**1. Introduction**

The world's present economy is highly dependent on various fossil energy sources such as oil, coal, natural gas, etc [1]. There are several alternative energies which can replace fossil fuels in the future, such as hydro, solar, wind, biomass and ocean thermal energy. Among these energy sources, biomass is the only carbon-based sustainable energy and is utilized by most people around the world [2]. Furthermore, it is also confirmed that the petroleum-based fuels can be replaced by biomass fuels such as bioethanol, bio-diesel, bio-hydrogen, which derives from agricultural residues, forestry residues, municipal solid waste, manufacturing waste, vegetable oils, dedicated energy crops, etc [3]. Recently, it is a growing interest in manufac‐ turing bioethanol using biomass materials. It is well known that production of ethanol from biomass includes three major processes, such as pretreatment, hydrolysis, and fermentation. One of the most important processes is biomass pretreatment in the production of biofuel. Biomass pretreatment can remove lignin and hemicelluloses, which significantly enhance the hydrolysis of cellulose. It is required to alter the biomass macroscopic and microscopic size and structure as well as its submicroscopic structural and chemical composition to facilitate rapid and efficient hydrolysis of carbohydrates to fermentable sugars [4]. Figure 1 shows simplified impact of pretreatment on biomass [5].

Pretreatment technology contains physical pretreatment (mechanical size reduction, pyroly‐ sis, microwave oven and electron beam irradiation pretreatment), physicochemical pretreat‐ ment (steam explosion or autohydrolysis, liquid hot water method, ammonia fiber explosion, CO2 explosion), chemical pretreatment (acid pretreatment, alkaline pretreatment, wet oxidation, organosolv pretreatment), and biological pretreatment [1]. Recently, the in‐ formation of various pretreatment methods is available. Lin et al. found that the yields of glucose and xylose were improved by adding any of the following dilute chemical reagents,

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such as H2SO4, HCl, HNO3, CH3COOH, HCOOH, H3PO4, and NaOH, KOH, CaOH2, NH3 H2O in the ball milling pretreatment of corn stover [6]. Bjerre et al. studied the wet oxidation process of wheat straw as a pretreatment method. By using a specially constructed auto‐ clave system, the wet oxidation process was optimized with respect to both reaction time and temperature (20 g/L straw, 170℃, 5 to 10 min) and gave about 85% w/w yield of con‐ verting cellulose to glucose [7]. Zhu and Pan evaluated the performances of three of the most promising pretreatment technologies, including steam explosion, organosolv, and sul‐ fite pretreatment to overcome lignocelluloses recalcitrance (SPORL) for softwood pretreat‐ ment. SPORL was the most efficient process and produced highest sugar yield [8]. Keshwani et al. examined the feasibility of microwave pretreatment to enhance enzymatic hydrolysis of switchgrass. It was found that the application of microwave radiation for 10 minutes at 250 watts to switchgrass immersed in 3% sodium hydroxide solution (w/v) produced the highest yields of reducing sugar [9]. Yu et al. studied a two-step liquid hot water pretreat‐ ment (TSLHW) mehod. The first step of pretreatment was temperature range from 180 to 200℃, and the highest yield of total xylose achieved was 86.4% after 20 min at 180℃. The second-step of pretreatment was temperature range from 180 to 240℃ for 0-60 min. The op‐ timum reaction conditions of pretreatment with minimal degradation of sugars were 200℃ for 20 min [10]. Sulfuric acid is widely used for acid pretreatment among various types of acid such as hydrochloric acid, nitric acid and phosphoric acid [11]. Maarten et al. compared the efficiencies of fumaric, maleic, and sulfuric acid in wheat straw pretreatment. At 150℃ and 20-30% (w/w) dry wheat straw, the pretreatment with dilute fumaric or maleic acid could be a serious alternative to dilute sulfuric acid pretreatment [12]. Sun et al. studied the effectiveness of different alkaline solutions by analyzing the delignification and dissolution of hemicelluloses in wheat straw. The optimal process condition was 1.5% NaOH for 144h at 20℃, releasing 60% and 80% lignin and hemicelluloses, respectively [13].

