On April 22, the United Nations Environment Program (UNEP) officially released the "Global Biobased Economic Assessment: Collaboratively Advancing Policy, Innovation and Sustainable Development for a Green Future" technical report. The report was jointly written by Fudan University and the United Nations Environment Program's International Ecosystem Management Partnership (UNEP-IEMP). It is the first technical report on global bio-based economic assessment released by UNEP.
Starting from the three dimensions of policy, innovation and sustainability, the report comprehensively assesses the development status and future trends of the global bio-based economy; comprehensively sorts out the policy context and future development trends of the bio-based economy in different countries around the world, and analyzes the bio-based economy. Product technology innovation and application prospects.
1. Main bio-based product types
1) Bio-based chemicals
The report points out that currently, in some areas, bio-based chemicals are gradually replacing traditional petroleum-based chemicals and becoming a new engine to promote the development of green and low-carbon economy.
Based on their properties, bio-based chemicals can be classified into biodegradable, non-biodegradable, monomers, polymers, platform compounds and derivative compounds. For example, ethanol, 2,5 furandicarboxylic acid (FCDA), platform compounds such as levulinic acid and 5-hydroxymethylfurfural (HMF), etc. These chemicals can be accessed through bio-based platform compounds, which can lead to a variety of high-value and more complex bio-based chemicals or materials, such as bioplastics and fibers. This is a key way to replace the traditional petrochemical and coal chemical industries and transition to green chemistry, providing huge prospects for the future market.
Table: Classification of bio-based platform chemicals
2) Bio-based plastics
Bio-based plastic is a plastic whose raw materials are partly or entirely derived from biomass. Whether bio-based plastics are biodegradable or not can be divided into degradable and non-degradable. The main target market for these materials is to supplement petroleum-based plastics and replace existing petroleum-based similar products to save petroleum resources and reduce carbon emissions. Its main application areas include packaging, consumer goods, textiles, etc.
Chart: Global bio-based plastics production capacity in 2022
According to the European Bioplastics Association (European Bioplastics Association), bio-based plastics account for approximately 1% of annual plastic production globally.
In 2022, the global bio-based plastic production capacity will reach 2.22 million tons, of which 1.08 million tons are non-biodegradable products. Commonly used products include bio-based polyethylene terephthalate (PET), polyethylene furanoate (PEF), polyamide (PA), polyethylene, polypropylene (PP), polyethylene terephthalate ester (PTT). The production capacity of biodegradable plastics is 1.14 million tons. Common products include bio-based polylactic acid (PLA), polyhydroxyalkanoate (PHA), polybutylene succinate (PBS), and polybutylene terephthalate. (PBAT), starch blends and cellulose films. These 12 products account for 99.9% of total bio-based plastic production, as shown in the chart above.
2. Transformation technology and prospects of bio-based products
With the continuous introduction of bio-based products, the production and transformation technology of bio-based products continues to innovate.
1. Biomass energy products
1) Biomass energy product conversion route
According to physical properties, biomass energy can be divided into solid fuels, liquid fuels and other fuels. The main biomass raw materials, conversion processes and products are shown in the figure.
Figure: Energy utilization pathways of different biomass resources
Solid fuel technology in Europe and the United States is at the forefront and has a complete standard system. Germany, Sweden and other countries have annual solid fuel production capacity of more than 20 million tons. China has made significant progress in the production and application of biomass solid fuels.
2) Bio aviation fuel
With the rapid development of the aviation industry and the continued growth of air traffic, the global demand for aviation fuel is growing rapidly. Furthermore, electrification of the aviation industry does not appear to be technically and economically feasible. Biojet fuel produced from biomass can relieve the pressure on fossil energy and reduce greenhouse gas emissions.
Australia, the United States and many European countries are actively promoting the application of bio-jet fuel. China, Japan, the United Arab Emirates and other countries are also piloting or planning to develop bio-aircraft fuel.
2. Bio-based platform chemicals
To reduce dependence on fossil resources and replace petroleum-based chemicals, it is crucial to convert biomass into key platform compounds through various technological pathways. It is important to promote a cost-effective and sustainable conversion process.
Figure: Biomass raw material bio-platform chemical flow chart
Bio-based platform chemicals are currently in focus, with all materials currently produced from fossil resources having the potential to be synthesized from biomass. Technology trends are gradually shifting from starch-based feedstocks to lignocellulosic feedstocks.
From a cost perspective, global annual waste biomass production provides a cost-effective feedstock for bio-based platform chemical production. Advances in biotechnology have significantly reduced production costs, making high-value product manufacturing more cost-effective and competitive.
Technically, lignocellulosic biomass conversion presents challenges due to the resistance of plant cell walls to microbial and enzymatic breakdown. However, genetic engineering and synthetic biology have lowered technological barriers and created opportunities for the development of lignocellulose synthesis pathways.
