Following the second generation of biofuels, traditional diesel fuels are encountering new alternatives - third-generation biofuels known as "Green Gold." This emerging biofuel mainly uses algae oil as raw material to produce ethanol, butanol, jet fuel and diesel. Wijffels, professor of biology at the University of Wageningen in the Netherlands, recently told reporters that microalgae is considered a promising biofuel, although it has not been mass-produced in large quantities. Rapid growth reduces pollution Although second-generation biofuels no longer need to be converted from food to non-edible cellulose, this is a big leap forward, but the cost of the enzymes used to break down cellulose is so high that the scale of production is difficult to expand. The third-generation biofuels are mainly extracted from seaweed and do not require land and freshwater resources, and the algae production is very high. According to information provided by Wageningen, the oil content of algae ranges from 20% to 60%, with an average of 20,000 to 80,000 liters of oil per hectare per year. The output of palm oil is 6000 liters/ha. According to a related person from Wageningen, the cultivation of microalgae can use carbon dioxide in industrial waste gas, it can also absorb nitrogen oxides from industrial waste gas, consume large amounts of greenhouse gases carbon dioxide, and clean the air, but algae also need to be basically equal when they grow. Carbon dioxide, and therefore its net carbon dioxide emissions are approximately zero. At the same time, the growth of microalgae is rapid. In normal growth, biomass can be doubled every 24 hours, and can be harvested throughout the year. The requirements for the growth environment are extremely low. Harvesting costs are still high Although the high density of microalgae per unit area is its greatest advantage. However, with the current state of the art, microalgal cultivation also has the problem of high energy consumption per unit area and high input costs. Wageningen University has invested about 5 million euros in algae pilot plants, but they estimate that the current cost of producing seaweed per hectare is about 10 euros/kg, the cost of producing 100 hectares is 4 euros/kg, and the future 100 hectares The production cost is likely to be reduced to 0.4 Euro/kg. Researchers from the University of Wageningen and the Netherlands Research Center wrote in the journal Science in 2010 that the cost of producing biodiesel from microalgae has fallen steadily over the past two decades, from hundreds of dollars per gallon. Dropped to tens of US dollars/gallon, microalgal biofuels will be at the same cost as conventional fuels in the next decade. The extraction and harvesting costs of microalgae are also high. At present, methods for extracting oil from microalgae include solvent extraction, mechanical pressing, and supercritical carbon dioxide extraction. These methods all have the problems of high energy consumption or high cost of solvent loss. In addition to the cost issue, some researchers said that algae biofuels also have a certain impact on the environment. According to a report from the University of Virginia, algae biofuels consume more energy and require more water than other biological materials such as corn and rapeseed. Microalgae fuel China started In this regard, Lu Xuefeng, a researcher at the Institute of Biology, Chinese Academy of Sciences, told reporters that in China, biofuels using seaweed as a raw material are also being used in certain fields. Some scientific research institutions and companies have also begun to pay attention to the research and development of oil-producing microalgae. Last year, the Ministry of Science and Technology also invested tens of millions of dollars to support related projects. For example, the relevant units of the Chinese Academy of Sciences have undertaken research on breeding and production of microalgae at various national and provincial levels, and cultivated an experienced microalgae biotechnology research and development team. In terms of the research on oil-producing microalgae, the Institute of Hydrobiology, Wuhan Botanical Garden, South China Sea Ocean Institute, Qingdao Ocean Institute and other units have carried out research on seed selection, breeding, mass culture, collection and oil extraction, and actively carried out research with China. Cooperation of large-scale petrochemical companies. In addition, some of Air China’s flights are being tested for the extraction of biofuels using seaweed as raw material. It is said that in the initial stage, the cost of using biofuels for flights may be higher than the use of petroleum fuels, but after the scale of production continues to expand, refinery technology can be improved and the cost may be lower than that of petroleum fuels. Qingneng also jointly invested with Boeing to set up a laboratory to research and develop large-scale aquaculture, harvesting, processing, and conversion technologies for oil-producing microalgae. Lu Xuefeng said that biofuels using seaweed as raw material are definitely the major trend in the future. However, due to the immature technology, the problem of high costs has not yet been solved. In China, it is not yet possible to cultivate large-scale algae on a large scale. Still relatively far. There are three basic types of fixed bed reactor: (1) axial adiabatic fixed bed reactor. The fluid flows through the bed along the axial direction, and there is no heat exchange between the bed and the outside world. (2) radial adiabatic fixed bed reactor. The fluid flows through the bed along the radial direction. Centrifugal flow or centripetal flow can be adopted. There is no heat exchange between the bed and the outside world. Compared with axial reactor, radial reactor has shorter flow distance, larger cross-sectional area and smaller fluid pressure drop. But the structure of radial reactor is more complicated than that of axial reactor. The above two forms are adiabatic reactors, suitable for the reaction heat effect is not large, or the reaction system can withstand adiabatic conditions caused by the reaction heat effect of the temperature changes. (3) The tubular fixed-bed reactor is composed of multiple reaction tubes in parallel. The catalyst is arranged in the tube or between the tubes, and the heat carrier flows through the tubes or tubes for heating or cooling. The diameter of the tubes is usually between 25 ~ 50mm, and the number of tubes can be as many as tens of thousands of roots. The tubular fixed bed reactor is suitable for the reaction with high thermal effect. In addition, there is a reactor composed of the above basic forms in series, called a multistage fixed bed reactor. Desulfurizer,filter,Reaction kettle,Reactor YANTAI DONGTAI STANDER OFFSHORE ENGINEERING CO.,LTD , https://www.dongtaicolumbus.com