter affecting the solubility of trace minerals, the ability of the water to form scale or to cause metallic corrosion, and the suitability of the water to sustain living organisms. It is a defined scale, based on a system of buffer solutions with assigned values. In pure water at 25°C, pH 7.0 is the neutral point, but this varies with temperature and the ionic strength of the sample. Pure water in equilibrium with air has a pH of about 5.5, and most natural uncontaminated waters range between pH 6 and pH 9.

9.2 The reference electrode may be subject to interferences and should be chosen to conform to all requirements of Sections 10 and 12.

9.3 The true pH of an aqueous solution or extract is affected by the temperature. The electromotive force between the glass and the reference electrode is a function of temperature as well as pH. The temperature effect can be compensated

62

automatically in many instruments or can be manually compensated in most other instruments. The temperature compensation corrects for the effect of changes in electrode slope with temperature but does not correct for temperature effects on the chemical system being monitored.

63

III. ASTM D1126-96: Standard Test Method for Hardness in Water

1. Scope

1.1 This test method covers the determination of hardness in water by titration. This test method is applicable to waters that are clear in appearance and free of chemicals that will complex calcium or magnesium. The lower detection limit of this test method is approximately 2 to 5 mg/L as CaCO3; the upper limit can be extended to all concentrations by sample dilution. It is possible to differentiate between hardness due to calcium ions and that due to magnesium ions by this test method.

1.2 This test method was tested on reagent water only. It is the user’s responsibility to ensure the validity of the test method for waters of untested matrices.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

4. Summary of Test Method

4.1 Calcium and magnesium ions in water are sequestered by the addition of disodium ethylenediamine tetraacetate. The end point of the reaction is detected by means of Chrome Black T 4, which has a red color in the presence of calcium and magnesium and a blue color when they are sequestered.

5. Significance and Use

5.1 Hardness salts in water, notably calcium and magnesium, are the primary cause of tube and pipe scaling, which frequently causes failures and loss of process efficiency due to clogging or loss of heat transfer, or both.

5.2 Hardness is caused by any polyvalent cations, but those other than Ca and Mg are seldom present in more than trace amounts. The term hardness was originally applied to water in which it was hard to wash; it referred to the soap-wasting properties of water. With most normal alkaline water, these soap-wasting properties are directly related to the calcium and magnesium content.

6. Interferences

6.1 The substances shown represent the highest concentrations that have been found not to interfere with this determination.

6.2 The test method is not suitable for highly colored waters, which obscure the color change of the indicator.

64

Appendix B. FULL EXPERIMENTAL DATA AND RESULTS

I. Moisture Content- Determination Test

A. Constant Weighing of Crucibles

Initial Masses in grams: Time 0

Crucible Number

Mass Cap Mass Container Total Mass

1 7.186 22.824 30.0072 10.064 31.627 41.6923 9.509 23.508 33.016

After 30 minutes of oven-drying: Time 30

Crucible Number Total Mass |Change in Mass|1 29.994 0.0132 41.683 0.0093 33.006 0.010

After 30 minutes of oven-drying: Time 60

Crucible Number Total Mass |Change in Mass|1 29.998 0.0042 41.685 0.0023 33.009 0.003

After 30 minutes of oven-drying: Time 90

Crucible Number Total Mass |Change in Mass|1 29.997 0.0012 41.686 0.0013 33.013 0.004

65

B. Moisture Content Determination Data

i. Wet Fiber

CrucibleInitial Mass

FiberFiber +

Crucible

After 2 hours of Drying

After Additional 30 minutes

1 0.987 30.984 30.362 30.361

ii. Dry Fiber

CrucibleInitial Mass

FiberFiber +

Crucible

After 2 hours of Drying

After Additional 30 minutes

2 1.001 42.684 42.366 42.3583 1.002 34.008 33.688 33.686

C. Results

CrucibleInitial Mass

FiberMass Water Evaporated

Percent Moisture

1 (wet) 0.987 0.364 63.12 %2 (dry) 1.001 0.674 32.67 %3 (dry) 1.002 0.678 32.33 %

II. Isotherm Test

A. Standardization

Data:EDTA Concentration 0.05 mol/LConcentration CaCO3 Sol, C 100 mg/LVolume Sample CaCO3 Sol, V 50 mlMass CaCO3 in Sample, M= C*V 5.0 mg

66

Run No. Volume EDTA (VE) B (M/VE)

1 9.9 0.5052 9.3 0.5383 9.4 0.532

Average 0.525

B. Single Component Isotherm Experiment

Data:EDTA Concentration 0.05 mol/LMass CHF 1.0 gVolume Sample 50 mlVolume Solution 230 mlFactor B 0.525 mg Ca/ ml EDTA

Concentration, C

(mg CaCO3/ L)

Volume EDTA

Used (ml), VE

Initial Mass CaCO3 in Sample, M1 = Volume

Sample*C(before CHF was added)

Final Mass CaCO3 in Sample, M2= B*VE

(after CHF was added)

0 0.00 0.0 mg 0.000 mg10 0.00 0.5 mg 0.000 mg20 0.21 1.0 mg 0.110 mg30 0.40 1.5 mg 0.210 mg40 1.55 2.0 mg 0.814 mg50 2.60 2.5 mg 1.365 mg60 3.15 3.0 mg 1.653 mg70 4.05 3.5 mg 2.126 mg

ConcentrationAmount Absorbed,

AA50=M1-M2(per 50 ml sample)

Amount Absorbed, AA230=AA50*230/50(in 230 ml solution)

q (mg Ca/g CHF),q= AA230/1g CHF

0 0.000 mg 0.000 mg 0.00010 0.500 mg 2.300 mg 2.30020 0.890 mg 4.093 mg 4.09330 1.290 mg 5.934 mg 5.93440 1.186 mg 5.458 mg 5.45850 1.135 mg 5.223 mg 5.22360 1.347 mg 6.195 mg 6.19570 1.374 mg 6.322 mg 6.322

Results:C. Isotherm Determination

67

i. Freundlich Isotherm

Plot log q vs. log C

Concentration, C

q (mg Ca/g CHF)

log q log C

10 2.300 0.361727836 1.0000020 4.093 0.612039502 1.3010330 5.934 0.773365506 1.47712140 5.458 0.737009749 1.6020650 5.223 0.717886385 1.6989760 6.195 0.792019082 1.77815170 6.322 0.800836300 1.845098

