Bioraffinerien auf Basis schwach verholzter Biomasse

Weakly lignified biomass, like brewers' spent grain and grass silage, is good feedstock for biorefineries. The biomass can be separated and converted into valuable products in different ways. In this study, brewers' spent grain is used to investigate solid state fermentations with Cellulomonas uda. Additionally, hydrothermal pretreatment and subsequent enzymatic saccharification, as well as formation of inhibitory compounds, is demonstrated. Hydrothermal pretreatment combined with simultaneous saccharification and fermentation is shown as an example for the utilization of grass silage.     

Development of Fluorogenic Probes for Rapid High-Contrast Imaging of Transient Nuclear Localization of Sirtuin 3

Protein labeling using fluorogenic probes enables the facile visualization of proteins of interest. Herein, we report new fluorogenic probes consisting of a rationally designed coumarin ligand for the live-cell fluorogenic labeling of the photoactive yellow protein (PYP)-tag. On the basis of the photochemical mechanisms of coumarin and the probe–tag interactions, we introduced a hydroxy group into an environment-sensitive coumarin ligand to modulate its spectroscopic properties and increase the labeling reaction rate. The resulting probe had a higher labeling reaction rate constant and a greater fluorescence OFF–ON ratio than any previously developed PYP-tag labeling probe. The probe enabled the fluorogenic labeling of intracellular proteins within minutes. Furthermore, we used our probe to investigate the localization of sirtuin 3 (SIRT3), a mitochondrial deacetylase. Although the nuclear localization of SIRT3 has been controversial, this transient nuclear localization was clearly captured by the rapid, high-contrast imaging enabled by our probe.     

The Role of Farm Advisors in Multifunctional Landscapes: A Comparative Study of Three Danish Areas, 1995 and 2008

This study investigates the influence of farm advisors on farmers’ decisions regarding ‘Multifunctional landscape commons’, a concept covering environmental and landscape values that benefit the public but which depend on farmers’ management practices. The influence of advisors is analysed by combining data about the source of advice with evidence of land use and landscape changes and participation in subsidy schemes. The study compares three agricultural areas in Denmark. Structured interviews were carried out with all farmers possessing more than 2 ha land in 1995–6 and in 2008. Vertical, production and business-oriented advisory services predominate, together with legal and organisational spatial competence networks. A new group of hobby farmers and pensioned farmers tend not to be included in traditional advisory networks, leaving them to carry out landscape changes and multifunctional landscape commons without professional guidance and consultancy. This means the horizontal coordination among farmers, that is, the territorial competences, decrease.     

Design and Fabrication of Transparent and Gas‐Tight Optical Windows in Low‐Temperature Co‐Fired Ceramics

Low‐temperature co‐fired ceramics (LTCC) enable the fabrication of microfluidic elements such as channels and embedded cavities in electrical devices. Hence, LTCC facilitate the realization of complex and integrated microfluidic devices. Examples can be applied in many areas like reaction chambers for synthesis of chemical compounds. However, for many applications it is necessary to have an optically transparent interface to the surroundings. The integration of optical windows in LTCC opens up a wide field of new and innovative applications such as the observation of chemiluminescent reactions. These chemical reactions emit electromagnetic radiation and thus offer a method for noninvasive detection. Thin glasses (≤500 μm) were bonded by thermocompression onto a LTCC substrate. As the bonding agent, a glass frit paste was used. Borosilicate glasses, fused silica as well as silicon were successfully bonded onto LTCC. To join materials with a large coefficient of thermal expansion mismatch (i.e., fused silica and LTCC), it is necessary to limit the heat input to the bond interface. Therefore, a heating structure was integrated into the LTCC substrate beneath the bond interface. This bonding process provides a gas‐tight optical port with a high bond strength.     

