**3. Results and discussion**

The lignin isolation process has been carried out several times with variations in the concentration of NaOH and the size of the mesh bagasse. Variations in bagasse mesh sizes used were 40 mesh, 60 mesh, 80 mesh, and 100 mesh, and the concentration of NaOH was 2, 3, 6, 8, and 10 M. **Figure 6** shows the results of lignin isolation in the form of a dark brown powder.

From the experiment as many as 15 variations, only four variations met the requirements, namely, lignin results above 60% and they had lignin-forming components, namely, lignin (80–3), lignin (60–8), lignin (40–10), and lignin (80–10). The results of lignin recovery can be seen in **Table 1**. In this table, it can be seen that

**69**

**Figure 7.**

*FTIR test results on lignin isolation.*

*Laboratory Optimization Study of Sulfonation Reaction toward Lignin Isolated from Bagasse*

 2 22.46 20.66 48.60 18.00 3 63.36 34.36 61.80 22.22 6 32.26 13.07 24.43 35.80 8 66.80 75.73 38.36 24.30 10 62.85 51.80 63.79 26.10

**Lignin (%) mesh 40 mesh 60 mesh 80 mesh 100**

the highest percentage of lignin recovery occurs in the lignin isolation process with a concentration of 3 M NaOH—40 mesh size of 63.36%, 8 M NaOH—60 mesh size

Based on the results of the percentage lignin obtained and the results of the lignin functional group absorption test, it turns out that not all research variations have three indicators of the lignin-forming functional groups. The lignin results were compared by looking at the percentage transmittance value; the best lignin results were lignin (80–3), which is bagasse lignin processed with 80 mesh size variations using NaOH 3 M. Lignin (80–3) is then compared with lignin commercial standards which are lignin of Aldrich and Kraft. **Figure 7** shows the FTIR test results on the sample result of isolated and sample of standard lignin. **Figure 7** shows the combined FTIR results for the four most lignin isolation processes, which produce lignin yields of more than 60%. The four variations of lignin isolation are represented as curve a, curve b, curve c, and curve e. This FTIR graphic overlay is then combined with the standard lignin FTIR results, namely,

*DOI: http://dx.doi.org/10.5772/intechopen.93662*

**NaOH (M)**

**No. Concentration of** 

**Table 1.**

of 75.73%, and 10 M NaOH—80 mesh size 63.79%.

*Results of lignin isolation at variations in bagasse size and NaOH concentrations.*

curve "d" at this figure (**Table 2**).

**Figure 6.** *Lignin from bagasse isolation.*

*Laboratory Optimization Study of Sulfonation Reaction toward Lignin Isolated from Bagasse DOI: http://dx.doi.org/10.5772/intechopen.93662*


#### **Table 1.**

*Biotechnological Applications of Biomass*

injected by the lignosulfonate.

**Figure 5.**

**3. Results and discussion**

isolation in the form of a dark brown powder.

*Schematic synthesis of bagasse into sodium lignosulfonate [35].*

(NMR). The structure of the lignosulfonate monomer is needed in order to help see the suitability of the use of the surfactant lignosulfonate against the crude oil to be

The lignin isolation process has been carried out several times with variations

From the experiment as many as 15 variations, only four variations met the requirements, namely, lignin results above 60% and they had lignin-forming components, namely, lignin (80–3), lignin (60–8), lignin (40–10), and lignin (80–10). The results of lignin recovery can be seen in **Table 1**. In this table, it can be seen that

in the concentration of NaOH and the size of the mesh bagasse. Variations in bagasse mesh sizes used were 40 mesh, 60 mesh, 80 mesh, and 100 mesh, and the concentration of NaOH was 2, 3, 6, 8, and 10 M. **Figure 6** shows the results of lignin

**68**

**Figure 6.**

*Lignin from bagasse isolation.*

*Results of lignin isolation at variations in bagasse size and NaOH concentrations.*

the highest percentage of lignin recovery occurs in the lignin isolation process with a concentration of 3 M NaOH—40 mesh size of 63.36%, 8 M NaOH—60 mesh size of 75.73%, and 10 M NaOH—80 mesh size 63.79%.

