Options of sugar beet pretreatment for hydrogen fermentation*

Hydrogen is expected to play a major role in covering the future energy demand. To make its future uses sustainable, hydrogen should be produced from renewable resources, for example by bacterial fermentation of biomass-derived feedstocks.

Sugar beet is recognised as one of the most interesting raw materials for hydrogen fermentation. Similar to other types of biomass, it has to be initially pretreated to obtain fermentable feedstock. Any sugar factory can be considered as a beet pretreatment unit to which a fermentation unit can be connected to produce hydrogen from such feedstocks as raw juice and thick juice, molasses or residual syrups from sugar crystallisation.

As an alternative approach, hydrogen production in stand-alone plants located close to beet growing areas can be considered. The proposed beet pretreatment is based on mechanical grinding and pressing to obtain raw juice which subsequently is upgraded by screening at ambient temperature yielding a feedstock for hydrogen fermentation. If applied in small-scale plants, this approach has the advantage of modest investment cost and low environmental impact.

In both options of beet pretreatment, beet pulp and beet leaves are potentially available for hydrogen production but the methods of conversion of these materials into fermentable feedstocks still are under development.