Novel secure carbon sequestration methods

将研究两种迄今尚未考虑用于大规模碳封存的新技术：浆液注入（SI）和二氧化碳富集气体注入。 SI是富C固体（石油焦、生物固体.）变成沉积物; C作为固体被永久隔离，注入液体是废水，并且对于生物固体S1，产生可回收的CH 4，并且来自生物分解的CO2溶解在地层水中。 研究问题包括模拟SI，生物固体的分解速率和产品，溶解行为在地层水中和色谱产生的气体分离，因为不同的溶解度。 生物固体SI的主要优点是废水和固体共处置，同时以固体和溶解形式安全地螯合碳，产生CH 4，以及共处置其他废物流的能力。SI也可以在城市规模（50，000人口）实施。 富CO2气体注入（在部分膜富集之后）促进快速溶解，降低压缩成本，并降低纯超临界CO2放置的高成本和严重逃逸危险。 通过最大化原位交换表面积、保持高浓度梯度以及共同注入废水和富含CO2的气体以最大化混合，可以实现足够的溶解速率。 研究课题包括共注入和原位吸附中的交换率研究（设想水平威尔斯井），理解并最大化密度驱动的对流混合原位以维持高浓度梯度，浮力驱动的分散的作用，CO2和N2的色谱分离（气体浓度的变化），以及改进气体混合物注入具有对流，分散，浮力和溶解进行储层模拟。 这些都是具有高度环境安全性的世界一流的新技术;它们有望实现成本较低的长期碳固存，因为它们具有重大的积极协同作用，如共同处置其他废物流。 从长远来看，它们将对碳固存政策产生重大影响。

Two novel technologies not heretofore considered for large-scale carbon-sequestration will be studied: slurry injection (SI), and carbon dioxide-enriched gas injection. SI is direct deep placement of C-rich solids (petcoke, biosolids...) into sediments; C is permanently sequestered as a solid, the injection liquid is waste water, and for biosolids SI, recoverable CH4 is generated and CO2 from biodecomposition dissolves in formation water. Research issues include simulation of SI, biosolids decomposition rates and products, dissolving behaviour in formation water and chromatographic produced gas separation because of different solubilities. Major advantages of biosolids SI are waste water and solids co-disposal while sequestering carbon securely in solid and dissolved form, CH4 generation, and ability to co-dispose other waste streams. SI can also be implemented at a municipal scale (50,000 population). CO2-enriched gas injection (after partial membrane enrichment) fosters rapid dissolution, reduces compression costs, and reduces high costs and serious escape hazards of pure supercritical CO2 placement. Adequate dissolution rates can be achieved by maximizing in situ surface area for exchange, maintaining a high concentration gradient, and co-injecting waste water and CO2-enriched gas to maximize mixing. Research issues include study of exchange rates in co-injection and adsorption in situ (horizontal wells are envisioned), understanding and maximizing density-driven convective mixing in situ to sustain high concentration gradients, the role of buoyancy-driven dispersion, chromatographic separation of CO2 and N2 (changes in gas concentration), and means of improving predictive models for gas mixture injection into porous media with convection, dispersion, buoyancy and dissolution to undertake reservoir simulation. These are novel world-class technologies with high environmentally secure; they promise to achieve lower-cost long-term C-sequestration because of major positive synergies such as co-disposal of other waste streams. They will have a major impact on carbon sequestration policy in the long run.