Based on the results of the percentage lignin obtained and the results of the lignin functional group absorption test, it turns out that not all research variations have three indicators of the lignin-forming functional groups. The lignin results were compared by looking at the percentage transmittance value; the best lignin results were lignin (80–3), which is bagasse lignin processed with 80 mesh size variations using NaOH 3 M. Lignin (80–3) is then compared with lignin commercial standards which are lignin of Aldrich and Kraft. **Figure 7** shows the FTIR test results on the sample result of isolated and sample of standard lignin.

**Figure 7** shows the combined FTIR results for the four most lignin isolation processes, which produce lignin yields of more than 60%. The four variations of lignin isolation are represented as curve a, curve b, curve c, and curve e. This FTIR graphic overlay is then combined with the standard lignin FTIR results, namely, curve "d" at this figure (**Table 2**).

**Figure 7.** *FTIR test results on lignin isolation.*


#### **Table 2.**

*Comparison of the typical absorption peak wave numbers of bagasse lignin with commercial standard lignin FTIR spectrum by Aldrich and Kraft [35].*

Based on the reference, standard lignin consists of five main components, namely, phenolic O▬H functional groups at wave number 3200–3550 cm−1, aliphatic and aromatic ▬CH▬ stretching groups at wave number 2900 cm−1, the C═C aromatic functional groups at wave number 1500–1600 cm−1, amine C▬N, and alkyl C▬H [37]. There are three main components that are the same as Aldrich lignin and Kraft lignin, namely, phenolic, aliphatic aromatic, and arenas.

In **Figure 7**, for the four curves that have a shape similar to the standard curve, curve "e" (colored black) shows peaks at phenolic, aliphatic, and aromatic wavelengths. So that based on the overlay of the FTIR results, it can be said that the most similar to the standard conditions is the "e" (black) curve which is the result of 80 mesh lignin isolation with 3-M NaOH reagent.

The selected lignin was then continued for the sulfonation process with several variations in the concentration of sodium bisulfite. The sulfonation process has been done with various variations in the concentration of sodium bisulfite and sulfonation time. The best results were achieved in the sulfonation process with a concentration of 0.25 M sodium bisulfite and a sulfonation time of 5 hours. Sulfonation process repeated three times and compare to find spectrum that compose lignosulfonate. The final result of the sulfonation process is lignosulfonate in the form of a light brown powder, as shown in the figure below **Figure 8** (**Table 3**).

From the result of FTIR test, lignosulfonate has been formed, indicated by difference a wavelength spectrum of lignosulfonates and a wavelength spectrum of lignin. The sulfonation process was done in 3 repetitions and the results were tested again by FTIR. With 3 repetitions of the process, the results are almost the same, so you

**71**

**Figure 9.**

*Overlay of FTIR surfactant—Lignin from bagasse.*

*Laboratory Optimization Study of Sulfonation Reaction toward Lignin Isolated from Bagasse*

**SLS standard (Patricia)**

**Wave numbers (cm−1)**

**SLS standard (Aldrich)**

**SLS bagasse**

can say the process is correct. To ensure the perfect result of the sulfonation process, a comparison was made with other lignosulfonates [34]. The standard lignosulfonate used for comparison were SLS Aldrich and SLS Patricia. From the FTIR results, the spectrum of SLS surfactant synthesized bagasse and sodium lignosulfonate standard spectrum, the absorption peak and its wave number in the FTIR spectrum of SLS surfactant synthesized from bagasse showed conformity with the spectrum of FTIR standard. This shows that the sulfonation process of lignin to lignosulfonate has

*Comparison of the FTIR spectrum of SLS surfactant-synthesized bagasse and the FTIR spectrum of SLS* 

1. Stretch alkene ═C═C 1630–1680 1608.34 1635.34 2 Stretch Sulfonate S═O 1350 1365 1384.64 3. Carboxylate C═O 1000–1300 1187.94 1114.64 4. Ester S-OR 500–540 499.83 462.83

In **Figure 9**, it is clear that there is a difference between the FTIR results of lignin and surfactant, where on the blue curve line, as in the surfactant FTIR curve, there is a shift in the absorption peak that occurs, especially at a wavelength of 1635.34 cm−1 as a function of the alkene group, at a wavelength of 1384.64 cm−1 as a function of the sulfate group, at a wavelength of 1114.65 cm−1 as a function of the carbolic acids group, and at a wavelength of 462.832 cm−1 as the ester

Some of the peaks read on FTIR showed lignin and lignosulfonate bagasse components. The lignin component consists of phenolic functional group elements OH, aliphatic and aromatic groups ▬CH▬, C═O ketone groups, arena functional groups ▬C═C▬, CN amine groups, and CH alkyl groups with similarity values for standard

Likewise for lignosulfonates, with indicator components consisting of C═C alkenes, sulfate S═O, C═O carboxylic acids, and S-OR esters, with spectrum

spectrum wavelengths, such as those shown in **Table 4** (**Figure 10**).

