Muhammad Aamer Mehmood, Umer Rashid, Muhammad Ibrahim, Farhat Abbas, and Yun Hin Taufiq-Yap

Contents

18.1 Microalgae as a Potential Feedstock…………………………………………………………………….. 308

18.2 Biomass Production Systems……………………………………………………………………………… 310

18.2.1 Open Pond Production…………………………………………………………………………. 310

18.2.2 Closed Photo-Bioreactors……………………………………………………………………… 313

18.3 Microalgae Cultivation Using Waste Water……………………………………………………………. 314

18.3.1 Fresh Water Versus Waste Water……………………………………………………………. 315

18.3.2 Microalgae Based Bioremediation……………………………………………………………. 315

18.3.3 High Rate Algal Ponds……………………………………………………………………….. 320

18.3.4 Pretreatment of Influent………………………………………………………………………… 320

18.3.5 Selection of Efficient Strains………………………………………………………………….. 321

18.3.6 Lower Input for Economical Production…………………………………………………… 321

18.4 Challenges in Using Waste Water as Growth Media………………………………………………….. 322

18.5 Conclusion and Future Prospects…………………………………………………………………………. 323

References …………………………………………………………………………………………………………….. 324

M. A. Mehmood (*)

Faculty of Science and Technology, Department of Bioinformatics and Biotechnology, Bioenergy Research Center, Government College University Faisalabad,

Faisalabad 38000, Pakistan e-mail: draamer@gcuf. edu. pk

U. Rashid

Institute of Advanced Technology, Universiti Putra Malaysia,

Serdang, Selangor 43400, Malaysia

M. Ibrahim • F. Abbas

Faculty of Science and Technology, Department of Environmental Sciences, Government College University Faisalabad , Faisalabad 38000 , Pakistan

Y. H. Taufiq-Yap

Institute of Advanced Technology, Universiti Putra Malaysia,

Serdang, Selangor 43400, Malaysia

Faculty of Science, Catalysis Science and Technology Research Center,

Universiti Putra Malaysia, Serdang, Selangor 43400, Malaysia

K. R. Hakeem et al. (eds.), Biomass and Bioenergy: Processing and Properties,

DOI 10.1007/978-3-319-07641-6_18, © Springer International Publishing Switzerland 2014

Abstract Microalgae have emerged as a potential feedstock for sustainable energy in recent years because of their higher biomass productivity and ability to eradicate air and water pollutants via bio-extraction. Augmentation of lipid contents through metabolic pathway engineering and growth conditions optimization along with the efficient harvesting and processing technologies are leading goals of today’s micro­algae research. Although microalgae have huge potential for biodiesel production yet there are several challenges for making it commercially available. Among sev­eral others, extensive water requirement for microalgae cultivation is a major chal­lenge because water is one of the basic requirements for algal cultivation. This chapter describes the current status of algal biomass production and its biotechno­logical potential as well as exploitation for biofuel production using waste water. The key challenges to algal biomass production on commercial scale, biorefinery concept, and future perspective of the technology are also discussed.

Keywords Microalgae • Biomass • Biofuel • Waste water • Bioremediation • Biorefinery

The process of moisture absorption in bamboo is observed to follow the kinetics described in Fick’s theory (Kushwaha and Kumar 2010). The moisture absorption of bamboo fibers is observed to be 13 %, which is more than that of cotton, lyocell, viscose rayon, modal, and soybean (Erdumlu and Ozipek 2008). Bamboo fiber pro­vides a reservoir of moisture, which usually diffuses into interfacial regions and decreases the shear strength (Chen et al. 2009). The moisture absorption of bamboo epoxy composite is 41 % and when it is subjected to benzoylation, moisture absorp­tion decreases to 16 % (Kushwaha and Kumar 2010). The moisture absorption in bamboo fibers after 9 days of water immersion results in decrease in interfacial shear strength (IFSS) to at least 40 % (Chen et al. 2009). Bamboo possesses very high moisture content; green bamboo has 100 % moisture with innermost layers having 155 % moisture (Li 2004). Phyllostachys bambusoides; bamboo specie has moisture content of 138 %. Increased moisture absorption in bamboo/vinyl ester composite fibers leads to a decrease in IFSS. This reduction in IFSS is due to the fact that bamboo strips provide reservoir of moisture which diffuse to interfacial area and inhibit the hardening of composite (Chen et al. 2009). Moisture absorption in bamboo can be decreased from 41 to 26 %. Silane treatment also reduces the water absorption (Kushwaha and Kumar 2010).

