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Oss, Netherlands

Turkin A.A.,National Science Center Kharkov Institute of Physics and Technology | Dutka M.,University of Groningen | Vainchtein D.,University of Groningen | Gersen S.,Nederland BV | And 6 more authors.
Applied Energy

Experimental results are presented on silica deposition in a typical domestic heat exchanger during combustion of siloxane-containing gas as a model of biogas that is produced naturally during the anaerobic degradation of organic material in landfills and waste water treatment plants. A model of silica deposition is developed. The main objective is to demonstrate that the mass flux of silica to heat exchanger surfaces is not sensitive to details of particle coagulation process and particle size distribution. It is shown that the deposition flux of silica depends linearly on siloxane concentration in input air/gas mixture. © 2013 Elsevier Ltd. Source

Smirnov B.M.,RAS Joint Institute for High Temperatures | Dutka M.,University of Groningen | Van Essen V.M.,Nederland BV | Gersen S.,Nederland BV | And 6 more authors.

Transmission electron microscopy (TEM) measurements and theoretical analysis are combined to construct the physical picture of formation of SiO 2 fractal aggregates in a methane/hexamethyldisiloxane/air atmospheric pressure flame. The formation of SiO 2 fractal aggregates is described as a multistage process. The first stage is combustion of fuel in a narrow flame front region with formation of main combustion products including SiO 2 molecules. Further downstream SiO 2 molecules join in liquid nanoclusters. After cooling combustion products due to heat losses to surroundings, the nanoclusters become solid in a cold flame region and join in fractal aggregates there. Along with growth of fractal aggregates, the restructuring process proceeds in a cold flame region that leads to the decrease of the fractal dimension of fractal aggregates. The measured parameters of fractal aggregates are in accord with those followed from theoretical models. © Copyright EPLA, 2012. Source

Leeuwenburgh O.,TNO | Neele F.,TNO | Hofstee C.,TNO | Weijermans P.-J.,Nederland BV | And 5 more authors.
Energy Procedia

Most of the gas fields in The Netherlands are approaching the end of their production. Within two decades, the production in the majority of offshore gas fields will have ceased. The preparation of the fields for any end-of-field-life measures to extend their lifetime and increase production needs to start as soon as possible. One such measure is Enhanced Gas Recovery (EGR), which consists of injecting gas (CO2 or N2) to drive out the gas that remains after conventional production. This paper presents the results of a first study into the feasibility of EGR for two Dutch offshore fields. Injection scenarios (volumes, choice of injection wells, timing of the start of injection) were defined in close cooperation with the operators of these fields. The results suggest that the potential for EGR in these two fields is limited to about 1% of additional gas and condensate production. The highest recovery increases were obtained for EGR scenarios in which gas injection started after the end of regular production. The results strongly depend on the drive gas concentration limits in the produced gas, with higher tolerances leading to higher recoveries. Furthermore, detailed analysis of the EGR simulations suggest that some optimization of choice of injection wells, or even infill well placement, may lead to further increases. This will have to be further investigated. For the two cases considered, the additional gas production amounts to about 50% to 60% of the injected drive gas volume with little or no difference between the use of N2 or CO2. The amount of stored CO2 at end of life of the two studied fields is about 0.4 Mt. The rather modest increase in ultimate recovery may be too little to justify investment costs for most of the smaller fields, but may be economically interesting for some of the larger fields. © 2014 The Authors. Published by Elsevier Ltd. Source

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