Research On A New Multi-Generation System Based On Solid Waste Pyrolysis And Hydrogen Methanolization

The increase of carbon dioxide emissions will lead to the increase of global temperature,the intensification of greenhouse effect,the induction of extreme weather,and serious damage to the global ecological environment.With the rapid improvement of China’s economic level,China has become the largest energy importer and consumer in the world,and its carbon dioxide emissions are often among the top in the world.In this context,President Xi Jinping has proposed the goal of "carbon peaking and carbon neutral," that is,to reach the peak of carbon dioxide emissions by 2030 and strive to achieve carbon neutrality by 2060.The key to achieving the "double carbon" goal is to reduce the use of fossil energy and transform the energy structure.Based on this,this paper proposes a new carbon-neutral energy technology route.Based on the source part of the novel technology route,this paper proposes a multicogeneration system based on waste tire pyrolysis,electrolytic water,methanol synthesis coupled with organic Rankine cycle.Among them,the waste tire pyrolysis system converts waste tires into high-value products such as pyrolysis gas,pyrolysis oil,and carbon black,realizing the recycling of solid waste resources.The electrolysis water system uses renewable energy power to electrolyze water to produce hydrogen,which realizes the consumption of renewable energy power.The primary function of the methanol synthesis system is to synthesize methanol from carbon dioxide-rich flue gas generated in the waste tire system with hydrogen,solving the problem of hydrogen storage and transportation difficulties.The main function of the organic Rankine cycle system is to utilize the waste heat from the flue gas in the scrap tire system for power generation.According to the terminal utilization part of the new technology route,this paper proposes a fuel cell and organic Rankine cycle coupling cogeneration system based on methanol reforming.The methanol reforming system converts methanol into hydrogenrich syngas to fuel the fuel cell system.The main function of fuel cell system is to convert the chemical energy in hydrogen-rich syngas into electrical energy.The main function of the fuel cell system is to convert the chemical energy contained in the hydrogen-rich syngas into electrical energy.The function of the organic Rankine cycle system is to recover the waste heat from the fuel cell flue gas for electricity generation.In this paper,Aspen Plus software is used as the simulation tool to establish the simulation models of the two systems and carry out energy analysis,exergy analysis,economic analysis and sensitivity analysis for the two systems.The calculation results show that the comprehensive energy efficiency of the polygeneration system based on the coupling of waste tire pyrolysis,electrolytic water,methanol synthesis and organic Rankine cycle is 64.12%,the total exergy efficiency is 67.48%,the dynamic payback period is 8.54 years,and the net present value is 4371.85 k$.The integrated energy efficiency of the fuel cell and organic Rankine cycle coupled cogeneration system based on methanol reforming is 51.29%,the total exergy efficiency is 40.56%,the dynamic payback period is 4.97 years,and the net present value is 199.91 k$.The sensitivity analysis shows that the output of pyrolysis gas and pyrolysis oil will also increase with the increase of pyrolysis temperature.When the carbon cycle ratio is 0.4,the thermal and economic performance of the polygeneration system based on the coupling of waste tire pyrolysis,electrolytic water,methanol synthesis and organic Rankine cycle will reach the best.The power generation of fuel cells increases with the increase of working pressure and fuel flow.According to the principle of energy cascade utilization,this paper combines the pyrolysis of waste tires,electrolytic water,alcohol synthesis and organic Rankine cycle power generation system in an efficient and flexible way to achieve the goal of harmless recycling of solid waste resources and reducing carbon dioxide emissions.At the same time,a coupling system with methanol reforming and fuel cell as the core was established with methanol as the hydrogen energy carrier,which realized the efficient utilization of hydrogen energy.The results show that the two integrated systems have the advantages of high comprehensive efficiency,low environmental pollution and carbon emissions,and provide new ideas for China’s energy transformation and the achieving of the goal of carbon neutrality.