Browsing by Author "Ramshaw, C."
Now showing 1 - 4 of 4
Results Per Page
Sort Options
Item Open Access Behaviour of Water in Aviation Fuels at Low Temperature(2011-12-07T00:00:00Z) Carpenter, Mark D.; Hetherington, Janice I.; Lao, Liyun; Ramshaw, C.; Yeung, Hoi; Lam, Joseph K.-W.; Masters, Simon; Barley, Sarah; Morris, R. E.Item Open Access Optimal operation of tubular reactors for naphtha cracking by numerical simulation(Wiley, 2011-12-06) Gao, G-Y.; Wang, M.; Ramshaw, C.; Li, X-G.; Yeung, HoiProcess gas temperature profile and steam-to-hydrocarbon ratio in the feed have important impact on product yields and coking rate in tubular reactors for naphtha cracking. This study is to evaluate these effects quantitatively based on numerical simulation. Steady-state operation of the tubular reactor in an industrial thermal cracking furnace was first simulated in HYSYS with a molecular reaction scheme. Various case studies then investigate the influence of process gas temperature profile and inlet steam-to-hydrocarbon ratio so that the ethylene/propylene product yields and coking rate can be evaluated. Finally, steady-state optimization was applied to the operation of this industrial furnace. The optimal process temperature profile and the optimal inlet steam-to- naphtha ratio were found to maximize the operation profit. This study will provide significant guidance to process engineers in the ethylene industry.Item Open Access Post-combustion CO2 capture with chemical absorption: a state-of-the-art review(Elsevier Science B.V., Amsterdam, 2011-09-01T00:00:00Z) Wang, Meihong; Lawal, Adekola; Stephenson, Peter; Sidders, J.; Ramshaw, C.Global concentration of CO2 in the atmosphere is increasing rapidly. CO2 emissions have an impact on global climate change. Effective CO2 emission abatement strategies such as Carbon Capture and Storage (CCS) are required to combat this trend. There are three major approaches for CCS: post-combustion capture, pre-combustion capture and oxyfuel process. Post-combustion capture offers some advantages as existing combustion technologies can still be used without radical changes on them. This makes post-combustion capture easier to implement as a retrofit option (to existing power plants) compared to the other two approaches. Therefore, post-combustion capture is probably the first technology that will be deployed. This paper aims to provide a state-of-the-art assessment of the research work carried out so far in post-combustion capture with chemical absorption. The technology will be introduced first, followed by required preparation of flue gas from power plants to use this technology. The important research programmes worldwide and the experimental studies based on pilot plants will be reviewed. This is followed by an overview of various studies based on modelling and simulation. Then the focus is turned to review development of different solvents and process intensification. Based on these, we try to predict challenges and potential new developments from different aspects such as new solvents, pilot plants, process heat integration (to improve efficiency), modelling and simulation, process intensification and government policy impact.Item Open Access Process intensification: water electrolysis in a centrifugal acceleration field(Springer Science Business Media, 2011-06-30T00:00:00Z) Lao, Liyun; Ramshaw, C.; Yeung, HoiIntensification of hydrogen production by carrying out water electrolysis in a centrifugal acceleration field has been demonstrated. A prototype single cell rotary water electrolyser was constructed, and a number of design challenges with regard to the practical application were addressed. The rotary electrolyser was tested over a range of current density, centrifugal acceleration, electrolyte concentration, temperature, and electrode geometry. The test results showed that at normal cell operating conditions (7.7M KOH solution, 348K) much of the cell voltage benefits were achieved at an acceleration of about 16g (g=9.81ms-2), equivalent to a rotational speed of 500rpm (revolution per minute) for the rotary cell. The rotary electrolyser cell voltage was about 0.25-0.5V, less than the equivalent static cell under similar operating conditions, depending on the current density. The cell voltages achieved, without an effective electrode catalytic coating, were comparable with typical industrial values of fully developed pressurised cells. At a higher acceleration of 41g, the rotary cell's current density can be up to 13.5kAm-2 without causing gas bubble blinding of the membranes and electrodes. When comparing with typical current densities (about 5kAm-2) found in commercial systems, this study demonstrated the potential of intensification.