Nicolaus Dahmen

The bioliq ® bioslurry gasification process for the production of biosynfuels, organic chemicals, and energy

BackgroundBiofuels may play a significant role in regard to carbon emission reduction in the transportation sector. Therefore, a thermochemical process for biomass conversion into synthetic chemicals and fuels is being developed at the Karlsruhe Institute of Technology (KIT) by producing process energy to achieve a desirable high carbon dioxide reduction potential.MethodsIn the bioliq process, lignocellulosic biomass is first liquefied by fast pyrolysis in distributed regional plants to produce an energy-dense intermediate suitable for economic transport over long distances. Slurries of pyrolysis condensates and char, also referred to as biosyncrude, are transported to a large central gasification and synthesis plant. The bioslurry is preheated and pumped into a pressurized entrained flow gasifier, atomized with technical oxygen, and converted at > 1,200°C to an almost tar-free, low-methane syngas.ResultsSyngas - a mixture of CO and H2 - is a well-known versatile intermediate for the selectively catalyzed production of various base chemicals or synthetic fuels. At KIT, a pilot plant has been constructed together with industrial partners to demonstrate the process chain in representative scale. The process data obtained will allow for process scale-up and reliable cost estimates. In addition, practical experience is gained.ConclusionsThe paper describes the background, principal technical concepts, and actual development status of the bioliq process. It is considered to have the potential for worldwide application in large scale since any kind of dry biomass can be used as feedstock. Thus, a significant contribution to a sustainable future energy supply could be achieved.

Hydrothermal gasification of biomass: consecutive reactions to long-living intermediates

The reaction of intermediates formed during hydrothermal biomass gasification (HBG) with each other or with hydrogen produced by the water-gas shift reaction has a significant influence on the process. To understand these reactions, the conversion of different C4 compounds (1-butanol, 1-butanal, cis-butendiol) was investigated in a batch reactor. These compounds carry different functional groups also found in intermediates of HBG. All compounds react to make products with aromatic ring systems, which shows that the intermediates can react with each other and aromatic rings are formed independently of the functional groups. The HBG intermediates can also react with hydrogen formed via the water-gas shift reaction (CO + H2O ⇔ CO2 + H2). This is shown by the reaction of deuterated glucose in H2O. The reaction of hydrogen originating from water leads to the formation of C–H bonds not present in the feedstock.

Partition coefficients of organic substances in two-phase mixtures of water and carbon dioxide at pressures of 8 to 30 MPa and temperatures of 313 to 333 K

Abstract A new apparatus is described for easy and quick determination of partition coefficients in a system containing an aqueous and a supercritical phase, and an organic substance. The partition coefficient in this case is defined as the ratio of molar fractions of a substance in two different phases in equilibrium. The apparatus consists of a high-pressure cell of 200-mL volume. Equilibrium is attained by recirculation of the fluid phases. Samples can be taken from either phase by using six-way sampling valves. Quantitative analysis is carried out either by UV-spectroscopy or by gas chromatography. In the measurements, carbon dioxide was used as the supercritical fluid in studies of partitioning behavior of the organic compounds, phenol, benzoic acid, benzyl alcohol, 2-hexanone, vanillin, and caffeine. The experiments were carried out at temperatures ranging from 313 to 333 K and pressure of 8 to 30 MPa. Partition coefficients between 0.2 and 1.5 were found for phenol which roughly match the data previously reported by other authors. Partition coefficients of benzyl alcohol and benzoic acid were found to be in a similar range, whereas those of 2-hexanone turned out to be between 10 and 140. The partition coefficients obtained ranged from 0.02 to 0.25 for caffeine and 0.2 to 3 for vanillin.

Control of homogeneously catalyzed reactions by phase equilibriaThis work was presented at the Green Solvents for Catalysis Meeting held in Bruchsal, Germany, 13–16th October 2000.

Carbon dioxide was used not only as a reaction medium but also as a renewable C1 feedstock for the palladium catalyzed coupling reaction of butadiene and carbon dioxide. By utilization of nitrile modified phosphine ligands, in the liquid phase complete butadiene conversion and selectivity for the formation of (3E)-3-ethylidene-6-vinyltetrahydro-2H-pyran-2-one (1) up to 47% were achieved. Phase equilibrium considerations were used for process development in order to realize single-phase conditions for the reaction. In contrast to a CO2 enriched phase composition, variation of the density only enables moderate conversion rates also with single-phase conditions and without further catalyst modification.