Animal bedding is another application of bagasse fibers which is generally used in poultry farms. The nonwoven and the bedding material (after collecting enough poultry wastes) are easy to layout and can be packed and sold as garden mulch directly. This approach not only promotes production of biodegradable and nutri­tional garden mulches, but also helps ease animal waste management.

4.5.3 Aquaculture

Aquaculture is also one of the useful applications of the nonwoven bagasse fibers. The bagasse fiber nonwovens can be enforced in aquaculture as bank weed control and filtration. Fish cultivation used artificial habitats that can profit the aquaculture system by giving shelter, nutrition, and improvement in water quality. Thus, avail­ability of inexpensive artificial habitat materials can help fish farmers with profits.

4.5.4 Sugarcane Bagasse Paper

For high quality paper making, sugarcane bagasse is one of the most eco-friendly, sustainable, and renewable resources. The bagasse fiber generally used state-of-the-art technology and creates a bagasse pulp which is suitable for high quality paper making. The important application of bagasse fiber can be found in newsprint papers which are produced from 100 % bagasse fiber. High quality office and printing papers generally have a 20 % internal fiber added to ensure that the paper is suitable for all office and print applications.

Paper products fall under the following categories:

1. Paper produced from a non-forest resource (alternative fiber)

2. Paper sourced from a renewable resource (crops are constantly renewed for sugar consumption)

3. Recycled paper (as per FSC’s description of papers which are considered recy­cled, Chiparus 2004)

The study found that an average of 0.076 fiber kg/plant is extracted from the two types of crops, which is equivalent to 2.6 % of the total weight of the leaves before scrapping and to 1.75 % of the plant’s total weight. The plant from the first crop

produces less fiber quantity than the plant from the second crop (Table 7.2). Plants from the second crop produced 59 % more fiber compared with the plants from the first crop. Projecting these values per crop unit (hectares) shows that an average 6,175 fiber kg/ha (Table 7.2) may be extracted. The inconvenience is, however, that a great amount of the plant is waste material, an average of 361,757 waste kg/ha (98.2 % of the plant weight). Nevertheless, it is important to point out that evalua­tions showed that 89.20 % of the waste material is moisture, which means that 322,687 kg (89.2 %) of waste correspond to water.

The values found for fiber are due to the fact that the central part of the pineapple leaf consists of bundles immersed into parenchymal tissue and the leaf surface is made of epidermal tissue (Bismarck et al., 2005, Moya et al. 2013a, b). Due to this anatomical characteristic of the leaf, a great amount of water is stored in the paren­chymal tissue, thus increasing weight due to moisture, which results in low fiber percentage (D’Eeckenbrugge et al. 2011; Aragon et al 2012).

According to the evaluations of moisture content of both extracted fiber and waste, extracted fiber presented an average moisture content of 74.24 %, whereas waste moisture content amounted to 89.20 %. In the case of fiber, the percentage found coincides with studies carried out by D’Eeckenbrugge et al. (2011), Aragon et al (2012), and Moya and Solano (2012), who reported moisture contents in A. comosus leaves of the variety MD-2 ranging from 70 to 75 %. Regarding ash quantity, the value is 4.75 % for leaf fiber, which is significantly higher than the value of 1.1 % reported by Mukherjee and Satyanarayana (1986) . On the other hand, the ash content of leaf waste was 10.37 %. High ash content, as is the case of the wastes, has a negative effect on some possible uses; if the waste is used as fuel for heating, the resulting ashes have to be constantly eliminated.

With regard to fiber color evaluation, the average values presented by the fiber coming out of the machine or green condition were L* of 56.02, a* of -10.81, and b* of 35.23. This is a combination of white, green, and yellow shades, which results in a greenish clear coloration of the fiber. No differences in color parameters of fiber in green condition were found between plants coming from the first or second crops (Fig. 7.4); therefore, color could be treated without distinction of crop.

