In 2005, Yao Wenbin and Zhang Wei of Zhejiang Forestry College put forward the cracking technology of bamboo fiber pyrolysis and separating (Yao and Zhang 2011).

Firstly, using high pressure-cooking vessel softens bamboo slices and then micro-cracks are formed. The slices are delaminated by splitting the bamboo through machine and the cracks and delamination expand along the direction paral­lel to the fiber leading to bamboo detaching. In external load synergies, the macro­crack of bamboo continues to expand, achieve its interfacial debonding stratified and obtain crude fiber bamboo. Coarse bamboo fibers become fine fibers after soft­ening, carding and a series of processes (Yao and Zhang 2011).

The notable feature in this method is small damage to the fiber intensity, fiber product has even type, and also very adaptable. Bamboo fiber processed by this method has the length of 50-90 cm and the fineness of 0.06 mm (Yao and Zhang 2011). The quality and yield of bamboo fiber produced by this method is shown in Table 2.1.

A tropical climate is necessary for the production or cultivation of sugarcane with minimum 24 in. of moisture annually. In growing regions, such as Mauritius, Dominican Republic, India, Peru, Brazil, Bolivia, Cuba, El Salvador, and Hawaii, sugarcane crop produces over 15 kg of cane per square meter of sunshine.

The cultivation of sugarcane is only possible in the tropical and subtropical areas with 6-7 months continuous supply of water through natural resources like rainfall or artificial resources like irrigation (George et al. 1917). The production of cane is only possible in the presence of plentiful sunshine and water supplies. This condi­tion provides good irrigation facilities to the countries where less availability of water supply is the major problem such as Egypt. Fig. 4.1 shows a general picture of sugarcane crops.

Sugarcane cultivation can be done by both mechanically and manually, i. e., by hand. Hand harvesting accounts for more than half of production. The process of hand harvesting involves the field to set on fire and burns dry leaves without harm­ing the stalks and roots. Harvesters then cut the cane manually by knives just above ground-level. The mechanical cutters cut the cane at the base of the stalk and take off the leaves, cut the cane into regular lengths and deposit it into a transporter. The structure of bagasse is shown in Fig. 4.2. From Fig. 4.2 it is observed that the bagasse mainly consists of cellulose and lignin (Fig. 4.2, b, respectively).

Figure 4.3a showed the morphology of the washed raw bagasse obtained from the sugarcane mill. The composition of this consists of a mixture of cellulosic short fibers and fine particles. The removal of lignin (Fig. 4.3b) makes the material fairly hard, coarse cellulosic particulates. The modified bagasse fibers shown in Fig. 4.3c display fluffy soft texture.

These tests were taken in two parts: In the first test, 11 plants per crop type in each region (11 plants x 2 crop types x 2 regions) were evaluated to determine the leaf’s morphological characteristics, the amount of leaves, and their weight in relation to the total weight of the plant (expressed in percentage). In the second test, fiber production was carried out ten times with intervals of 15 min, with the purpose of finding the costs and the level of production of the prototype machine.

7.2.3 Morphological Parameters of the Leaf and Bleaching

All plants (11 in each site) were randomly selected in the plantation. The plants were manually extracted and the roots were eliminated. Posteriorly, the leaves of the base of the plants (small stalk) were separated and each part was weighed. Each leaf was measured lengthwise and then all leaves were put together to determine their weight. Following that, fiber was extracted using the prototype machine and three fiber bleaching treatments (Table 7.1) were applied. Next, the fiber was dried using the drying system developed by Moya and Solano (2012).

Resin transfer moulding is a profitable technique for natural fibre composites. In this technique, resin and hardener are pumped separately to the mixing head before injection into the mould. The required amount of resins injected into the prear­ranged fabrics. Pressure can be applied from the opposite direction of injected mould. The wastage of resin is very less and good shape of product is found by this method. Indira et al. (2013) studied the effect of fibre length and fibre loading on the properties of banana fibre-reinforced phenol formaldehyde resin (PFR) composites. They found greater tensile and flexural properties in resin transfer moulded compos­ites than in compression moulded composites. However, it needs big investment for large-scale production.

10.3.2.3 Bulk Moulding

A male-female combination of a closed mould is needed for bulk moulding. Short fibres are specially used in this process. Nowadays, thermoset bulk moulded product occupied the market of thermoplastic injection moulded compounds such as motor parts, electrical component and housing appliances. (Samivel and Babu 2013). The surface smoothness of finish product is good but contains some void portion which reduces composite strength.

Another widely used configuration is the flat-plate PBR, which is constructed by employing slender rectangular containers composed of transparent material. These cylinders are tilted at certain angle, which allows maximum coverage of sunlight. Photoautotrophic cells cultivated in this PBR have high densities (>80 g/L). These are more appropriate for cultivation since they allow low accumulation of dissolved oxygen and allow photosynthesis to occur proficiently. Still, problems like tempera­ture control and adherence of algae to reactor walls exist.

