Design And Experimental Study Of Vertical Biomass Continuous Pyrolysis Equipment Based On In-situ Reformin

Biomass pyrolysis technology is currently the most commonly used thermochemical conversion method for biomass energy utilization.Through pyrolysis,straw can not only be converted into biochar and pyrolysis gas with high utilization value,but also produce difficult-to-use biomass.Tar,not only affects the normal operation of equipment,but also reduces the quality of pyrolysis products.Carbon-gas in-situ coupled reforming,also known as in-situ reforming,is a tar reduction method.Its principle is to use the contact reaction between biochar and pyrolysis gas to achieve tar removal and quality improvement.By using the in-situ reforming method combined with the continuous pyrolysis technology,the high-efficiency co-production of biochar and pyrolysis gas can be realized,and the quality of both can be improved.In this paper,the biomass continuous pyrolysis process is mainly used,combined with the in-situ reforming technology,the vertical biomass continuous pyrolysis equipment is developed.The key components such as the furnace body,double-layer air distribution mechanism and rotary discharge mechanism are designed,and the equipment assembly,debugging and test analysis are carried out to realize the optimization of the working parameters of the equipment.The main research contents are as follows:(1)In order to achieve the reduction of tar and the improvement of the quality of carbon gas,the overall process flow of the equipment combined with the in-situ reforming method and the biomass continuous pyrolysis technology was formulated by studying the relevant mechanism of biomass pyrolysis,including feed drying,thermal The steps of decomposing,in-situ reforming,pyrolysis gas discharge,cooling and charcoal are clarified,and the design requirements,overall structure,working process and main parameters of the equipment are clarified.(2)The furnace body of the equipment and its internal key components are designed.The key components include compaction mechanism,multiple stirring mechanism,double-layer air distribution mechanism and rotary discharge mechanism.The furnace body is divided into sealing drying area,heating drying area,pyrolysis carbonization area and coupling reforming area according to the design requirements.The compaction mechanism is composed of three inclined rectangular plates,which can compact and level the loose materials in the compaction area,which not only improves the overall reliability of the pyrolysis gas reflux reforming process,but also ensures that the volume in the furnace can be maximized.of is utilized.The multiple stirring mechanism is composed of 9 stirring rods,which can crush the formed slag and keep the material in an uninterrupted motion state,thereby preventing the material from slagging.The double-layer air distribution mechanism is composed of a pointed air cap,an upper air distribution plate,and a lower air distribution plate.The upper air distribution plate is responsible for the air distribution in the pyrolysis and carbonization zone to support combustion,and the lower air distribution plate is responsible for the return of the pyrolysis gas in the coupling reforming zone.Through the fluid simulation,it can be seen that the flow of pyrolysis gas in the lower air distribution plate can achieve the design goal of air distribution and diversion,and solve the problem of air distribution obstruction.The rotary discharge mechanism is composed of three arc-shaped dialing rods.The material has a steadily increasing discharge speed on the dialing plane of the dialing rod,which can realize the uniform falling of the material.The statics simulation analysis shows that the rotary The structural strength of the discharge mechanism meets the requirements and can achieve normal operation.(3)After the equipment is assembled,carry out the cold state calibration test and the pyrolysis reforming operation test.The cold state calibration test uses corn stalk charcoal as the material to calibrate the actual discharge capacity of the rotary discharge mechanism.The test results show that:the equipment When each mechanism operates normally and the actual operating speed of the rotary discharge mechanism is 8r/min,it meets the requirements of the designed throughput.The pyrolysis reforming operation test uses coarsely pulverized corn stalk as raw material,and tests are carried out at different reforming temperatures and the products are analyzed.The raw material processing capacity is 1521 kg/h,the biochar yield is 25.3%,the pyrolysis gas productivity is 0.89 Nm~3/kg,the tar productivity is 6.1 mg/m~3,the pyrolysis gas calorific value is 6.9 MJ/Nm~3,and the biochar specific surface area is 72.83 m~2/g,the design goal is achieved.