posted on 2015-12-17, 07:55authored byElia Armandina Ramos-Tercero, Alberto Bertucco, D. W. F. (Wim) Brilman
In this work, the effect of recycling
the process water (PW) of
hydrothermal liquefaction (HTL) to the HTL reactor was investigated,
with the objective being to recover carbon from the organic content
of the PW and to develop a solvent-free process. When recycling twice
the PW at 220, 240, and 265 °C, a significant increase in bio-oil
production is observed at all temperatures. An extended series of
recycle experiments was performed at 240 °C, showing that the
bio-oil yield increased up to stationary level, after six recycles.
To investigate the role of accumulated compounds as acetic acid, additional
experiments were carried out with dilution and spiking of recycled
PW. PW recycling not only increases bio-oil yield but also enables
to reduce operating temperature (and, hence, costs) of HTL; therefore,
it is an essential element in developing a solvent-free process for
biocrude production from microalgae.