An Onboard Air Conveyer Oil Skimmer
A high power air conveyer oil skimming system and implementation on a real oil recovery vessel are presented. Port and Airport Research Institute (PARI) has succeeded in development of a new type of onboard oil recovery system. Development of the project has been in cooperation with the Shikoku Regional Bureau, Ministry of Land Infrastructure and Transport Japan (MLIT). The system employs a high-power vacuum blower for sucking liquid in gas-liquid multiphase form. Its applicability to an onboard oil recovery system has been experimentally investigated. The experiments have shown that the method can respond to the wide range of viscosity of the spilled oil and works well even in wavy sea condition. These results have been applied to the oil skimming system mounted on ISHIZUCH - an oil recovery vessel owned and operated by MLIT recently refitted by Mitsui Engineering & Shipbuilding Co., LTD
Adaptive cleaning of oil spills by autonomous vehicles under partial information
Oil spill pollution is a critical issue because of its severe influence on our economy and ecological environment. A large amount of efforts have been made for detection, monitoring and localization of oil spills; however, the cleaning of oil spills remains a challenging problem. Due to dynamic currents on the ocean surface and the limitations of the localization systems, it is not feasible to obtain the exact information of the oil spill location. Therefore, the oil spill region is approximated by an area which may not match the shape of the oil spill. Thus, an effective complete oil spill cleaning algorithm is needed that allows the autonomous vehicle to adapt its trajectories to the oil spill shape. This paper presents a concept of multi-resolution navigation for oil spill clean-up using an autonomous vehicle. The exact a prior knowledge of the oil region is assumed to be unknown or only partially known. This algorithm can dynamically discover and adaptively clean the oil spill in the workspace. A concept of multi-resolution navigation is developed which integrates local navigation and global navigation to avoid being stuck into a local minima that is generally encountered by potential field based methods. The algorithm provides complete coverage and cleaning of the oil spill via minimum overlapping trajectories, and its efficiency is validated on the high-fidelity Player/Stage simulator of mobile robots.
Chemical-Looping Combustion of Biomass in a 10 kWth Reactor with Iron Oxide As an Oxygen Carrier
Chemical-looping combustion of biomass was carried out in a 10 kWth reactor with iron oxide as an oxygen carrier. A total 30 h of test was achieved with the same batch of iron oxide oxygen carrier. The effect of the fuel reactor temperature on gas composition of the fuel reactor and the air reactor, the proportion of biomass carbon reacting in the fuel reactor, and the conversion of biomass carbon to CO2 in the fuel reactor was experimentally investigated. The results showed that the CO production from biomass gasification with CO2 was more temperature dependent than the CO oxidation with iron oxide in the fuel reactor, and an increase in the fuel reactor temperature produced a higher increase for the CO production from biomass gasification than for the oxidation of CO by iron oxide. Although the conversion of biomass carbon to CO2 in the fuel reactor decreased with the increase of the fuel reactor temperature, there was a substantial increase in the proportion of biomass carbon reacting in the fuel react...