Evaluation of the three bleaching treatments (water, hydrogen peroxide 5 %, and chlorine 1 %) for both the bleaching and drying stages showed that parameter L* (luminosity) increased for all treatments (Fig. 7.4a) , which means that the fiber became clearer; however, differences were found among the bleaching treatments. The fiber in green condition bleached with chlorine 1 % showed a significantly higher value for L*, followed by water treatment, and lastly by hydrogen peroxide 5 % (Fig. 7.4a). After the fiber drying, the L* value decreased with chlorine 1 % treatment; the fiber bleached with the latter treatment shows no statistical differences with water treatment. When the fiber is treated with hydrogen peroxide 5 %, the L* value after drying is significantly higher than for the fiber treated with water or chlo­rine 1 % (Fig. 7.4a).

Parameter a* for fiber color increased its value in both the bleaching and drying stages (Fig. 7.4b), which means that the reddish shade of the fiber was intensified. Chlorine 1 % bleaching was the only treatment showing positive a* values

Fig. 7.4 Variations of the L* (a), a* (b), b* (c), and ДЕ* (d) color parameters after the application of the three treatments for fiber bleaching and after the drying process of natural fiber obtained from A. comosus leaves from the first and the second crops

(Fig. 7.4b) unlike hydrogen peroxide 5 % treatment, which showed the lowest increments of a* in both stages (bleaching and drying). Lastly, water treatment also showed an increment in the value of a* (Fig. 7.4b).

Parameter b* decreased significantly with the bleaching and drying process (Fig. 7.4c), which means that the yellow shades of the fiber diminished. Also, differences were found in this parameter between the bleaching and drying process. For bleaching, water treatment showed the highest reduction of parameter b*, fol­lowed by hydrogen peroxide 5 %, and next by chlorine 1 % with the lowest reduc­tion. After fiber drying, the behavior of the parameter varied, since bleaching with water and hydrogen peroxide 5 % showed no differences (in the b* value) between both treatments, although the values were significantly lower than for bleaching with chlorine 1 % (Fig. 7.4c).

With regard to color change (ДЕ*), it varied from 18 to 33. The highest color changes were found in the bleaching process with water and chlorine 1 %, among which there were no differences; these values were significantly higher than for bleaching with hydrogen peroxide 5 %. For dried fiber, chlorine 1 % was the bleaching treatment showing the highest value of ДЕ* and therefore the most effective, followed by hydrogen peroxide 5 %, and lastly by water.

C. Santulli, F. Sarasini, E. Fortunati, D. Puglia, and J. M. Kenny

Contents

11.1 Introduction………………………………………………………………………………………………….. 176

11.2 Okra Fibre as the Reinforcement for Thermosetting Polymers………………………………………… 178

11.3 Okra Fibre Based Thermoplastic Composites…………………………………………………………… 181

11.4 Okra Fibres as a Possible Source of Nanocrystalline Cellulose……………………………………….. 184

11.5 Conclusions and Future Perspectives…………………………………………………………………….. 187

References………………………………………………………………………………………………………….. 187

Abstract The need to find environmentally friendly alternatives to traditional synthetic fibres such as glass fibres to be used as reinforcement in polymer matrix composites has attracted a growing interest in natural plant fibres in the last decade. In this regard, this chapter provides a comprehensive overview on a less common, but promising, natural fibre known botanically as Abelmoschus esculentus. It focuses on the origin, history and use of this plant with a particular emphasis on the fibres extracted from the stem of this plant, also known as okra fibres. A comprehensive mechanical, morphological and thermal characterization of the fibres is addressed in this work aiming at investigating their possible use as reinforcement in polymer matrix composites. The addition of okra fibres in thermoplastic and thermosetting

C. Santulli (*)

Universita degli Studi di Camerino, School of Architecture and Design, viale della Rimembranza, Ascoli Piceno 63100, Italy e-mail: carlo. santulli@unicam. it

F. Sarasini

Department of Chemical Engineering Materials Environment, Sapienza—Universita di Roma, Via Eudossiana 18, Rome 00184, Italy

E. Fortunati • D. Puglia • J. M. Kenny

Materials Science and Technology, Civil and Environmental Engineering Department, Universita di Perugia, Strada di Pentima 4, Terni 05100, Italy

K. R. Hakeem et al. (eds.), Biomass and Bioenergy: Processing and Properties,

DOI 10.1007/978-3-319-07641-6_11, © Springer International Publishing Switzerland 2014 matrices is reviewed, while the last part of the chapter is devoted to the development of cellulose-based nanocomposites, which is unanimously perceived as one of the most promising research fields related to plant-based products. The extraction of cellulose nanocrystals from okra fibres and their incorporation in thermoplastic composites is described. The problems that appear as limiting factors for possible application of okra fibres as reinforcement for semi-structural components are high­lighted and discussed.

