Selection of efficient strains is a continuous process and it should never stop to fulfill the commercialization needs. It needs to launch a massive strain selection program across the globe. Different microalgae species have been studied under various experimental designs with respect to nutrient starvation and heterotrophic conditions to evaluate their lipid contents and the lipid productivity. The Chlorella sp. has been reported to be the most suitable for such systems (Chu et al. 2009; Bhatnagar et al. 2010). Among these, C. kessleri was shown to produce a very high biomass density (2.01 g L-1) when cultivated using municipal waste water (Li et al. 2011a). Naturally, a consortium of microalgae (Chlorella spp., Micractinium spp., Actinastrum spp.) may be established when cultivated in waste water for treatment purposes. A maxi­mum lipid productivity of 24 mg L-1 day-1 has been reported (Woertz et al. 2009) in such cases. Other microalgae, for instance, Botryococcus braunii is widely distrib­uted in freshwater, brackish, and saline lakes and is capable to accumulate unsatu­rated long-chain hydrocarbons at a concentration of 15-75 % of its dry biomass (An et al. 2003; Orpez et al. 2009) but still needs optimization of growth conditions for each water source. An efficient strain of Scenedesmus sp. LX1 showed biomass yield @ 0.11 g L_1, lipid contents ranging from 31 to 33 % with a lipid productivity @8 mg L-1 day-1 in a batch culture study using secondary effluent as growth medium (Xin et al. 2009). Moreover, LX1 was shown to remove total nitrogen and phospho­rous as high as 90.4 % and nearly 100 %, respectively. When ammonium was used as the nitrogen source, LX1 reached a very high specific growth rate of 0.82 day-1 (Xin et al. 2010). Similar findings have been reported in literature (Zhou et al. 2012a, b). Chlamydomonas reinhardtii is another microalga with the potential to treat waste water along with oil production. It was cultivated in waste water collected at three different stages (influent, effluent and centrate) of a municipal waste water treatment plant. In this case, a lipid productivity of 505 mg L-1day-1 was achieved, which may be the highest lipid productivity reported for microalgae production in waste water (Kong et al. 2010). The use of olive mill waste water as media for biomass produc­tion from Scenedesmus dimorphus and Arthrospira platensis was reported to be another hopeful strategy, recently (Cicci et al. 2013).

Several studies have been published on steam gasification using CaO as sorbent. Acharya et al. (2009) worked on the hydrogen production from sawdust using steam gasification and CaO as CO2 sorbent in bubbling fluidized bed reactor. Furthermore, they proposed the regenerator along the gasifier for the regeneration of calcium carbonate in the system. They predict through experimental setup around 71 vol.% of H2 with 0 vol.% of CO2 at 853 K, steam/biomass ratio of 1.0, and Ca/C ratio of 1. They also proved that using CaO as sorbent the purity of hydrogen increased more than 30 vol.% compared to the process without CaO. Moreover, CaO not only cap­tures CO2 from the system, but also increases the efficiency of the system due to the exothermic nature of carbonation reaction as follows.

Carbonation reaction

CaO + CO2 ® CaCO3 — 178.3kJ / mol

They also reported that in steam gasification with in situ CO2 capture, the water gas shift reaction moves in the forward direction due to the low partial pressure of CO2 in the system, as CaO absorbs the CO2.

Pfeifer et al. (2009) used duel fluidized bed gasifier to study the effect of CaO on the product gas composition from biomass steam gasification. The hydrogen content in the product gas achieved 40 vol.% without CaO, but with the CaO the hydrogen content increased to 75 vol.%. They named this concept as “absorption enhanced reforming—AER concept.”

Furthermore, they presented a simplified flow sheet for power generation using AER process for 100 kW at Vienna University of Technology, Austria.

Guoxin and Hao (2009) studied hydrogen production using pine tree sawdust as wet biomass in quartz reactor. They investigated the effect of temperature, Ca/C ratio, and the moisture content of the biomass on hydrogen production. They pre­dicted that the CaO not only acts as sorbent but also acts as catalyst. Furthermore, CaO has strong impact on watergas shift reaction rather than steam reforming of methane. Moreover, the high temperature is not in favor of carbonation reaction. They reported that the optimum temperature for biomass steam gasification with CaO as sorbent is 923-973 K. Their results showed more than 55 vol.% of hydrogen in the product gas at 923 K with Ca/C ratio of 0.5.

