RESULTS AND DISCUSSION
Catalyst characteristics were studied using several techniques. Absorption Atomic Spectroscopy (AAS) was used to analyseze Si/Al ratio in the samples. Brunauer Emmet Teller (BET) was used to measure surface area and pore sizes of the catalysts, while X-ray diffraction (XRD) was used to study the type and structure of the catalysts. The catalyst characterization results were shown in Table 1 and Figure 2.
It can be seen from Table 1 that all catalysts have pore sizes > 13 A°. It is reported that the minimum pore size of a catalyst used in the cracking process is 8 A° [15]. The surface area of the catalysts >200 m /g. also cited that the minimum su 1 rface area of a standard catalyst used in a catalytic cracking is 100 m /g. Thus, the catalysts used in the current research meet the requirement of a standard catalyst used in the catalytic cracking process [15]. Meanwhile, Figure 2 shows the XRD diffractogram of standard HZSM-5, while Figure 3 shows XRD spectra of synthesized HZSM-5. HZSM-5 peaks were monitored at 2è value between 7- 9° and 22 - 25°. It can be seen that HZSM-5 peaks of the standard (Figure 2) is somewhat similar to the synthesized samples (Figure 3). This confirms that the synthesized products were HZSM-5. Figure 4 shows the effect of temperature on the yield of gasoline-like, kerosene-like and diesel oil-like during the
catalytic cracking of palm oil using synthesized HZSM-5 at N2 flowrate of 100 ml/min. It can be seen that the yield
of gasoline-like, kerosene-like and diesel oil-like increases with increasing cracking temperatures. The increase in
yield relates to the increase in a catalyst activity and reaction rate. According to the Arrhenius equation: k = k0
e-E/RT, with k is a reaction constant, k is activity factor, E0
is activation energy, R is ideal gas constant and T is reaction temperature [16], k will increase by increasing the reaction temperature. If k increases then the reaction rate
is greater, so that the yield is also greater. However, at the
highest temperature the yield decreases, this is due to the
decrease in the catalyst activity with the increase in the
temperature.
Figure 5 shows effect of N2 flowrate on the yield of
gasoline-like, kerosene-like and diesel oil-like during the
catalytic cracking of palm oil using synthesized HZSM-5
at 450°C. It was found that at 450°C and N2 flowrate of 100
m. min 1 produced the highest yield of gasoline fraction
of 28.87%, 16.70% kerosene and 1.20% diesel oil. It can be
seen that the yield of diesel oil-like increases with
increasing N2 flowrate. However, the yield of gasoline-like
and kerosene-like decreases with increasing N2 flowrate.
Acrolein in gasoline-like and kerosene like tends to
decompose to C1-C4 at high temperature. By increasing N2
flowrate it seems that acrolein decomposition in gasolinelike
and kerosene like favours, so that the yield of
gasoline-like and kerosene like decreases.
RESULTS AND DISCUSSIONCatalyst characteristics were studied using several techniques. Absorption Atomic Spectroscopy (AAS) was used to analyseze Si/Al ratio in the samples. Brunauer Emmet Teller (BET) was used to measure surface area and pore sizes of the catalysts, while X-ray diffraction (XRD) was used to study the type and structure of the catalysts. The catalyst characterization results were shown in Table 1 and Figure 2.It can be seen from Table 1 that all catalysts have pore sizes > 13 A°. It is reported that the minimum pore size of a catalyst used in the cracking process is 8 A° [15]. The surface area of the catalysts >200 m /g. also cited that the minimum su 1 rface area of a standard catalyst used in a catalytic cracking is 100 m /g. Thus, the catalysts used in the current research meet the requirement of a standard catalyst used in the catalytic cracking process [15]. Meanwhile, Figure 2 shows the XRD diffractogram of standard HZSM-5, while Figure 3 shows XRD spectra of synthesized HZSM-5. HZSM-5 peaks were monitored at 2è value between 7- 9° and 22 - 25°. It can be seen that HZSM-5 peaks of the standard (Figure 2) is somewhat similar to the synthesized samples (Figure 3). This confirms that the synthesized products were HZSM-5. Figure 4 shows the effect of temperature on the yield of gasoline-like, kerosene-like and diesel oil-like during thecatalytic cracking of palm oil using synthesized HZSM-5 at N2 flowrate of 100 ml/min. It can be seen that the yieldof gasoline-like, kerosene-like and diesel oil-like increases with increasing cracking temperatures. The increase inyield relates to the increase in a catalyst activity and reaction rate. According to the Arrhenius equation: k = k0e-E/RT, with k is a reaction constant, k is activity factor, E0is activation energy, R is ideal gas constant and T is reaction temperature [16], k will increase by increasing the reaction temperature. If k increases then the reaction rateis greater, so that the yield is also greater. However, at thehighest temperature the yield decreases, this is due to thedecrease in the catalyst activity with the increase in thetemperature.Figure 5 shows effect of N2 flowrate on the yield ofgasoline-like, kerosene-like and diesel oil-like during thecatalytic cracking of palm oil using synthesized HZSM-5at 450°C. It was found that at 450°C and N2 flowrate of 100m. min 1 produced the highest yield of gasoline fractionof 28.87%, 16.70% kerosene and 1.20% diesel oil. It can beseen that the yield of diesel oil-like increases withincreasing N2 flowrate. However, the yield of gasoline-likeand kerosene-like decreases with increasing N2 flowrate.Acrolein in gasoline-like and kerosene like tends todecompose to C1-C4 at high temperature. By increasing N2flowrate it seems that acrolein decomposition in gasolinelikeand kerosene like favours, so that the yield ofgasoline-like and kerosene like decreases.
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