Kinetic Study On Hydrolysis Of Cellulose (Saw-Dust)

Thesis Overview

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 (C6H10O5 )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.
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-1,4-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;