Summary Output: By Linear Regression (Microsoft® Excel)

Regression StatisticsMultiple R 0.917764047R Square 0.842290846Adjusted R Square 0.810749016

CoefficientsIntercept -0.051722932Slope 0.481848012

68

ii. Langmuir Isotherm

Plot 1/q vs. 1/C

Concentration, C

q (mg Ca/g CHF) 1/q 1/ C

10 2.300 0.435 1/1020 4.093 0.244 1/2030 5.934 0.169 1/3040 5.458 0.183 1/4050 5.223 0.191 1/5060 6.195 0.161 1/6070 6.322 0.158 1/70

Summary Output: By Linear Regression (Microsoft® Excel)

Regression StatisticsMultiple R 0.9751666R Square 0.950949898Adjusted R Square 0.941139877 Standard Error 0.024015437

CoefficientsIntercept 0.102328644Slope 3.184257727

69

Comparing,

Regression coefficient, r2

→Langmuir 0.95 Freundlich 0.84

Therefore, Isotherm: Langmuir IsothermMaximum Capacity CHF: 9.772 g Ca2+/g CHFAdsorption Behavior:

III. Single Component Kinetic Experiment

Data:Experiment Proper

70

Concentration CaCO3 Solution, C 100 mg/LVolume CaCO3 Solution, V 1000 mLMass CHF 10 gInitial Mass CaCO3 in Solution, V*C 100 mgTitrationVolume Sample, vs 50 mLInitial Mass CaCO3 in Solution, vs*C 5 mgB 0.525 mg Ca/ ml EDTA

Time, minAve. Vol.

EDTA Used

Mass Ca2+ in 50-ml sample

Mass Adsorbance per

50-ml sample

Final Solution Conc. (C)

Total Amount Adsorbed

0 9.53 ml 5.00 0.00 mg 100.00 mg/L 0.00 mg10 7.69 ml 4.04 0.96 mg 80.71 mg/L 19.29 mg15 4.30 ml 2.26 2.74 mg 45.14 mg/L 54.86 mg20 3.73 ml 1.96 3.04 mg 39.19 mg/L 60.81 mg30 1.90 ml 1.00 4.00 mg 19.94 mg/L 80.06 mg

Using Linear Regression, plot Ln C/Co vs Time

Time Concentration C/Co Ln C/Co0.00 100.00 1.00 0.0010 80.71 0.81 0.2115 45.14 0.45 0.8020 39.19 0.39 0.9430 19.94 0.20 1.61

Summary Output: Using Microsoft® Excel

Regression StatisticsMultiple R 0.975878982R Square 0.952339787Adjusted R Square 0.93645305

71

Observations 5Coefficients

Intercept -0.122116861Slope 0.055590264a = e(-intercept) 1.129886134b = slope 0.055590264

Therefore,

72

Thus,Minimum Contact Time ≈ 30 minutes

IV. Breakthrough Test

A. Experimental Breakthrough Time Determination

Data:Average Conc. of CaCO3 Solution, C 27 mg/LAverage Volumetric Flow rate 2.76 mL/sBed Depth CHF 30.5 cmAverage Length CHF 1.0 cmApprox. Mass CHF for Given Depth, M 20 gBed Depth Sand 15 cmColumn Diameter, D 3.8 cmColumn Area, CA = πD2/4 11.33 cm2

Density CHF 1.4 g/cm3

Bulk Density CHF, M/(CA*BD) 0.06 g/cm3

Capacity CHF 9.772 g Ca/g CHFBreakthrough Concentration 4.0 mg Ca/LB 0.2625 mg Ca/ ml EDTA

Time (s)Volume Sample

(ml)Volume EDTA (ml)

Hardness, mg/L

C/Co

0 20 0.00 0.00 0.001 20 0.00 0.00 0.003 20 0.00 0.00 0.005 20 0.00 0.00 0.0010 20 0.00 0.00 0.0015 20 0.40 0.80 0.3920 20 0.65 1.30 0.6325 20 0.60 1.25 0.6130 20 0.40 0.85 0.4135 20 0.35 0.78 0.3840 20 0.35 1.17 0.5750 20 0.93 1.60 0.7855 20 1.60 2.00 0.9760 20 2.00 1.95 0.9565 20 2.00 1.95 0.9570 20 1.95 1.75 0.8575 20 1.95 1.90 0.92

73

80 20 1.90 1.75 0.8585 20 1.85 1.85 0.9090 20 1.85 0.00 0.00

Interpolating from times 10 min and 15 minutes, the breakthrough time at breakthrough concentration, Cb = 4 mg/L is:

tb = 11.90 minutes

B. Theoretical Breakthrough Time Determination

Summary Output: Calculated using Microsoft® Excel

Formula Value Units

1. No/εCapacity x Bulk

Density565.01 mg Ca/L

2. K Co K Co = b1 0.0556 1/min

3. Loading, vVol. Flow Rate x

Column Area0.1462 m/min

4. Depth, D CHF Bed Depth 0.305 m

74

5. Breakthrough Time, tb

12.24 minutes

1The kinetic parameter b of the kinetics experiment

V. Comparison Tests

A. Performance

Hard WaterCHF Cation Exchanger

Commercial Zeolite

1. Capacity, (mg Ca/g medium)

-- 9.772 851

2. Effluent pH 7.15 6.35 6.01

3. Apparnt Color (PCU)

60 85 900

1 Brown, et al. “Wastewater Treatment Using Low-Cost Adsorbents and Waste Materials”

Effluent pH: Representative Statistical Analysis

75

A B C D E F G H I

1

2 ANOVA: Null: There is no significant difference among the three.

3

4 Hard Water CHF Resin

5 8.1 7.38 7

6 8.05 7.43 6.99

7

8

9 SUMMARY

10 Groups Count Sum Average Variance

11 Hard Water 2 16.13 8.065 0.00045

12 CHF 2 14.81 7.405 0.00125

13 Resin 2 13.99 6.995 5E-05

14

15 ANOVA

16Source of Variation

SS df MS F P-value F crit

17 Bet Groups 1.165733333 2 0.58286666 999.2 5.8E-05 9.552094496

18 Within Groups 0.00175 3 0.0005833

19

20 Total 1.167483333 5

21

22

23 DECISION: Reject Ho. There is at least one inequality24

25 1. Compare Hard water and CHF

26

27 t-Test: Two-Sample Assuming Equal Variances

28

76

29 Hard Water CHF

30 Mean 8.065 7.405

31 Variance 0.00045 0.00125

32 Observations 2 2

33 Pooled Variance 0.00085

34

Hypothesized Mean Difference

0

35 df 2

36 t Stat 22.63781324

37 P(T<=t) one-tail 0.000972819

38t Critical one-tail

2.91998558

39 P(T<=t) two-tail 0.001945638

40t Critical two-tail

4.30265273

41

42

43 DECISION: Reject Ho, there is significant difference: Hard water > CHF44

45 2. Compare Hard Water and Resin

46

47 t-Test: Two-Sample Assuming Equal Variances

48

49 Hard Water Resin

50 Mean 8.065 6.995

51 Variance 0.00045 5E-05

52 Observations 2 2

53Pooled Variance

0.00025

54

Hypothesized Mean Difference

0

55 df 2

56 t Stat 67.67274193

57P(T<=t) one-tail

0.000109144

58t Critical one-tail

2.91998558

59P(T<=t) two-tail

0.000218288

60t Critical two-tail

4.30265273

61

62

63 DECISION: Reject Ho, there is significant difference: Hard water > Resin64

65

66 3. Compare CHF and Resin

67

68 t-Test: Two-Sample Assuming Equal Variances

69

70 CHF Resin

77

71 Mean 7.405 6.995

72 Variance 0.00125 5E-05

73 Observations 2 2

74Pooled

Variance0.00065

75

Hypothesized Mean

Difference0

76 df 2

77 t Stat 16.08152308

78P(T<=t) one-

tail0.001922231

79t Critical one-tail

2.91998558

80P(T<=t) two-

tail0.003844462

81t Critical two-tail

4.30265273

82

83 DECISION: Reject Ho, there is significant difference: CHF > Resin84

B. Cost Comparison

Softening Capacity (mg Ca/g media)

Cost per kg (PhP)

Material Requirement

(kg)

Material Cost [M] (PhP)

78

CHF 9.77 26.5 516.55 13, 688.50

Synthetic Resin 85 281.18 59.37 16, 694.37

Total Annual Absorbent Material Cost Savings if CHF is employed 3, 005.87

Volume Req’t (cubic meter)

Theo. # of Exchangers

Actual # of Exchangers

Equipment Cost [E] (PhP)

Total Cost [M]+[E]

CHF 8.61 1.82 2 65, 534.00 79, 222.50

Synthetic Resin 0.07 0.02 1 32, 767.00 49, 461.37

Total Material + Equipment Costs Savings if CHF is employed -29, 761.13

Appendix C. CALCULATIONS, MATERIAL AND ENERGY BALANCES

i. Wash Tank

Volume of Fibers

100 kg/hr CHF in 1 Batch operation

ρ = 1400 Kg/m3

VCHF = (100 kg) / (1400 kg/m3)

= 0.0715 m3

Volume of Water

200 gal/hr water in 1 Batch Operation

VWATER = 200 gal (1 m3/264.17 m3)

= 0.758 m3

Tank’s Capacity

Tank’s Capacity = VCHF + VWATER + Space Allowance

79

= 0.0715m3 + 0.758m3 + Space Allowance

= 1.00 m3

Diameter of the Tank

Assume height = 1.00 m

П/4D2h = 1.00 m

П/4D2 (1.00m) =1.00 m

D = 1.13 m

Tank Thickness

For the shell: t = (PR) / (SE -0.60 P)

Where P = 1 atm (14.7 psig)

R = diameter of tank= 0.565 m=22.244 in

S = for SA -240 Grade 316 steel @ T = 30˚ C=86˚ F

=18700 psig

E (joint efficiency) =1

t = (14.7 psig) (22.244 in)/ (18700 psig- 0.6* 14.7 psig)

= (326.99 in)/ (18691.18)

t = 0.0175 in (0.4443 mm)

Standard available thickness for stainless steel type 316: 0.45 mm

POWER REQUIREMENT: Washing Tank

Given:

Agitator Diameter (Da) = 0.80 D = 0.90 m = 2.95 ft

Speed (n): 45 rev/min = 0.75 rev/s

Density Water = 62.1342 lb/ft3

Viscosity of Brine (31˚ C) = 1.2 cP = 8.06364x10-4 lb/ft-s

g=32.17 ft/s2

gc=32.17 lbm-ft/lbf-s2

80

Solve NRe (Reynolds #)

NRe = Da2nρ/µ

= (2.95272 ft)2 (0.75/sec)(62.1342 lb/ft3)/(8.06364x10-4 lb/ft-s)

= 503,854.77

Unbaffled Tank: Fig. 9.13.Power Number Np versus NRE for three- blade propellers.

Np= 0.59

Solve NFr ( since it is unbaffled)

NFr = n2Da/g

= (0.75/sec)2(2.95272 ft)/(32.17 ft/sec2)

= 0.0516

Solve m, a=1.7 b=18.0

m = a (-log10NRe)/b

= (1.7-log 503854.77)/18.0

= -0.2224

Solve Corrected Value of Np

NP =NP from curve X Frm

= 0.59 *(0.0516 -.2224)

= 1.140

Solve Power Requirement for the Agitator to operate:

P =Npn3Da5ρ/gc

= (1.140)(0.75/sec)3(2.95272 ft)5(62.1342 lb/ft3)/(32.17 lbm-ft/lbf-sec2)

= (208.487 lbf-ft/sec)/(550)

P = 0.379 hp = 0.283 KW

A 0.50 hp motor power is recommended because it is commercially available.

