Abstract

The purpose of this article is to study the impact of oxyfuel combustion applied to a rotary kiln producing lime. Aspects of interest are product quality, energy efficiency, stack gas composition, carbon dioxide emissions, and possible benefits related to carbon dioxide capture. The method used is based on multicomponent chemical equilibrium calculations to predict process conditions. A generic model of a rotary kiln for lime production was validated against operational data and literature. This predicting simulation tool is used to calculate chemical compositions for different recirculation cases. The results show that an oxyfuel process could produce a high-quality lime product. The new process would operate at a lower specific energy consumption thus having also a reduced specific carbon dioxide emission per ton of product ratio. Through some processing, the stack gas from the new process could be suitable for carbon dioxide transport and storage or utilization. The main conclusion of this paper is that lime production with an oxyfuel process is feasible but still needs further study.

Abstract

Within the EU-funded GeoCapacity project an economic analysis computer tool is developed for the evaluation of carbon capture and storage (CCS) systems comprising of a set of multiple sources of CO2 and storage locations. As a part of that tool, an algorithm has been developed to create low-cost pipeline networks to connect sources of CO2 and storage reservoirs. The main features of the algorithm are: •Input parameters are the size and location of CO2 sources and storage reservoirs•The algorithm determines the trajectory, capacity and costs of the connecting pipes•If necessary junctions are created, i.e. connections are created between sources and pipelines and/or storage locations and pipelines•The algorithm has a step wise approach. The pipeline network is built-up by successively adding a pipe in each step, until all sources are connected to storage reservoirs•In each step all possible combinations are examined and the one with the lowest costs is added to the system•The pipe costs have a non linear relation with the flow rate•Cost ranges for pipeline network are presented reflecting uncertainties in data of supply of CO2 from sources as well in storage capacity of sinks. © 2009 Elsevier Ltd. All rights reserved.

Abstract

International audience; The development of an homogeneous relaxation flow model for simulating the discharge behaviour following the full bore rupture of dense phase CO2 pipelines is presented. Delayed liquid-vapour transition during the decompression process is accounted for using an empirically derived equation for the relaxation time to thermodynamic equilibrium. The flow model's robustness is successfully demonstrated based on a series of hypothetical shock tube tests. Model validation on the other hand is performed by comparison of the predictions against experimental data obtained for the full bore rupture of realistic scale CO2 pipelines. Within the ranges investigated, it is found that although delayed phase transition effects have negligible impact on the pipeline decompression rate, ignoring such phenomena results in underestimating the transient discharge rate. This is important since the latter governs the minimum safety distances to CO2 pipelines and emergency response planning in the unlikely event of pipeline failure.