Second Round of Studies on Advanced Power Generation Based on Combined Cycle Using a Single High-Pressure Fluidized Bed Boiler and Consuming Biomass

Abstract

Following a preliminary study of power generation processes consuming sugar-cane bagasse; this second round indicates the possibility of almost doubling the current efficiency presently obtained in conventional mills. A combined cycle uses highly pressurized fluidized bed boiler to provide steam above critical temperature to drive steam-turbine cycle while the flue-gas is injected into gas turbines. The present round also shows that gains over usual BIG/GT (Biomass In-tegrated Gasification/Gas Turbine) are very likely mainly due to the practicality of feeding the biomass as slurry that can be pumped into the pressurized boiler chamber. Such would avoid the cumbersome cascade feeding of the fibrous bio-mass, usually required by other processes. The present stage assumes slurry with 50% added water. Future works will concentrate on thicker slurries, if those could be achieved. All studies apply a comprehensive simulator for boilers and gasifiers [CSFMB™ or CeSFaMB™] and a process simulator (IPES) to predict the main features of the steam and gas tur-bine branches.

Theoretical Study on the Effect of Glycerol Fraction in Slurries with Biomass Consumed by a Power-Generation Process

“…The gasification optimization was possible through the application of comprehensive simulator of fluidized and moving bed equipment (CeSFaMB, ), which has been validated − and applied ,− to gasifiers and other equipment consuming a wide variety of fuels. Detailed description of its mathematical structure can be found elsewhere .…”

“…Optimizations of every one of those situations were performed using the Industrial Process and Equipment Simulator (IPES) software. That program has been applied in previous works. − , It performs mass and energy balances around each equipment to satisfy the first and second laws of thermodynamics. The simulations provide the temperature, pressure, and composition as well other properties of every process stream.…”

“…Nonetheless, if the gas distributor is properly designed, such occurrences lead to no operational problems because heavier materials would fall at the bottom of the bed and could be withdrawn from the reactor without interrupting its operation. , The basic characteristics of SCB are presented in Table . Those have been taken from the literature and used in previous works. − ,− The average size of feeding fuel particles is computed from the usual particle size distribution of SCB leaving sugar mills. A cylindrical shape is assumed for the SCB feeding fibers into the gasifier. SCB at a rate of 10 kg/s (wet basis) is continuously fed into the gasifier. This is compatible with the average production of large sugar-alcohol mills.…”

“…Additionally, it is important to stress that pumping slurries largely simplifies feeding solid particles into vessels. This method has been applied for a long time and explored in several previous studies. − …”

Theoretical Models for Rates of Heterogeneous Reactions During Combustion and Gasification of Liquid Fuels in Fluidized Beds

“…An existing simulation program (www.csfmb.com) has been validated (de Souza-Santos, 1987, 1989, 1994a, 1994b, 2007, 2008, 2009Rabi and de Souza-Santos, 2003, 2004, 2008Krzywanski et al, 2016;Englebrecht et al, 2011) and used in studies involving various possibilities and consuming many fuels, including low-quality ones (Muskala et al, 2011;de Souza-Santos, 1989, 1994a, 1994b, 2007, 2008, 2009, 2015Rabi and de Souza-Santos, 2003, 2004, 2008Krzywanski et al, 2016;Englebrecht et al, 2011;de Souza-Santos and Chaves, 2012a, 2012b, 2012cCeribeli, 2012, 2013;de Souza-Santos and Beninca, 2014;de Souza-Santos and Lima, 2015;.…”