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Abstract This paper characterized the wood pellet and torrefied wood pellet fuel as compared to coal for 100 MW co-firing power generation plant. There were five experiments to characterise the chemical and physical properties of coal, wood pellet and torrefied wood pellet namely moisture analysis, Thermo gravimetric Analyser (TGA), Bomb Calorimeter, Organic Elemental Analyser and Scanning Electron Microscope (SEM). The moisture analysis result from moisture analyser and TGA shows that the moisture content of torrefied wood pellet is lower than wood pellet at 6.760% and 3.629%. Moreover, the volatile matter, hydrogen and nitrogen content of torrefied wood pellet is lower than wood pellet at 65.20%, 5.993% and 0.4078% correspondingly. The calorific value, fixed carbon content, ash and sulphur also increase in torrefied wood pellet at 20.68 MJ/kg, 28.85%, 2.321% and 0.1656% respectively. In general, torrefaction improve the fuel properties of wood pellet similar to coal. The 100 MW direct co-firing power plant provides less capital investment, operation and maintenance cost for low rate co-firing ratio. However, there is economic challenges for high rate co-firing substation of torrefied wood pellets.

AbstractA metal-organic framework, UiO-66, has been evaluated as adsorbent in a post-combustion vacuum swing adsorption (VSA) process. Equilibrium isotherms of the most relevant gases (CO2 and N2) as well as breakthrough curves measured using synthetic flue gas containing 15 mol% CO2 without and with 9 mol% water vapor are reported. Based on the breakthrough data, a six step one-column VSA cycle is designed and the effects of adsorption and CO2 rinse times used on the CO2 recovery and CO2 purity are examined. With the chosen process configuration and cycle design CO2 purities around 60% and CO2 recoveries up to 70% are achieved. 50 cycle adsorption-desorption experiments show that the cyclic CO2 capacity is reduced by approximately 25% in the presence of water vapor. No reduction in cyclic capacity is observed with increased cycle number; there is rather a slight increase in cyclic capacity with cycle number indicating that a cyclic steady state still not has been reached after 50 cycles.

Abstract The work discusses a problem of harvesting and upgrading of ultra-low grade heat with thermochemical energy storage technology for space and domestic water heating in residential area. The laboratory scale prototype, operating on the principle of an open packed bed sorption reactor and using moist air as a heat/mass transfer fluid, is experimented. The range of experimental air temperature was set to 17–40 °C, which corresponds to the typical range of domestic waste thermal energy. The tested sorbent was a salt-in-matrix composite material composed of a silica gel containing 43 wt.% of calcium chloride (CaCl2) salt. Hygrothermal behavior and energy performances of the prototype control volume filled with 245 g of material, representing the reactive front of a thermal wave, were analyzed at constant inlet hydration conditions (water vapor pressure of 12.5 mbar). The average temperature lift was recorded as 9–13 °C, representing the amplification of a supplied heat on 23% – 75% depending on the inlet temperature. The average specific thermal power inside the material bed was measured to be 168–267 W kg-1. The apparent energy density, based on the prototype control volume, ranged between 1.0 and 1.6 GJ m-3. Taking into account the heat of water vaporization, the coefficient of performance of the process was determined to be 0.96–1.57.

Swirl combustors have proven as effective flame stabilisers over a wide range of operation conditions thanks to the formation of well-known swirl coherent structures. However, employment of swirl combustors to work on lean premixed combustion modes while introducing alternative fuels such as high hydrogen blends result in many combustion instabilities. Under these conditions, flame flashback has been considered as one of the major instability problems that have the potential of causing considerable damages of the combustion systems hardware in addition to the significant increase in pollutant levels. Combustion Induced Vortex Breakdown (CIVB) is considered a very particular mode of flashback mechanism in swirling flows as this type of flashback occurs even when the fresh mixture’s velocity is higher than the flame speed, consequence of the interaction between swirl structures and swirl burner geometries. Improvements of burner geometries and manipulation of swirl flows can produce good resistance against this type of flashback. However, increase flame flashback resistance against CIVB can lead to an increase in the propensity of another flashback mechanism, Boundary Layer Flashback (BLF). Thus this paper presents an experimental and numerical approach that allows the increase in CIVB resistance by using diffusive air injection and simultaneously avoid BLF by changing the wall boundary layer characteristics using microsurface grids as a liner for the nozzle wall. Results show that using those two techniques together has promising potentials regarding wider stable operation for swirl combustors, enabling them to burn a great variety of fuel blends safely.

