Deliverable 2.1 - Upstream Steps: Acidogenic Fermentations and Pretreatments, 1st Report

Abstract:

Deliverable 2.1 reports on the activities undertaken by RES URBIS partners in task 2.1. The task forms part of Work Package 2 and deals with upstream acidogenic fermentation and pre-treatments and incorporates five discrete subtasks led by USW (the task leader), UB, UNIVR, UNIRM (together with INRA) and NOVAID.

As detailed in the Work package description, each of these subtasks addresses different technical challenges related to upstream, acidogenic fermentation of biomass feedstocks. Some of the technical challenges being addressed include biomass pre-treatment, co-digestion of different substrates, novel technologies for extracting and influencing VFA production and demonstration of fermentation processes at a range of scales up to and including pilot scale.

Several subtasks in this task faced longer lead times for the construction and commissioning of experimental apparatus and are now beginning to produce fermentation data. Other subtasks have already produced fermentation for a variety of substrates using different experimental processes and conditions. Progress achieved in each of these sub tasks is detailed in separate sections below.

The majority of acidogenic fermentation experiments have commenced with the number and duration of these experiments being contingent on the complexity of the fermentation apparatus required for their particular substrates or methods of investigation.

At this point in the project several industrial or municipal substrates have been shown to be applicable to the production of VFA via acidogenic fermentation. Some partners have also demonstrated that manipulation of VFA production patterns is feasible by altering the parameters such as fermentation temperature and pH. A number of pretreatment strategies are being investigated including thermal treatment and enzymatic saccharification which has been successful in increasing substrate availability for more efficient conversion to VFAs.

Further work within the task will focus on increasing fermenter efficiencies and VFA yields, manipulating VFA production patterns, evaluating the potential for co-digestion of different substrates and on integrating novel extraction technologies to increase fermenter performance and extract VFAs for downstream use in PHA production.