(German title: Lignocellulose-Bioraffinerie – Aufschluss lignocellulosehaltiger Rohstoffe und vollständige stoffliche Nutzung der Komponenten)

The joint project "Lignocellulose Biorefinery" focuses on the use of woody biomass to provide platform chemicals for use in the chemical industry. A biorefinery based on lignocellulose requires plant concepts that provide wood by digestion and fractionation into basic materials and then for further processing in chemical and biotechnological processes. The overall objective of this application-oriented project is to develop and establish a process for the complete material utilization of all components of lignocellulose by obtaining biobased products based on cellulose, hemicellulose and lignin.

The project builds on the knowledge gained in the "Lignocellulose Biorefinery" pilot project (phase 1). As part of this project, an economically viable plant concept was developed for the digestion of beech and poplar wood and the fractionation of the by-products. The project presented here (phase 2) has two main objectives:

1. Development, construction, commissioning and optimization of a pilot plant with a processing capacity of approx. 620 kg wood atro per week.
2. Provision of the fractions (C5, C6 sugar and lignin) and further processing into higher-value products.

For infrastructural reasons, it is planned to operate the pilot plant at the Leuna industrial site. In addition, there is the opportunity to utilize synergy effects that will arise from the activities planned there in the field of industrial biotechnology. The pilot plant serves to optimize the process under true-to-scale conditions and to provide larger quantities of the various fractions for scale-up and optimization of further processing. Using selected physical, chemical and biotechnological processes, the fractions obtained will be examined for their suitability for the production of platform chemicals and polymers. New partners from industry have been acquired for the implementation of the lignin fraction.

The work carried out at the Department of Bioprocess Engineering deals with the scale-up and optimization of the hydrolysis of the pulp fraction, the subsequent fermentation to solvents and carboxylic acids, as well as the enzymatic conversion of the lignin fraction. Different process variants for saccharification up to the 100 L scale are being investigated and characterized. Among other things, the use of a solid-state bioreactor will be tested. The hydrolysates obtained are to be used for subsequent fermentations to ABE, succinic and itaconic acid. Different process variants will also be tested, such as simultaneous saccharification and fermentation (SSF), which proved to be a promising process in phase 1. Furthermore, the extent to which lignin can be broken down into its basic building blocks using biotechnological methods and whether such treatment can improve its usability will also be investigated.