Keywords Okra fibres • Thermoset composites • Thermoplastic composites • Nanocellulose extraction

11.1 Introduction

Okra (Abelmoschus esculentus (L.) Moench), also known as Hibiscus esculentus L., is a member of the mallow (Malvaceae) family, which includes also hibiscus and cotton among other species, and can be found as a tall-growing, warm-season annual (primarily in the United States) or perennial (in India and Africa) that is well suited to a wide range of soil types. It represents the only vegetable crop in the Malvaceae family, whose products have significant use in the food sector. In several parts of the world it is known also as Okra, Quingumbo, Lady’s finger, Gombo, Gumbo, Bamia, Bhendi and Bhindi. The origin of Okra is disputable, but it seems to be native to the so-called Abyssinian centre of origin of cultivated plants, an area that includes Ethiopia, Eritrea and the eastern part of the Anglo-Egyptian Sudan. It is currently grown throughout tropical Asia, Africa, the Caribbean and southern United States.

Okra can grow up to 2 m tall and has leaves 10-20 cm long and broad, with lobes ranging from 5 to 7. The five white to yellow petals that constitute the flowers of diameters in the range 4-8 cm, are often characterized by a red or purple spot at the base of each petal. The seeds are contained in a capsule up to 18 cm long and that shows from 4 to 10 distinct ribs or ridges (Fig. 11.1). The immature young seed pods are the edible part of this plant. Most okra cultivars produce green pods, but a few varieties produce yellow or dark red pods. These pods are harvested when immature and high in mucilage, generally within 2-6 weeks after flowering. In some countries the most interesting part of okra plant is represented by the seeds, which yield edible oil with a pleasant taste and odour, and high in unsaturated fats such as oleic and linoleic acid. The ripe seeds can also be roasted and ground and used as a substitute for coffee. The last years have witnessed an increasing interest in fibres that can be extracted from the stem of okra plants, which are often considered as an agricultural waste product after the collection (Shamsul Alam and Arifuzzaman Khan 2007; Arifuzzaman Khan et al. 2009; De Rosa et al. 2010a, 2011). This is not surprising since roselle (Hibiscus sabdariffa, L.), a close relative of okra, is traditionally used as a source of fibres (Athijayamani et al. 2009, 2010; Methacanon et al. 2010).

The fibres can be obtained from the stems of okra plants by water retting for about 15-20 days (Arifuzzaman Khan et al. 2009; De Rosa et al. 2010a). From a

morphological point of view, the microstructure of okra fibres is similar to that of other natural fibres, being a hierarchical structure, as confirmed by the investigation of both cross section and longitudinal surface by means of optical and electron microscopy (Fig. 11.2). As observed, okra technical fibre is made up of several elementary fibres (known as ultimate fibres) which appear to overlap each other along the whole length of the fibre while being firmly bonded together by pectin and other non-cellulosic compounds that provide strength to the bundle (De Rosa et al. 2010a; Fuqua et al. 2012). The highly irregular polygonal shape of okra fibre is apparent from Fig. 11.2a, b and its typical diameter is found to be in the range of about 40-180 pm. The shape variability affects the mechanical strength of fibres, being dependent on agricultural factors (stem age and plant variety, for instance) as well as the position of the fibres along the stem height (Ayre et al. 2009). The ultimate fibre appears to be roughly polygonal, with a central hole (lumen) of very variable dimensions. In particular, cell wall thickness and lumen diameter are reported being in the range 1-10 and 0.1-20 pm, respectively (De Rosa et al. 2010a).

The composition of okra fibres in terms of cellulosic and non-cellulosic constitu­ents is reported in Table 11.1 along with the composition of other bast and leaf fibres commonly used as reinforcements in natural fibre composites. It is worth noting that the composition of okra fibres is very similar to that of other bast or leaf fibres. In this regard, comparable thermal behaviour and stability are expected. Okra fibres showed a traditional TG (thermogravimetric) curve characterized by three distinct weight loss steps, with a two-stage decomposition process (De Rosa et al. 2010a). The initial weight loss («8 %) occurring between 30 and 110 °C is due to water vaporization, while the onset of degradation occurs after 220 °C. The first stage (220-310 °C) is well described in terms of thermal depolymerization of hemicellulose, pectin and cleavage of glycosidic linkages of cellulose (weight loss of 16.1 %), while the second stage (310-390 °C) is characterized by the degradation of the a-cellulose that consti­tutes the fibre (Albano et al. 1999). The degradation of lignin is a phenomenon that takes place slowly in the whole temperature range owing to its rather complex struc­ture. It can be concluded that okra fibres experienced a thermal stability comparable with that of other natural fibres, as can be inferred from Table 11.2.

