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Carbon dioxide capture and storage (CCS) is an essential part of the portfolio of technologies to achieve climate mitigation targets. Cost efficient and large scale deployment of CCS necessitates that all three elements of the supply chain (capture, transportation and storage) are coordinated and planned in an optimum manner both spatially and across time. However, there is relatively little experience in combining CO2 capture, transport and storage into a fully integrated CCS system and the existing research and system planning tools are limited. In particular, earlier research has focused on one component of the chain or they are deterministic steady-state supply chain optimisation models. The very few multi-period models are unable to simultaneously make design and operational decisions for the three components of the chain. The major contribution of this thesis is the development for the first time of a multi-period spatially explicit least cost optimization model of an integrated CO2 capture, transportation and storage infrastructure under both a deterministic and a stochastic modelling framework. The model can be used to design an optimum CCS system and model its long term evolution subject to realistic constraints and uncertainties. The model and its different variations are validated through a number of case studies analysing the evolution of the CCS system in the UK. These case studies indicate that significant cost savings can be achieved through a multi-period and integrated system planning approach. Moreover, the stochastic formulation of the model allows analysing the impact of a number of uncertainties, such as carbon pricing or plant decommissioning schedule, on the evolution of the CSS system. In conclusion, the model and the results presented in this thesis can be used for system planning purposes as well as for policy analysis and commercial appraisal of individual elements of the CCS network.

A biological early warning system (EWS) was developed to screen wastewater containing nitrification inhibitors and identify nitrifying bacteria activity reduction without relying on absolute values of sensor signals. To do so, numerous sensors were evaluated using a tiered approach to aid the analysis and made it easier to convey the current state of the technology. The research then produced a framework for the development of an EWS and the applicability of sensors to the wastewater matrix. The research identified a need for the development of a strategy and guidance that can help in the prevention and detection of nitrification inhibitors. Initial tests focussed on sewer biofilm N2O emissions, however, despite average nitrification rates of 19.5 g-NH4 + - N.m- 2 .d- 1 the response was unreliable due to inadequate control. To address this, a circulating floating bed biofilm reactor (CFBBR) was designed as a sidestream. The CFBBR biofilm’s toxicity response was compared to the sewer biofilm, a 2850 mg.L- 1 MLSS culture and a 10.5 mg.L- 1 MLSS culture (with equivalent biomass concentration to the CFBBR biofilm). The cultures responded differently with an inhibitory effect scale of Cu2+ > ATU > Ni2+ > Cr6+ for CFBBR biofilm, ATU > Cu2+ > Ni2+ > Cr6+ for 2850 mg L- 1 MLSS, ATU > Ni2+ > Cr6+ > Cu2+ for 10.5 mg.L- 1 MLSS and ATU > Cu2+ > Cr6+ > Ni2+ for sewer biofilm. This was firstly attributed to suspended growth nitrification stimulation by Cu2+ doses up to ~45 mg.L- 1 resulting in a lower inhibitory effect. Secondly, very high Cr6+ and Ni2+ doses were required for biofilm nitrification inhibition, due to diffusion limitations and slow transport through cell membranes. The CFBBR biofilm response to heavy metals was characterised through N2O and CO2 spikes and a post shock emissions recovery period was observed with the trend Ni2+ > Cr6+ > Cu2+ . A 10 minute hydraulic retention time allowed quick detection and steady state nitrification rates of 0.4 g-NH4 + -N.m- 2 .d- 1 despite high organic loading rates. Additionally, a suspended growth based monitor (Nitritox) was assessed as an inlet works toxicity detector. Incorporation of a Nitritox with a CFBBR based sewer monitor offered increased robustness over a CFBBR only system and was shown to be viable system in catchments >200,000 population equivalent. This information is useful to water utilities so that they can plan for and experiment with upset early warning protocols. It is also useful to manufacturers as they can determine product performance needs.

This study arises from the development of carbon capture and storage technology (CCS) as a means of disposing of the large quantities of CO2 emitted by industry. In particular the need is identified to measure the impact of impurities such as N2 and H2 on solubility of H2O in dense phase CO2 since the formation of an aqueous phase in CO2 bearing carbon steel pipelines presents a risk of corrosion or blockage. Chapter 1 describes this background, paying attention to the current state of affairs with regard to the development and deployment of CCS. An historical review is undertaken of the significant body of literature reporting the maximum H2O content of pure CO2. Analytical sampling methods are found to predominate in this literature, but particular attention is paid to several in situ infra-red methods upon which this thesis builds. The significant mathematical model of Spycher et al. is described along with equations of state relevant to the thesis. A discussion is presented of the limited literature concerning the effect of impurities on the H2O content of CO2. The aims of the thesis are then clearly set out: they pertain to the accurate measurement of H2O solubility in pure and impure CO2 at conditions relevant to CCS pipelines by an in situ infra-red method.

Post combustion carbon capture is a promising and relatively mature method of reducing carbon dioxide emissions from fossil fuel combustion. Power generation utilising post combustion carbon capture technology has the potential to achieve near zero carbon dioxide emissions whilst maintaining the security of electricity supply associated with fossil fuel power generation. A key issue associated with any new technology is achieving accurate designs, producing feasibility studies and completing capital and operating cost estimation. This thesis describes and validates methods of simulating post combustion carbon capture in Aspen HYSYS. Simulations are completed in both equilibrium and rate- based methods. This work is in association with Doosan Power Systems, who are the designer and installer of the UK's largest carbon capture pilot plant at Ferrybridge in Yorkshire. The Ferrybridge pilot plant, which is known as the CCPilotlOO+, is capable of capturing in excess of 100 tonnes of carbon dioxide per day, and is one of the first in the world to be integrated into a live power plant. Equilibrium and rate-based simulations are validated against the best available pilot plant performance data taken from the literature and against comprehensive data sets from the Ferrybridge CCPilotlOO+ pilot plant. The equilibrium methods are found to have a limitation in that they cannot accurately predict the performance of packed columns. The rate-based simulation method is pursued as the best option for technical design and cost estimation of post combustion carbon capture systems. Rate-based simulation methods based on the electrolyte non-random two liquid model are validated against pilot plant data for systems using aqueous monoethanolamine, and aqueous blends of monoethanolamine and methyl diethanolamine.

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In the studies related to trace analysis in meteorology, hydrology, medical and clinical research, the measurement and monitoring of tritium released from nuclear facilities and its health physics aspects on human and the environment are of growing importance. The techniques employed currently for the enrichment of tritium are carried out using large samples and require long periods of operation (7 days or more) to obtain the enriched tritium sample. In the present investigation, a laboratory scale chromatography based system was designed, constructed and commissioned successfully to collect enriched tritiated water samples which were then counted to determine the levels of activity. The total time taken to conduct the complete enrichment procedure and counting of the collected samples was less than one working day. This system also showed the capability of enriching quantities of water samples as small as 20 ml. This was about ten times less than required in the conventional enrichment techniques. Extensive efforts were made to attain optimum operational, reproducible and efficient measurements of tritium enrichment for quantitative analysis. The developed experimental technique involved injecting a known volume of water into a preheated furnace to react with magnesium turnings, in the presence of a carrier gas, to produce the hydrogen isotopes. These isotopes were separated using the principles of chromatography. Liquid scintillation counting method was employed to determine the activity of the collected samples. Two gases, nitrogen and helium, were utilized as the carrier gases during this investigation. Best values of enrichment were obtained with the use of nitrogen as a carrier gas, but the samples collected were difficult to count due to the formation of ammonia with consequent chemical complications.