13.3.2.2 Column Photobioreactors

This configuration of a photobioreactor offers the finest mixing, most manageable cultivation conditions and greatest volumetric mass relocation rates. They are eco­nomic and the setup is comparatively easy. Column PBR are aerated from the base and their translucent walls allow maximum exposure to light. They can also be illumi­nated internally.

13.3.2.3 Continuously Stirred Tank Reactors

The tank is in the shape of a broad, hollow, and capped cylindrical duct that has the potential to operate both outdoor and indoor. Risk of culture infection is extremely low. Stirring and illuminating apparatuses are inserted from above. Drainage systems and gas injectors are placed at the bottom and in the mid-section. The consistent turbulent flow induces algal growth and averts fouling of the culture.

When judged against the open pond systems, in a PBR the algal culture is efficiently protected from any sort of pollutant and loss due to low evaporation. The cultivation parameters (level of nutrients, temperature, pH level, etc.) can also be effectively managed.

The natural cellulosic fibers using agricultural by-products have become more urgent and currently used due to higher price and availability of natural and synthetic fibers (Reddy and Yang 2009). These agricultural by-products can be used for the develop­ment of novel cellulose, protein, and synthetic fibers for textile, composite, and biomedical applications (Huda et al. 2007). Research groups have been encouraged to develop suitable technologies such as the use of raw material for textile fiber pro­duction due to the availability and composition of sugarcane straw which would give innovative and nonpolluting destination. Lu et al. (2009) reported that sugarcane straw has three main macromolecular components: cellulose, polyoses, and lignin. The physical, biological, and chemical processes can be used for separation of the macromolecular fractions of lignocellulosic materials. The sugarcane straw cellulose fiber could be produced by a wet-spinning method that can show tensile strength compatible with lyocell fibers in the textile market.

There are very limited literature on kinetics modeling for biomass gasification sup­ported by kinetics parameters determined using experimental data. Sheth and Babu (2009) estimated kinetics parameters for biomass pyrolysis process using kinetics modeling approach. The kinetics constant of two reactions involved in the pyrolysis was calculated by minimization of least square error between the model results and the experimental data. The experimental data were chosen from the literature. The values of activation energy and pre-exponential factor of Arrhenius constants for both reac­tions were calculated by the minimization of the objective function as follows:

F (ЛЛЛЛ ) = £(,j — Wt, j )2

І=1

Wang and Kinoshita (1993) developed a reaction kinetics model for biomass O2- steam gasification. The wood was taken as biomass and the generalized equation was presented as follows:

CH14O0.59 + yO2 + zN2 + wH2O = XjC + x2H2
+x^CO + X4H2O + X5CO2 + x6CH4 + x7N

Furthermore, four main reactions were considered including char gasification, boudouard, methanation, and methane reforming reaction as follows:

Char Gasification

C + H2O ® CO + H2

Boudouard

C + CO2 ® 2CO

Methanation

C + 2H2 ® CH4

Steam Reforming

CH4 + H2O ® CO + 3H2

The rate constant of all these reactions was calculated by the minimization of the difference between the experimental data and calculated data. The equation used was as follows:

m 0 2

Minf (*ap К2 . К3 . К4 ) = МІП ZZ (j — Xexp, j)

The experimental data were taken from their previous work on O2-steam gasification using sawdust as biomass (Wang and Kinoshita 1992). Moreover, the modeling results were validated with the experimental work. In addition, residence time, temperature, pressure, equivalence ratio, and moisture have been investigated on the product gas composition.

Resende and Savage (2010) described the kinetics model for the supercritical steam gasification for hydrogen production. The model consists of 11 reactions. The rate equations of each reaction were taken as first order for each species. The final concentration was calculated using mole balance equations; for example, the con­centration of CO2 was calculated using the equitation as follows:

where k10 is for forward water gas shift reaction and k10r is for reversible water gas shift reaction. The equilibrium constant for the water gas shift reaction was calculated as follows:

C C

H2 CO2

C C

CO H2O

The kinetics parameters were calculated by the minimization of the objective function which is the sum squared difference between the model results and experi­mental values. The experimental data were taken from their previous work based on the supercritical steam gasification of lignin and cellulose (Resende and Savage

2009) . Furthermore, the model was validated with the experimental data and the results showed good agreement.

Salaices (2010) developed a reaction kinetics model for catalytic steam gasifica­tion of biomass surrogates using as model compounds. The kinetics model was based on the coherent reaction engineering approach. The reaction rates were based on the dominant reactions. The reactions like methanation and boudouard reactions were neglected. So the rate of each species was calculated as follows;

ri = Ifij = rWRG + rSR + rDRM

There are only dominant reactions, i. e., water gas shift, steam reforming, and dry methane reforming considered. For example, the rate of formation of hydrogen was calculated as follows:

Furthermore, the kinetics constants have been calculated using experimental data with best parameter estimations and minimizing the least squares objective function via optimization toolbox of MATLAB.