As regards the mechanical behaviour, okra fibres are characterized by a brittle behaviour in single filament tensile test with a wide scattering of data (De Rosa et al. 2010a). This behaviour is common to the other vegetable fibres, being dictated by test parameters, plant characteristics and fibre diameter measurement (Symington et al. 2009; da Silva et al. 2012). The effect of okra fibre diameter can be reasonably described by a two-parameter Weibull distribution (De Rosa et al. 2010a) and the resulting mechanical properties are summarized together with the ones of other veg­etable fibres in Table 11.3, from which the comparable mechanical behaviour with soft bast fibres, such as kenaf, and leaf fibres, such as date palm, henequen and sisal, is evident. From these results, the suitability of okra fibres as reinforcement in poly­mer matrix composites can be easily inferred.

Combined flocculation is a multi-step process, which consists of the use of more than one type of flocculants and electro-flocculation or electrocoagulation (Chen et al. 2011). For harvesting of marine and fresh water algae, Vandamme et al. (2011) has inspected the method of electrocoagulation-flocculation. Continuous-flow elec­trocoagulation has also been examined by Azarian et al. (2007) for the separation of algae from industrial wastewater. Throughout electrocoagulation, no sulphate chlo­rine anions are produced. It is also noted that unlike centrifugation process, power consumption is less in electrocoagulation-flocculation (Vandamme et al. 2011). These are the advantageous reasons, due to which electrocoagulation-flocculation is considered as a convenient procedure, which can be used for harvesting of algae. There are certain shortcomings such as inconsistency in speciation of metal hydroxides as well as disturbances by pH, chemical configuration and conductivity of water required to be considered and addressed.

Several pretreatment techniques such as alkaline pretreatment, dilute acid hydrolysis, and fungal pretreatment have been used for ethanol production. The acid pretreat­ment was the best pretreatment for ethanol production followed by alkaline and fungal pretreatment.

16.5.1.1 Alkaline Pretreatment

Generally, the alkaline pretreatment has been used for delignification. The removal of lignin is needed for cellulose that is available for enzymes. Delignification has been tested by using different concentrations of hydrogen peroxide at different pH for vari­ous time intervals. However, 2 % hydrogen peroxide has been used at alkaline pH for the removal of lignin from sugarcane biomass (Dawson and Boopathy, 2008). Lignocellulosic biomass cannot be saccharified by enzymes without pretreatment. Proper pretreatment would reduce the lignin content of sugarcane straw. Hydrogen peroxide can play an important role for the delignification of sugarcane straw. Krishna and Chowdary (2000) reported that alkaline peroxide pretreatment was more effective for delignification of leaves. Alkaline pretreatment has an advantage for by-products which are released during lignin degradation by alkaline peroxide (Gould and Freer 1984). Suhardi et al. (2013) reported that alkaline pretreatment at pH 12 was the opti­mum for maximum ethanol production in variety of cane L 79-1002.

Abrar Inayat, Murni M. Ahmad, Suzana Yusup, M. I. Abdul Mutalib, and Zakir Khan

Contents

19.1 Introduction………………………………………………………………………………………………….. 330

19.2 Steam Gasification for Hydrogen Production……………………………………………………………. 331

19.3 Steam Gasification with In Situ CO2 Capture for Hydrogen Production…………………… 332

19.4 Catalytic Steam Gasification for Hydrogen Production………………………………………………… 335

19.5 EFB Gasification for Hydrogen Production……………………………………………………………… 336

19.6 Kinetics Modeling for Hydrogen Production via Biomass Gasification…………………………. 336

19.6.1 Kinetics Modeling Along with Kinetics Parameters Determination……………………… 338

19.7 Conclusion…………………………………………………………………………………………………… 340

References…………………………………………………………………………………………………………… 341

Abstract The production of hydrogen as a clean and sustainable fuel is becoming attractive due to the energy crisis and increasing environmental issues associated with fossil fuel usage. Biomass steam gasification with in situ carbon dioxide cap­ture has good prospects for the production of hydrogen-rich gas. Furthermore, hydrogen yield can be enhanced using catalyst steam gasification. This chapter comprises the literature review on both the approaches, i. e., experimental and mod­eling used to study the hydrogen production from biomass gasification specifically using pure steam as gasification agent. There were several modeling approaches for

