Biopolymers are natural polymers produced by the cells of living organisms. Like other polymers,biopolymers consist of monomeric units that are covalently bonded in chains to form larger molecules. There are three main classes of biopolymers,classified according to the monomers used and the structure of the biopolymer formed:polynucleotides,polypeptides,and polysaccharides. The Polynucleotides,RNA and DNA,are long polymers of nucleotides. Polypeptides include proteins and shorter polymers of amino acids;some major examples include collagen,actin,and fibrin. Polysaccharides are linear or branched chains of sugar carbohydrates;examples include starch,cellulose,and alginate. Other examples of biopolymers include natural rubbers,suberin and lignin,cutin and cutan,melanin,and polyhydroxyalkanoates (PHAs).
Cellulose is an organic compound with the formula (C
6H
10O
5)
n,a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall of green plants,many forms of algae and the oomycetes. Some species of bacteria secrete it to form biofilms. Cellulose is the most abundant organic polymer on Earth. The cellulose content of cotton fiber is 90%,that of wood is 40–50%,and that of dried hemp is approximately 57%.
Photosynthesis is a biological process used by many cellular organisms to convert light energy into chemical energy,which is stored in organic compounds that can later be metabolized through cellular respiration to fuel the organism's activities. The term usually refers to oxygenic photosynthesis,where oxygen is produced as a byproduct,and some of the chemical energy produced is stored in carbohydrate molecules such as sugars,starch,glycogen and cellulose,which are synthesized from endergonic reaction of carbon dioxide with water. Most plants,algae and cyanobacteria perform photosynthesis;such organisms are called photoautotrophs. Photosynthesis is largely responsible for producing and maintaining the oxygen content of the Earth's atmosphere,and supplies most of the biological energy necessary for complex life on Earth.
A renewable resource is a natural resource which will replenish to replace the portion depleted by usage and consumption,either through natural reproduction or other recurring processes in a finite amount of time in a human time scale. When the recovery rate of resources is unlikely to ever exceed a human time scale,these are called perpetual resources. Renewable resources are a part of Earth's natural environment and the largest components of its ecosphere. A positive life-cycle assessment is a key indicator of a resource's sustainability.
Artificial photosynthesis is a chemical process that biomimics the natural process of photosynthesis to convert sunlight,water,and carbon dioxide into carbohydrates and oxygen. The term artificial photosynthesis is commonly used to refer to any scheme for capturing and storing the energy from sunlight in the chemical bonds of a fuel. Photocatalytic water splitting converts water into hydrogen and oxygen and is a major research topic of artificial photosynthesis. Light-driven carbon dioxide reduction is another process studied that replicates natural carbon fixation.
A biorefinery is a refinery that converts biomass to energy and other beneficial byproducts. The International Energy Agency Bioenergy Task 42 defined biorefining as "the sustainable processing of biomass into a spectrum of bio-based products and bioenergy ". As refineries,biorefineries can provide multiple chemicals by fractioning an initial raw material (biomass) into multiple intermediates that can be further converted into value-added products. Each refining phase is also referred to as a "cascading phase". The use of biomass as feedstock can provide a benefit by reducing the impacts on the environment,as lower pollutants emissions and reduction in the emissions of hazard products. In addition,biorefineries are intended to achieve the following goals:
- Supply the current fuels and chemical building blocks
- Supply new building blocks for the production of novel materials with disruptive characteristics
- Creation of new jobs,including rural areas
- Valorization of waste
- Achieve the ultimate goal of reducing GHG emissions
The methanol economy is a suggested future economy in which methanol and dimethyl ether replace fossil fuels as a means of energy storage,ground transportation fuel,and raw material for synthetic hydrocarbons and their products. It offers an alternative to the proposed hydrogen economy or ethanol economy,although these concepts are not exclusive. Methanol can be produced from a variety of sources including fossil fuels as well as agricultural products and municipal waste,wood and varied biomass. It can also be made from chemical recycling of carbon dioxide.
