TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The mesoporous silicon dioxide hollow sphere catalyst filled with TiO2 or ZrO2 is prepared by taking titanium tetrachloride or zirconium oxychloride to prepare 0.1-1.0 mol/L ethanol solution; adding the mesoporous silicon dioxide hollow sphere in the solution; vacuumizing the suspension for 30 minutes under ultrasonic condition; closing the vacuum pump and adjusting the pressure in the container to normal pressure; continuously ultrasonic processing for 10 minutes; centrifuging the mixture; blow drying at room temperature; quickly washing the dried powder with absolute ethyl alcohol twice; blow drying at room temperature; and roasting the dried powder for 2 hours at 500 degrees C to obtain the mesoporous silicon dioxide hollow sphere catalyst filled with TiO2 or ZrO2. The oxygen-free condition refers to maintaining the reaction system in an inert oxygen-free protective gas environment. The volume space velocity of high temperature pyrolysis gas in the reactor is 5000-20000/hour.    TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred Method: The reactor is fixed bed reactor or bubbling fluidized bed reactor.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The mesoporous silicon dioxide hollow sphere carrier is prepared by taking tetrapropylammonium hydroxide and sodium hydroxide; dissolving in deionized water; controlling the mass ratio of tetrapropylammonium hydroxide and sodium hydroxide at 2:1-4:1; obtaining solution 1; taking aluminum sulfate; dissolving in deionized water; adding ethyl orthosilicate and quickly stirring for 20 minutes, where mass ratio of aluminum sulfate and ethyl orthosilicate is 1:30-1:100 and the mass ratio of tetrapropylammonium hydroxide and ethyl orthosilicate is 1:3-1:5; obtaining solution 2; mixing solution 1 and solution 2; stirring for 4 hours at 5 degrees C; standing for 24 hours to obtain solution 3; taking alkyltrimethylammonium bromide; dissolving in deionized water; adding the solution 3, where mass ratio of tetrapropylammonium hydroxide and alkyltrimethylammonium bromide is 1:0.8-1:1.3; vigorously stirring for 8 hours at room temperature; transferring the white solution into a stainless steel reaction kettle with PTFE lining; hydrothermally treating at constant temperature of 140 degrees C in an oven for 24 hours; cooling, filtering, and washing for multiple times with deionized water; drying the white solid at 100 degrees C for 6 hours; and roasting for 8 hours at 500 degrees C to obtain mesoporous silicon dioxide hollow sphere.    TECHNOLOGY FOCUS - POLYMERS - Preferred Method: The biomass is lignocellulosic biomass.