1) Bio-based organic acids
Organic acids are essential commodities widely used in the food and chemical industries. Lactic acid is one of the three largest organic acids in the world and an important bio-based platform chemical. It can be converted into materials such as polylactic acid, coatings, resins, solvents and fragrances through biological/chemical transformation.
Figure: Platform Chemical-Lactic Acid
For the synthesis of lactic acid, using synthetic biology technology to explore straw fermentation lactic acid as a raw material has broad prospects.
2) Bio-based ethanol
Technological advances in ethanol have enhanced its potential as a feedstock for chemical production. Ethanol and related alcohols are precursors to dehydrated olefins and can also replace methyl tert-butyl ether, helping to reduce emissions of carbon, carbon dioxide, nitric oxide and nitrogen dioxide. Currently, the production of cellulosic ethanol from agricultural and forestry wastes such as straw can improve resource utilization and provides good market prospects.
Figure: Production of cellulosic ethanol from lignocellulosic biomass
Due to the inherent structural barriers of lignocellulosic biomass, it is crucial to utilize and develop more favorable fermentation microorganisms. Furthermore, bioprocessing of syngas to produce ethanol offers a promising avenue for future non-food ethanol production.
3) Bio-based furans
4) 2,5-Furandicarboxylic acid (FDCA) has wide applications in many fields, especially as the most promising substitute for terephthalic acid (PTA), which has gained widespread attention. The synthesis routes of FDCA mainly include HMF route, sugar acid route, gluconic acid route and diglycolic acid route. The HMF route is currently the most prominent and has made significant progress, with the potential to lead industrial-scale production.
Figure: Platform chemicals FDCA
However, there are some challenges in the synthesis of HMF, such as multiple side reactions, separation difficulties, and the instability of HMF, resulting in higher costs. In addition, although a large number of studies have explored the catalytic effect of precious metal catalysts such as platinum on the conversion of HMF into FDCA, there is still a lack of an economical, efficient, and stable catalytic oxidation system. Therefore, the efficient and green conversion of cellulose into high-purity HMF and the development of a cheap catalytic system for the conversion of HMF into FDCA are the focus of future research.
3. Bio-based materials
Bioplastics are expected to expand and become a promising alternative, especially biodegradable plastics. From a cost perspective, cost-effectiveness and applicability are the major constraints limiting the productivity of various bioplastics. Low oil prices, narrow profit margins and existing fossil fuel subsidies reduce the cost competitiveness of biobased manufacturers.
Some companies rely on selling higher-margin products, such as in the medical or nutritional fields, to generate the profits needed to expand bioplastic production. To reduce the production cost of bioplastics, cheap and abundant raw materials such as lignocellulosic waste, microalgae, and food waste can become excellent raw materials for the bioplastic industry. From a technical perspective, the production technology of bio-based plastics has made significant progress in recent years, and its properties are continuously improved and improved, making it a technically feasible change.
1) Bio-based PEF
PEF is produced from FDCA, obtained from abundant sources of starch or cellulose through hydrolysis and oxidation. FDCA and ethylene glycol condensation polymers can be obtained from the bio-based aromatic polyester PEF. The aromaticity and electronic conjugation effect of the furan ring structure facilitate the synthesis of high-performance polymer materials with excellent physical and mechanical properties within a specific temperature range. Therefore, PEF has excellent electrical insulation properties, creep resistance, fatigue resistance, friction resistance and dimensional stability. However, its corona resistance is relatively poor.
Picture: PEF production process
2) Bio-based PA
Polyamide (PA) is a linear polymer with an amide structure on the main chain. The main products include aliphatic PA, aromatic PA and semi-aromatic PA (such as PA 6, PA 66, PA 610, PA 6T, PA 11, PA 46, PA 10, etc.). PA has good mechanical properties, heat resistance, wear resistance, chemical resistance, corrosion resistance, self-lubricating properties, low friction coefficient, a certain degree of flame retardancy, and self-extinguishing properties. The excellent properties of PA materials make them widely used in electronics and electrical appliances, automobiles, mechanical components, medical and pharmaceutical fields.
3) Bio-based PTT
PTT is obtained by the esterification and polycondensation reaction of PTA and 1,3 propylene glycol. 90% of PTT downstream is used for synthetic PTT fibers, while 10% is used for engineering plastics. It has excellent heat resistance, solvent resistance and mechanical strength. It can be used to make a variety of products such as textiles, packaging materials and electronics casings. In addition, bio-based PTT plastic is also widely used in automotive parts manufacturing and wear-resistant industries due to its good dyeability, moldability and injection moldability.
Picture: PTT production process
4) Bio-based PLA
The monomer raw material of polylactic acid is lactic acid. There are two main methods for the synthesis of polylactic acid: direct polycondensation of lactic acid and ring-opening polymerization of propylene glycol ester (also known as the two-step method). The two-step method is the most commonly used method. First, lactic acid is distilled under reduced pressure to produce lactic acid. Using lactide as a monomer, polylactic acid is prepared under initiator, high temperature, and high vacuum conditions for several hours.
Picture: PLA production process
