G. van Rossum

Pyrolysis based bio-refinery for the production of bioethanol from demineralized ligno-cellulosic biomass

This paper evaluates a novel biorefinery approach for the conversion of lignocellulosic biomass from pinewood. A combination of thermochemical and biochemical conversion was chosen with the main product being ethanol. Fast pyrolysis of lignocellulosic biomasss with fractional condensation of the products was used as the thermochemical process to obtain a pyrolysis-oil rich in anhydro-sugars (levoglucosan) and low in inhibitors. After hydrolysis of these anhydro-sugars, glucose was obtained which was successfully fermented, after detoxification, to obtain bioethanol. Ethanol yields comparable to traditional biochemical processing were achieved (41.3% of theoretical yield based on cellulose fraction). Additional benefits of the proposed biorefinery concept comprise valuable by-products of the thermochemical conversion like bio-char, mono-phenols (production of BTX) and pyrolytic lignin as a source of aromatic rich fuel additive. The inhibitory effect of thermochemically derived fermentation substrates was quantified numerically to compare the effects of different process configurations and upgrading steps within the biorefinery approach.

Liquefaction of Lignocellulosic Biomass: Solvent, Process Parameter, and Recycle Oil Screening

The liquefaction of lignocellulosic biomass is studied for the production of liquid (transportation) fuels. The process concept uses a product recycle as a liquefaction medium and produces a bio-oil that can be co-processed in a conventional oil refinery. This all is done at medium temperature (≈ 300 °C) and pressure (≈ 60 bar). Solvent-screening experiments showed that oxygenated solvents are preferred as they allow high oil (up to 93% on carbon basis) and low solid yields (≈ 1-2% on carbon basis) and thereby outperform the liquefaction of biomass in compressed water and biomass pyrolysis. The following solvent ranking was obtained: guaiacol>hexanoic acid ≫ n-undecane. The use of wet biomass results in higher oil yields than dry biomass. However, it also results in a higher operating pressure, which would make the process more expensive. Refill experiments were also performed to evaluate the possibility to recycle the oil as the liquefaction medium. The recycled oil appeared to be very effective to liquefy the biomass and even surpassed the start-up solvent guaiacol, but became increasingly heavy and more viscous after each refill and eventually showed a molecular weight distribution that resembles that of refinery vacuum residue.

Lipid accumulation from pinewood pyrolysates by rhodosporidium diobovatum and chlorella vulgaris for biodiesel production

This study evaluated the suitability of pinewood pyrolysates as a carbon source for lipid production and cultivation of the oleaginous yeast Rhodosporidium diobovatum and the microalgae Chlorella vulgaris. Thermal decomposition of pinewood and fractional condensation were used to obtain an oil rich in levoglucosan which was upgraded to glucose by acid hydrolysis. Blending of pyrolytic sugars with pure glucose in both nitrogen rich and nitrogen limited conditions was studied for R. diobovatum, and under nitrogen limited conditions for C. vulgaris. Glucose consumption rate decreased with increasing proportions of pyrolytic sugars increasing cultivation time. While R. diobovatum was capable of growth in 100% (v/v) pyrolytic sugars, C. vulgaris growth declined rapidly in blends greater than 20% (v/v) until no growth was detected in blends >40%. Finally, the effects of pyrolysis sugars on lipid composition was evaluated and biodiesel fuel properties were estimated based on the lipid profiles.

Liquefaction of Lignocellulose in Fluid Catalytic Cracker Feed: A Process Concept Study

We report a process concept for lignocellulose liquefaction in a refinery stream that will be coprocessed with the resulting biocrude and that, therefore, does not require the recovery and recycling of the liquefaction solvent. Light cycle oil and vacuum gas oil were found to be the two most promising solvents. Both refinery streams could provide a liquid yield of 58 C % (64 % energy yield). A techno-economic assessment indicates that the biocrude could be produced at an energy-equivalent crude oil price of 51-64 

Production of biofuels via biomass reforming.

per barrel at a wood cost of 85 

Catalytic gasification of dry and wet biomass

per dry ton.

Liquefaction of lignocellulose: process parameter study to minimize heavy ends

Abstract: This chapter describes various technologies for biomass reforming for the production of high-value gases. These gas mixtures can be used for the production of fuels and chemicals or as a product itself (like hydrogen). Both ‘wet’ and ‘dry’ biomass conversion technologies are detailed with and without intermediate processing steps. Throughout the chapter, the conversion of biomass via fast pyrolysis and subsequent reforming is highlighted.