Acharya et al. (2010) have reported biomass steam gasification using sawdust as biomass and CaO as sorbent. They investigated the effect of variables (temperature, steam/biomass ratio, and CaO/biomass ratio) on the hydrogen purity and hydrogen yield. They predicted 54.43 vol.% of hydrogen at 943 K, steam/biomass ratio of 0.83, and CaO/biomass ratio of 2. Furthermore, they have reported that hydrogen yield increased by increasing temperature.

Han et al. (2011) studied on biomass steam gasification in the presence of CaO. They investigated the effect of temperature (762-1,013 K), steam/C ratio (1.2-2.18), and CaO/C ratio (0-2) on the hydrogen purity and yield. Taking sawdust as biomass they performed experiments in the fluidized bed gasifier.

They reported that all three factors, i. e., temperature, steam/C ratio, and CaO/C ratio, are in favor of hydrogen production. The addition of steam along with CaO is in favor of more hydrogen as it shifts the thermodynamic equilibrium of char gasification and water gas shift reaction to product side. They have predicted the maximum hydrogen concentration 62 vol.% with yield of 72 g/kg of biomass at 1,013 K, steam/C ratio of 2.18, and CaO/C ratio of 1. In addition, they observed that carbonation reaction temperature range is 753-1,043 K best for the gasifica­tion process in order to get more pure hydrogen by absorbing CO2 from the system. They reported that within these temperature ranges not only the carbonation reac­tion moves in forward direction but also water gas shift reaction moves to product side due to the lower partial pressure of CO2 in the system. In addition the results showed that by increasing temperature H2 and CO2 increase while CO and CH4 decrease.

A detailed comparison of the literature based on the operating conditions, optimized parameters, and results based on optimum conditions is given in Table 19.1.

Fresh bamboo shoots and shoot fibers are used as foods. Bamboo shoots and fibers are very popular in Asian stir-fry and as pickled condiment. Most important genus for production of edible shoots is Phyllostachys. Bamboo fiber derived food products include bamboo tea, bamboo wine, bamboo vinegar, and charcoal coated dry fruits (Diver 2001). Bamboo fibers are also used for preparation of food packaging mate­rial like cellophane. The nutritive value of bamboo exposes that total carbohydrate content of bamboo leaves decreases throughout the growing season, remains stable for some time and increases during winter. Unlike carbohydrates, crude protein con­tent is high in growing season and is decreased in winter season. The concentration of fiber and proteins make it a good source for feedstock. The bamboo has a potential for winter forage for goats and some other livestock. Bamboo also reduces the expo­sure of livestock animals to gastrointestinal parasites (Halvorson et al. 2011).

5.4.1 Biomass Fibre Design

Agricultural fibres are presently a major area of research for various end product applications. The major strength of fibres can be utilized as reinforcement in bio­degradable composites and as alternative raw materials for several manufacturing industry. Figure 5.3 shows that the design of fibre biomass varies according to the type of species and sizes. Each size also varies according to each specific applica­tion of particle, pulp, fibre, fibrils, micro and nano. In terms of strength per unit weight, the fibres have strength comparable to that of man-made fibres, while the modulus is very high (Chinga-Carrasco 2011a). The micro and nano-microchips invisible to the normal view were widely used in many modern applications for various purposes and is also a very important technology in the future (Chinga — Carrasco 2011b) . Several modern and high-tech nano-applications were intro­duced because of the excellent result as for medical applications, cosmetic, pharmaceutical, aerospace and others. In addition, the successful applications have been demonstrated in military research and development, and by-products have also been explored.