Material Balance of 1st Washing

Basis: Producing 50 Kg of Bone Dry CHF per hour

½ hour per washing in batch operation

Spent Brine, B100 gal

2% NaCl (Salt Solution)

Density = 1,009 Kg/m3

Used Water, U 100 gal 30% Dust Particle (From Previous batch) Density of Water @ 31°C = 997.8 Kg/m3

Wet Fiber, F 64% Moisture (Wet Basis) 30% Dust present

Waste Water, W 70% Dust in raw fiber 30% Dust from previous batch

Raw Fiber, R 5% Dust Particle 32% Moisture (Wet Basis)

1st Washing1st Washing

81

For Spent Brine, B

B =100 gal for 1st washing

ρBrine (2%, 31 ˚C)= 1,009.844 kg/m3

B =100 gal (1m3/264.17 gal)* (1009.844 kg/m3)

82

= 382.27 kg Brine Solution

Mass NaCl =0.02 (382.27 Kg )= 7.6454 Kg NaCl

For Raw Fiber, R

5% Dust Particles Based on Karan-Carpet.com (Bone-Dry Basis)

R=50 Kg Bone-Dry/(1-0.05)=50/0.95= 52.632 Kg

XR,Dust = 0.05

Amount of Dust = 0.05 (52.632 Kg) =2.6316 Kg

R contains 32% moisture (wet basis)

(32/100) = Water in R/(R + Water in R)

R= 52.632 Kg (dry basis)

0.32= Water in R /( 52.632 Kg + Water in R)

16.84224 + 0.32 (water in R) = Water in R

Water in R = 16.84224 / (1-0.32)

Water in R = 24.768 Kg

New Value of R = 52.632 Kg + 24.768 Kg

R= 77.400 Kg

For Wet Fiber, F

F contains 64% moisture on wet basis including the dust particle (From

the FYPS Experiment)

F also contains 30% of the dust present in R (From the assumptions)

Dust in F = 0.30(2.6316 Kg) = 0.78948 Kg

Thus,

0.64 = Amount of water/ (50 Kg + 0.78948 Kg + Amount of water)

Amount of Water in F = 50.78948 Kg / (1-0.64)

Amount of Water in F = 141.082 Kg Water

For Used Water, U

U = 100 gal

* Contains 30% of the dust particle coming from the previous batch

Dust in U = 0.30 *(2.6316 Kg) = 0.78948 Kg

83

ρH2O (31 ˚C) = 997.8 Kg/m3

Amount (Volume of Water used) = 100 gal (1m3 /264.17 gal) (997.8 Kg/m3)

Amount of Water used= 377.71 Kg Water

Thus, total amount of Water used:

U= 377.71 Kg + 0.78948 Kg = 378.4995 Kg

To account for all the materials that goes into the tank:

B + U + R = 382.27 Kg + 378.4995 Kg + 77.40 Kg

= 838.1695 Kg of material that goes into the tank

The amount of water that goes inside the tank is:

B water + U water + R water = (382.27 -7.645) Kg + (377.71 Kg) + (24.768 Kg)

= 777.103 Kg Water

After agitation and just before draining the waste water, the concentration of NaCl in the

tank caused by the spent brine solution (accounting only the water and NaCl ):

= 7.645 Kg / (7.645 Kg NaCl + 777.103 Kg Water)

= 0.009742 or 0.9742%

Hence, the NaCl concentration of the water left on the fiber after draining the

wastewater for the 1st washing is 0.9742%.

So, Amount of NaCl in F is:

0.009742 = Amount NaCl in F / Amount of NaCl in F + Water in F

= Amount of NaCl in F / (Amount of NaCl in F + 141.082 Kg)

Amount of NaCl = 1.37442 Kg /( 1-0.009742)

= 1.3879 Kg NaCl

84

Hence, the total amount of F:

=0.78948 Kg Dust + 50 Kg Fiber + 141.082 Kg Water + 1.3879 Kg NaCl

=193.25938 Kg

OVER-ALL Material Balance:

B + U + R = F + W

382.27 Kg + 378.4995 Kg + 77.400 Kg = 193.25938 Kg + W

W= 644.91012 Kg

For Waste water, W

Amount of Fiber in W=0

Amount of dust in W = 0.70 (Dust in raw fiber ) + 0.30 ( Dust from

previous batch)

=0.70 (2.6316 Kg ) + 0.30 (2.6316 Kg )= 2.6316 Kg

Amount of salt in W = 7.645 Kg -1.3879 Kg NaCl

Amount of salt in W =6.2571 Kg

Summary:

Stream Water (kg) NaCl (kg) Fiber (kg) Dust (kg)Total IN

(kg)Total OUT

(kg)

B (IN) 374.625 7.645 -------- --------- 382.27 ---------

R (IN) 24.7684 ------- 50 2.6316 77.400 --------

U (IN) 377.71 ------- ------- 0.78948 378.4995 --------

F (0UT) 141.082 1.3879 50 0.78948 ------- 193.25938

W (OUT) 636.02142 6.2571 -------- 2.6316 ------- 644.91012

Total 777.1034 7.645 50 3.42108 838.1695 838.1695

Wet CHF, C 64% Moisture (Wet Basis) 50 Kg CHF 1.3879 Kg NaCl

Used Water,U 377.71 Kg Water 0.78948 Kg Dust

Wet Fiber,F 141.082 Kg Water 1.3879 Kg NaCl 50 Kg Fiber 0.78948 Kg Dust

2nd Washing2nd Washing

Softwater, S 100 gal softwater

85

Material Balance in 2nd Washing

For Wet Fiber, F: from material balance in 1st washing

F= 193.25938 Kg

Containing: 141.082 Kg H2O

1.3879 Kg NaCl

86

50 Kg fiber

0.78948 Kg Dust

For Used water, U: is used for the first washing of the next batch: (from material

balance in 1st Washing)

U= 378.4995 Kg containing 377.71 Kg H2O

0.78948 Kg Dust

Note: The amount of NaCl presents in wet fibers are assumed to attach on the fiber so the

Wet CHF will contain H2O, and the NaCl attached to the fiber.

