39 research outputs found
Compact gasification and synthesis for flexible production of transport fuels and heat
No full textSummary of FLEXCHX and COMSYN webinar
Glycolysis and mixed acid fermentation pathway overlaid with FNR and O<sub>2</sub> regulation.
No full text<p>Pathway map showing the glycolysis and mixed acid fermentation pathway overlaid with FNR ChIP-seq peak occupancy and expression changes <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1003565#pgen.1003565-Neuweger1" target="_blank">[124]</a>. Reactions are represented by arrows connecting metabolites and each operon is represented by a box with three ovals. The first oval of each box indicates the presence (blue) or absence (white) of a FNR ChIP-seq peak upstream of that operon. The color of the second oval indicates the impact of FNR on the expression of the operon (red is FNR repression, while green is FNR activation). The color of the third oval indicates the expression under WT aerobic and anaerobic growth conditions (red is WT aerobic expression, while green is WT anaerobic expression). The blue stars indicate newly identified direct targets of FNR regulation within this pathway.</p
Advances in the techno-economic assessment to identify the ideal plant configuration of a new biomass-to-liquid process
No full text2nd generation biofuels constitute a promising candidate to provide part of the future demand on renewable fuels. Within biomass-to-liquid (BTL) processes synthetic hydrocarbons can be produced via Fischer-Tropsch (FT) synthesis, which meet current fuel requirements. Due to its high similarity to conventional fuels these liquids can be utilized in existing infrastructure. Hence, a potential market launch is only limited by their production costs.
Exactly that is what the EU-project COMSYN (Compact Gasification and Synthesis process for Transport Fuels) is aiming at. With its process concept the project can reach a significant reduction of the biofuel production costs by up to 35 % compared to alternative fuels. To achieve this ambitious goal, the project pursues two major approaches:
- Firstly, combining multiple high-efficient process steps, such as a new gasification concept (developed by VTT) together with a hot gas filtration and a FT-microreactor (developed by INERATEC).
- Secondly, investigating decentralized production sites of FT-products in combination with a centralized fuel upgrading concept at existing refineries.
To find the optimal process configuration regarding the site specific boundary conditions a flowsheet model has been set up based on experimental data received during the project's test runs at VTT. Furthermore, the existing DLR in-house software TEPET (Albrecht et al ) is extended by an automated utility and heat integration to receive comparable economic results during a simultaneous variation of technical and economical process parameters.
The influence of site factors on the optimal process design will be presented, which allows the definition of required boundary conditions and a preliminary site selection for future stand-alone or integrated biomass-to-liquid processes
Life cycle assessment of a new biomass-to-liquid process comparing different process configurations
No full text2nd generation biofuels are promising alternatives for their fossil counter parts when it comes to greenhouse gasreductions. Therefore, a novel biomass-to-liquid process concept is investigated for its greenhouse gas savings potential while also considering other environmental impacts. The results compare three process configurations, two biomass feedstocks and will elaborate the benefits of process simulation based life cylce assessment
Compact Gasification and Synthesis Process for Transport Fuels - H2020 Project Presentation COMSYN
No full textThe investigation of 2nd generation biofuels has gained in importance in recent years. Mostly because they hold the potential of reducing the greenhouse gas emissions of the transport sector on a larger scale. Inter alia, these alternative fuels can be produced via a Biomass-to-Liquid (BtL) process based on Fischer-Tropsch (FT) synthesis. The produced synthetic hydrocarbons can directly be used as drop-in fuels in the existing infrastructure. Though, the market launch of this technology depends strongly on its economic feasibility.
The EU-project COMSYN (Compact Gasification and Synthesis process for Transport Fuels) aims to scratch at this economic limitation by combining a number of compact and highly efficient process steps. Besides the new gasification concept (developed by VTT) and the subsequent hot gas filtration, a FT-microreactor (developed from INERATEC) is attempting to achieve the ambiguous goal of reducing the biofuel production costs by up to 35 % compared to alternative routes.