*DOI: http://dx.doi.org/10.5772/intechopen.93662*

**structure of lignosulfonates**

**No. Functional groups in the** 

been successfully.

*standard Patricia and Aldrich.*

**Table 3.**

functional group.

**Figure 8.** *Sodium lignosulfonate surfactant from bagasse.*

*Laboratory Optimization Study of Sulfonation Reaction toward Lignin Isolated from Bagasse DOI: http://dx.doi.org/10.5772/intechopen.93662*


**Table 3.**

*Biotechnological Applications of Biomass*

**No. Typical functional group** 

2 Aliphatic and aromatic stretch groups ▬CH▬

*FTIR spectrum by Aldrich and Kraft [35].*

**Table 2.**

**vibrations in lignin structure**

Based on the reference, standard lignin consists of five main components, namely, phenolic O▬H functional groups at wave number 3200–3550 cm−1, aliphatic and aromatic ▬CH▬ stretching groups at wave number 2900 cm−1, the C═C aromatic functional groups at wave number 1500–1600 cm−1, amine C▬N, and alkyl C▬H [37]. There are three main components that are the same as Aldrich lignin and

*Comparison of the typical absorption peak wave numbers of bagasse lignin with commercial standard lignin* 

**Wave number (cm−1)**

2900 2919.70 2930.17 2926.01

**Aldrich lignin**

**Kraft lignin**

**Standard Bagasse lignin** 

1. Stretch the phenolic O-H 3200–3550 3405.67 3436.62 3414

3. Stretch the arena▬C═C 1500–1600 1511.92 1599.14 1614.42

**(80–3)**

In **Figure 7**, for the four curves that have a shape similar to the standard curve, curve "e" (colored black) shows peaks at phenolic, aliphatic, and aromatic wavelengths. So that based on the overlay of the FTIR results, it can be said that the most similar to the standard conditions is the "e" (black) curve which is the result of 80

The selected lignin was then continued for the sulfonation process with several variations in the concentration of sodium bisulfite. The sulfonation process has been done with various variations in the concentration of sodium bisulfite and sulfonation time. The best results were achieved in the sulfonation process with a concentration of 0.25 M sodium bisulfite and a sulfonation time of 5 hours. Sulfonation process repeated three times and compare to find spectrum that compose lignosulfonate. The final result of the sulfonation process is lignosulfonate in the form of a light brown powder, as shown in the figure below **Figure 8** (**Table 3**). From the result of FTIR test, lignosulfonate has been formed, indicated by difference a wavelength spectrum of lignosulfonates and a wavelength spectrum of lignin. The sulfonation process was done in 3 repetitions and the results were tested again by FTIR. With 3 repetitions of the process, the results are almost the same, so you

Kraft lignin, namely, phenolic, aliphatic aromatic, and arenas.

4. Amine C▬N 1000–1250 1100 5. Alkyl C▬H 600–700 650

mesh lignin isolation with 3-M NaOH reagent.

**70**

**Figure 8.**

*Sodium lignosulfonate surfactant from bagasse.*

*Comparison of the FTIR spectrum of SLS surfactant-synthesized bagasse and the FTIR spectrum of SLS standard Patricia and Aldrich.*

can say the process is correct. To ensure the perfect result of the sulfonation process, a comparison was made with other lignosulfonates [34]. The standard lignosulfonate used for comparison were SLS Aldrich and SLS Patricia. From the FTIR results, the spectrum of SLS surfactant synthesized bagasse and sodium lignosulfonate standard spectrum, the absorption peak and its wave number in the FTIR spectrum of SLS surfactant synthesized from bagasse showed conformity with the spectrum of FTIR standard. This shows that the sulfonation process of lignin to lignosulfonate has been successfully.

