I. Dafnomilis
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11 records found
1
This work uses pilot examples of CO2 enhanced oil recovery to analyze whether and under which circumstances it is exergetically favorable to sequester CO2 through enhanced oil recovery. We find that the net storage efficiency (ratio between the stored and captured CO2) of the carbon capture and storage (CCS)-only projects is maximally 6–56% depending on the fuel used in the power plants. With the current state of technology, the CCS process will re-emit a minimum of 0.43–0.94 kg of CO2 per kg of CO2 stored. From thermodynamics point of view, CO2 enhanced oil recovery (EOR) with CCS option is not sustainable, i.e., during the life cycle of the process more energy is consumed than the energy produced from oil. For the CCS to be efficient in reducing CO2 levels (1) the exergetic cost of CO2 separation from flue gas should be reduced, and/or (2) the capture process should not lead to additional carbon emission. Furthermore, we find that the exergy recovery factor of CO2-EOR depends on the CO2 utilization factor, which is currently in the low range of 2–4 bbl/tCO2 based on the field data. Exergetically, CO2 EOR with storage option produces 30–40% less exergy compared to conventional CO2 enhanced oil recovery projects with CO2 supplied from natural sources; however, this leads to storage of >400 kg of extra CO2 per barrel of oil produced.
Port terminals on floating modular platforms are a conceivable solution for the problem of limited space and water depths restrictions of ports in estuary regions. A design of a dedicated Transport&Logistic hub has been developed in the scope of the Horizon 2020 project Space@Sea. This paper addresses dedicated options of waterborne hinterland transports and discusses opportunities for bypassing onshore terminals by means of river-sea or sea-going inland vessels. A tailored simulation method for ship operations utilises a specific cost model and is applied to derived demand scenarios. Cargo flow statistics of an onshore port have been projected onto the hub to identify relevant waterborne transports to the hinterland. Three different vessel types are implemented, whereas inland vessels are considered with two different sizes. A comparison of round trip durations and transport costs per transported container between a floating terminal and a relevant hinterland port pointed out, that a non-stop connection with sea-going inland vessels is the economically favourable solution. A feeder vessel is the faster solution in coastal waters but it can not compensate the time saved by omitted terminal visits on a direct hinterland connection.
Green Bulk Terminals
A Strategic Level Approach to Solid Biomass Terminal Design
This paper investigates the optimization of biomass terminal equipment deployment. A mixed integer linear programming model is developed and applied to minimize the terminal's investment and operational costs related to dedicated and partially used or shared equipment between a terminal's operational steps. The results minimize annual terminal costs through equipment and infrastructure selection and utilization. Tipping points where the technology and equipment type or size change in relation to the increasing throughput are highlighted. Analytical results emphasize the importance of storage costs in all biomass terminals, as well as the critical influence of operational costs in larger facilities.
Wood pellet imports are expected to increase in the European Union and Southeast Asia by 2030, considering pellets are the main feedstock used for co-firing in power plants throughout these regions. Due to the material's physical and biological properties, the equipment at an import terminal need to be different than what is used for other bulk material. Thus, most of the common problems associated with handling can be avoided. Dust emission and explosions, degradation in storage, self-heating and ignition are important criteria when designing a wood pellet port terminal, and can greatly affect associated logistics. Despite some availability of data concerning the handling of pellets, there is a lack of insight into the equipment and operations of actual handling facilities. A detailed literature research was performed in order to ascertain the level of the scientific background on the subject. Subsequently, visits in pellet facilities in the Netherlands and in-depth interviews with representatives were conducted and serve as a means of gaining an overview of current industry practices and equipment used for the handling of wood pellets. The main objective of this work is to evaluate the state-of-the-art in wood pellet handling in import terminals. This way, future bottlenecks can be identified and actions needed to overcome them can be determined. The analysis performed shows that while wood pellet terminals might be able to cope with the low amounts being traded currently, a reexamination and redesign of terminal facilities to accommodate the increased volumes will probably be required by 2030.
Assessing the representativeness of durability tests for wood pellets by DEM Simulation
Comparing conditions in a durability test with transfer chutes
This paper assesses the representativeness of the tumbling can test in relation to transfer chutes, by comparing forces acting on wood pellets in durability tests and in transfer chutes using DEM. The study also incorporates effects such as shape and size variations. The results showed that the tumbling can test underestimates compressive and tangential forces. Since the tested material is subject to milder conditions than in reality, it can be concluded that this test is not representative for the conditions in the supply chain of wood pellets. ...
This paper assesses the representativeness of the tumbling can test in relation to transfer chutes, by comparing forces acting on wood pellets in durability tests and in transfer chutes using DEM. The study also incorporates effects such as shape and size variations. The results showed that the tumbling can test underestimates compressive and tangential forces. Since the tested material is subject to milder conditions than in reality, it can be concluded that this test is not representative for the conditions in the supply chain of wood pellets.
Review of solid and liquid biofuel demand and supply in Northwest Europe towards 2030
A comparison of national and regional projections
Biomass is the largest source of renewable energy carrier in the European Union (EU) contributing to over 60% of renewable energy, with the majority of supply coming from domestic sources. However, an increasing significant amount of feedstock is imported, either due to domestic undersupply or higher production costs within the country. This article provides an up-to-date view of bioenergy supply, demand and trade in Northwest Europe to 2030. Projections of the energy system model Green-X are compared to recent national studies concerning bioenergy imports. The results show that there is a sizeable gap of the projection bandwidths after the 2020 horizon. Projections might under- or overestimate biomass potential in certain cases, depending on whether they are derived from national reports or regional models, whether future policy developments were taken into account etc. The ranges of biomass consumption are multiple times apart by 2020 already, and the gap increases by 2030. Total biomass imports in the region can range between 14 and 44.3 Mt by 2020 and 18.5–60 Mt by 2030.
The objective of this paper is to assess the representativeness of the socalled
tumbling can test in relation to handling conditions in the supply chain for wood pellets. Therefore forces acting on particles in the tumbling can on the one side and during loading and discharging of a flat bottom silo on the other side were compared by Discrete Element Model simulations.
It can be concluded that in the presented cases the tumbling can underestimates the handling conditions of the material in reality. ...
The objective of this paper is to assess the representativeness of the socalled
tumbling can test in relation to handling conditions in the supply chain for wood pellets. Therefore forces acting on particles in the tumbling can on the one side and during loading and discharging of a flat bottom silo on the other side were compared by Discrete Element Model simulations.
It can be concluded that in the presented cases the tumbling can underestimates the handling conditions of the material in reality.
Torrefied biomass and its handling aspects
A state-of-the-art review