For Wet CHF, C:

Also contains 64% moisture on wet basis without the dust particle

Does not contain dust particle anymore

Has 50 Kg CHF and 1.72169 NaCl

So, 0.64= Amount H2O / (Amount H2O + 50 Kg + 1.3879 Kg)

Amount H2O = 51.3879 Kg / (1-.064)

Amount H2O = 142.7442 Kg of H2O

Thus, Total C = 142.7442 kg of water + 1.3879 Kg NaCl + 50 Kg Fiber

= 194.1321 Kg of Wet CHF,C

OVER-ALL Material Balance:

F + S = C + U

231.3584 Kg + S = (194.1321Kg + 378.4995 Kg)

S= 379.37222 Kg of Softwater

S = 379.37222 Kg ( 1m3/ 997.18 Kg) (264.18 gal /1m3)

S = 100.502 gallons

Summary:

Stream Water (kg) NaCl (kg) Fiber (kg) Dust (kg)Total IN

(kg)Total OUT

(kg)

S (IN) 379.37222 --------- ---------- ---------- 379.37222 --------

F (IN) 141.082 1.3879 50 0.78948 193.25938 --------

87

C (OUT) 142.7442 1.3879 50 ---------- --------- 194.1321

U (OUT) 377.71 ---------- ---------- 0.78948 --------- 378.4995

TOTAL 520.4542 1.3879 50 0.78948 572.6316 572.6316

Energy Balance:

∆ (H + ½ u2 +Zg) m = Q+W

Assumption:

No temperature rise during the 1st Washing operation

∆H = Q = 0 So, m (1/2 u2 +Zg )= W Let:

W = Power requirement of the agitator P = 0.379 hp = 0.283 kW (1000W/1kW) = 283 W = 283 J/s P = 24, 451.2 kJ/s

Thus, m [1/2(u2

2-u12) + 9.81 Z] = 24,451.2 KJ/s

where m = W + F W = 644.91012 Kg/hr F = 141.082 Kg/hr

644.91012+141.082 Kg/hr [1/2(u22-u1

2) + 9.81 Z] = 24,451.2 KJ/s 24 451.2 Kg/hr/785.99212 Kg/hr = /[1/2(u2-u2) + 9.81 Z]

[1/2(u22-u1

2) + 9.81 Z] = 31,108.70883 kJ/ kg

ii. CHF Dryer

88

Since it is assumed that no water was lost during the pelletizing operation, we can represent the two drying operations as one process,

I. Material Balance

Let

x = mass fraction of water (wet-basis) in all liquid and solid streams, defined as:

For the succeeding calculations, values of the data used are tabulated in Table 8.

Parameter Value

Raw Fiber Length1 6- 8 in

Diameter1 16 microns

Moisture Content3 32 %

Air Porosity2 23.5 %

Wet Fiber Moisture Content3 64 %

Dry CHF Moisture Content3 32 %

Flow rate 500 kg/day

Wet Fiber, WF Dry CHF, DC

Moist Air, MA

CHF DryerCHF Dryer

Feed Air, FA

89

Air Relative Humidity4 70.5%

Thermal Conductivities (J/s-m-oC) 0.02423 (0oC)

0.03185 (100oC)

Viscosities 0.0205 cP

Specific Heat 0.1046 kJ/kg-oC

Density 1.027 kg/m3

Water Heat of Vaporization 2317.11 kJ/kg (77oC)

Mean Heat Capacity 4.185 kJ/kg-oC

Source: Unit Operations of Chemical Engineering, 7th Ed., 1karan-carpets.com, 2dpo.uab.edu, 3FYPS Expt., 4ChE 510 Expt. “Psychometry”

i. Over-all Material Balance

(1)

ii. Water Balance

From the Relative Humidity Chart (See Appendix D)

Absolute Humidity, H = 21.3 g/m3

Volume of Feed Air

Vair = mass air (density) = FA (1.027)

Mass Water in the feed air

Mass fraction of water in feed air

From Figure 19.2, p. 621 McCabe, Smith and Harriott (2005)

Air is heated to 110 oC (230 oF) and leaves the dryer at 50 oC (122 oF)

90

The specific volume of air from the same chart,

V = 14. 5 ft3/lb dry air

= 0.8212 m3/kg DA

Mass of water in moist air

Thus,

(2)

iii. Fiber Balance

From (2)

iv. Air Balance

HB = 0.022

HA = 0.048

230 oF122 oF

91

(3)

From Over-all Mass Balance:

II. ENERGY BALANCE

Assumption:

1. The sum of potential and kinetic energies is much smaller than (or negligible compared to) the value of Q:

PE + KE << Q

Thus,

∆Ĥ = Q + W

(i) Find

For 10 hrs/day of operation,

Q

Moist Air, MA50oC

Wet Fiber, WF30 oC

CHF DryerCHF Dryer

Feed Air, FA30oC

Dry CHF, DCTDC

92

(ii) Find

(iii) Find

(iv) Find

(v) Find

(vi) Find work done by fan, W

Data: Centrifugal fan

93

Parameter Value

Efficiency 70 %

Pressure at Standard Cubic Feet rating

29.92 in. Hg

Temperature at Standard Cubic Feet rating

32 oF

Molecular Weight Air 28.42 g/mol

Velocity of discharged Air1 0.5 m/s (1.64 ft/s)

Feed Air: Temp. 1 30oC(86oF)

Feed Air: Pressure1 29.0 in Hg

Discharge Pressure1 30.1 in Hg

Discharge Temp1 30oC(86oF)

Mass Flow rate air, FA2 0.493 kg/s (1.087 lb/s)

Sources: Unit Operations… (McCabe, et. al.), 1Design, 2Material Balance

a. Find the average density of flowing air

The actual suction density is

The discharge density is

The average density is,

b. Calculating work required

The developed pressure is

94

The velocity head is

By Equation 8.2b, (McCabe, Smith and Harriott)

Power requirement,

(0.4 kJ/s)

(vii) Solving for Q

+

(viii) Therefore, total electrical input is

iii. Ion Exchanger

Material Balance

Assume: steady-state conditions: the amount of material adsorbed onto the media

95

M

VCC

M

Xe 0

Where: X/M = amount of Ca2+ removed/mass of CHF pellets C0 = initial hardness concentration Ce = hardness concentration after equilibrium has been reached V = volume of the solution to which the CHF pellets are exposed M = mass of the CHF pellets

Experimental Result for CHF:

Regression coefficient, r2

→Langmuir 0.95 Freundlich 0.84

Therefore, Isotherm: Langmuir IsothermMaximum Capacity CHF: 9.772 mg Ca2+/g CHFAdsorption Behavior:

Data: Design flow rate = 1000 gal/hCe = 4 mg/lCo = 200 mg/lCHF capacity = 9.772 mg Ca2+ / g CHF CHF bulk density = 60 kg/m3

CHF density = 1400 kg/m3

*** The gallons of water to be treated per day are multiplied by the difference in the initial concentration and the desired final concentration (Co-Ce) times the conversion factors of 1.006 x 10-6 L/mg and 3.76 kg/gal (density of water at 30°C) to obtain the amount of Ca2+ to be adsorbed per day (Tolar, 2006). Dividing by the experimental CHF capacity (X/M) in mg Ca2+ per g CHF pellets yields the CHF requirement in kg per day.

