Abstract
The biorefinery is a concept of converting plant-based biomass to chemicals, energy and materials that run our civilization, replacing the needs of petroleum, coal, natural gas, and other non-renewable energy and chemical sources. Biomass is renewable, in that a plant synthesizes chemicals by drawing energy from the sun and carbon dioxide and water from the environment, while releasing oxygen. Combustion of biomass releases energy, carbon dioxide and water. This process or cycle continues without human intervention. Harvesting and utilization of biomass does not affect the environment as it mimics natural disturbances such as mortality due to old age, predation, death due to diseases and catastrophic events such as natural forest fires. Therefore, the Biorefinery plays a natural role in ensuring the cycle of biomass through its production and consumption includes satisfying human needs for energy and chemicals within the concept. The biorefinery process concept is analogous to that of an oil refinery. The oil refineries take petroleum or crude oil and fractionates the potential molecular feedstocks for further processing and blending to produce a vast array of fossil-fuel based products that we use today. Adopting this approach to be used with plant-based biomass is a biorefinery. Biomass contains a large collection of organic and inorganic compounds. Cereal grains, nuts and seeds contain mainly starch, oil and protein that are "food" for new plant growth. Cereal grains, nuts and oil seeds are direct food sources for humans and animals, and they are excellent raw materials for chemicals, energy and materials. Woody biomass, on the other hand, is the structural material for plants. There are four main categories of substances in woody biomass: cellulose, hemicellulose, lignin, and extractives. Fractionation and conversion of the lignocellulosic biomass can produce vast array of chemicals, energy and materials. Developing the capabilities of converting a variety of plant-based biomass to chemicals, energy and materials is a key step to moving the world economy to be based on the sustainably renewable biomass.
Biorefinery applications have gained considerable steam in the last decade, with many pilot and industrial applications beginning in the USA and world. A summary of the industrial opportunities is presented ad discussed.