Ojt Report Annexes

8/10/2019 Ojt Report Annexes

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Annexes and Exhibits (Optional)

The following findings, results and figures are some of our outputs that were included

in our activity reports and oral presentations.

I. Investigating the Properties of Blood

Coagulating Temperature

The first two weeks of the training was dedicated to lectures and experiments on the

properties of blood and its coagulating temperatures. Figure 1 shows the appearance

of blood at different heating temperatures. It was found out that blood starts to

coagulate at 65 degrees Celsius upon heating. Blood starts to separate into distinct

liquid and solid phase (coagulum) when it reaches a temperature of 90 degrees

Celsius.


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Figure 1. Blood at different heating temperatures

Coagulating Properties

Another important finding during the experiment is the coagulating properties of blood.

When blood coagulates, the fibrin (see Figure 2), a fibrous, non-globular protein strands are

formed from the fibrinogen present in the plasma. These strands of fibers act like spider webs

that hold blood together to prevent flow (see Figure 3) as it clots resulting to a gelatin-like mass

formed when blood coagulates.

Figure 2. Fibrin strands


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Figure 3. Microscopic View of Coagulated Blood

Just very few minutes after bleeding, the pigs blood starts to clot and forms a gelatin-like

mass that takes the form of its container. When allowed to stand without agitation, the huge

gelatin-like mass liquefies and the globule size decreases up to 70%-75% of its original mass

after 3 hours. It was also found out that if blood is constantly agitated (high turbulence) right

after the pig is bled, the fibrin fibers are separated from the rest of the liquid blood. On the other

hand, if blood is allowed to stand without agitation, it forms into a large gelatin-like mass that

can size reduced up to a certain extent by agitation.

Therefore when blood is allowed to coagulate, the solids present may either be in a form

of fibrin strands, or globules (sizes depend on the degree of agitation). When blood with fibrin

strands is heated and dried, a product similar to that of Figure 4 is observed. When blood

containing globules is heated and dried, a product similar to that of Figure 5 is observed. Fibrin

strands are easier to dry than blood with globular coagulates because it has greater surface area

and experimental results proved this true. However, producing fibrin strands is not economical

because in would require high RPM and constant agitation from the beginning till the end of the

slaughter operation.


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Figure 4. Dried Fibrin


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Figure 5. Dried blood globules

II. Gravity settling and addition of anticoagulant

Because solids that are present in blood is difficult to dry, another way of treating the blood

right after bleeding is the addition of anticoagulant to prevent blood from forming into large

lumps of globules. The anticoagulant used is sodium citrate solution. The citrate anions in

attracts the calcium cations present in the blood. Since calcium cations triggers the coagulation

process, minimizing the calcium ions in the blood prevents the blood from coagulating right after

bleeding. Blood treated with anticoagulant does no longer have to deal with solids upon

transportation and heating.

A concentration of 2% (w/w) sodium citrate was found to effectively prevent coagulation

process. When the blood is pure liquid and added with anticoagulant, it was found out that the

liquid blood separates into two layers at a faster rate compared to a pure liquid blood sample

(without any anticoagulant added). These observations lead the team to an idea of a possible

process that would partially dewater the blood by gravity settling. Since blood proteins are

denser than water, the bottom layer must consist of the proteinaceous component of the blood

while the top is the water-rich layer. (See Figure 6 for the separation into layers of blood by

gravity settling)


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Figure 6. Separation of Layer in a Raw Blood and Blood with added anticoagulant

Figure 6 shows the comparison of the separation rate of two layers in containers

containing only raw blood and the other being added with sodium citrate as anticoagulant. The

amount of top layer formed is weighed with respect to time.


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Figure 7. Amount of Water-rich layer removed with respect to time

The results of the experiment on addition of anticoagulant shows the effectiveness of sodium

citrate to prevent blood from clotting after bleeding and hastens the separation of blood into two

layers. However, there are disadvantages:

IF anticoagulant is used, it should be added RIGHT AFTERbleeding before blood starts

to clot. It is therefore necessary to introduce the anticoagulant solution along side of the

bleeding trough to serve its purpose. Hence, this requires a MIXING TANKfor solution

preparation.

It was found out that anticoagulant only DELAYS coagulationbut does not completely

prevent it from occurring. It is not practical to be used in the current process since the

process is not continuous and blood would be allowed to stand for some time and would

still coagulate after 2-3 hours.

This leads the team to the decision of focusing on the path that deals with the coagulated blood

instead of the means of preventing it from coagulating.

0

20

40

60

80

100

120

0 100 200 300 400 500

TopLayerRemoved(g

)

Settling Time (mins)

Top Layer Removed vs time

Raw Blood [1]

w/ Citrate [1]


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III. HEATING AS MEANS OF INCREASING THE RATE OF SEPARATION

INTO LAYERs

Besides making use of anticoagulants, the group has found out that heating blood below its

coagulation temperature can improve the rate at which the protein-rich layer settles at the bottom

of the container. Figure 8 shows that heating the blood to 45 degrees Celsius gives the best result

in increasing the rate of settling.