M = ((1000 gal/h) * 3.76 kg/gal * (24 h/day) * (200-4) mg/L* 1.006 x 10-6 L/mg) / (9.772 mg Ca2+ /g CHF) * (1g/1000mg)

M = 1822.218 kg/day

96

(This mass will be divided between the two ion exchange column, IE 1-A and 1-B, thus, each column will have a mass of about 930 kg/day)

Basis: 1835.744 kg/day (mass of CHF required operating at 24 h/day)

Volume CHF = m CHF / ρ CHF

= (1822.218 kg/day) / (368.4231929 kg/m3) 4.95 m3

Volume sand = VolumeCHF * Factor = 4.95 m3 (15.3/ 30.5) = 2.48 m3

Volume gravel = Volume Media * Factor = 4.95 m3 (7/ 30.5) = 1.14 m3

***Using Solver from Microsoft® Excel, the optimum diameter and length of the ion exchanger tank are:

OPTIMUM TANK DESIGN

Parameters Constraints

Volume (CHF), m3 4.94599185

Volume Sand 2.481104109 D1 2.306128 > 1.537418537

Volume Gravel 1.135145671 D1 4.612256 > 1.537418537

D 1.537419 > 0

L 4.612256 > 0

V 8.562242 = 8.5622416

Design Variables

D 1.537418537

L 4.612255612

Computed values

Area (side) = 2*pi*D/2*L 22.2769307

Area(bottom) = 2*pi*D^2/4 3.712821784

Total Area of the tank,m2 25.98975249

Volume Tank = 8.562241555

97

1 L/D = 1.5:1 to 3:1

***BV (CHF Bed Volume) = A * L = 4.95 m3 = (π D2/4 * L)Where: A = Area occupied by the pellets

L = bed depth L = 2.66 m

Thus, length of the sand is 50% of the CHF bed depth = 1.33 m

***Length of the nozzle from the CHF bed (space for swelling) = Length of the tank – length (sand, gravel, pellets) = 4.61 m – (2.66+ 1.33+0.07) = 0.55 m

***Pipe = assume 2 in Schedule 40 piped = 0.0508 m

Liquid flow rate (softening) = V (design flow rate) /A = (1000gal/hr) *(1 m3/264.17 gal)* (1 h/3600 s)/ (π*(0.0508)2/4)

= 0.519 m/sLiquid flow rate (regeneration) = (200gal/hr)*(1hr/3600s)* (1 m3/264.17 gal)/

(π*(0.0508)2/4) = 0.104 m/s

***This application employs a fixed-bed approach where the water flows through a stationary mass of CHF pellets. During the flow through the pellets, many of the Ca2+

and Mg2+ are expected to come in contact with active surface sites and thus retained on the surface of the adsorbing media. The design requires the determination of two significant design parameters: minimum contact time and life of the bed.

***from the experiment, the minimum contact time of the adsorbent and water is 30 minutes.

To calculate the service life, the single-component kinetics study data was regressed using time in minutes as the independent variable and Ce/C0 as the dependent variable. The equation being fitted was the following:

Ce/C0 = a exp (-bt) = a exp (-kC0t)

From the experiment: a = 1.1299b = kCo = 0.0556 /min

The linearized BDST model equation is as follows (Cooney 1999; McKay 1996):

98

1ln

1

10000

00

0

bb C

C

kCD

vC

Nt

The ‘1000’ is included in the above equation as the conversion factor between liters and cubic meters, i.e., 1000 L per cubic meter.

***To get the term N0/, the bulk density of CHF which is 60 kg/m3 is multiplied by the capacity of 9.772 mg Ca2+/g CHF to get a capacity (expressed as mg Ca2+/m3 CHF) of 5.65 x 105 mg Ca2+/m3 media. This is the N0/ term since it accounts for only the volume of the ion exchange media in the system.

D = 2.66 mCo = 200 mg/LCb = 4 mg/Lv = V/A = V/πd2/4 = 0.0631 m3/min/ (π*1.552/4) = 0.034 m/min

By substitution: tb = 151.47 minutes = 2.52 h

***Thickness of the column

For cylindrical shells,t = (P ri / S Ej-0.6 P) + CC

Where P = internal pressure

P = Patm + ρghpellets + ρghwater + ρghsand + ρghgravel = 101,325Pa + (368.423 kg/m3)*(9.81m/s2)*(2.66 m) + (995.612kg/

m3)*(9.81 m/ s2) * (4.61) + (1922 kg/ m3)*(9.81 m/ s2) * (1.33 m) + (2002 kg/ m3) * (9.81 m/ s2) * (0.07 m)

P = 137.45 kPa

S = maximum allowable working stress = 128,900 kPa (Table 12-10 for Stainless steel)

Ej = efficiency of joints expressed as a fraction = 1 (fully radiographed double-welded butt joints)Cc = allowance for corrosion

t = 0.820 mm

99

***The thickness of the plate should not be less than 2.5 mm for stainless steel plates and the corrosion allowance for plates used for the shell and other pressure parts of the pressure vessel should not be less than 1 mm (JICOSH Home Guidelines Construction CODE FOR PRESSURE VESSELS.htm).

Recommended plate thickness: 3 mm

Regeneration Process

Data: V = 100 gal/h softwater Brine concentration, cb = 0.10 ρ H20 (35°C) = 995.612kg/ m3= 3.763 kg/gal

Retention time of the brine solution for the two exchangers, t= 40 minutes***for every breakthrough period of 4.26 days, a 10% brine solution is passed to the exchangers for 40 minutes

MNaCl = (V * ρ H20) * cb * t= (100 gal/h*3.763 kg/gal)*(10kg NaCl/90 kg H20) = 41.81 kg/h * (40 minutes/0.105 days) * (1 h/60min)= 265.46 kg/day

***after reaching the breakthrough time, 265.46 kg of NaCl is added with 100 gal of softwater to make a 10% NaCl solution as a regenerant.

