1Biomass and Sustainability
Valentin I. Popa
CONTENTS
1.1Introduction
1.1.1What Is Sustainability?
1.2How the Biomass Could Contribute to the Sustainability?
1.3Biorefining as a Possibility to Obtain Energy and Bioproducts
1.4Resources
1.4.1Evaluation of Resources
1.4.1.1Forestry and Wood Processing Wastes
1.4.1.2Agricultural and Food Processing Residues
1.4.1.3Food Processing
1.4.1.4Municipal Wastes
1.4.1.5Dedicated Crops (Terrestrial and Aquatic)
1.5Energy and Bioproducts
1.5.1Energy
1.5.1.1Direct Combustion
1.5.1.2Burning in an Excess of Air
1.5.1.3Burning in a Controlled Atmosphere
1.5.1.4Heating in the Absence of Air
1.5.1.5Producer Gas Generation
1.5.1.6Anaerobic Digestion
1.5.2Biofuels
1.5.3Bioproducts
1.5.3.1Butadiene (1,3-)
1.5.3.2Butanediol (1,4-)
1.5.3.3Ethyl Lactate
1.5.3.4Fatty Alcohols
1.5.3.5Furfural
1.5.3.6Glycerin
1.5.3.7Isoprene
1.5.3.8Lactic Acid
1.5.3.9Acrylic Acid
1.5.3.10Propanediol (1,3-)
1.5.3.11Propylene Glycol
1.5.3.12Succinic Acid
1.5.3.13Adipic Acid
1.5.3.14Xylene (Para)
1.5.3.15Furan Dicarboxilic Acid
1.5.3.16Carbon Fibres
1.5.3.17Polymer Modifiers
1.5.3.18Resins/Adhesives/Binders
1.5.3.19BTX Chemicals
1.5.3.20Monomeric Lignin Molecules
1.5.3.21Low Molecular Weight By-products
1.5.3.22Fermentation Products
1.5.3.23Socio-economic Benefits
1.6Concluding Remarks
References
1.1INTRODUCTION
1.1.1What Is Sustainability?
There have been many approaches to sustainability over the years and many different private and public organizations have demonstrated leadership. Most recently, there have been actions to broaden the approach to sustainability and to increasingly recognize how social, economic, and environmental systems are interrelated. An example of both identifying and working to address these interconnections are the Sustainable Development Goals (SDGs). The United Nations SDGs are 17 goals with 169 targets that all 191 UN Member States have agreed to try to achieve by the year 2030.
Thus, United Nations defined the sustainable development goals as the following: (1) no poverty; (2) zero hunger; (3) good health and well-being; (4) quality education; (5) gender equality; (6) clean water and sanitation; (7) affordable and clean energy; (8) decent work and economic growth; (9) industry, innovation, and infrastructure; (10) reduced inequalities; (11) sustainable cities and communities; (12) responsible consumption and production, (13) climate action; (14) life below water; (15) life on land; (16) place, justice, and string institutions; (17) partnership for the goals (1).
1.2HOW THE BIOMASS COULD CONTRIBUTE TO THE SUSTAINABILITY?
The term biomass is defined as any organic matter that is available on a renewable basis, including dedicated energy crops and trees, agricultural food and feed crop residues, aquatic plants, wood and wood residues, animal wastes, and other waste materials. The annual production of biomass is about 1.7–2.0×1011 tons; however, only 6×109 tons are currently used for food and non-food applications. Food applications are by far most important (96.5–97%). The remainder is used in non-food applications, for example, as a feedstock for the chemical industry.
The chemical composition of biomass depends strongly on its source. Generally biomass consists of 38–50% cellulose, 23–32% hemicelluloses, and 15–25% lignin. Cellulose is a non-branched water-insoluble polysaccharide consisting of several hundred up to tens of thousands of glucose units. Cellulose is the most abundant biopolymer synthesized by nature; its amount is estimated at approximately 2×109 tons year−1. Hemicelluloses are polymeric materials although lower in molecular weight than cellulose, consisting of C6-sugars (glucose, mannose, and galactose) and C5-sugars (mainly xylose and arabinose) The third component (lignin) is a highly cross-linked polymer made from substituted phenylpropene units. It acts as glue, holding together the cellulose and hemicelluloses fibres (2).
A wide variety of biomass sources is available for further conversion and utilization. Selection of the biomass feedstock is of paramount importance from both techno- and socio-economical points of view. For ethical reasons, the biomass feedstock should not compete with the food chain. Waste streams with low or even negative value, such as agricultural waste are preferred. Furthermore, it is also advantageous to select sources that are not prone to diseases, only require a limited amount of fertilizer, have a high growth rate per hectare per year and are preferably available throughout the year.
We are entering a new age, the age of science, high technology, and science-based industry, agroforetsry, and services but we are entering the age of environmentalism as well.
1.3BIOREFINING AS A POSSIBILITY TO OBTAIN ENERGY AND BIOPRODUCTS
The concept of biorefinery was originated in late 1990s as a result of scarcity of fossil fuels and increasing trends of use of biomass as a renewable feedstock for production of non-food products. The term of ‘Green Bioefinery’ was first introduced in 1997 as: ‘Green biorefineries represent complex (to fully integrated) systems of sustainable, environmentally and resource-friendly technologies for the comprehensive (holistic) material and energetic utilization as well as exploitation of biological raw materials in form of green and residue biomass from a targeted sustainable regional land utilization’.
According to the US Department of Energy (DOE), ‘A biorefinery is an overall concept of a processing plant where biomass feedstocks are converted and extracted into a spectrum of valuable pro...
