Modern peat is mostly lignin. The cellulose and hemicellulose component ranges from 5% to 40%. Various other organic compounds, such as waxes and nitrogen- and sulfur-containing compounds, are also present. Lignins are polymers of monolignols, a family of alcohols whose common feature is a benzene ring with a allyl alcohol side chain. These are crosslinked by carbohydrate chains to form the lignin, which has an overall composition approximating (C31H34O11)n Cellulose is a polymer of glucose with the approximate formula (C6H10O5)n. Lignin has a weight composition of about 54% carbon, 6% hydrogen, and 30% oxygen, while cellulose has a weight composition of about 44% carbon, 6% hydrogen, and 49% oxygen. Bituminous coal has a composition of about 84.4% carbon, 5.4% hydrogen, 6.7% oxygen, 1.7% nitrogen, and 1.8% sulfur, on a weight basis. This implies that chemical processes during coalification must remove most of the oxygen and much of the hydrogen, leaving carbon, a process called "carbonization".