Energy Balance

IE-

1A

IE-

2A

4.6 m

Centrifugal pumpCapacity: 1 hp

ή = 0.65

99

Given Parameters:

Liquid water₣ = 1000gal/hr (water softening) = 1.0515x10-3 m3/sd = 0.051 m

ε = 0.000046 (Figure 12-1 for commercial steel)L = 10m (assumed sum of the length of the pipes in which the water flows)ή = 0.65

(From the Appendices of McCabe)υH2O (35°C) = 0.8012ρH2O (35°C) = 995.612kg/ m3

v.p. = 0.8162 lb/in2

(Table 12-1 by Peters and Timmerhaus)90° elbows std. radius, Le/D = 32Gate valves, Le/D = 7α = 1 (for turbulent flow)kc = 0.05

For non compressible liquids, the Mechanical Energy Balance would be:

Wo = g Δz + Δ (V2/2α) + Δ (pv) + ΣF (Eq. 12-12)

Where: z = vertical distance above an arbitrarily chosen datum planeg = local gravitational accelerationp = absolute pressurev = specific volume of the fluidV = average fluid velocityα = correction factor to account for the use of average

velocityWo = mechanical workF = mechanical loss due to friction

For friction factor, f

Average velocity in the pipe = Water flow rate/Area = ₣/ (πd2/4)

Solving for Reynold’s number and relative roughness, Re = D V ρ / υ

From Fig. 12-1, estimated f = 0.1The total Le for fittings and valves is,

Le = 2(7) (D) + 3(32) (D)Friction due to flow through pipe and all fittings is, Fp = (2 f V 2 (L + Le))/D Friction due to contraction and enlargement (from Table 12-1) is, Fc, e = Fe + Fc Where: Fe = (V1-V2)2/2α

100

Fc = KcV22

Using Excel,

Data:

Liquid water

Flow rate, cu.m/s 1.05E-03 υH2O, Pa.s 8.01E-04

d,m 0.051 ρH2O, kg/m3 995.612

ε 0.000046 v.p., lb/in2 0.8162

ή 0.65 h,m 10

Le/D, elbows 32 velocity,m/s 0.514729

Le/D,valves 7 Re 3.26E+04

α 1 E/D 0.000902

kc 0.05 f 0.1

L 10 Le = 5.61

Fp,f 83.75424

F,e 0.132473

F,c 0.013247

Fc,e 0.145721

ΣF 83.89997

Pt = 405.6

P, hp = 0.541653

Appendix D. MATERIAL SAFETY DATA SHEETS

101

Soft Water

I. PRODUCT IDENTIFICATION

Manufacturer’s Name: Pacific Soft Water and CHF Pellets Manufacturing, Inc.

Synonyms: Dihydrogen Monoxide; H20

II. HAZARDOUS INGREDIENTS

NONE when compound is in the pure state.

III. PHYSICAL DATA

Boiling point (760 mm Hg): 100oC (212oF)

Melting point: 0oC (32oF)

Specific gravity (H2O = 1):1

Vapor pressure - 100oC (212oF) 760 mm Hg

- 0oC (32oF) 17.5 mm Hg

Solubility in water (% by wt.): 100%

% Volatiles by volume: 100%

Evap. rate (Butyl acetate = 1): Not available

Appearance and Odor: Light brown- colored liquid; No odor

IV. FIRE & EXPLOSION DATA

Flash Point: Not applicable

Auto-ignition Temperature: Not applicable

Flammable limits in air (% by Vol.): Not applicable

Unusual Fire and Explosion Hazard: Rapid temperature rise of liquid can result in explosive vaporization, particularly if in a sealed container.

V. HEALTH HAZARD INFORMATION

InhalationAcute over exposure: Inhalation can result in asphyxiation and is often fatal.Chronic overexposure: Chronic inhalation overexposure not encountered.

Skin ContactAcute overexposure: Prolonged but constant contact with liquid may cause a mild dermatitis.Chronic overexposure: Mild to severe dermatitis.

IngestionAcute overexposure: Excessive ingestion of liquid form can cause gastric distress and mild diarrhea.Chronic overexposure: No effects noted.

Emergency and First Aid ProceduresEyes: NoneSkin: None

102

Inhalation: Remove to fresh air; Provide artificial respiration; Provide oxygen.Ingestion: None

VI. REATIVITY DATA

Conditions contributing to instability: Exposure to direct current electricity.

Incompatibility: Strong acids and bases can cause rapid heating. Reaction with sodium metal can result in explosion.

Hazardous decomposition products: Hydrogen - Explosive gas Oxygen - Supports rapid combustion

Conditions contributing to hazardous polymerization: None

VII. SPILL or LEAK PROCEDURES

Steps to be taken if material is released or spilled:

Small quantities can be mopped or wiped up with rags.

Large quantities should be directed to collecting basin or drain with dikes or swabs.

Waste disposal method:

Process contaminated material through treatment plant prior to discharge into environment. Discharge permit may be required.

VIII. SPECIAL PROTECTION INFORMATION

Ventilation requirements:

Remove hot vapor from environment using local exhaust systems.

Specific personal protective equipment:

Respiratory: None required.

Eyes: Goggles or full face splash shield when dealing with hot liquid.

Hands: Use insulating gloves when extensive exposure to solid state or high temperature liquid state is contemplated.

Other clothing and equipment: Use heat protective garment when exposed to large quantities of heated vapor.

IX. SPECIAL PRECAUTIONS

Precautionary statements:

Compound readily exists in all three phases at atmospheric pressure. Phase changes occur over a narrow (100oC/212oF) temperature range.

Compound is known as "the universal solvent" and does dissolve, at least to some extent, most common materials.

Compound will conduct electricity when dissolved ionic solutes are present.

Other handling and storage requirements:

A high pressure containment vessel should be used for the vapor at high temperatures.

Do not allow filled, closed containers to solidify as compound expands upon freezing.

