[en] Highlights: • Pioneering work applying Surface Renewal Theory to model rotating packed bed. • The first dynamic distributed process model for rotating packed bed absorber. • Dissecting physical phenomenon of mass transfer inside rotating packed bed process. • New experimental data for RPB Absorber for model validation. • Case studies for RPB absorber through both steady state and dynamic simulations. Rotating packed beds can reduce the equipment size and costs in solvent-based carbon capture. However, difficulties are encountered when modelling rotating packed beds due to turbulent fluid flows inside rotating packed beds and the cross-sectional area of mass transfer unit that changes with radius. This study aims to develop a validated dynamic model of a rotating packed bed absorber and to carry out process analysis through steady state and dynamic simulations. Innovatively, the dynamic model was developed based on surface renewal theory for mass transfer. The model can calculate distributed mass transfer coefficients and other key variables related with absorption performance. Experiments were carried out and new experimental data for the rotating packed bed absorber under realistic operating conditions were obtained for model validation. Process analysis about the effects of key operational variables such as rotating speed, liquid-gas ratio and solvent concentration on absorption performance was performed with benchmark MEA solvent. It was found that the optimal MEA concentration is around 70 wt%. Dynamic simulation results reveal that the RPB absorber has fast responses for process changes. This new distributed dynamic model and the insights obtained through process simulation will promote rotating packed bed technology towards its industrial deployment in large scale carbon capture processes.

[en] Current deficiencies in oil spill cleanup processes have resulted in research and development of new cleanup technologies at the University of Notre Dame. Emphasis on reducing, reusing and recycling equipment and waste at a cleanup site has prompted advances in oil recovery technology as well as improvement in sorbent materials. (author)

[en] This paper examines the physical limitaions on spill encounter rate and how these limitaions affect the are that can be covered in spill response. Since mechanical recovery devices may not be able to cover the affected area in a large spill, in situ burning must be considered as a response option. Further, effective recovered oil logistics is essential to successful response operations and keeping skimmers operating. A successful spill response effort in a very large oil spill often depends on: Prompt response, Skimmer encounter rate, Making a decision for in situ burning, Recovered oil logistics

[en] A propane-fuelled system for testing fire-resistant booms was installed at Ohmsett in the fall of 1998, the objective being to expose candidate booms to air-enhanced propane flames and waves, to reproduce a realistic in situ burning environment equal to that of a diesel or crude oil fire. Four fire boom systems have been successfully tested to date. The larger objective is to develop a complete boom performance evaluation system included this and other parameters such as towing performance and the ability to contain hot oil after exposure to flames. 5 refs., 8 figs

[en] The second series of fire tests for fire-resistant containment booms were conducted in a wave tank at the U.S. Coast Guard Fire and Safety Test Detachment in Mobile, Alabama, utilizing ASTM F-20 draft standards. Six different fire-resistant containment booms were used. Three of the six were modified designs of booms used in the first series of tests. The tests in this series were designed to address issues raised in the first series, namely the location of heat fluxes and thermocouples, and the protocol for water-cooled booms. The results of the second series of tests are discussed and compared to the first. Strengths and weaknesses of the test protocol and other possible improvements are also discussed. 5 refs., 5 tabs., 7 figs

No abstract available

[en] Highlights: • Random Forest analysis combined with SEM to evaluate the abiotic and biotic driving factors effects on vegetation carbon stocks. • Canopy density and forest age were the most crucial driving factors. • Provides new insights into the potential response of subtropical forest ecosystems carbon sequestration to climate change. Subtropical forests play an important role in global carbon cycle and in mitigating climate change. Knowledge on the abiotic and biotic driving factors that affect vegetation carbon stocks in subtropical forest ecosystems is needed to take full advantage of the carbon sequestration potential. We used a large-scale database from national forest continuous inventory in Zhejiang Province, and combined the Random Forest analysis (RF) and structural equation modeling (SEM) to quantify the contribution of biotic and abiotic driving factors on vegetation carbon stocks, and to evaluate the direct and indirect effects of the main driving factors. The RF model explained 50% of the variation in vegetation carbon stocks; canopy density accounted for 17.9%, and forest age accounted for 7.0%. Moreover, the SEM explained 52% of the variation in vegetation carbon stocks; the value of standardized total effects of canopy density and forest age were 0.469 and 0.327, respectively, suggesting that they were the most crucial driving factors of vegetation carbon stocks. Since the forests in our study were relatively young, the forests had a large potential for carbon sequestration. Overall, our study provided new insights into the sensitivity and potential response of subtropical forest ecosystems carbon cycle to climate change.

[en] Carbon sequestration is the option that will make possible to keep fossil energies in the future energy mix. This technology could be used for fixed carbon emission sources like fossil power plants or oil refineries or steel works or cement factories. Today 3 technologies to capture carbon have to be considered: post-combustion, pre-combustion and oxy-combustion, these technologies are expected to be used equally. The second step is the construction of a network of gas pipelines to transport CO₂ to the storage place. The last step is the storage that can be done in ancient oil or natural gas fields or in deep coal layers on in deep salt aquifer. The latter being the most promising. With a carbon emission price comprised between 30 and 50 euros a tonne, carbon sequestration is expected to be economically competitive around 2030 under the condition that the feedback experience gained from the first industrial installations on a large scale have made investment costs drop sharply. Because of its need for important initial investment carbon sequestration appears to be as capitalistic as nuclear energy and will require public funding. Demonstration programs have been launched in Europe, United-States, Canada and Australia. (A.C.)

[en] A method of containing oil or like spillage floating on the surface of the sea or other waterway is described. It is achieved by means of a disposable self inflating boom assembly which is launched into the sea. Inflation of the assembly via control valves and supply lines is from a gas supply module, and both are launched from within a mobile assembly or container on a ship, platform, helicopter or by parachute from an aeroplane. Gas may be supplied from compressed gas cylinders, or by chemical reaction on contact with water, or from an air compressor or blower. Various arrangements of boom are described including having a membrane to create separately inflatable compartments, having at least one lower skirt, and using two adjacent boom assemblies. When the containment operation is completed the boom is recovered from the sea, cleaned and disposed of. (Author)

[en] Over the last decade, many energy experts have supported carbon sequestration as a viable technological response to climate change. Given the potential importance of sequestration in US energy policy, what might explain the views of communities that may be directly impacted by the siting of this technology? To answer this question, we conducted focus groups in two communities who were potentially pilot project sites for California's DOE-funded West Coast Regional Partnership (WESTCARB). We find that communities want a voice in defining the risks to be mitigated as well as the justice of the procedures by which the technology is implemented. We argue that a community's sense of empowerment is key to understanding its range of carbon sequestration opinions, where 'empowerment' includes the ability to mitigate community-defined risks of the technology. This sense of empowerment protects the community against the downside risk of government or corporate neglect, a risk that is rarely identified in risk assessments but that should be factored into assessment and communication strategies.