Gewinnung leichter Kohlenwasserstoffe aus schweren Ölen — Verfahren und Entwicklungen

Manufacture of light hydrocarbons from heavy oils – processes and developments . High quality crude oils are running short and their price continues to increase. At the same time there is a trend towards light petroleum products for use as transportation fuels or petrochemical raw materials. Consequently, the conversion of heavy oils, i.e., particularly distillation residues but also heavy oils from tar sands, is gaining increasing commercial importance. The cracking processes currently used in the refining industry are reviewed. Emphasis is placed on their application to metal-and asphaltene-containing heavy oils. Feed pretreatment by solvent deasphalting is discussed and the manufacture of syncrude from tar sands is considered. New developments for conversion of heavy oils are outlined. The future production of shale oil and of transportation fuels from oil shale is briefly treated.     

Heat-integrated reactor concepts for catalytic reforming and automotive exhaust purification

Optimal solutions in environmental catalysis require a well-coordinated development of catalysts and of process design. This contribution is devoted to energy integrated design concepts for fuel reforming and for automotive exhaust purification. The examples presented demonstrate the importance of an innovative process design for optimal utilization of existing catalysts and show the potential of future developments.

New concepts for steam reforming through the efficient coupling of the endothermic reforming reaction with an exothermic combustion reaction are discussed in the first part. These concepts have been implemented for methanol steam reforming in a counter-current reactor with distributed side feed of burner gas and for methane steam reforming in a modular reactor with a co-current reaction section for the endothermic and the combustion reaction and attached counter-current heat exchangers. Both applications employ the so-called folded sheet reactor design, which ensures an excellent heat transfer between the reforming and combustion channels and efficient heat recovery.

A similar design solution is introduced for the apparently different case of automotive exhaust purification. The proposed concept aims at decoupling exhaust after-treatment from engine control. Its main component is a counter-current heat exchanger with integrated purification stages for HC-oxidation, NO_X storage and reduction and soot filtering. A small catalytic burner at the hot end of the heat exchanger provides both heat and oxidizing or reducing agents on demand. A new soot filter design allows for safe soot filter regeneration.     

Peptide Bioconjugates of Electron‐Poor Metallocenes: Synthesis,Characterization, and Anti‐Proliferative Activity

We report the synthesis of metallocene compounds Cp₂M with two different electron‐withdrawing substituents on both cyclopentadienyl rings (hexafluoroacetone (HFA) and chlorobenzoyl ( 1 – 5 ); HFA and COOH ( 6 and 7 ), M=Fe or Ru). The COOH‐containing derivatives were used to synthesize peptide bioconjugates with enkephalin ( 8 and 9 ) and neurotensin ( 10 and 11 ) as well as fluorescein‐labeled neurotensin ( 12 ). All the molecules were fully characterized, including X‐ray structures for 6 and 7 . The physicochemical properties (lipophilicity and electrochemistry) and cytotoxicity on MCF‐7, HT‐29, and PT‐45 cancer cells were evaluated for selected compounds. Electrochemical investigation by cyclic voltammetry revealed that all bis‐substituted metallocenes are up to 300 mV harder to oxidize compared to the monosubstituted 2‐ferrocenylhexafluoropropan‐2‐ol (FcHFA: Δ${E{{{\rm f}\hfill \atop 0\hfill}}}$ =214 mV; disubstituted derivatives: up to Δ${E{{{\rm f}\hfill \atop 0\hfill}}}$ =512 mV; both vs. FcH^0/+). For the bis‐substituted compounds, log P determinations by RP‐HPLC showed increased lipophilicity in comparison to the monosubstituted FcHFA and RcHFA. Cellular uptake was investigated by fluorescence microcopy, and this revealed endosomal entrapment for 12 .     

