摘要或動機

On account of the rapid development of human activities, much more fossil fuel is burnt and thus a greater amount of greenhouse gases are emitted to the atmosphere including carbon dioxide (CO2). CO2, is considered as the major cause of the exacerbating global warming. “Geo-engineering”, literally, means the options that would involve large-scale engineering of our environment in order to combat or counteract the effects of changes in our atmosphere. As a carbon neutral CO2 scrubber is proposed to be a large-scale scheme to fix carbon globally through reducing the CO2 emitted to the atmosphere and our ultimate goal is to implement the CO2 scrubber scheme to the whole globe, that is, a large-scale scheme to our environment, it is a project of geo-engineering. The procedures of the project are as the following: (a)Investigating on the absorption of CO2 produced by calcium carbonate (CaCO3), using different basic substances at different temperatures (b)Investigating the absorption of CO2 in car exhaust produced by combustion of petrol in car engine using basic solid (c)Feasibility of using a prototype of CO2 scrubber in exhaust pipe of car (d)Feasibility of fixing carbon by turning CO2 into dry ice and stored in deep water (e)Feasibility of growing plant in used basic solution Results: 1.The CO2 scrubber prototype had an average CO2 removal ability over 50%, which was considered to be efficient. The concentration of CO2 (561ppm) was even lower than that in the ambient air (CO2 612ppm). During the experiment, the prototype was closely attached to the exhaust pipe and did not fall down. Thus, a CO2 scrubber was feasible to be used in the vehicles. Besides, our prototype was more energy efficient than LM2500 PE simple cycle gas turbine (consumed 21MW electricity) though our prototype had a lower CO2 removal efficiency. The cost of our prototype would be much lower than membrane technology as the production cost of the membrane was high. 2.Unlike existing CO2 scrubber prototype installed in open area (with electric fan installed), our CO2 scrubbers installed in the chimneys of power stations and exhaust pipes of cars are carbon neutral as exhaust gas has high kinetic energy and would pass into the scrubber. 3.dry ice would not evolve carbon dioxide gas at high water pressure such as at the bottom of the ocean. 4.Plants grew well in alkaline environment, it was feasible to grow plants in basic solution. Conclusion: CO2 scrubber is a suitable choice in combating the climate change through absorbing the excess carbon dioxide, with the utilization of the carbonates produced in the reaction, it is hoped that the climate change can be relieved using an environmentally-friendly device.