CHAPTER ONE

1.1 INTRODUCTION

Cellulose is a naturally occurring polymeric material containing thousands of glucose-

like rings each of which contain three alcoholic OH groups. Its general formula is

represented as (C

6

H

10

O

5

)n. The OH-groups present in cellulose can be esterified or

etherified the most important cellulose derivatives are the esters. Cellulose is the name

given to a long chain of atoms consisting of carbon hydrogen and oxygen arranged in a

particular manner. Cellulose is found in nature in almost all forms of plant life and

especially in cotton and wood. A cellulose molecule is made up of large number of

glucose units linked together by oxygen atom. Each glucose unit contains three(3)

Hydroxyl groups the hydroxyl groups present at carbon-6 is primary while two other

hydroxyl are secondary. Cellulose is the most abundant organic chemical on Earth more

than 50% of the carbon in plants occurs in the cellulose of stems and leaves. Wood is

largely cellulose and cotton is more than 90% cellulose. It is a major constituent of plant

cell walls that provides strength and rigidity and presents the swelling of the cell and

rupture of the plasma membrane that might result when osmotic conditions favor water

entry into the cell. Cellulose is a fibrous tough water-insoluble substances it can be seen

in cell walls of plants particularly in stalks stems trunks and all woody portions of the

plant.

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Cellulose is polymorphic i.e there are a number of different crystalline forms that reflect

the history of the molecule. It is almost impossible to describe cellulose chemistry and

biochemistry without referring to those different forms. Cellulases are gotten from

cellulose cellulose is also found in protozoa in the gut of insects such as termites. Very

strong acids can also degrade cellulose the human digestive system has little effect on

cellulose. The word cellulose means β-14-D-glucan regardless of source because of the

importance of cellulose and difficulty in unraveling its secrets regarding structure

biosynthesis chemistry and other aspects several societies are dedicated to cellulose

lignin and related molecules.

1.2 SOURCES OF CELLULOSE

Cellulose for industrial conversion comes from wood and scores of minor sources such as

kenaf paper and rayon are now made mostly from wood pulp. cotton rings were

historically important for paper making and cotton linters (short fibres are used to spin

yams) are now used in high quality writing and currency papers.

Cellulose forms very tightly packed crystallites these crystals are sometimes so tight that

neither water nor enzymes can penetrate them; cellulose consists of two cellulose

molecules;

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Crystalline and amorphous cellulose. The crystalline cellulose is insoluble because of the

inability of water to penetrate cellulose On the other hand amorphous cellulose allows

the penetration of endogluconase another subgroup of cellulose that catalyze the

hydrolysis of internal bonds. The natural consequences of this difference in the

crystalline structure is that the hydrolysis rate is much faster for amorphous cellulose than

crystalline cellulose.

Some cellulose comes from the hairs (trichomes) on seeds example: cotton kapo and

milk weed. A commercial bacterial cellulose product (cellulon) was introduced by

Weyerhaeuser(22) for use in foods the product is called primacel and is available from

Nutrasweet kelco. Recently cellulose from sugar belt pulp and from citrus pulp has

aroused interest for use as a fat substitute.

1.3 HYDROLYSIS

Hydrolysis of cellulose is the process of breaking the glucosidic bonds that holds the

glucose basic units together to form a large cellulose molecule it is a term used to

describe the overall process where cellulose is converted into various sweeteners.

Hydrolysis is a chemical reaction during which one or more water molecules are split into

hydrogen and hydroxide ions which may go to participate in further reactions.

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1.4 SUGAR

Sugars (also called saccharides) are compounds containing an aldehyde or ketone

group and two or more hydroxyl groups. Sugar can also a sweet crystalline substance

obtained from sugar-cane and sugar beet. It includes sucrose glucose and fructose.

1.5 STATEMENT OF THE PROBLEM

The clamour for the diversification of Nigerian economy through low quality products

has motivated researchers to explore the numerous domestic industrial and economic

importance of one Nigeria`s major product (cellulose) which forms the bedrock of this

project.

Sugar is a commodity of high demand for both domestic and industrial applications on

daily basis in homes small and medium scale industries e.t.c. this is why Nigeria

government spends huge sums of money on importation of sugar and sugar products to

meet the demand of citizens. Among the many processes of sugar production is acid

hydrolysis of (cellulose) has proved to be a process which encourages the production of

high quality with minimum skill and materials. This work is therefore an effort to

encourage industrialists researchers and students to carry out more intensive studies on

production of sugar from cellulose for production of sugar and enhanced economic

resources for the nation.

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1.6 RELEVANCE OF THE STUDY

Nigeria is the largest producer of cellulose for which paper wood is made. A large

percentage of produced cellulose is consumed as paper textiles newspaper and

containers in form of writing reading e.t.c.

The method of acid hydrolysis of cellulose:

 It creates job opportunities hence reducing unemployment in the country.

 It helps to know the best acid for the hydrolysis of cellulose.

 It establishes the industries for government to contribute immersely towards the

country economy.

 With the methods of glucose and cellulose production the cost of glucose and

cellulose will reduce.

 It produces research workdone on the digestion of cellulose into glucose which I

will engage on it after my graduation.

1.7 OBJECTIVES.

The research project covers the processes operations and pathways involved in the Acid

hydrolysis of cellulose to produce (glucose) sugar. The research study aims at:

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 Quantifying and calculating the yield of glucose from the hydrolysis of cellulose

using two different acids.

 The hydrolysis of cellulose into sugar using different concentration of hydrochloric

acid and sulphuric acid.

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