Figure 8. Amount of Water-rich layer removed with respect to time at different heating temperatures

The group has also improvised ways to be able to estimate the drying curve of

the blood at certain heating conditions. With the use of simple heating set-up, balances and

means of measuring temperature and time, we were able to compare the behavior blood when

dried at different conditions. In Figure 9, the dark blue curve represents 300 grams of blood

heated in a constant temperature water bath of 100 degrees Celsius with slow stirring. The red

curve represents 300 grams of blood heated in a constant temperature water bath of 100 degrees

Celsius but with fast stirring. The green curve represents 300 grams of blood heated at a constant

temperature saturation salt solution bath of 109 degrees Celsius with fast stirring. The purple

0

10

20

30

40

50

60

70

80

0 50 100 150 200 250

RateofSedimentation(g/min)

time (min)

Amount of Top LayerRemoved vs. t

46C [2]

55C [1]

55C [2]

60C


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curve, which requires the least amount of time to dry (since it is initially dewatered) is 300 grams

of blood that has undergone sedimentation prior to drying.

Figure 9. Mass of Water removed versus time at different heating Conditions

Table 1. Raw liquid Blood heated at a constant temperature of 100 C with fast stirring

TEMPERATURE:100

C

RPM: fast stirring

time

mass

sample

mass

H2O

removed total mass H2O removed

(mins) (g) (g) (g)

0 300 -- 0

10 230 70 70

20 173 57 127

30 140 33 160

40 110.5 29.5 189.5

50 83 27.5 217Product description:

small particle size, dry flaky pieces (rubbery)

dark brown

0

50

100

150

200

250

0 10 20 30 40 50 60

totalmassH2

Oremoved(g)

time (mins)

100C slowstir

100C faststir

109C faststir

100C faststir sedimented


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TEMPERATURE: 109 C

RPM: fast stirring

time

mass

sample

mass

H2O


(mins) (g) (g) (g)

0 300 -- 0

5.62 247.5 52.5 52.5

7.63 234 13.5 66

11.58 214.5 19.5 85.5

20 152.5 62 147.5

30 115 37.5 185

40 84.5 30.5 215.5

50 65 19.5 235

TEMPERATURE: 100C

RPM: slow stirring

time mass sample mass H2O removed total mass H2O removed

(mins) (g) (g) (g)

0 300 -- 0

10 256 44 44

20 212 44 88

30 166 46 134

40 142 24 158

50 122.5 19.5 177.5

60 105 17.5 195

Dried Product description:

Dry on the outside, wet inside

Consistency similar to hard clay

Big particles are reddish brown in color

smaller particles are about as dark as the product from faststirring


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From Figure 9 and Tables 1-4, the following conclusions can be made:

Lower rpm results to larger particle size and lower rate of drying

Rate of drying decreases with time

the effect of an increased drying temperature is more significant at longer drying times

From second and third conclusion, it is therefore best to first operate at a just around the boilingpoint of water and increase the temperature when the rate of drying starts to decrease.

IV. PROPOSED PROCESSES DEALING WITH COAGULATED BLOOD

Gravity Settling

This process takes the action of gravity in separating the water-rich or PLASMA phase from the

proteinaceous layer of the liquid phase blood, which is separated from the globules by screening.

The globules are allowed (by batch) to liquefy (the liquid being separated also by gravity

settling) and is pressed to further separate the liquid phase. Both pressed material and

proteinaceous layer from the sedimentation tank are cooked in the batch cooker.

Table 4. Liquid Blood that has undergone gravity settling prior to drying

TEMPERATURE: 100 C

RPM: fast stirring

time

mass

sample

mass

H2O


(mins) (g) (g) (g)

0 300 -- 0

10 237.5 62.5 62.5

20 183.5 54 116.5

30 156.5 27 143.5

35 141.5 15 158.5

38 132 9.5 168

Product Description:

slightly burnt

particle size the same with 109 deg C, fast stirring

Sedimented Blood Data: (grams)

Raw Blood: 1172

Proteinaceous Phase: 790.5

Water-rich Phase: 381.5


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Figure 10. Process Flow employing gravity settling as partial dewatering

The following are the Pros and Cons of the process:

PROS:

Allows agitation and heating only once (bunker fuel is saved)

Allows time for sedimentation to occur in the settling tank and would not require

agitation & heating in the tank anymore

Provides avenue for production of plasma product

CONS:

Plasma not as clear as fibrin plasma

Requires a screening mechanism above the sedimentation tank and the return pipe for the

pressed blood in the same tank at plant start-up


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Caking in the batch cooker occurs

Formation of Coagulum

This process deals with the formation of the coagulum (see Figure 8). This avoids the

problem of gelatinous blood solids formed during clotting while initially dewatering the bloodprior to final drying. It cooks the blood up to its coagulating temperature with constant agitation.

As blood is cooked, globules (and fibrins) are easier to be reduced in size. The coagulum is then

pressed where water is initially separated from the solids while reducing the size of large solid

lumps.

Figure 11. The coagulum: blood heated at temperatures 90-95 degrees Celsius.


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Figure 12. Process Flow employing mechanical dewatering of coagulum before drying

The following are the Pros and Cons of the process:

PROS:

Does not have to deal with large globules in the batch cooker

Proteins in plasma will not go to waste

Not much caking in cooker and agitator

CONS:

Requires a larger overall production cost and loss of material

. Requires agitation and heating for both sedimentation tank and batch cooker

Requires larger volume to be heated up in the coagulation tank


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. Varying size of particles causing uneven distribution of heat throughout the coagulation

tank

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Ojt Report Annexes