The main objective of this project is to assist EPA to set up a pilot facility about the biomass torrefaction process and to evaluate its feasibility for expanding its applied field. This project is primarily aimed to design a practical pilot-scale continuous torrefaction reactor and to set up suitable operating parameters by collection of torrefaction technology and patent analysis in advanced countries and characteristics of domestic raw material source in Taiwan. Furthermore, based on the testing results of the pilot-scale torrefaction reactor, the plan for the demonstration system has been also completed.
In this final report, six completed works were described as following: (1) the torrefaction technology and patent map analysis in advanced countries were completed. The analysis showed that torrefaction technologies have been developing in many countries. These designs of the torrefaction reactor are mainly focused on the rotary-kiln reactor and moving-bed reactor. The patents emphasize on exhaust emission control, heat integration, and product quality improvement. (2) Torrefying three batch reactor biomass (municipal solid waste, rice straw, and wood ) and measuring their properties testing were achieved. The testing results showed that the heating values for three kinds of biomass, torrefied at 350℃ for 90 min, increased by 73%、63%、55%, respectively. Among these three biomasses, MSW exhibited the largest increase in the heating value. (3) Completed two conceptual designs of continuous pilot reactors such as rotary-kiln type and moving-bed type reactor, the features of these designs involve specifications of equipment, size, reactor type, capacity of the reactor, and so on. After authorized by the EAL (Environmental Analysis Laboratory) of EPA, the rotary-kiln type was chosen as the torrefaction reactor for further detailed design. (4) According to the previous point 3, the treating capacities of the dryer reactor and the pilot-scale torrefaction reactor were designed and constructed to be 45 kg/hr and 25kg/hr, respectively. The torrefaction tests and evaluation for this system were implemented. In the case of producing the biocoal from crushed wood, the power consumption cost is about NTD 4,193 /ton and the amount of CO2 emission is about 503 kg/ton-biocoal in the producing process. Therefore, the ratio of energy output to input is 2.88. (5)Proposed a conceptual plan of a demonstration torrefaction system with treating capacity of 500 kg/hr is completed and the setup cost of this system is estimated about 21 million NTD. (6) Economic analysis for using rice straw converted to biofuel were completed. The average of operating cost for the rice pelletizing process and torrefaction after pelletizing process were NTD 4,516.6/ton and NTD 14,640/ton, respectively.