Fig. 5.3 Variations of agriculture raw materials

Agricultural biomass or lignocellulosic fibres can be described as resources comprising primarily cellulose, hemicellulose and lignin (Rowell et al. 2000). Detailed observation of the fine structure of biomass fibre is achieved by using elec­tron microscope that provides a clearer understanding of biomass cell wall structure organization. Figure 5.4 depicted the schematic illustration of biomass fibre cell wall structure which consists of primary and secondary multilayered structure (Abdul Khalil et al. 2006). Each cell wall layer comprises different chemical com­position, microfibril alignment which depends on the development and functionalities of the plant that provides mechanical support and stability to the structure. Advanced biocomposite production has dominated the world of manufacturing industry to increase value-added bamboo materials to produce innovative products such as bamboo fibre reinforced, particleboard, pulp, medium density fibre board and com­posites for the construction industry. The production of green composites derived from renewable sources such as palm trees, bamboo, kenaf, and others have poten­tial to provide positive benefits to the manufacturing industry, consumers and the natural environment (Koronis et al. 2013).

With increase in fiber content, the tensile strength of untreated and treated IDL fiber reinforced polyester (FRP) composites is increased. IDL CT FRP composites have shown 39.65 % more tensile strength than IDL FRP composites at maximum fiber volume fraction which is shown in Fig. 8.8. The specific tensile strength of the com­posites is also determined and is graphically represented in Fig. 8.9 against fiber volume fraction.

The IDL FRP composites under tensile load have exhibited relatively more elonga­tion than load at 12.08 % fiber volume fraction; thereby, tensile modulus is decreased (Fig. 8.10). An increase in trend of tensile modulus is observed at all volume fractions in case of IDL CT FRP composites. Chemical treatment to IDL fibers resulted in good locking between fibers and matrices, evidenced from the experimental results. Though IDL CT FRP composites have taken more load at all fiber volume fractions, they exhibited more elongation, thereby resulting in nearer tensile modulus of the IDL FRP composites. Similar trend was observed in the case of PALF FRP composites rein­forced with 2 % NaOH treated fibers for 1 h and has shown enhancement in tensile strength and modulus than untreated FRP composites, and its values are 55.4 MPa and 1.46 GPa, respectively (Uma Devi et al. 1997). The specific tensile modulus of IDL and IDL CT FRP composites is 906.44 and 871.72 (MPa/kg. m-3).10-3 respectively at maximum fiber volume fraction and is shown in Fig. 8.11.

The tensile strength and modulus of 22.5 MPa and 1,095-1,100 MPa, respec­tively, were observed in PALF fiber reinforced LDPE composites where the fibers were longitudinally oriented at 30 % fiber content (George et al. 1995). From the experimental results, it is obvious that the IDL CT FRP composites showed supe­rior performance than pineapple leaf fiber reinforced LDPE composites at maximum fiber content, and its value is 56.03 MPa, whereas tensile modulus of untreated and

treated IDL FRP composites exhibited similar trend to that of PALF-LDPE composites.

The influence of benzoylation treatment on tensile properties was reported in 1996. The bond between fiber and matrix was evidenced from the experimental results of the composites reinforced with treated fibers, in polystyrene matrix (Manikandan Nair et al. 1996). In the present work, NaOH-treated IDL FRP composites at 16.92 % fiber content exhibited 1.16 times more tensile strength than the composites (at 30 % fiber content) made of polystyrene matrix, benzoylate — treated sisal fiber.

PALF (30 mm fiber length) FRP composites have exhibited tensile strength of

63.3 MPa and are 1.13 times higher than IDL long FRP composites experimentally studied in this research (Uma Devi et al. 1997). Due to fiber entanglements that occurred above optimum size of the fibers, which was resulted in decrease in the tensile strength in PALF FRP composites when they were reinforced with 30 mm fiber length.

The CO2 emissions released during the combustion of woody biomass from short rotation of plantations were recently captured by some plants during their growth process. Therefore, it is the very standard convention to assume that burning bio­mass generates zero GHG emissions. However, emissions from fertilizers use (NO) and management activities represent a net contribution to the stock of GHG in the atmosphere on a wide range. While considering the emissions from long-distance transport, it is not possible to count all the emissions from fertilizers or from other local management activities, because of the lack of reliable data and also the exact
information is not estimated yet. In this way, the biomass is exempted from any carbon-related taxes. This implies that a power plant that generates BECCS electricity receives a financial support which is equal to the value of the tax for capturing and storing CO2 and pays tax only on emissions from the international transport of woody biomass. The price of BECCS electricity is obtained by modifying Eq. 12.5 as follows:

= Jft.,,+JgTCD + sC“- (TCCS>

+ — + -(r + S)(p — ew — T + — gXD. T. (12.6)

Z h P P

BECCS power generation firms are eagerly willing to demand biomass subject to the optimality condition obligatory to Eq. 12.6. This states that, for a given price of electricity, the higher the tax is, the higher will be the price of biomass that they are willing to pay. The price of biomass increases with a proportional rate of carbon tax: dpF jdT = ew + y%D. This suggests that the regional social planner may be willing to pay a price higher than the global marginal cost of biomass production, if the global demand of biomass is exceeding the global maximum endowment. Even if the carbon tax increases the marginal production, the cost of biomass remains the same when there are limitations for production. However, the value of biomass increases with the carbon tax and thus BECCS firms are willing to pay a higher price in the international market as well. A firm in the forestry sector captures all the rent as overall hinders are done to the BECCS firms. This is a peculiar outcome of the non-cooperative interaction in the environment. According to different settings, with strategic coalition formation, a group of importing countries would have the incentive to form and motivate a cartel to extract a part of rents from the forestry sectors of exporting regions (Rose et al. 2012).

Dynamic Mechanical Thermal Analysis (DMTA) was performed on the natural fiber composites in order to study and establish the viscoelastic behavior. The vis­coelasticity of materials is determined by applying a sinusoidal strain and measur­ing the stress as response (Essabir et al. 2013b). Measures of viscoelasticity can be expressed by the equation of strain and stress:

e = e0 sin (at)

s = s0 sin (at + d)

where e0 is the strain amplitude, ю is the angular frequency and S is the angular shift between stress and strain.

The dynamic modulus or complex modulus (E*) is given by equation:

E* =>/E’2 + E"2

where E’ is the elastic modulus and E" the viscous modulus. E’ and E" are expressed in the equation:

E’ = 1^—J cosd

( „ A S0

£o

where є0, a0, and m represent respectively the amplitude of the deformation cycle, the amplitude of the stress cycle, and the pulsation in rad/s.

The elastic modulus (storage modulus), is proportional to the energy stored by cycle (elastic behavior). However viscous modulus (loss modulus), represent dissi­pated energy by cycle (viscous behavior). The Loss factor is the relationship between the loss modulus and storage modulus and is expressed by equation:

tanS = E" / E’

In dynamic mode, the mechanical properties of the material depend on the defor­mation of the excitation frequency and temperature.

The Dynamic mechanical thermal tests were performed on a rheometer Solid Analysis (RSA) operating with a dual cantilever configuration. Samples dimension were 45 mm in length, 5.5 mm in width, and 2 mm in thickness. A strain sweep test was carried out and strain from this linear regime was 0.002. After a dynamic fre­quency sweep tests were performed using this strain amplitude (0.002) between

0. 015 and 15 Hz, finally temperature sweep tests were ranged from 30 to 120 °C with a heating rate at 5 °C/min, frequency and strain were fixed at 1 Hz and 0.002 respectively.

Figure 14.8 shows the frequencies sweep tests, complex modulus (E*), and mechanical loss factor (tan S), for PP/Doum composites. It was observed that the complex modulus increases with increases in frequency. This behavior is due to the molecular time response. At higher frequencies have not enough time to relax and attend permanent deformation. It was also observed that the loss factor (tan S) was less sensitive to changes related to the fibers’ content. Generally a change in the tan S curve indicates a relaxation process which is associated to the movement of molecular chains within the polymer structure.

The temperature at which the tanS peak occurs is commonly known as the glass transition temperature (Tg). The glass temperature (Tg) was determined from the deriva­tive curves of tan S vs. temperature (Fig. 14.8). Figure 14.8 shows the Tg variation as function of Doum fibers content in PP matrix. It was observed that the addition of fiber improves the Tg of composites from 76.6 °C for neat PP to 90.25 °C for composite with 30 wt.% fiber content. These results show a gain of gain of 17.8 % in Tg.