AbstractThe effect of heat distribution or inter-heating on the total energy requirement for CO2 stripping is investigated. Here we look at retrofit design of an existing column. It means the height and diameter of the stripper is given. The results show that inter-heating can have both negative and positive effects on the total energy requirement. If only one heat source at constant temperature exist, the inter-heating will increase the total energy requirement. If there are other heat sources at different temperatures, inter-heating can be beneficial. It depends on the energy price of the different heat sources and the temperature profile of the column. If there are some hot streams available to utilize the heat in the inter-heater, the total energy requirement will decrease. As a case study utilizing heat from lean amine in the inter-heater is investigated. The simulation results show a saving up to 6.4 and 11.3 percent by one and two inter–heater respectively

AbstractDuring the last decades significant effort has been put into research on the social, economical, political and technical issues related to large scale deployment of Carbon Capture and Storage (CCS). A complete CCS cycle requires safe, reliable and cost efficient solutions for transmission of CO2 from the capturing facility to the location of permanent storage. The current initiative originates from DNV’s long engagement in developing standards and guidelines for offshore pipelines and an identified need to specifically address the technical challenges related to transmission of CO2 with associated contaminants. The guideline will be based on a comprehensive literature review and gathering of experience from existing (both onshore and offshore) CO2 pipeline operators. Available pipeline codes, standards, guidelines and regulations combined with the latest available research and technical developments is set as the point of departure for this guideline development. Issues related to pipeline design, commissioning and operation as well as re-qualification/conversion of existing pipelines for transmission of CO2 will be addressed. The guideline is being developed as a joint industry project and is scheduled for delivery by end of July 2009. After completion of the JIP, the guideline will be converted into a public available Recommended Practice (RP) by Det Norske Veritas (DNV). The guideline will give “how to?” answers for safe, reliable and cost-effective transmission of CO2 in pipelines. This paper addresses main technical issues one need to manage.

Power generation from the renewable energy sources is usually intermittent and uncontrollable which challenges the grid frequency stability. The smart control of loads is an effective means to mitigate the challenge. A decentralized control of heating loads -- industrial melting pots (MPs), was developed which dynamically changes the power consumption of loads in response to grid frequency. A thermodynamic model of MPs was developed and validated based on site measurements by Open Energi. An aggregation of MP models with the control was integrated with a simplified Great Britain power system model. Results showed that MPs are able to provide frequency response in a way similar to generators, which provide a means for the system operator to quantify the benefits of demand response.

Solar concepts show potentially an improved cost-performance (energy) ratio when applied as the integrated parts of building renovations. This paper reported a compact solar thermal facade (STF) module with the internally extruded flow channel suiting for solar renovation concept in buildings. A few of impact factors were considered for the parametric study in order to optimize the STF's configuration for various applications through the validated simulation model. The overall research results are expected to be useful for further improvement in the thermal performance of solar renovation measures.

“Off-the-shelf” devices have attracted much consideration lately, especially in emulsions production in droplet-based microfluidics. While many simple and cost-effective designs have been proposed and demonstrated, the functionability of these purported simple devices has been questioned, especially in emulsions generation for commercial scale. In this work, a simple needle-based device was used in the production of functional core-shell microcapsules of uniform sizes, typically in the range of 600 to 720 µm, and shell thickness of 20 to 110 µm, and C.V of 0.97 to 3.0%. These core-shell microcapsules are a new form of carbon capture materials, with carbon solvent encapsulated in thin polymeric shell. The microcapsules synthesized were subjected to absorption-desorption tests. This work has successfully demonstrated the use of off-the-shelf microdevice and its reliability for the production of functional microcapsules.