**5. Vermiculite composites/activated carbon**

In order to facilitate the application of carbonaceous material in environmental problems, was produced a composite based in vermiculite clay and activated carbon, derived from the polyglycerol. This composite was designed, considering (i) some properties of the expanded vermiculite clay (Figure 10), which has low cost and ability to float in water, (ii) large adsorption capacity of Activated carbon derived from polyglycerol and (iii) facility removal of the composite in case of water application, requiring only one net.

Fig. 9. Adsorption of methylene blue by carbonaceous material derived from the polyglycerol at different activation times (0, 3, 5, 10 and 15 h).

Chemical Conversion of Glycerol from

activated at different times.

obtained by BET method.

off.

layers.

Biodiesel into Products for Environmental and Technological Applications 297

The SEM images for pure EV (Figure 11 (a)) show regular flat surfaces with an interlamellar space between 10-100 µm with some fragments attached to the edges (arrow). Figure 11 (b) shows large amounts of regular deposits on the EV layers with materials connecting some

To obtain a good adsorbent material, the composite GVE4 was submitted to physical activation with CO2 for periods of 0.5 (GVE4CA0.5); 1 (GVE4CA1), 2 (GVE4CA2) and 4 hours (GVE4CA4). Table 3 shows the surface area and burn off the composite GVE4,

To observe the data presented in Table 3 and Figure 12, perceives a linear increase in surface area, depending on the activation time, until the limit value of 835 m2g-1 (2h of activation), when the value of surface area begins to decrease to 143 m2g-1, 4h of activation. A similar performance is observed for the surface area as a function of burn off (detail of Figure 12).

**Sample Burn off/ % Surface Area / m2g-1**

Table 3. Data for surface area GVE4CA0, GVE4CA0.5, GVE4CA1, GVE4CA2 and GVE4CA4,

Fig. 12. Surface area of the activated composites. Detail: surface area as a function of burn

SEM images presented in Figure 13 show how the carbon deposits on the surface of the composites was changed during activation. After the first hour of activation, the amount of material deposits on the surface of the composite is significantly lower when compared to the composite without activation (Figure 11 (b)), because of the oxidizing action of CO2,

**GVE4CA0** 0 9 **GVE4CA0.5** 23,4 387 **GVE4CA1** 44,2 648 **GVE4CA2** 58,0 835 **GVE4CA4** 73,0 146

Fig. 10. (a) Sample vermiculite *in natura*; (b) Sample expanded vermiculite.

The composite vermiculite/carbon is prepared the same way that the pure carbon, except that the clay expanded vermiculite (EV) is added before the initial stage of polymerization of glycerol, which will occur on the surface of clay.

The best condition for prepare of the composite (GVE4), which has carbon content of 25% (compared to the mass of the composite) is 3 mol% H2SO4 and 580°C/3h and ratio (by mass) glycerol/VE = 4. This condition was obtained after tests with different reaction conditions. The images of scanning electron microscopy (SEM) for pure EV and composite (GVE4) showed significant differences in their surfaces (Figure 11).

Fig. 11. SEM images of: (a) EV; (b) GVE4.

Fig. 10. (a) Sample vermiculite *in natura*; (b) Sample expanded vermiculite.

glycerol, which will occur on the surface of clay.

Fig. 11. SEM images of: (a) EV; (b) GVE4.

showed significant differences in their surfaces (Figure 11).

The composite vermiculite/carbon is prepared the same way that the pure carbon, except that the clay expanded vermiculite (EV) is added before the initial stage of polymerization of

The best condition for prepare of the composite (GVE4), which has carbon content of 25% (compared to the mass of the composite) is 3 mol% H2SO4 and 580°C/3h and ratio (by mass) glycerol/VE = 4. This condition was obtained after tests with different reaction conditions. The images of scanning electron microscopy (SEM) for pure EV and composite (GVE4) The SEM images for pure EV (Figure 11 (a)) show regular flat surfaces with an interlamellar space between 10-100 µm with some fragments attached to the edges (arrow). Figure 11 (b) shows large amounts of regular deposits on the EV layers with materials connecting some layers.

To obtain a good adsorbent material, the composite GVE4 was submitted to physical activation with CO2 for periods of 0.5 (GVE4CA0.5); 1 (GVE4CA1), 2 (GVE4CA2) and 4 hours (GVE4CA4). Table 3 shows the surface area and burn off the composite GVE4, activated at different times.

To observe the data presented in Table 3 and Figure 12, perceives a linear increase in surface area, depending on the activation time, until the limit value of 835 m2g-1 (2h of activation), when the value of surface area begins to decrease to 143 m2g-1, 4h of activation. A similar performance is observed for the surface area as a function of burn off (detail of Figure 12).


Table 3. Data for surface area GVE4CA0, GVE4CA0.5, GVE4CA1, GVE4CA2 and GVE4CA4, obtained by BET method.

Fig. 12. Surface area of the activated composites. Detail: surface area as a function of burn off.