In **Figure 9**, it is clear that there is a difference between the FTIR results of lignin and surfactant, where on the blue curve line, as in the surfactant FTIR curve, there is a shift in the absorption peak that occurs, especially at a wavelength of 1635.34 cm−1 as a function of the alkene group, at a wavelength of 1384.64 cm−1 as a function of the sulfate group, at a wavelength of 1114.65 cm−1 as a function of the carbolic acids group, and at a wavelength of 462.832 cm−1 as the ester functional group.

Some of the peaks read on FTIR showed lignin and lignosulfonate bagasse components. The lignin component consists of phenolic functional group elements OH, aliphatic and aromatic groups ▬CH▬, C═O ketone groups, arena functional groups ▬C═C▬, CN amine groups, and CH alkyl groups with similarity values for standard spectrum wavelengths, such as those shown in **Table 4** (**Figure 10**).

Likewise for lignosulfonates, with indicator components consisting of C═C alkenes, sulfate S═O, C═O carboxylic acids, and S-OR esters, with spectrum

**Figure 9.** *Overlay of FTIR surfactant—Lignin from bagasse.*


#### **Table 4.**

*FTIR of lignin and lignosulfonate bagasse.*

**Figure 10.** *Sugarcane becomes lignosulfonate [35].*

wavelengths close to the standard spectrum wavelength values. Lignin from bagasse can be completely synthesized into sodium lignosulfonate surfactant completely with lignosulfonate components consisting of alkene, sulfonate, carboxylate, and ester.

Furthermore, from the results of the NMR test, the components form the lignosulfonate. In the HMQC data, it can be seen that the proton nuclei are directly correlated with carbon-13 (13C) or have one bond (1JC, H) so that their own pairs can be known with certainty. The broad singlet signal on the δ H 6.64 ppm chemical shift (2H, bs, H−3, and H-5) correlates directly with carbon at δ C 102.2 ppm (C-3 and C-5). In addition, the HMQC spectrum also indicates the presence of methylene protons bound to C-9, methane bound to oxygen, and sulfate bound to C-8 and C-7, respectively.

From the HMBC spectrum, it can be seen that there is a correlation between protons and carbon with a distance of two bonds (2 J) to three bonds (3 J), which can be seen in **Figure 3**. From the HMBC data, it can be seen that there is a correlation between H-3 and H-5 with C-5/C-3, C-1, and C-7; H-7 correlates with C-8 and H-9 correlates with C-8 and C-7. These data support the existence of phenyl propanoid compounds as the basis for lignosulfonates [38]. The correlation between HMQC and HMBC can be seen in **Figure 11**. With the results that look like this, it shows that the isolation process of lignin from bagasse has been successful. Likewise, the sulfonation of lignin to lignosulfonate has also been successful.

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*Laboratory Optimization Study of Sulfonation Reaction toward Lignin Isolated from Bagasse*

Based on the results of the lignin sulfonation process on lignin sulfonation

1.Bagasse as biomass is a raw material that can be processed into lignosulfonate surfactants. The lignosulfonate obtained from bagasse is processed in two stages, namely, the lignin isolation process using sodium hydroxide and the

2.Based on the FTIR test, the lignin-forming components were shown by the presence of phenolic functional groups O▬H, aliphatic ▬CH▬ and aromatic stretching groups, and C═O ketone functional groups, while the lignosulfonate-forming components were indicated by the presence of alkene groups, sulfate groups, and carbocyclic acids and ester functional groups, each with a

spectrum wavelength corresponding to the standard spectrum.

3.Based on the results of the NMR test, the presence of phenyl propanoid compounds as the basis of the lignosulfonate compounds indicates that the sulfonation process has reached the expected target, namely, the formation of

optimization, several conclusions can be drawn, namely:

*NMR test results—HSQC and HMBC correlation of bagasse lignosulfonate H4S4 isolates.*

sulfonation process using sodium bisulfite.

lignosulfonates completely.

*DOI: http://dx.doi.org/10.5772/intechopen.93662*

**4. Conclusions**

**Figure 11.**

*Laboratory Optimization Study of Sulfonation Reaction toward Lignin Isolated from Bagasse DOI: http://dx.doi.org/10.5772/intechopen.93662*

**Figure 11.** *NMR test results—HSQC and HMBC correlation of bagasse lignosulfonate H4S4 isolates.*
