• Energy Research
• 6. Clean water close
• Energy Procedia close

AbstractWe measured dissolved inorganic carbon (DIC) stable isotopes (813CDIC in ‰) of brine from an observation well within the first aquifer above the CO2 reservoir at the Ketzin pilot site, to test weather these can detect potential CO2 leakage. The monitoring revealed that DIC concentrations and 813CDIC values were masked by the used high alkaline drilling mud, even eight months after well development. However, subsequent changes in 813CDIC and DIC from of -27 ‰ and 165mg L−1 to -23.5 ‰ and 116mg L−1 reflect most likely a shift towards pristine values of the aquifer.

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Abstract Solid waste is generally disposed as landfills due to the simplest and cheapest disposal procedures, as compared to incineration and composting. High amount of organic material, particularly food waste (approximately 45%) can be found in the solid waste in this country. Being the most practical solution, landfilling however does not seem to be the most rational approach considering its byproducts, i.e. methane gas and fluidic leachate which could cause high contamination to the air and water. Lately, researchers have placed emphasis in food waste as its high organic content has a great potential of being turned into ethanol or a source of biofuel. Bioethanol is one of the most promising alternative energy sources to diminish the dependence on fossil fuel. It could be produced by the fermentation of sugar-rich crops and food wastes. This paper investigates the use of an electrostatic separator to segregate the food waste and non-food waste from the waste mixtures. Electrostatic separator is capable of separating particles based on the conductivities of the constituent components. It is widely used to sort out particles with high conductivities from those with relatively low conductivities, e.g. to recover conductors from non-conducting mixtures, serving as an environmentally friendly way for recycling without negative impact to the surrounding. In this study, influences of various volumetric ratios of non-food waste, i.e. plastic and glass, on recovery process of food waste would be studied. The findings contribute to reduction of landfill size with rare existence of organic matters in landfills. In addition to the environmental protection, the proposed food waste recovery process would enable the Waste-to-Energy (WtE) development and economical growth from biogas and potential biomass energy generation.

Abstract This paper presents an integrated numerical framework to co-optimize EOR and CO 2 storage performance in the Farnsworth field unit (FWU), Ochiltree County, Texas. The framework includes a field-scale compositional reservoir flow model, an uncertainty quantification model and a neural network optimization process. The reservoir flow model has been constructed based on the field geophysical, geological, and engineering data. A laboratory fluid analysis was tuned to an equation of state and subsequently used to predict the thermodynamic minimum miscible pressure (MMP). A history match of primary and secondary recovery processes was conducted to estimate the reservoir and multiphase flow parameters as the baseline case for analyzing the effect of recycling produced gas, infill drilling and water alternating gas (WAG) cycles on oil recovery and CO 2 storage. A multi-objective optimization model was defined for maximizing both oil recovery and CO 2 storage. The uncertainty quantification model comprising the Latin Hypercube sampling, Monte Carlo simulation, and sensitivity analysis, was used to study the effects of uncertain variables on the defined objective functions. Uncertain variables such as bottom hole injection pressure, WAG cycle, injection and production group rates, and gas-oil ratio among others were selected. The most significant variables were selected as control variables to be used for the optimization process. A neural network optimization algorithm was utilized to optimize the objective function both with and without geological uncertainty. The vertical permeability anisotropy (Kv/Kh) was selected as one of the uncertain parameters in the optimization process. The simulation results were compared to a scenario baseline case that predicted CO 2 storage of 74%. The results showed an improved approach for optimizing oil recovery and CO 2 storage in the FWU. The optimization process predicted more than 94% of CO 2 storage and most importantly about 28% of incremental oil recovery. The sensitivity analysis reduced the number of control variables to decrease computational time. A risk aversion factor was used to represent results at various confidence levels to assist management in the decision-making process. The defined objective functions were proved to be a robust approach to co-optimize oil recovery and CO 2 storage. The Farnsworth CO 2 project will serve as a benchmark for future CO 2 –EOR or CCUS projects in the Anadarko basin or geologically similar basins throughout the world.

AbstractThe microorganisms growth kinetics is determined by the physical and chemical characteristics of the environment in which they find themselves and multiply; It is therefore essential to understand the effect of these environmental factors to master cell multiplication and hence the pollution biodegradation. Respirometry has been used in recent years in the laboratory as an assessment technique of microbial activity and an effect detector of the contamination (presence of toxic, stress, increase or decrease in pH, temperature variation .) on bacterial respiration and hence on the biological waste water treatment plant. In this study respirometry has been used as a relatively quick and efficient means to detect the effect of the presence of a salt of up to 5g/l (low salt stress) on the degradation of carbon and nitrogen pollution and on bacterial floc aggregation.

In order to reduce the required volume for thermal energy storage, a finned plate latent heat thermal energy storage system for domestic applications is presented in this paper. This innovative design allows the exchanging of energy between water and the RT60, used as the phase change material. The simulation of that system is covered by a validated mathematical model. The model, based on a simplified numerical approach, is used for the optimal design of the final prototype, which is compared with a conventional 500 l hot water tank usually integrated in domestic heating and domestic hot water applications. It is obtained that the resulting design is in the order of one half of the water tank volume, resulting in a more compact configuration which can be easily integrated in the space. This solution will bring a great opportunity for thermal storage especially in those applications where there is a lack of available space, as it is the case of residential flats.

AbstractBanana peel and biodiesel derived glycerol are one of the most abundant agricultural waste in Southeast Asian countries. This current research demonstrated potential biomethane production from co-digestion of agricultural wastes under mesophilic fermentation. The wastes used include (1) banana peel (varying total solids in the range 2.5-10% w/v) and (2) Banana peel mixed with pure or waste glycerol. All treatments were setup in duplicate in 0.5 L batch reacotr. Gas and liquid samples were collected every 12 and 24 hr, respectively. Maximum methane production potential and yield were 181 mL and 188mL g-1 TS at 7.5% banana peel. The maximum methane production potential and yield of 7.5% banana peel mixed with 7.5 g L-1 pure glycerol (in the presence of buffer) were 467 mL and 151 mL g-1 COD, respectively, while those of 7.5% banana peel mixed with 7.5 g L-1 waste glycerol (in the presence of buffer) were 652 mL and 281 mL g-1 COD, respectively. Small amount of VFAs and ethanol was accumulated in the reactor content. The current findings indicate the potential use of glycerol waste as a co-substrate in biomethane production.

AbstractIn this study, a supported amine sorbent was prepared by impregnating silica particles (150∼300 um) with methanol solution of polyethylenimine (PEI with the molecular weight of 600 g· mol-1) to immobilize amine into the pores of the silica support. The optimal CO2 capacity of the PEI-based sorbent was as high as 2.0 mmol· g-1. During the adsorption and desorption of 10 times, the CO2 capacity of the PEI-based sorbents kept stable, indicating PEI-based sorbents had excellent thermal stability.Dual bubbling fluidized bed reactors were constructed to demonstrate the process feasibility of continuous CO2 capture from flue gases with supported amine sorbent. Long-term stable operation and continuous solids circulation between the two reactors was achieved, and the CO2 in the flue gases was continuously captured by the supported amine sorbent. Experimental results indicated that ∼84.4% CO2 capture efficiency could be achieved in the absence of water. The low regeneration temperature, high adsorption temperature and the short sorbent residence time in absorber were considered to be the limiting factors affecting the working capacity of sorbents. Water vapour could promote the adsorption process and increase the CO2 capture efficiency to approximately 90.6∼97%. The effect of water vapour on reaction mechanism between CO2 and various amine groups was discussed.