Secondary chemical building blocks from novel biorefining of agrifood wastes for a future bio-based industrial chemistry

The cost of primary chemical building blocks, the basic chemicals for synthesis, is about 1-3 €/kg. Phenol and cresols represent a good example of primary chemical building blocks of which 2.8 million tons are currently produced in Europe each year. Currently, these primary phenolic building blocks are produced by refining processes from fossil hydrocarbons: 5% of the world-wide production comes from coal (which contains 0.2% of phenols) through the distillation of the tar residue after the production of coke, while 95% of current world production of phenol is produced by the distillation and cracking of crude oil. In nature phenolic compounds are present in terrestrial higher plants and ferns in several different chemical structures while they are essentially absent in lower organisms and in animals. Biomass (which contain 3-8% of phenols) represents a substantial source of secondary chemical building blocks presently under exploited. These phenolic derivatives are currently used in tens of thousand of tons to produce high cost products such as food additives and flavours (i.e. vanillin), fine chemicals (i.e. non-steroidal anti-inflammatory drugs such as ibuprofen or flurbiprofen) and polymers (i.e. poly p-vinylphenol, a photosensitive polymer for electronic and optoelectronic applications). The cost of the secondary chemical building blocks are range from 40 €/kg to 60.000 €/kg. European agrifood waste represents a low cost abundant raw material (250 millions tons per year) which does not subtract land use and processing resources from necessary sustainable food production.. The class of phenolic compounds is essentially constituted by simple phenols, phenolic acids, hydroxycinnamic acid derivatives, flavonoids and lignans. As in the case of coke production, the removal of the phenolic contents from biomass upgrades also the residual biomass. Focusing on the phenolic component of agrifood wastes, huge processing and marketing opportunities open since phenols are used as chemical intermediates for a large number of applications, ranging from pharmaceuticals, agricultural chemicals, food ingredients etc. PHENBUSTER proposes a novel concept for the bio-refinering of agrifood wastes with the aim of substituting secondary chemical building blocks with the same compounds naturally present in biomass. The phenols obtained from wastes will be used as versatile intermediates to obtain a wide range of final products. This project proposes a “Whole Crop Approach” allowing the combination of phenolic recovery, as main strategic goal, with the extraction of fine chemicals, bio-based polymers and energy. By recovering phenols from plant wastes as chemical building blocks, PHENBUSTER develops a bio-refinery approach with a general validity, since the chemical building blocks feed numerous chemical processes. In this way, our proposal represents the general project exhausting the phenolic, the saccharidic and finally the energy content from agrifood wastes implementing integrated enzymatic and microbial technologies.