A. Inayat (*) • S. Yusup • M. I.A. Mutalib

Department of Chemical Engineering, Universiti Teknologi PETRONAS,

31750 Tronoh, Perak, Malaysia e-mail: abrar. inayat@petronas. com

M. M. Ahmad

Universiti Teknologi PETRONAS, 31750 Tronoh, Perak, Malaysia Z. Khan

Department of Chemical Engineering, COMSATS Institute of Information Technology, 54000 Lahore, Pakistan

K. R. Hakeem et al. (eds.), Biomass and Bioenergy: Processing and Properties,

DOI 10.1007/978-3-319-07641-6_19, © Springer International Publishing Switzerland 2014 gasification process based on the kinetics, equilibrium, and the fluid dynamics behaviors. A detailed discussion has been carried out in this chapter on modeling and simulation for hydrogen production from biomass based on kinetics modeling. Experimental studies have been published on steam gasification and steam gasifica­tion with CO2 capture and catalytic steam gasification has been discussed. Gasification for hydrogen production from oil palm empty fruit bunch has also been discussed.

Keywords Biomass • Steam gasification • CO2 capture • Hydrogen • Kinetics modeling

19.1 Introduction

Hydrogen is one of the potential alternative energy sources that could be used to replace the existing fossil fuels. Besides the zero carbon footprints, hydrogen is expected to become a prominent energy carrier for stationary and mobile power generation applications such as in transport, industrial, commercial, and residential applications (Clark Ii and Rifkin 2006; Solomon and Banerjee 2006). The utiliza­tion of renewable sources including the biomass of forestry, agricultural, and municipal waste has become a new source of energy due to the abundance of these wastes. Consequently, producing hydrogen from biomass not only offers a zero net carbon emission and burning to get electricity and heat which is clean, it can also be stored and transported and be used in existing technology and infrastructure (Jacobson 2009). Biomass gasification is considered as one of the potential alterna­tives for the production of hydrogen, but the quality of hydrogen and product gas varies with the different gasification agents used (Holladay et al. 2009; Kalinci et al. 2009; Kumar et al. 2009). Biomass gasification can be performed using different gasification agents such as air, air-steam and oxygen-steam mixtures, or pure steam. It is reported that the use of pure steam is more economical and in favor of producing more hydrogen yield compared to the other conventional gasification agents (Gil et al. 1999; Balat 2008; Corella et al. 2008a, b; Balat et al. 2009). This chapter comprises the literature review on both the approaches, i. e., experi­mental and modeling used to study the hydrogen production from biomass steam gasification. Studies have been published on steam gasification (Ptasinski 2008) and steam gasification with CO2 capture (Florin and Harris 2008) and catalytic steam gasification has been discussed (Guo et al. 2010; Tanksale et al. 2010; Serrano-Ruiz and Dumesic 2011). Furthermore, the availability of palm oil empty fruit bunch (EFB) is abundant in Malaysia (Sumathi et al. 2008; Mohammed et al. 2011a, b), so the work reported on EFB gasification for hydrogen production has also been dis­cussed. There were several modeling approaches for gasification process based on the kinetics, equilibrium, and the fluid dynamics behaviors (Nemtsov and Zabaniotou 2008; Wang and Yan 2008; Gomez-Barea and Leckner 2010; Puig-Arnavat et al. 2010; Ahmed et al. 2012; Guo et al. 2012). A detailed discussion has been carried out in this chapter on modeling and simulation for hydrogen production from biomass based on kinetics modeling. Finally, chapter comprises a short summary to identify the gap of study in the specific fields.

Materials have critical roles in engineering design and applications that can lead to successful sustainable products. The proper compatibility between the material and products’ functions, performance, and recyclability became critical for engineering applications. Moreover, finding new materials with desirable distinctive characteristics can expand new design possibilities (Ashby 1992). On the other hand, several criteria and limitations usually affect the usage of a specific type of material in a particular application (Ashby 1992). Thus, selecting a proper material type for a particular appli­cation is a matter of multi-criteria decision making problem (Dweiri and Al-Oqla

2006) where proper decisions have to be carried out based upon several factors.