SEM images presented in Figure 13 show how the carbon deposits on the surface of the composites was changed during activation. After the first hour of activation, the amount of material deposits on the surface of the composite is significantly lower when compared to the composite without activation (Figure 11 (b)), because of the oxidizing action of CO2,

Chemical Conversion of Glycerol from

adsorbing dye after 100 minutes of testing.

polymers and, later, special carbonaceous materials.

V. *Energy Fuels*, 21, 3698-3701, 2007.

Costa Neto, P.R., Rossi, L.F.S. *Quím. Nova*, 23 (4), 531-537, 2000.

Ferrari, R.A., Oliveira. V.S., Scabio, A. *Quim. Nova*, 28, 19-23, 2005.

Freedman, B., Pryde, E.H., Mounts, T.L. *J. Am. Oil Chem. Soc.*, 61, 1638, 1984. Garcia, R., Besson, M., Gallezot, P. *Applied Catalysis A: Gen.*, 127, 165-176, 1995.

Chiang, W. H. *Biodiesel – Sebrae*, 2007

14279–14291, 2000.

**6. Conclusions** 

production of biodiesel.

**8. References** 

**7. Acknowledgements** 

7398, 2007

2006.

UFMG, UFT, Capes, CNPq and Fapemig.

Biodiesel into Products for Environmental and Technological Applications 299

After the activation process of the composite GVE4, samples of 0.5, 1 and 2h of activation

It is possible notice that the EV practically no adsorbs or reacts with the contaminant during all the test period. The composite GVE4CA2 adsorbs 90% of the dye in only 60 minutes, tending to 100% until the end of the test (100 min). It is also notable, the action of the composite GVE4CA1, which absorbs more than 50% of the dye in the first 30 minutes of testing, tending to an equilibrium around 70% of contaminants adsorbed to the end of the test. Already the composite GVE4CA0.5, has unsatisfactory result, with only 20% of

Glycerol is a very versatile chemical species which can produce different materials to distinct applications. In this chapter, we discussed some possibilities for the glycerol that

Study of oligomerization of glycerol, by ESI-MS, is an important step in understanding how the molecules of glycerol were initially organized to enable the formation of thermosetting

The preparation of carbonaceous materials from glycerol, for environmental applications is a way to consume an important portion of glycerol introduced in the market from the

Aparício, C., Guignon, B., Rodriguez-Antón, L.M., Sanz, P.D. *J. Agric. Food Chem.*, 55, 7394-

Bunyakiat, K., Makmee, S., Sawangkeaw, R., Ngamprasertsith, S. *Energy Fuels*, 20, 812-817,

Catharino, R.R., Milagre, H.M.S., Saraiva, S.A., Garcia, C.M., Schuchardt, U., Eberlin, M.N.,

Davis, W. R., Tomsho, J., Nikam, S., Cook, E. M., Somand, D., Peliska, J. A. *Biochemistry*, 39,

Dorado, M.P., Ballesteros, E., Mittelbach, M., López, F.J. *Energy Fuels*, 18, 1457-1462, 2004. Encinar, J.M., Gozález, J.F., Rodrigues, J.J., Tejedor, A. *Energy Fuels*, 18, 443-450, 2002.

Augusti, R., Pereira, R.C.L., Guimarães, M.J.R., de Sá, G.F., Caxeiro, J.M.R., Souza,

Barrault, J., Clacens, Y., Pouilloux, Y. *Topics in Catalysis*, 27, 137-142, 2004. Barrault, J., Jerome, F., Pouilloux, Y. *Lipid Technol.*, 17, 131-135, 2005.

Blytas, G.C., Frank, H. US Pat. US5401860, 1993 – atribuída à Shell Oil Company.

boost its use in the production of polymers and adsorbents for organic contaminants.

were tested as adsorbents for organic contaminants (methylene blue) (figure 14).

850°C/1h. SEM images show that 2 h of activation are sufficient to make large part of the surface of the EV is exposed, reducing the carbonaceous deposits, although the surface area is the largest obtained (835 m2g-1). But it's after 4 h of activation that the composite loses most part of the carbon deposits and therefore reduces the surface area to only 146 m2g-1.

Fig. 13. SEM images of GVE4, actived by: (a) 1h; (b) 2h and (c) 4h.

Fig. 14. Adsoption of methilene blue by EV and composites actived by 0.5, 1 and 2h.

After the activation process of the composite GVE4, samples of 0.5, 1 and 2h of activation were tested as adsorbents for organic contaminants (methylene blue) (figure 14).

It is possible notice that the EV practically no adsorbs or reacts with the contaminant during all the test period. The composite GVE4CA2 adsorbs 90% of the dye in only 60 minutes, tending to 100% until the end of the test (100 min). It is also notable, the action of the composite GVE4CA1, which absorbs more than 50% of the dye in the first 30 minutes of testing, tending to an equilibrium around 70% of contaminants adsorbed to the end of the test. Already the composite GVE4CA0.5, has unsatisfactory result, with only 20% of adsorbing dye after 100 minutes of testing.
