Jari Heinonen

Adsorptive removal of fermentation inhibitors from concentrated acid hydrolyzates of lignocellulosic biomass

Adsorptive purification of concentrated acid hydrolyzate of lignocellulose was investigated. Cation exchange resin (CS16GC), neutral polymer adsorbent (XAD-16), and granulated activated carbon (GAC) were studied to remove furfural, HMF, and acetic acid from a synthetic hydrolyzate containing 20 wt.% H(2)SO(4). Adsorption isotherms were determined experimentally. Loading and regeneration were investigated in a laboratory scale column. GAC has the highest adsorption capacity, but regeneration with water was not feasible. XAD-16 and CS16GC had lower adsorption capacities but also shorter cycle times due to easier regeneration. Productivity increased when regenerating with 50 wt.% EtOH(aq) solution. To compare adsorbents, process performance was quantified by productivity and fraction of inhibitors removed. GAC yields highest performance when high purity is required and ethanol can be used in regeneration. For lower purities, XAD-16 and GAC yield approximately equal performance. When using ethanol must be avoided, CS16GC offers highest productivity.

Evolutionary multi-objective optimization based comparison of multi-column chromatographic separation processes for a ternary separation

Performance characteristics of two advanced multi-column chromatographic separation processes with discontinuous feed, Multi-Column Recycling Chromatogrphy (MCRC) and Japan Organo (JO), were investigated for a ternary separation using multi-objective optimization with an evolutionary algorithm. Conventional batch process was used as a reference. Fractionation of a concentrated acid hydrolysate of wood biomass into sulfuric acid, monosaccharide, and acetic acid fractions was used as a model system. Comparison of the separation processes was based on selected performance parameters in their optimized states. Flow rates and step durations were taken as decision variables whereas the column configuration and dimensions were fixed. The MCRC process was found to be considerably more efficient than the other processes with respect to eluent consumption. The batch process gave the highest productivity and the JO process the lowest. Both of the multi-column processes gave significantly higher monosaccharide yield than the batch process. When eluent consumption and monosaccharide yield are taken into account together with productivity, the MCRC process was found to be the most efficient in the studied case.

Chapter Five - Chromatographic Fractionation of Lignocellulosic Hydrolysates

Abstract Monosaccharides (glucose, xylose, etc.) are valuable platform chemicals that can be produced from lignocellulosic (polysaccharide containing) biomasses via hydrolysis. Their cost-effective recovery from lignocellulosic biomass hydrolysates and further purification requires sophisticated separation technology. Adsorption and electrolyte exclusion chromatography can be used for the fractionation of hydrolysates containing mineral acids. The recovered hydrolysis acid can be recycled, which saves and reduces chemicals consumption. Chromatographic separation can be done either batchwise, using steady-state recycling chromatography, or using continuous simulated moving bed chromatography. The latter two process options offer significant increase in productivity when compared to the batchwise fractionation process. In this chapter, chromatographic and adsorptive fractionation techniques for the treatment of acidic lignocellulosic hydrolysates are reviewed. The relevant physical phenomena affecting the separation efficiency as well as various industrially applicable process options are discussed.

Sensory profile of ethyl β-d-glucopyranoside and its contribution to quality of sea buckthorn (Hippophaë rhamnoides L.)

The contribution of ethyl β-d-glucopyranoside (EG) to sensory profile of sea buckthorn (Hippophaë rhamnoides ssp. rhamnoides) was studied. The content of natural existing EG varied between 0.6 and 19.8g/L in the sea buckthorn studied. The taste threshold of pure EG was estimated in water solution as 1.1±1.3g/L, and the suprathreshold aqueous EG solution (5.0g/L) was perceived mainly as bitter. In aqueous sugar-acid mixtures, acids were the major contributors to sourness and astringency, whereas the added EG or sugars showed little impact on the overall sensory profile. EG addition increased the bitterness of sea buckthorn juice. The sensory profiles of the juices were dominated by intense sourness correlating with the malic acid content. The bitterness of the juices correlated with the EG content as well as the ratios EG/acids and EG/sugars. EG content shall be considered when selecting raw materials for industrial processing.

CHROMATOGRAPHIC RECOVERY OF MONOSACCHARIDES AND LIGNIN FROM LIGNOCELLULOSIC HYDROLYSATES ON LABORATORY AND PILOT SCALES

Abstract The chromatographic recovery of monosaccharides and lignin from lignocellulosic hydrolysates was studied at laboratory and pilot scale. A weak cation‐exchange resin in sodium form and a water eluent gave good separation efficiency. Scale‐dependent phenomena, especially viscous fingering resulting from the large viscosity and density differences between the hydrolysate feed and eluent, were observed. The issue was resolved in the pilot scale with appropriate selection of the flow direction, and a high productivity was achieved at 95 % recovery yield. The pH value of the feed was found to have no effect on the actual separation; however, the resin was significantly less colored at a higher pH value.