103

CHF Pellets

I. PRODUCT IDENTIFICATION

Manufacturer’s Name: Pacific Soft Water and CHF Pellets Manufacturing, Inc.

II. HAZARDOUS INGREDIENTS

NONE when compound is in the pure state.

III. PHYSICAL DATA AND CHEMICAL COMPOSITION

Physical Data

Diameter 16 micron

Length 1- 2 cm

Density 1.4 g/cc

Breaking Elongation 30%

Moisture 32%

Swelling in Water 5%

Chemical Composition

Water Soluble 5.25%

Pectin and Related Compounds 3.00%

Hemi-cellulose 0.25%

Lignin 45.84%

Cellulose 43.44%

Ash 2.22%

IV. FIRE & EXPLOSION DATA

Flash Point: Not available

Auto-ignition Temperature: Not available

Flammable limits in air (% by Vol.): Not available

Unusual Fire and Explosion Hazard: Not available

V. HEALTH HAZARD INFORMATION

InhalationIf a person breathes in large amounts, move the exposed person to fresh air.

Skin ContactNo effects noted.

IngestionIf large amounts were swallowed, give water to drink and get medical advice.

Eye Contact In case of eye contact, immediately flush with plenty of water for at least 15 minutes.

104

VI. REATIVITY DATA

Conditions contributing to instability: Not available

Incompatibility: Strong acids and bases can cause oxidation

Conditions contributing to hazardous polymerization: Not available

VII. SPILL or LEAK PROCEDURES

Steps to be taken if material is released or spilled:

Small quantities can be sweep or brushed.

Large quantities should be directed to collecting bin.

Waste disposal method:

Whatever cannot be saved for recovery or recycling should be managed in an appropriate and approved waste disposal facility. Processing, use or contamination of this product may change the waste management options. Dispose of container and unused contents in accordance with government requirements.

VIII. SPECIAL PROTECTION INFORMATION

Specific personal protective equipment:

Respiratory: Mask

Eyes: Goggles.

Hands: Gloves.

105

Appendix D. HAZARDS AND OPERABILTY (HAZOP) STUDY

Hazards and operability studies (HAZOPS) are employed by engineers, safety personnel,

and operators for a variety of reasons. These reasons vary from identifying potential

safety hazard to evaluating potential operational problems to characterizing potential

consequences to the surrounding communities in the event of a release of a hazardous

material. The small-scale plant for the processing of CHF and the production of soft

water is currently in the detailed design of the project. The HAZOP study, therefore, aims

to identify deviations from the design intent in the parts of the process and make an

assessment to whether such deviations and their consequences can have a negative effect

upon the safe and efficient operation of the plant.

The study considers the identification of the potential releases of hazardous materials

from the process and discusses the likelihood and severity of such releases. It gives

emphasis on the total operability of the process and shows critical analyses of the three

types equipment designed by the group, namely: the ion exchanger, the wash tank and the

CHF dryer.

The HAZOP Study Approach

The study has been conducted using a combination of two hazard evaluation procedures,

the cause-consequence analysis and the hazard and operability study. These procedures

are described in detail in “Hazard And Operability Studies (HAZOPS)” by Mike Lihou

and in the notes for the “Guidelines for Hazard Evaluation Procedure” prepared for the

Chemical Process Safety of the American Institute of Chemical Engineers as obtained

from the web site of the Environmental Protection Agency (EPA).

In the HAZOP study, techniques revolve around the effective use of keywords, the

combination of the “Primary Keywords” and the “Secondary Keywords”. Accordingly,

the primary keywords “focus attention upon a particular aspect of the design intent or an

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associated process condition or parameter, while the secondary keywords “when

combined with the primary keyword, suggest possible deviations” (Lihou,

lihoutech.com). Typical primary keywords generally used in HAZOP studies are

parameters such as the Flow, Pressure, Temperature, and Composition, and operational

words such as Isolate, Drain, Purge and Inspect. These keywords are dependent upon the

plant being studied. On the other hand, the secondary keywords generally used follows a

standard set and this is shown in Table 1.

Table 1. Set of Secondary Keywords Used in HAZOP Studies

Word Meaning

NoThe design intent does not occur (e.g. Flow/No), or the operational

aspect is not achievable (Isolate/No)

LessA quantitative decrease in the design intent occurs (e.g.

Pressure/Less)

MoreA quantitative increase in the design intent occurs (e.g.

Temperature/More)

Reverse The opposite of the design intent occurs (e.g. Flow/Reverse)

Also

The design intent is completely fulfilled, but in addition some

other related activity occurs (e.g. Flow/Also indicating

contamination in a product stream, or Level/Also meaning

material in a tank or vessel which should not be there)

Other (than)

The activity occurs, but not in the way intended (e.g. Flow/Other

could indicate a leak or product flowing where it should not, or

Composition/Other might suggest unexpected proportions in a

feedstock)

FluctuationThe design intention is achieved only part of the time (e.g. an air-

lock in a pipeline might result in Flow/Fluctuation)

Early

Usually used when studying sequential operations, this would

indicate that a step is started at the wrong time or done out of

sequence

Late As for Early

As well as/ Part of Qualitative increase, e.g. extra-activity occurs

Source: www.lihoutech.com; www.chemeng.mcmaster.ca

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For the study’s purpose, primary keywords with selected, applicable secondary keywords

are also tabulated. These combinations as shown in Table 2 are used all through out the

study and it is assumed that they are the only relevant combinations for this HAZOP

study of the small-scale plant.

Table 2. Selected Primary Keywords with Applicable Guide Words

Keyword Guide Words

Flow No, more, less, reverse

Temperature Higher, lower

Pressure Higher, lower

Level None, higher, lower

Composition None, more, less, as well as, other than

Action Early, late, longer, shorter

Source: www.chemeng.mcmaster.ca

Results

The results of the HAZOP analysis are shown on the action sheets that follow. The node

that was considered in the study are the dry CHF streams (for the CHF dryer), the feed

hard water (for the ion exchanger), and the feed spent brine (for the wash tank). From

these tables, we can conclude that the operability of the process is mainly dependent on

the parameters such as the temperature and stream flows. That is why, after the

identification of the design intent deviations, appropriate actions were also listed.