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Chemical building blocks from versatile MSW biorefinery

Periodic Reporting for period 2 - PERCAL (Chemical building blocks from versatile MSW biorefinery)

Reporting period: 2018-10-01 to 2020-12-31

Today in Europe each habitant generates around 500 kg of municipal solid waste (MSW) every year, which accounts for a total of 247 million tons of MSW in EU-28. The organic fraction of MSW (OFMSW) ranges between 30-50% of this amount, so that it is estimated that more than 100 million tons of municipal biowaste are yearly generated in our continent. Currently, 24% of MSW is landfilled, 27% is incinerated, 29% is recycled and 16% is treated by means of composting or anaerobic digestion. In spite of the strong shift from MSW landfilling in the last years to recycling of materials such as plastics, glass or metals and energy production from combustible fraction through incineration, there is still a challenge to turn the organic waste into higher value products than bioenergy or compost.
PERCAL project introduces a new concept of biowaste valorization, with the aim of improving environmentally and economically the current MSW treatment model by producing added-value chemical products from the OFMSW with huge industrial interest. The valorization of the OFMSW will reduce pressure on conventional raw materials and will increase the competitiveness of European industry, contributing to the reduction of municipal waste flows to landfill and incineration. PERCAL is using previous knowledge developed in PERSEO Bioethanol technology, as a starting point to produce new high added value bioproducts from MSW in a versatile biorefinery concept based on fermentation and valorization processes;
• Lactic acid to produce eco-friendly solvents to be used in cleaning products, inks, and hot-melt adhesives to be used in cardboard packaging for non-food applications.
• Succinic acid that will be used as raw material for the production of polyurethanes for the textile industry.
• Biosurfactants by extraction and modification of proteins and lipids from the by-products of OFMSW fermentations that will be used in cleaning products.
An overview of the main results achieved in the project are described below.
Characterization and pre-processing of MSW from different localizations and seasons
Several OFMSW samples from the EU were characterized showing that despite the heterogeneity and variation in composition, the chemical components of biowaste are usually within a relatively short range of values. Specific requirements and standards for PERCAL’s products based on a review of current petrol or renewable products available in the market were defined. Pretreatment and enzymatic hydrolysis of biowaste were optimized.
Microbial conversion to bioethanol, lactic acid and succinic acid
Fermentation tests with different strains indicate that ethanol yeast, LA and SA bacteria are not inhibited and can effectively use the sugars from OFMSW hydrolysate. The optimization of fermentation of OFMSW into LA achieved conversion yields over 90 %, with L-LA purities up to 98 %. SA to sugar conversion yield was 0.26 g g-1 and productivity was 0.53 g L-1 h-1.
Valorisation of fermentation by-products as surfactants
Regarding biosurfactant production from fermentation by-products the targeted fractions are protein and lipids. PERCAL surfactant was industrially validated for three different detergent applications, showing a good performance compared to a standard formulation.
Green chemical routes to produce solvents, hot melt adhesives and polyols and their further industrial validation
A reactive distillation process for the production of the biosolvent ethyl lactate from ethanol and LA was developed. When ethyl lactate was used as green preservative in cleaning products, promising results were obtained. The synthesis of lactide from LA was carried out at lab scale following a two steps approach. PLA and PLA copolymers were obtained by ring opening polymerization of lactide and used to formulate Hot Melt Adhesives (HMAs) for closing carboard applications, showing improved performance in comparison with fossil-based EVA HMAs. Bio-SA served as raw material for the production of polyester polyols, which were used to produce polyurethane dispersions and for the synthesis of thermoplastic polyurethanes.
Study of adaptation and monitoring of PERSEO plant for the production of bioethanol, LA & SA
A versatile biotechnological plant to produce bioethanol, LA and SA from the OFMSW was studied. PERSEO biorefinery plant, which currently produces bioethanol from OFMSW, was used as a reference to study this versatile biorefinery model. PERSEO plant can be easily adapted for pre-treatment and fermentation processes. The monitoring of critical parameters such as the concentration of glucose, ethanol, LA and SA could be monitored with the NIR technology developed. Overall, this task served as a basis for the development of an industrial biorefinery that uses OFMSW as feedstock for the production of different added value bioproducts.
Environmental, regulatory & economic analyses
The assessment of all pillars underlines that the development of biorefineries using as feedstock the OFMSW and the production of the selected products could be feasible and successful. One of the important achievements is the savings in GHG emissions that arise when OFMW is valorised via bioprocessing. The economic results indicate that the selected products can be competitive in the market when compared to current fossil or bio-based counterparts, while an assessment of social performance also expresses that OFMSW biorefinery can benefit the community by increasing the job opportunities. Finally, it should be stressed that the production process using OFMSW is well aligned to the regulations of the EU and therefore OFMSW is a suitable feedstock for biorefinery development.
Communication, Dissemination, Exploitation, Business plan & Tech. Transfer
Scientific publications, workshops, newsletters, a publicly available technical guide and a final project webinar were prepared. Business models were developed. The identification of exploitation risks, competitors and other market dynamics is expected to help guide future projects and increase the chance of reaching commercialisation. The business models and overall potential of PERCAL technologies were validated by external stakeholders.
With the development of PERCAL project progress beyond the state of the art has been made in several technical fields. In the field of enzymatic hydrolysis of carbohydrates contained in OFMSW PERCAL focused on the improvement of the hydrolysis process by the synergic combination of the most effective commercial enzyme cocktails taking advantage of 9 years experience of PERSEO Bioethanol® technology. Chemical intermediates LA and SA were produced from OFMSW by using novel electrodialysis and membrane electrolysis purification processes. PERCAL also focused on the valorisation of the protein and lipid content coming from the by-products of the fermentation processes in order to produce new biobased surfactants.
Moreover, the production of renewable hot melt adhesives (HMA) by reactive extrusion of LA and other co-monomers using suitable catalysers were carried out. PERCAL also used a prototype reactive distillation to upscale the production of ethyl lactate from produced ethanol and LA to a continuous process. PERCAL layed the foundation for a truly biobased industry to produce a new range of bio based building blocks for polyols, resins and polyurethane dispersions using OFMSW as raw material.
PERCAL project