Innovation and the catalytic process industry-The science and the challenge

The process industry faces new challenges. In particular, environmental objectives call for processes with much higher conversion and better selectivities to minimize the release or removal of products to a degree which would not be economic without considering the environmental objectives. These challenges call for a better understanding of the design basis. The paper analyzes by examples the strength of the “state-of-art” of chemical reactor engineering which as examples formed the basis for progress in ammonia synthesis and in steam reforming. The importance of an integrated approach in process development is illustrated by examples from synthetic gasoline and direct and indirect manufacture of methanol. The new challenges to reactor engineering require more research in a field which has been developed almost to maturity. The better understanding of the micro-kinetics of catalysis has also revealed a complexity which is difficult to describe by the conventional approach. This is in particular true for “ppm reactions” in which one component should be removed down to a ppm level. There is a need to integrate the conventional reactor design models with models describing the fluid mechanics, in particular for reactions carried out with critical mixing (SCR, hydrotreating). Breakthroughs may come from new concepts in combining separation with catalysis and use of transient reactors. This is illustrated by a new solid state alkylation process. In conclusion, chemical engineering science needs more explorative research, if it should not become mature.     

Extraction of heavy metals from soils using biodegradable chelating agents

Metal pollution of soils is widespread across the globe, and the clean up of these soils is a difficulttask. One possible remediation technique is ex-situ soil washing using chelating agents. Ethylenediaminetetraacetic acid (EDTA) is a very effective chelating agent for this purpose but has the disadvantage that it is quite persistent in the environment due to its low biodegradability. The aim of our work was to investigate the biodegradable chelating agents [S,S]-ethylenediaminedisuccinic acid (EDDS), iminodisuccinic acid (IDSA), methylglycine diacetic acid (MGDA), and nitrilotriacetic acid (NTA) as potential alternatives and compare them with EDTA for effectiveness. Kinetic experiments showed for all metals and soils that 24 h was the optimum extraction time. Longer times only gave minor additional benefits for heavy metal extraction but an unwanted increase in iron mobilization. For Cu at pH 7, the order of the extraction efficiency for equimolar ratios of chelating agent to metal was EDDS > NTA> IDSA > MGDA > EDTA and for Zn it was NTA > EDDS > EDTA >MGDA > IDSA. The comparatively low efficiency of EDTA resulted from competition between the heavy metals and co-extracted Ca. For Pb the order of extraction was EDTA > NTA >EDDS due to the much stronger complexation of Pb by EDTA compared to EDDS. At higher concentration of complexing agent, less difference between the agents was found and less pH dependence. There was an increase in heavy metal extraction with decreasing pH, but this was offset by an increase in Ca and Fe extraction. In sequential extractions EDDS extracted metals almost exclusively from the exchangeable, mobile, and Mn-oxide fractions. We conclude that the extraction with EDDS at pH 7 showed the best compromise between extraction efficiency for Cu, Zn, and Pb and loss of Ca and Fe from the soil.     

Adsorption of arsenic from water using activated neutralized red mud

In this paper activated seawater-neutralized red mud, herein referred to as activated Bauxsol (AB), is used as a novel adsorbent for removing inorganic arsenic (As) from water. The adsorption of As onto AB is studied as a function of contact time, particle size, pH, initial As concentration, AB dosage, and temperature. Kinetic data indicate that the process pseudoequilibrates in 3 and 6 h for As(V) (arsenate) and As(III) (arsenite), respectively, and follows a pseudo-first-order rate expression. Within the range tested, the optimal pH for As(V) adsorption is 4.5, and close to 100% removal can be achieved irrespective of the initial As(V) concentration. Desorption of As(V) is greatest at pH 11.6 where a maximum of 40% can be achieved. In contrast, the optimum pH for As(III) removal is 8.5, and the removal efficiency changes with the initial As(III) concentration. The adsorption data fit the Langmuir isotherm and its linearized form well, with thermodynamic data indicating the spontaneous and endothermic nature of the process. The FITEQL (V.4) and PHREEQC (V.2) computer programs are used to predict As(V) adsorption at various pH values (based on diffuse double layer models). The modeling results fit the experimental results very well and indicate that surface complexation modeling is useful in describing the complex AB surface during the adsorption process. This study shows that As(III) needs to be oxidized to As(V) for a favorable removal using AB and that AB can be a very efficient unconventional adsorbent for removing As(V) from water.