Economy-of-scale contributes to profitability because less investment is required per unit product manufactured. This economy-of-scale is often explained because the volume of a reactor increases with the power of three while the investment itself increases often with the power of two since this is dependent on the outer surface of the reactor itself (Lange, 2001). When major heat exchange capacities are required, the need for larger factories becomes apparent because the surface of heat exchangers needs to be in correlation with the volume of the reactor or in other words with the amount of heat that is produced in the volume of the reactor. If one could circumvent the need for heat exchangers, then the need for building large units will diminish and many small units can do the job that initially was done by the large factory. This will enable a totally different architecture of the processes and certainly of the logistics of biomass value chains.

Raw materials that contain a lot of water, and that are perishable, and before were not attractive to be transported to a large factory, can nowadays be (pre) processed at small scale. Cassave roots are a good example of this (Sanders et al, 2005). Ten small scale mobile factories of 4000 tons of starch product each are in operation at different locations in Nigeria. Also residues like beet leaf or carrot leaf can now be pre-processed, as is the case for meadow grass. It will be understood that for other crops that contain a lot of water like potato and grass, small scale processing will have a lot of advantages. Developments of small scale production of ethanol from corn is in progress in The Netherlands, where because of the reduction of unit operations that need heat exchange, the capital cost per litre of ethanol is not higher for these small units than for the large scale corn to ethanol plants in the USA, that operate at 100 times larger scale (Sanders et al., 2008).