19.2 Conclusion

The literature review on the experimental work of biomass steam gasification showed that the pure steam is best gasification agent for hydrogen production. Steam gasification with CaO as sorbent improved the concentration of hydrogen in

the system and also acts as catalyst. Catalytic steam gasification showed higher yield of hydrogen. So, there is need to integrate steam, CaO, and catalyst together for high purity and higher yield. Furthermore, EFB has potential for hydrogen pro­duction, so there is also need to study the biomass steam gasification using EFB as biomass for hydrogen production. The literature review on the modeling and simu­lation of biomass gasification showed that there are several works published on kinetics modeling for conventional gasification but limited work on biomass steam gasification specifically for hydrogen production. So there is a need to develop reac­tion kinetics model including the carbonation reaction along with the main steam gasification reactions. As kinetics model provides important data regarding the con­version of biomass to hydrogen which is essential to improve the process. The pre­dictions from the kinetics model are more accurate compared to the thermodynamic equilibrium models, so the process can be simulated better with the experimental data. In addition, there is also need to work on the determination of the Arrhenius kinetic constant for all reactions involved in steam gasification with CaO for hydrogen production from biomass.

Bamboo fibers reinforced composites with poly lactic acid and poly butylene suc­cinate are easily degraded by enzymes like proteinase K and lipase PS. Degradation rate of these composites is reduced by the addition of lysine based diisocyanate (LDI), which also enhances their tensile properties, water resistance, and inter facial adhesion (Lee and Wang 2006). Bamboo fibers obtained from compression molding technique and roller mill technique are reinforced into unidirectional composites of polyester. These composites are highly degradable by the use of enzymes (Deshpande et al. 2000). Water bamboo husk and poly butylene succinate novel reinforced com­posites are biodegradable in nature (Shih et al. 2006). Bamboo fiber filled poly lactic acid composites are ecocomposites as they are biodegradable and save the environment from pollution (Lee et al. 2005). Micro-sized bamboo fibers and modi­fied soy protein resin are used to fabricate environmentally friendly composites.

These composites have increased fracture stress and young’s modulus. These composites are fully biodegradable and have a great potential to replace traditional and expensive petroleum based materials in many applications (Huang and Netravali

2009) . Bamboo fiber reinforced in poly butylene succinate matrix produces long fiber unidirectional composites. These composites have high values for tensile and mechanical properties. The mechanical properties are enhanced as the amount of bamboo fiber is increased. Young’s modulus of these composites is predicted by laminate theory but experimental results show that ratio obtained by laminate theory is lower than the actual (Ogihara et al. 2008).

The properties of biomass has been studied for decades; however the data were different among cited works because different types of biomass were used, different moisture conditions were present and different methods were employed. Researchers concluded that the overall properties of agricultural biomass are determined by large variables including its structure, chemical composition, cell dimension and microfibril angle. Furthermore these properties are also varying considerably between plant species and even in the same individual plant (John and Anandjiwala 2008).

5.3.1 Chemical Properties

Plant biomass is primarily composed of cellulose, hemicelluloses and lignin along with smaller amounts of pectin, protein and ash (Kumar et al. 2009). Cellulose is a semicrystalline polysaccharide made up of D-anhydroglucose (C6H11O5) units linked together by p-(1-4)-glycosidic bonds. It provides strength, stiffness and structural stability of the fibre which help to maintain the structure of plants and serves as a deciding factor for mechanical properties. Hemicelluloses are branched and fully amorphous polymers. Meanwhile, lignin is a complex hydrocarbon polymer with both aliphatic and aromatic constituents. Lignin is associated with the hemicellu — loses in plant cell wall and plays an important role in the natural decay resistance of the biomass material (Majhi et al. 2010). Table 5.1 shows the variability in cell wall composition in biomass. The table shows that content of the polymers are highly variable depending on the plant species. The composition, structure and properties of biomass depend on plant age, soil condition and other environmental factor including stress, humidity and temperature (Jawaid and Abdul Khalil 2011). The polymer chemistry of these fibres will affect their characteristics, functionalities and properties processing in different applications (Gorshkova et al. 2012).

Many experiments were conducted based on the literature review. Finally, the leaves are treated in NaOH solution at the concentration of 0.25 M, and the soaking time is 12 h. Now onwards, the chemically treated fibers are called as IDL CT.

8.2.2 Fiber Characterization

The extracted and chemically treated IDL fiber is examined under JEOL JSM — 5350A SEM to understand the morphology of the fiber. Single fiber tensile test (SFTT) is also conducted on specimens as per ASTM C 1557-03Є1. An SFTT speci­men is carefully fixed in a wing-type fixture, and the tensile test is conducted on PC

2000 Electronic Tensometer which has a load cell of 20 kg. The density of the fiber is determined by the ASTM D 3800-99 Procedure A-Buoyancy (Archimedes) method and pycnometry procedure. Fiber density determined by both methods is nearly equal, but the Archimedes method is used in the present work.