Bioplastics are plastic materials produced from renewable biomass sources,such as vegetable fats and oils,corn starch,straw,woodchips,sawdust,recycled food waste,etc. Some bioplastics are obtained by processing directly from natural biopolymers including polysaccharides and proteins,while others are chemically synthesised from sugar derivatives and lipids from either plants or animals,or biologically generated by fermentation of sugars or lipids. In contrast,common plastics,such as fossil-fuel plastics are derived from petroleum or natural gas.
The photosynthetic efficiency is the fraction of light energy converted into chemical energy during photosynthesis in green plants and algae. Photosynthesis can be described by the simplified chemical reaction
Biodegradable plastics are plastics that can be decomposed by the action of living organisms,usually microbes,into water,carbon dioxide,and biomass. Biodegradable plastics are commonly produced with renewable raw materials,micro-organisms,petrochemicals,or combinations of all three.
Renewable Fuels are fuels produced from renewable resources. Examples include:biofuels,Hydrogen fuel,and fully synthetic fuel produced from ambient carbon dioxide and water. This is in contrast to non-renewable fuels such as natural gas,LPG (propane),petroleum and other fossil fuels and nuclear energy. Renewable fuels can include fuels that are synthesized from renewable energy sources,such as wind and solar. Renewable fuels have gained in popularity due to their sustainability,low contributions to the carbon cycle,and in some cases lower amounts of greenhouse gases. The geo-political ramifications of these fuels are also of interest,particularly to industrialized economies which desire independence from Middle Eastern oil.
Biobased economy,bioeconomy or biotechonomy is economic activity involving the use of biotechnology and biomass in the production of goods,services,or energy. The terms are widely used by regional development agencies,national and international organizations,and biotechnology companies. They are closely linked to the evolution of the biotechnology industry and the capacity to study,understand,and manipulate genetic material that has been possible due to scientific research and technological development. This includes the application of scientific and technological developments to agriculture,health,chemical,and energy industries.
Bioproducts or bio-based products are materials,chemicals and energy derived from renewable biological material.
An autotroph is an organism that produces complex organic compounds using carbon from simple substances such as carbon dioxide,generally using energy from light (photosynthesis) or inorganic chemical reactions (chemosynthesis). They convert an abiotic source of energy into energy stored in organic compounds,which can be used by other organisms. Autotrophs do not need a living source of carbon or energy and are the producers in a food chain,such as plants on land or algae in water. Autotrophs can reduce carbon dioxide to make organic compounds for biosynthesis and as stored chemical fuel. Most autotrophs use water as the reducing agent,but some can use other hydrogen compounds such as hydrogen sulfide.
Carbon-neutral fuel is fuel which produces no net-greenhouse gas emissions or carbon footprint. In practice,this usually means fuels that are made using carbon dioxide (CO2) as a feedstock. Proposed carbon-neutral fuels can broadly be grouped into synthetic fuels,which are made by chemically hydrogenating carbon dioxide,and biofuels,which are produced using natural CO2-consuming processes like photosynthesis.
James C. Liao is the Parsons Foundation Professor and Chair of the Department of Chemical and Biomolecular Engineering at the University of California,Los Angeles and is the co-founder and lead scientific advisor of Easel Biotechnologies,LLC.
Transparent wood composites are novel wood materials which have up to 90% transparency. Some have better mechanical properties than wood itself. They were made for the first time in 1992. These materials are significantly more biodegradable than glass and plastics. Transparent wood is also shatterproof.
Florence Gschwend is a Swiss chemical engineer and Royal Academy of Engineering Enterprise Fellow at Imperial College London. She is the founder and CEO of Lixea,a spin-out company that commercialises wood fractionation to enable a circular bioeconomy.
Carbon capture and utilization (CCU) is the process of capturing carbon dioxide (CO2) from industrial processes and transporting it via pipelines to where one intends to use it in industrial processes.
Amar K. Mohanty is a material scientist and biobased material engineer,academic and author. He is a Professor and Distinguished Research Chair in Sustainable Biomaterials at the Ontario Agriculture College and is the Director of the Bioproducts Discovery and Development Centre at the University of Guelph.