Agricultural and forest residues represent a major fuel source for potential bio-energy projects in many developing countries [14]. Bamboo, like wood and agricultural residue, is mainly composed of hemicelluloses, cellulose and lignin, even though the contents of these compo‐ sitions are different. The cellulose, hemicelluloses and lignin content in some agriculture, wood and bamboo wastes is showed in Table 1. Bamboo has been widely cultivated in the west and south of China. Currently, bamboo resources are very abundant. The total area of bamboo is about five million hectares and that of moso bamboo is about 3 million hectares in China [15]. Annual yield of moso bamboo is about eighteen million tons, and it is widely used to produce furniture, flooring and interior decoration materials. It has great potential as a bio-energy resource of the future in China. Despite these previous researches are very helpful in under‐ standing the pretreatment of biomass materials, bamboo is a different type of material. To date, no research about bamboo biofuel is available. In this research, moso bamboo was therefore pretreated by 2% of sulfuric acid (w/w bamboo) and 10% sodium hydrate (w/w bamboo). Characteristics of pretreated bamboo were determined by Fourier transform infrared spectro‐ scopy (FTIR) and X-ray diffraction (XRD), respectively. Pretreatment method was evaluated through comparing with characteristics of untreated and pretreated bamboo. The objective of this research is to investigate characteristics of bamboo pretreated by chemical methods and

Characteristics of Moso Bamboo with Chemical Pretreatment

http://dx.doi.org/10.5772/55379

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select a pretreatment method for exploring the biofuel using bamboo.

**Table 1.** Chemical composition of bamboo, wood and agriculture residue

**2. Materials and methods**

**2.1. Material**

**Biomass type Species Cellulose (%) Hemicelluloses (%) Lignin (%) Ash (%)** Wood Pine (hardwood) 40-45 25-30 26-34 ----

Bamboo Moso bamboo 42-50 24-28 24-26 1.3-2.0 Agriculture residues Rice straw 41-57 33 8-19 8-38

Moso bamboo aging with 4 years was used in this study. They were taken from a bamboo plantation located in Anhui province, China. The initial moisture content of samples was about 6.13%, and the density was about 0.65g/cm3. Bamboo materials were cut off to sample size 40mm (longitudinal) by 3-8mm (radial) by 20-30mm (tangential). Then, they were broken down to particles with a Wiley mill and the size of bamboo particles used in the test was about

Maple (softwood) 45-50 21-36 22-30 ----

Rice husk 35-45 19-25 20 14-17 Baggasse 40-46 25-29 12.5-20 1.5-2.4 Cotton stalk 43-44 27 27 1.3

**Figure 1.** Simplified impact of pretreatment on biomass modified from Mosier et al. [5]

Agricultural and forest residues represent a major fuel source for potential bio-energy projects in many developing countries [14]. Bamboo, like wood and agricultural residue, is mainly composed of hemicelluloses, cellulose and lignin, even though the contents of these compo‐ sitions are different. The cellulose, hemicelluloses and lignin content in some agriculture, wood and bamboo wastes is showed in Table 1. Bamboo has been widely cultivated in the west and south of China. Currently, bamboo resources are very abundant. The total area of bamboo is about five million hectares and that of moso bamboo is about 3 million hectares in China [15]. Annual yield of moso bamboo is about eighteen million tons, and it is widely used to produce furniture, flooring and interior decoration materials. It has great potential as a bio-energy resource of the future in China. Despite these previous researches are very helpful in under‐ standing the pretreatment of biomass materials, bamboo is a different type of material. To date, no research about bamboo biofuel is available. In this research, moso bamboo was therefore pretreated by 2% of sulfuric acid (w/w bamboo) and 10% sodium hydrate (w/w bamboo). Characteristics of pretreated bamboo were determined by Fourier transform infrared spectro‐ scopy (FTIR) and X-ray diffraction (XRD), respectively. Pretreatment method was evaluated through comparing with characteristics of untreated and pretreated bamboo. The objective of this research is to investigate characteristics of bamboo pretreated by chemical methods and select a pretreatment method for exploring the biofuel using bamboo.


**Table 1.** Chemical composition of bamboo, wood and agriculture residue