Within the project the DLR is assigned with the techno-economic assessment and optimization of the process concept. The necessary flowsheet model is set up in Aspen Plus. Various different process setups are evaluated technically, economically as well as ecologically with the DLR in-house software tool TEPET
Methodische Fortschritte zur techno-ökonomischen Analyse der Kraftstofferzeugung am Beispiel eines Biomass-to-Liquid Prozesses
No full textUm trotz des stetigen, jährlichen Wachstums von etwa 4,5 %, auch in der Luftfahrt den CO2-Ausstoß verringern zu können, sind auf lange Sicht sehr einschneidende Veränderungen am aktuellen Verfahrenskonzept erforderlich. Zum einen kommt dabei ein radikaler Technologiewechsel, wie z.B. 'elektrisches Fliegen' in Frage, zum anderen die Erzeugung des benötigten Treibstoffs auf Basis von erneuerbaren Energien und Rohstoffen.
Durch die simultane Berechnung der technischen und ökonomischen Prozessdaten können die einzelnen Prozesse sowohl technisch als auch ökonomisch optimiert werden. Außerdem werden durch Variation von technischen und ökonomischen Randbedingungen, Prozesssensitivitäten festgestellt und etwaige kritische Prozessschritte identifiziert. Im Rahmen des Vortrages wird auf die Weiterentwicklungen des DLR-Tools TEPET1 (Techno-Economic Process Evaluation Tool) und dessen neu dazugewonnene Analysemethoden eingegangen. Durch Kopplung von TEPET mit Fließbildsimulationen können transparent und zeiteffizient Verfahren zur Kraftstofferzeugung nach technischen und ökonomischen Aspekten studiert werden. Zum Beispiel können mittels automatisierter Pinch-Analyse energetische Wirkungsgrade technisch optimiert und z.B. der Bedarf für Kühlwasser oder Zugewinn durch Dampferzeugung quantifiziert werden.
Am Fallbeispiel des EU-Projektes COMSYN werden die Möglichkeiten der automatisierten Prozessanalyse aufgezeigt. In diesem Projekt werden Kraftstoffe über Biomassevergasung und anschließende Fischer-Tropsch Synthese dezentral erzeugt (Abbildung 1). Mit einer bisherigen Projektlaufzeit von zwei Jahren, kann die Simulation auch auf, im Projekt erhobene, experimentelle Daten zurückgreifen. Die Arbeiten am DLR fokussieren sich dabei unter anderem auf die technische Prozessoptimierung durch verbesserte stoffliche Verschaltung, Prozessführung und/oder Wärmenutzung. Die Ergebnisse der laufenden Evaluation werden vorgestellt und diskutiert
New biomass-to-liquid process from wood chips to motor fuels
No full text2nd generation biofuels gained more importance in recent years since they enable greenhouse gas emission reductions in the transport sector on a larger scale. One promising way to produce alternative fuels is the Biomass-to-Liquid (BtL) process with the Fischer-Tropsch synthesis which produces synthetic hydrocarbons that could directly be used as liquid fuels in an existing infrastructure. One major issue of this process is the production cost. Within the European COMSYN project (Compact Gasification and Synthesis process for Transport Fuels), a new BtL process concept is developed that aims to reduce biofuel production cost up to 35 % compared to alternative routes.
