Deepak Verma, P. C. Gope, Inderdeep Singh, and Siddharth Jain

Contents

4.1 Introduction……………………………………………………………………………………………………… 64

4.2 Sugarcane: A World Scenario…………………………………………………………………………………. 66

4.2.1 Cultivation and Production of Sugarcane………………………………………………………… 67

4.3 Processing Techniques/Extraction Methods of Bagasse Fibers from Sugarcane

and Bagasse Compositions…………………………………………………………………………………… 69

4.3.1 Atmospheric Extraction Process to Obtain Bagasse Fibers…………………………………….. 69

4.3.2 Chemical Extraction……………………………………………………………………………….. 69

4.4 Bagasse Composition, Properties and Physical Characteristics of Bagasse Fibers…………………….. 70

4.4.1 Physical Properties of Bagasse Fibers…………………………………………………………….. 71

4.5 Applications of Bagasse Fibers……………………………………………………………………………….. 72

4.5.1 Oil Spill Sorption…………………………………………………………………………………… 72

4.5.2 Agricultural End-Use……………………………………………………………………………….. 72

4.5.3 Animal Bedding…………………………………………………………………………………….. 72

4.5.4 Aquaculture…………………………………………………………………………………………… 73

4.5.5 Sugarcane Bagasse Paper…………………………………………………………………………… 73

4.5.6 Production of Ethanol from Sugarcane Bagasse…………………………………………………. 73

4.6 Conclusion and Future Perspective………………………………………………………………………….. 74

References ………………………………………………………………………………………………………………. 75

D. Verma (*) • S. Jain

Department of Mechanical Engineering, College of Engineering Roorkee,

Roorkee, Uttarakhand 247667 , India e-mail: dverma. mech@gmail. com

P. C. Gope

Department of Mechanical Engineering, College of Technology,

Pantnagar, Uttarakhand 263445 , India

I. Singh

Mechanical and Industrial Engineering Department, Indian Institute of Technology, Roorkee, Uttarakhand, India

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

DOI 10.1007/978-3-319-07641-6_4, © Springer International Publishing Switzerland 2014

Abstract Botanically, sugarcane belongs to an economically important seed plant family that includes maize, wheat, rice, and sorghum known as Saccharum offici — narum . Bagasse, an agricultural residue not only becomes a problem from the environmental point of view, but also affects the profitability of the sugarcane indus­tries. This chapter discusses the properties and processing methods for the extraction of the bagasse fibers from sugarcane and its current status of research. The applica­tions of the bagasse fibers in different fields have also been discussed.

Keywords Sugarcane • Bagasse • Extraction methods • Image analysis

4.1 Introduction

Sugarcane is a tropical, perennial grass typically 3-4 m high and has approximately 5 cm in diameter and become mature stalk. The composition of mature stalk is com­posed of 11-16 % fiber, 12-16 % soluble sugars, 2-3 % non-sugars, and 63-73 % water. Sugarcane is the world’s largest crop. There is a variation in the properties of the sugarcane stalk which generally depends on variety. Under normal field condi­tions it has been observed that the height of sugarcane stalk varies from 1.5 to 3 m and has diameter range from 1.8 to 5 cm. The color of the surfaces of the stalk may be green, yellow, or red and covered by a thin layer of wax (van Dillewijn 1952). The stalk (cane) generally comprises shorter segments and also some joints. The length of these joints varied from 5 to 25 cm. It is also observed that the lower joints are longer and larger in diameter. Generally it has been seen that every joints com­prise of two parts, one is the node and the other is internode (Elsunni and Collier

