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Chemical building blocks from versatile MSW biorefinery

Periodic Reporting for period 1 - PERCAL (Chemical building blocks from versatile MSW biorefinery)

Reporting period: 2017-07-01 to 2018-09-30

Today in Europe each habitant generates around 500 kg of municipal solid waste (MSW) every year, which accounts for a total of 247 Mt 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 Mt of 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 valorisation, 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 by IMECAL in PERSEO technology (bioethanol plant with capacity to process 25 ton/day of OFMSW), 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 (LA) to produce eco-friendly solvents to be used in cleaning products and inks, and hot-melt adhesives to be used in cardboard packaging for non-food applications.
• Succinic acid (SA) that will be used as raw material for the production polyurethane for the textile industry.
• Biosurfactants by extraction and modification of proteins and lipids from the by-products of the OFMSW fermentations that will be used in cleaning products.
The main results achieved so far in the project are described below.
WP1. Characterization, handling and pre-processing of MSW from different localizations and seasons
Specific requirements and standards for PERCAL’s intermediate and final products based on a review of current petrol or renewable products available in the market were defined. The factors that affect the variability of the OFMSW and their influence on its physicochemical composition were studied and evaluated. Several OFMSW samples from the EU were fully characterized showing that despite the heterogeneity and variation in composition, the chemical components of biowaste are usually within a relatively short range of values. Pretreatment and enzymatic hydrolysis of biowaste were optimized. 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.
WP2. Microbial conversions to lactic acid
The OFMSW hydrolysate has shown good properties as a fermentation substrate for LA production. Fermentations have shown promising results with conversion yields for some strains higher than 0.9 gLA/gsugars. Additionally, work has been carried out to evaluate a pre-treatment before the fermentation in order to remove indigenous undesired D-lactic acid from the hydrolysate.
WP3. Microbial conversions to succinic acid
SA was successfully produced from MSW hydrolysate at relevant rates and yields. Optimization of the minerals and nitrogen source in the medium for B. succiniciproducens fermentations was carried out. The in-line extraction of produced SA has been done with a membrane electrolysis cell. The SA becomes concentrated and enriched over LA, in the final extract, which shows the potential of membrane electrolysis to improve the economics of the extraction and purification.
WP4. Valorization of fermentation by-products as surfactants
A complete characterization of by-products generated from the ethanol, LA and SA fermentation processes was made. Regarding biosurfactant from fermentation by-products the targeted fractions are protein and lipids (fatty acids), which accounted over 21% by weight. The development of biosurfactant production is under development at this moment.
WP5. Green chemical routes to produce solvents, hot melt adhesives and polyols and their further industrial validation
The work for the production of ethyl lactate solvent via reactive distillation of ethanol and LA started with a good initial progress. The synthesis of lactide from LA was carried out successfully but the reaction conditions and process set-up have to be improved. PLA and PLA copolymers were successfully obtained by ring opening polymerization (ROP) of lactide in presence of alcohols and polycaprolactone polyols as initiators and stannous octoate as catalyst. The stabilization of PLA is a must and was successfully carried out. First tests with SA obtained from WP3 for the production of polyols were performed.
WP6. Study of adaptation and monitoring of PERSEO plant for the production of bioethanol, LA & SA.
The study for adapting PERSEO Bioethanol® semi-industrial plant for the versatile production of lactic and succinic acid and determination of the main process parameters to be monitored has started, with a detailed analysis of the process and the main parameters involved.
WP7.Environmental regulatory & economic analyses
CORDIS database has been used to identify more than 60 companies and 500 MSW valorization projects that could be possible stakeholders for the project. Gabi software will be used for LCA for all the processes involved in PERCAL project. Safety and regulation risks were gathered from all partners and will be provided at the end of the project.
WP8. Communication, Dissemination, Exploitation, Business plan &Tech. Transfer
Regarding communication and dissemination, a number of activities have been developed including website, promotional material (video, press releases, newsletter) design. In terms of exploitation, workshops and teleconferences with the partners have been carried out to identify exploitable results and potential routes for exploitation.
With the development of PERCAL project it is expected to progress beyond of the state of the art in several technical fields. In the field of enzymatic hydrolysis of carbohydrates contained in OFMSW PERCAL will focus 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 will be produced from OFMSW by using novel electrodialysis and membrane electrolysis purification processes. PERCAL will also focus 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 and peroxides will be carried out. PERCAL will also use a prototype reactive distillation to upscale the production of ethyl lactate from produced ethanol and LA to a continuous process. Finally, PERCAL will lay the foundation for a truly biobased industry to produce a new range of bio based building blocks for polyols, resins and polyurethane dispersions.