J. curcas L., a potential bioenergy crop 70 million years old, is a monoecious, decidu­ous perennial small tree or shrub belonging to family Euphorbiaceae, to the tribe Jatropheae of the subfamily Crotonoideae. In 1737 Karl von Linne first described and in 1753 classified J. curcas. The genus name Jatropha comes from the Greek words “iatros” meaning doctor and “trophe” meaning food. It is commonly known as “Physic nut” in English and “Ricino d’inferno” in Italy. Southern Mexico and parts of central America are believed to be centers of origin of Jatropha (Dehgan and Webster 1979). The plant was later spread by the Portuguese settlers to other continents of the world (Gubitz et al. 1999). However in some parts of the world, including the United States, Australia, South Africa, and Puerto Rico, Jatropha is recognized as an invasive spe­cies (Global Invasive Species Programme 2008).

The plant initially develops five roots; one thick deep primary taproot and four lateral roots, followed by many straight secondary roots (Heller 1996). The stem arises from perennial root stock, has reddish or grey bark which exudates latex white in color. Generally, the tree attains a height between 6.0 and 18.0 ft but under favorable conditions can grow up to 30.0 ft. Leaves are green, simple, petiolated, having 3-5 lobed ovate lamina and are alternate in arrangement. Inflorescence is terminal bearing unisexual flowers. The fruit is ellipsoid capsule, containing three seeds. Seeds are 1-2 cm long, granular, and black in color. Agents of pollination are beetles, honeybees, and moths (Bhattacharya et al. 2005; Henning 2007). In flower­ing, the male flowers open 1 or 2 days after opening of female ones, with former lasting only for 1 day. Plants bear fruits from midsummer to late winter. In indoor cultivation seed never sets unless the flowers are pollinated by hand.

The seeds become mature in 2-4 months with the capsule changing from green to yellow. Upon seed maturity, fleshy exocarp dries and three bivalved cocci are formed. The seeds contain oil which contains 21 % saturated and 79 % unsaturated fatty acids (Heller 1996; Gubitz et al. 1999; Deng et al. 2010). Linoleic and oleic acids are the main components of oil (List and Horhammer 1979). The seeds also contain fructose, glucose, galactose, raffinose, saccharose, stachyose, and protein. Arachidic, curcasin, myristic, stearic, and palmitic acids are also present in Jatropha (Perry 1980). Jatropha also contains toxic compounds such as curcin and phorbolester.

17.2 Plantation and Ecological Requirements of Jatropha curcas

The main inputs for J. curcas production are land, local climatic conditions, planta­tion establishment, and management practices. The outputs are the fruits, seeds, wood, and other biomass elements (Achten et al. 2008).

Lignocellulosic biomass consists mainly of lignin and the polysaccharides cellulose and hemicellulose. Compared with the production of ethanol from G1 feedstocks, the use of lignocellulosic biomass is more complicated because the polysaccharides are more stable and the pentose sugars are not readily fermentable by Saccharomyces cerevisiae. In order to convert lignocellulose to biofuels the polysaccharides must first be hydrolyzed, or broken down into simple sugars using either acid or enzymes.

Production process of lignocellulosic biomass to ethanol mainly consists of four steps: pretreatment, saccharification of cellulose to simple sugars, fermentation of simple sugars to ethanol, and product separation/purification to fuel grade ethanol. Schematic flow sheet for the production process of bioethanol from lignocelullosic biomass is shown in Fig. 20.1.

Renewable energy and steps toward achieving more sustainable societies are the key drivers for conducting more scientific research regarding different aspects of natural resources. A proper utilization of the available resources can enhance better living standards as well as reducing energy consumption behavior. Implementing natural fibers for getting more bioenergy as an alternative source to the fossil fuel energy, as well as utilizing the natural fiber/nanoclay reinforced polymeric materials are emphasized by several governing and industrial sectors. Achieving the optimum desired properties for the completely recyclable hybrid composites are the future game of the world to expand the sustainable design possibilities that can widen the applications of such composite to reach all aspects of the modern living standards. Hybrid recyclable packaging material from natural fiber developed at lower cost but contributes to the sustainability as well as functionality. Mechanically stronger materials are recommended for the packaging as well as gas sensitive materials such as electronic and pharmaceutical packaging. Although those hybrid materials are degradable, the poor interfacial adhesion and the lack of compatibility between the filler and the matrix limited their widespread commercial impact.