Peer Review Session #2

Right after the second round of Living Labs, a Peer Review session took place online on 27 October. Six international biowaste management experts discussed open questions for each identified value chain in the pilot areas, added additional factors and barriers to those already identified in the second Living Lab and voted on the most important ones.

  • Province of Pazardzhik (PP)

For Pazardzhik, the experts were asked to nominate a forestry specialist to expand the current understanding of opportunities and barriers. In particular, the pros and cons of recycling this waste stream in general need to be weighed: comparing the impacts of forestry residue collection on biodiversity and soil erosion versus the benefits of reducing forest fire risk (LCA). 

In addition, experts of the PRS discussed potential new collection technologies and new local recycling routes (e.g., composting plants) for forestry residues. The introduction of separate (biowaste) collection in PP – now the separate collection rate is not exceeding 3% – will most probably lead to the construction of new composting plants, where lignocellulosic streams are required for co-composting. 

  • Metropolitan City of Naples (MCN)

The discussion focused not only on the current coffee value chain but also on agro-industrial waste streams in general. The following general barrier is an example: “Depending on the technological path chosen, a very specific and continuous type (quality) of biowaste is required throughout the year, but the range of agricultural products depends largely on the season and climatic changes.”  

Another important topic was “to avoid unnecessary competition for the use of a biowaste type”, e.g., growing mushrooms on coffee waste vs. using it to produce carotenoids or oil. It was also stressed that a partial incorporation of crop residues into the soil must be maintained. 

As an important driver, increasing industrial awareness of the benefits of a circular biowaste management was identified as well as easily available information on new exploitation routes for product developers. Moreover, experts highlighted the importance of creating new jobs and income in innovative value chains as well as the clear promotion of this. 

Especially for the marketing of functional food ingredients from biowaste, it was stressed to conduct in-depth risk analysis and to provide clear information on the absence of contamination or potential harm from waste-derived products to prevent reluctance to use them. 

  • Metropolitan area of Barcelona (MAB)

For MAB, improving the quality and quantity of separately collected biowaste and an available updated database on municipal biowaste flows (quantity, quality, destination) can create new treatment options. 

For food waste prevention, the difficulty in changing personal habits (shop locally, planning for shopping, sharing food etc.) was listed as the most important barrier and basic awareness raising of people (education at all levels) as the most important driver. An important tool to lower waste generation consists in decreased waste fees for those who produce less waste. 

Experts emphasised the necessity of increasing the quality of biowaste on the one hand and at the same time reducing food waste. Seasonal fluctuations of the amounts of separately collected biowaste and high heterogeneity and impurities of input material for specific treatment processes also need to be taken into account. For these reasons, new recycling technologies should not be oversized.  

For the biomethane valorisation chain, policy incentives for the biomethane production for injecting in the local gas grid were stressed as an important driver. 

For changing the current collection system, environmental impact analyses about the pros and cons are needed. For a conversion of the current collection system with open containers to smart bins, uncontrolled tourism flows were mentioned in the MAB as an important obstacle, as full cooperation of the population and responsible tourism would be required. Another challenge related to smart bins is Big Data Management and the Citizen’s acceptance of (new) biowaste collection systems. 

  • For all the chains


  • Raise awareness (among young people) to promote behavioural change 
  • Promoting taxes on fossil fuels for fair competition with bioproducts 
  • Putting a real value on recycled carbon (e.g., compost) 
  • Legal and/or economic incentives for new local value chains (e.g., tax reductions) 
  • Lower costs of biowaste-based compared to fossil-based products through e.g., VAT reduction 
  • EU quality certifications for bio-based products (e.g., biochemicals)  
  • Grants to do biowaste research 


  • Political unwillingness to change the current situation 
  • A profit-driven free market may not be ready for new strategies in this field. State interventions – also in form of incentives – may be appropriate. 
  • Lack of regulations to define the status “from biowaste to product” (e.g., biochemicals production) 
  • Old products (for example products from fossil fuels) are advertised very well. How can we promote the innovative products and their benefits? This is crucial. 
  • Too complex/ contradictory regulations 


27 October 2022

3:00 pm to 5:00 pm