The novel production concept is based on double integration benefits. The primary biomass conversion to FT product is realized in medium scale units which are heat integrated to industrial sites or district heating networks and are located close to biomass re-sources. The main product of the initial biomass conversion plants of COMSYN is liquid FT crude, solid FT-wax or hydro-treated middle distillate from various biomass sources and residue-derived feedstocks. The final conversion of FT-product to transportation fuels, primarily diesel, is realized at refinery sites, using several integration benefits and product portfolio adaptation to specific market needs (diesel, motor gasoline, kerosene components or propylene and other petrochemicals). The target capacity range of the primary conversion plant is 30 – 150 MW (feedstock input) that typically produce 10-50 kt/a FT product by 55 – 60 % energy efficiency (based on LHV). By utilizing the generated heat the total efficiency of the plant can be increased to 75 – 80 %, which is comparable to highly efficient combined heat and power production plants. To determine the feasibility of this process concept, a techno-economic assessment of the process concepts is carried out and its results are presented in this study. This includes steady-state process simulation in Aspen Plus® and standardized techno economic process evaluation for comprehensible production cost estimation. Different process options like the refinery upgrading of light diesel fraction via blending with existing hydrodesulfurization feedstock and further co-processing at hydrotreating or separate isomerization will be discussed
Runaway Growth During Planet Formation: Explaining the Size Distribution of Large Kuiper Belt Objects
No full textRunaway growth is an important stage in planet formation during which large protoplanets form, while most of the initial mass remains in small planetesimals. The amount of mass converted into large protoplanets and their resulting size distribution are not well understood. Here, we use analytic work, that we confirm by coagulation simulations, to describe runaway growth and the corresponding evolution of the velocity dispersion. We find that runaway growth proceeds as follows. Initially, all the mass resides in small planetesimals, with mass surface density σ, and large protoplanets start to form by accreting small planetesimals. This growth continues until growth by merging large protoplanets becomes comparable to growth by planetesimal accretion. This condition sets in when Σ/σ ~ α^(3/4) ~ 10^(–3), where Σ is the mass surface density in protoplanets in a given logarithmic mass interval and α is the ratio of the size of a body to its Hill radius. From then on, protoplanetary growth and the evolution of the velocity dispersion become self-similar and Σ remains roughly constant, since an increase in Σ by accretion of small planetesimals is balanced by a decrease due to merging with large protoplanets. We show that this growth leads to a protoplanet size distribution given by N(>R) α R ^(–3), where N(>R) is the number of objects with radii greater than R (i.e., a differential power-law index of 4). Since only the largest bodies grow significantly during runaway growth, Σ and thereby the size distribution are preserved. We apply our results to the Kuiper Belt, which is a relic of runaway growth where planet formation never proceeded to completion. Our results successfully match the observed Kuiper Belt size distribution, they illuminate the physical processes that shaped it and explain the total mass that is present in large Kuiper Belt objects (KBOs) today. This work suggests that the current mass in large KBOs is primordial and that it has not been significantly depleted. We also predict a maximum mass ratio for Kuiper Belt binaries that formed by dynamical processes of α^(–1/4) ~ 10, which explains the observed clustering in binary companion sizes that is seen in the cold classical belt. Finally, our results also apply to growth in debris disks, as long as frequent planetesimal-planetesimal collisions are not important during the growth
Techno-economic evaluation of a new Biomass-to-Liquid process concept for reduced biofuel production cost
No full textIntroduction
2nd generation biofuels have gained in importance in recent years, since they enable greenhouse gas emission reductions in the transport sector on a larger scale. One promising way to produce alternative fuels is the Biomass-to-Liquid (BtL) process based on Fischer-Tropsch (FT) synthesis, which produces synthetic hydrocarbons that could directly be used as drop-in fuels in the existing infrastructure. One major issue defining the feasibility of this process is the fuel production cost.
COMSYN Project
Within the European COMSYN project (Compact Gasification and Synthesis process for Transport Fuels), a new BtL process concept is developed that aims to reduce biofuel production cost by up to 35 % compared to alternative routes. To achieve these cost reductions experimental data for a new gasification concept (developed from VTT) as well as a highly efficient FT reactor (developed from INERATEC) are implemented into various flowsheet models. To determine the feasibility of these process concepts, a techno-economic assessment is carried out. The results of the preliminary study are presented. So far three process concepts with different configurations have been developed: one base case with steam gasification, autothermal reforming and once-through Fischer-Tropsch synthesis, a second case with CO2 removal prior to the FT reactor (to improve kinetics) and a third case with an externally heated reformer (no air supply, to improve efficiency). Additionally, one-stage vs. two-stage Fischer-Tropsch synthesis is analyzed. Each configuration will be heat integrated, evaluated and compared, to determine the key processes which enable highest energy efficiency and economic cost saving potentials