Recently, due to the tremendous need and awareness of environmental impact and as a result of the governmental emphasizing on the new regulations regarding the environmental impact issues and sustainability concepts as well as the growing of social, economic, and ecological awareness (Faruk et al. 2012; Kalia et al. 2011a, b), the utilization of natural resources was strongly encouraged (Govindan et al. 2014). Consequently, the natural fiber reinforced polymer composites (NFRPC), (simply NFC), became a valuable alternative material type for wide range of applications. In this NFC, natural fibers (such as jute, hemp, sisal, oil palm, kenaf, and flax) are utilized to be fillers or reinforcing material for polymer-based matrices. Such utili­zation of natural fibers can decrease the amount of waste disposal problems, and enhance reducing in environmental pollution (Kalia et al. 2011b). Such materials are attractive from environmental point of view where they can be used as an alter­native to the traditional glass/carbon polymer composites (Faruk et al. 2012; Kalia et al. 2011a, b). They can be used in different applications such as packaging, dis­posable accessories, furniture, building, insulation, and automotive industries (Al-Oqla and Sapuan 2014). Moreover, these NFC have several advantages over the traditional types of materials like the low costs and density as well as acceptable specific strength and modulus (Alves et al. 2010 ; Faruk et al. 2012; Kalia et al. 2011b) which can lead to low weight products.

Furthermore, natural fiber composites are acceptable from environmental points of view because they can participate in producing recyclable and biodegradable products after use (Alves et al. 2010; Kalia et al. 2011a; Mir et al. 2010). Comparable to synthetic fiber composites, NFC are much cheaper, good thermal as well as acous­tic insulating properties that can widen their industrial applications (Alves et al. 2010; Faruk et al. 2012). On the other hand, natural fibers have several advantages over the traditional glass fibers such as: availability, CO2 sequestration enhanced energy recovery, reduced tool wear in machining, and reduced dermal and respira­tory irritation (Al-Oqla and Sapuan 2014 ; Faruk et al. 2012 ; Kalia et al. 2011b; Sarikanat 2010). Despite of that, natural fibers have some considerable drawback demonstrated in poor water resistance, poor bonding with the matrix, and low dura­bility, The weak interfacial bonding between natural fibers and the polymer matrix can lead to undesirable properties of the composites a

and bonding. Consequently, the usage of the coupling agents and surface treatments via mechanical, chemical, and/or physical modifications was implemented (Al-Khanbashi et al. 2005; Arbelaiz et al. 2005; Faruk et al. 2012). A general clas­sification of the natural fibers can be classified based upon their origin as bast fibers, leaf fibers, fruit, and seed-hair fibers as seen in Fig. 1.1. Wide different natural fiber types had been used to reinforce different polymer matrices. Such fibers include wood, cotton, bagasse, rice straw, rice husk, wheat straw, flax, hemp, pineapple leaf, coir, oil palm, date palm, doum fruit, ramie, curaua, jowar, kenaf, bamboo, rapeseed waste, sisal, and jute (Jawaid and Abdul Khalil 2011; Majeed et al. 2013). A sche­matic diagram of the general classifications of natural fibers is shown in Fig. 1.1.

Bamboo fibers have an excellent characteristic of inhibition of bacterial growth, absorption of peculiar smells, and hygroscopicity. Due to these characteristics, bamboo fibers are used as non-woven medical and hygienic materials (Yi 2004). Flavones can be extracted from bamboo leave fibers by leaching method. These flavones are used in preparation of many drugs (Gang et al. 2000). Chemical con­tents of bamboo fiber are bacteriostatic and bacteriolytic (Zhong-Kai et al. 2005). Eating bamboo fiber reduces the rate of intestinal natural flora and pathogens. This property is applied to produce a bamboo drug for gastrointestinal infections (Anping et al. 2005). Moreover bamboo fibers can also be used for the production of sanitary towels, gauze, bandages, absorbent pads, surgical wear, doctors’ coats, and medical masks. Bamboo fibers have gentle make up, due to this reason only a few people are allergic to bamboo fibers; this property plays a role in production of masks etc. It is light, durable, and inexpensive (Bamboo Groove 2008).