An experimental study presents a new innovative cyclone combustor, known as the three-way swirling combustion (TSC), utilizing non-pulverized wood biomass. The study shows that the combustor reached near-complete combustion, as evident in the measurements of CO and NOx emissions, and the excess air ratio. It also demonstrates the unique features of the TSC combustor, which includes an air curtain insulation effect with a high ash removal rate that reduces clinker and slag formation, alongside a chamber that does not need a refractory brick. It compares against conventional combustion technology, such as the stoker and the fluidized bed in terms of the amount of emission gases, maximum temperature, and excessive air ratio. Six geometrical and operational design criteria of the TSC for wood biomass combustion are identified for future work of design optimization. Ultimately, the implementation of the TSC for non-pulverized wood biomass and possibly for other biomass holds great potential for economically and technically beneficial incineration and power generation.

The purpose of this study is to optimize the processing conditions (temperature, pressure, process time, yield rate) for the conversion of biomass to a high-energy density biofuel. The hydrothermal polymerization (HTP) catalytic process has been developed for production of biofuel via hydrothermal processing using an acid-based catalyst. This study has shown that the HTP catalytic process for a reference feedstock lowered the temperature by 10 to 40 • C, reduced the pressure requirement by 1 to 2 MPa, increased the rate of yield by 22%, and shortened the total processing time by up to 3 h when compared to the conventional hydrothermal carbonization (HTC) process. FTIR spectrum analysis of the HTP catalytic biofuel has shown that lignin in the biomass is preserved, while the pure HTC process destroyed the lignin in the biomass. GC/MS analysis of the process liquid determined the changes of the intermediate soluble components as a function of time. By measuring the 2,5-hydroxymethyl furfuralde concentration in solution, an endpoint determination could be made. This study also determined the approximate analysis of the HTP biofuel from various organic wastes such as cotton, cow manure, wood waste, paper waste, sugarcane bagasse waste, and food waste.

Despite the technology for wood biomass combustion being much more advantageous when compared to traditional burners, such as the Stoker or fluidized burner, there has been scant research on the topic of wood biomass cyclone burners. The purpose of this paper is to review biomass cyclone burner technology, which includes theory, design, and combustion, in terms of the chemistry and properties of wood biomass, emission related to NOx and CO, and application of the burner, such as co-firing with coal and gasification firing. The design factors for type 2 cyclone burners have been identified through the following three dimensionless numbers: swirl intensity (S), Strouhal number (St), and Reynolds number (Re). The lowest CO and NOx of type 2 cyclone burners have been sought for pulverized and non-pulverized wood biomass. The benefits of the co-firing of wood biomass in a cyclone burner with coal, have been presented in respect to combustion efficiency, alkali retention, and the amount of K and Na. The results evidently reveal the reduction in clinker and slag generation, which are the biggest concern to wood biomass combustion. The recent results of gasification studies using type 2 cyclone burners are compared, in terms of producer gases and syngases (H2, CO, CO2, CH4).

In order to improve low combustion efficiency of typical incinerators like a stoker type, a new unique cyclone combustor, three-way swirling combustion (TSC), is being introduced through a commercial scale pilot plant experiment for refused plastic fuel (RPF). TSC provides air curtain insulation, substituting the refractory brick and lowering the generation of flying ash, for clinker prevention at the boiler. Its excellent emission measurement has also been reported. Through the study of three-dimensionless numbers (swirl number, Strouhal number, and Reynolds number) and previous researches conducted on cyclone combustors, their design criteria—geometrical and operational parameters—has been identified and suggested for future designs.

Through the previous study a hydrothermal polymerization (HTP)—a catalytic methodology for treating various biomass and organic wastes—has been developed on a lab scale with a 1 L reactor and the results published. The research work described herein aims to ensure that the catalytic process is scalable for pilot and even commercial scale plants. A 1700 L binary reactor system has been built and the assumptions of a commercial scale plant that would have 10,000 to 20,000 L pressure vessels tested. The HTP catalytic biofuel process converts mono- and polysaccharides into a solid polymer fuel that is based on a furfuraldehyde ring system. The calorific value of the material obtained from the pilot plant is on the order of 27 MJ/kg and the material typically has low ash and fixed carbon content order of 48% which are about same as the lab results for various wood biomass feedstocks. Though a 1700 times scale up binary reactor system the scalability of the HTP catalytic methodology has been confirmed and the mass and energy balance of the binary reactor identified in order to provide fundamental data for commercial scale establishment in future.