Vapor–liquid equilibria of different lactones in supercritical carbon dioxide

Abstract Vapor–liquid equilibria of different lactones, γ-butyrolactone, e-caprolactone, γ-caprolactone, γ-decalactone, and a δ-lactone with supercritical CO 2 have been measured applying the synthetic method using a high pressure view cell with variable volume in a temperature range from 313 to 363 K and in a pressure range from 9 to 27 MPa. The experimental data have been reasonably correlated using the Peng–Robinson equation of state (PR-EOS) combined with the Margules mixing rule. The binary critical points determined from the different isotherms show a type-II phase behavior for most of the systems, but indicate a type III or even a IV behavior for the δ-lactone.

Detection of aromatic compounds in artificial gasoline with hybrid surface acoustic wave sensor array and a short packed column (SAW-GC)

A self-developed and newly re-designed SAW sensor system composed by 4 polymer coated and 4 differently modified nano-diamond coated SAW sensors was applied to measure aromatic compounds in gasoline in a low cost, fast and easy way. An additional short packed column at system inlet improved the selectivity. The short packed column separated selectively the aromatics from the rest of the sample. Since all employed sensors show linearity for the concentration range tested an easy quantification of single fuel components was possible.

Chapter 8:Green Fuels – Sustainable Solutions for Transportation

The importance of biofuels is growing rapidly and this is reflected in steadily increasing research activities in both academia and industry as well as an increasing number of joint ventures comprising several institutions. Thus, not only is the extent of publications on this highly dynamic topic st...

Fast Pyrolysis of Biomass Residues in a Twin-screw Mixing Reactor

Fast pyrolysis is being increasingly applied in commercial plants worldwide. They run exclusively on woody biomass, which has favorable properties for conversion with fast pyrolysis. In order to increase the synergies of food production and the energetic and/or material use of biomass, it is desirable to utilize residues from agricultural production, e.g., straw. The presented method is suitable for converting such a material on an industrial scale. The main features are presented and an example of mass balances from the conversion of several biomass residues is given. After conversion, fractionated condensation is applied in order to retrieve two condensates — an organic-rich and an aqueous-rich one. This design prevents the production of fast pyrolysis bio-oil that exhibits phase separation. A two phase bio-oil is to be expected because of the typically high ash content of straw biomass, which promotes the production of water of reaction during conversion. Both fractionated condensation and the use of biomass with high ash content demand a careful approach for establishing balances. Not all kind of balances are both meaningful and comparable to other results from the literature. Different balancing methods are presented, and the information that can be derived from them is discussed.

Synthetic fuels from biomass: Potentials and viability

In view of a world-wide growing fuel demand coming along with a strong environmental impact, exploration of alternative resources, preferably renewable ones, is vastly stimulated. Regarding carbon-based fuels, biomass is the only renewable feedstock which can be converted efficiently to fuels employing either fermentative or chemical processes. Naturally, the use of residues and wastes is preferred to circumvent competition with customary markets, especially the nutrition sector. Typical fermentative procedures, which are already employed on large scale, are the production of ethanol from sugars, starch or cellulose as well as methane production via anaerobic digestion of biomass.

Das Bioliq-Verfahren Konzept, Technologie Und Stand Der Entwicklung

Synthesekraftstoffe aus Restbiomasse konnen einen wesentlichen Beitrag zur Erzeugung von Flussigkraftstoffen leisten. Hochwertige Benzin- und Dieselqualitaten sind auf diesem Weg zuganglich. Zur grostechnischen Nutzung von Biomasse sind jedoch logistische und technische Besonderheiten zu berucksichtigen, denen das Bioliq- Verfahren des KIT entspricht. Eine dezentrale Vorbehandlung der Biomasse zur energetischen Verdichtung durch Schnellpyrolyse erlaubt eine grosraumige Versorgung zentraler wirtschaftlicher Grosanlagen, wie sie zur Erzeugung von Synthesegas und dessen Weiterverarbeitung zu Kraftstoffen notwendig sind.