Chapter 4 - Management of biomass

Abstract

It is hard to imagine life on earth without the existence of plants, which have several hundreds of thousands of varieties. Most of the plants are with green leaves and divided further into several categories such as leafy, flowering, conifers and other gymnosperms, ferns and their allies, hornworts, liverworts, cactus, mosses, and green algae. The significance of plants in our lives is to be judged from the fact that they meet our daily needs of food, clothing, shelter, medicine, paper, etc. Plants that produce grains, fruits, and vegetables have been domesticated for millennia as food for human beings and fodder for domesticated animals. It is a wonder of nature's chemistry that plants produce most of the world's molecular oxygen, which is the basis of most of Earth's ecosystems and is essential for respiration for most living species. These plants, rooted in earth's subsurface, are essentially consisted of three distinct chemical components namely, cellulose, hemicellulose, and lignin, and collectively termed as lignocellulosic (LC) biomass; whereas, the left over material from agricultural and forestry processes and dead wild plants all of them with no food, fodder or any other commercial utility is known as LC biomass waste. LC biomass is consisted of cellulose (35%–52%), hemicelluloses (19–34 wt.%), and lignin (11–30 wt.%). This LC biomass waste, 40–50 millions of metric tons of which is produced annually in India alone, were mainly used for centuries as fuel for cooking food, making charcoal, or heating purposes particularly in rural areas or used in land filling or left in the open to emit greenhouse gases. However, LC biomass is realized now as a rich renewable resource for conversion into many useful products ranging from bioenergy, bio-fuels, to replace fossil fuels, chemicals including significant intermediates, nanomaterials, energy, biodegradable plastics, and so on. These products can be achieved by (i) Thermo combustion of LC biomass to produce heat and electrical energy, (ii) Biorefineries with biomass as the basic feed material to produce liquid biofuels (gasoline, diesel, H2, etc.) and solid bio-char, chemicals and intermediates for polymers, resins and bio-degradable plastics, and (iii) Pyrolysis of biomass to produce biochar and bio-oils.