1996) . Stalk structures like the root band, bud, and the shoulder lies at the node (Clements 1980). From the point of view of internode it has been observed that there are two particular areas. The primary one is the outer layer, which is also known as the rind and is so hard and dense. The secondary is the inside layer which has soft region where the fibro vascular bundles are firmly fixed in a surrounding mass, and known as the pith. It is found that there is a wide space lies between the fibro vascular bundles in the middle part of the stalk, but at the boundary the number of bundles increases and their sizes decrease. Generally the compositions of the bundles are fiber cells bounded by lignin and hemicellulose. On aging of the cane the deposition of the lignin like compound occurs around the fibro vascular tissues (van Dillewijn 1952). Advancement of cane aging results removal of lignin and softening and weakening of bundles. The nature of the soft rind is only because of the cellulosic effect (Elsunni and Collier 1996). The fibrous strands of the fibro vascular bundles extended for long distances in the stem. The separation of fibrous strands is found to be at the secondary part (internode). At the internode the bundle grows just in parallel to the stalk. The fibro bundles are dispersed through inside of the stalk and are more ample at the region of rind, as compared to the center of the stalk. This type of the positioning of bundles not only improves the strength but also improves the rigidity of the stalk. The stalk hardness is a characteristic regarding both in the sugarcane mill and also in the pasture. The varieties of hard cane result in so many mechanical problems (van Dillewijn 1952). The hard rinds cane are very difficult to operate by manual cutters and results excessive failure of mechanical harvesting units which also ultimately results the loss of spare parts and crushing time (Barnes 1964). Similarly the varieties of hard rind also have some advantages over softer cane varieties associated with resistance to attacks by animals such as rats, pigs, and mongooses.

It has been also observed that from the point of view of biomass energy sugar­cane is found to be one of the important agricultural sources. There are generally two main types of biomass produced by the sugarcane; these are cane trash and bagasse. Cane trash is the remainder after harvesting of the cane stalk while on the other hand milling of the cane results bagasse which is the fibrous residue with 45-50 % moisture content.

The use of bagasse (after combustion) is in the production of steam for power generation. Bagasse is also recognized and used for the production of bioethanol. The important application of bagasse is found in paper making. In paper making industries it is utilized as the raw material. The calorific value estimation of bagasse as a fuel also describes its value, which is influenced by its composition and also on the calorific value of the sugarcane crop mainly because of the content of sucrose present. Moisture content generally decides the calorific value of the sugarcane. A good milling process results low moisture content of sugarcane which is of about 45 % whereas poor milling results 52 % moisture content. Generally it has been observed that most of the mills produce bagasse of 48 % moisture content, and most boilers burn bagasse at around 50 % moisture. Bagasse generally composed of fiber (cellulose), which contains carbon, hydrogen, oxygen, sucrose (1-2 %), and ash originating from extraneous matter. Sugar factory produces 30 tons of wet bagasse after crushing 100 tons of sugarcane. Bagasse is generally found as a primary fuel source for sugar mills which when burned then generates sufficient electrical energy, used to fulfill all the basic needs of a sugar mill.

The most energy projects have been demonstrated and presented in many sugar­cane producing countries. The power generation from sugarcane is a good option as renewable energy that increases sustainable development, increases profitability and competitiveness in the industry.

In 2010, Food and Agriculture Organization (FAO) estimates that sugarcane was cultivated in more than 90 countries in 23.8 million hectares, with a worldwide harvest of 1.69 billion tons. Brazil produces the sugarcane on a larger scale in the world. Another five main producers, in descending order of production, are India, China, Thailand, Mexico, Pakistan (Duttamajumder et al. 2011). To obtain bagasse fiber first the sugarcane is crushed in a series of mills, which consists of at least three heavy rollers. Crushing process of sugarcane results breaking of the cane stalk in small pieces, and milling will squeeze the juice out. The juice obtained from sugar­cane is collected for the production of sugar. The crushed and squeezed cane stalk named as bagasse (Elsunni and Collier 1996). Collier et al. (1992) suggested that bagasse will be a good source for the pulp and paper industry ahead and compared to other crops. The annual estimated amount of bagasse production is about 80,000,000 metric tons (MT), from which 25,000,000 MT will be utilized for pulping. The value added agricultural products development not only optimizes the extraction process and process parameters on fiber properties, but also optimizes the sampling and mea­suring technique (Romanoschi et al. 1997). Image analysis will allow to determine physical parameters for unconventional fiber such as bagasse in an easy and inexpen­sive way. The research in this field will have an impact on economic development by providing alternatives to agriculturists in crop choices and providing value to the sug­arcane crop. Conversion of agricultural by-products to the value added products not only provides benefit to the economy of country but also developed new markets for agricultural crops. In this chapter, various properties and extraction methods of bagasse fibers and their applications are discussed. The various applications of the bagasse fibers in nonwoven form have also been reported.