Edgardo Olivares Gómez

Preliminary tests with a sugarcane bagasse fueled fluidized-bed air gasifier

This paper discusses the performance characteristics of a 280 kWth fluidized bed gasifier fueled with bagasse pellets. The gasifier was designed by the State University of Campinas (UNICAMP) and built by TERMOQUIP Energia Alternativa Ltda, based in Campinas, Brazil. Preliminary tests were performed in 1996 to determine the reactor performance as part of the gasification pilot plant test programme. A series of parameters, such as the lower heating value, heat losses, cold and hot gas thermal efficiency and gas yield, were measured as a function of the gasification air factor.

Biomass photo-chemistry. A review and prospects

Abstract Photo-chemical degradation of lignocellulosic materials such as wood, cotton, lignin and cellulose and its importance in the development of biotechnology is reviewed. Single cell protein and glucose production related to alcohol production, which are currently undergoing development through photo-chemistry, are also discussed. We present a background of the different aspects of these photo-chemical techniques applied to the biomass. This review demonstrates, in general, an improvement of industrial photo-chemistry.

Constructive features, operation and sizing of fluidized-bed gasifiers for biomass

In this paper a few considerations about constructive features, operation and sizing of biomass atmospheric fluidized bed gasifiers are presented. The analysis is carried out on the base of papers and reports on different authors, and also based on the own authors` experience. The state-of-the-art of this technology is presented, as well as the main problems to solve for its wide industrial application. Successful commercial plants are mentioned. A method to calculate main design parameters using recommended values for the air factor, gas superficial velocity and bed temperature is given. The results are the gas, air and biomass flows, the reactor inner diameter and the expanded bed height. Calculations for three different biomass (sugarcane trash and bagasse, and rice husk) are presented.

Biomass photochemistry XIV: Photosensitized pre-treatment of cellulose and its role on cellulase efficiency

Abstract α-Cellulose, methylcellulose and filter paper (Whatman No. 1) were irradiated with UV light at λ > 254 nm and λ > 300 nm in the presence of sodium nitrite as sensitizer. The degradation of cellulose derivatives was monitored by viscosity, weight loss and thermogravimetric measurements. For the samples irradiated at λ > 254 nm and λ > 300 nm in the presence of the sensitizer, the intrinsic viscosities were similar for fluences in the range 0 – 64 kJ m −2 . The sensitizer, which generates OH radicals through photochemical activation, improves tenfold the efficiency of the enzymatic hydrolysis of a -cellulose by cellulase. The results clearly indicate that irradiation at λ > 300 nm is a good pre-treatment for the enzymatic hydrolysis of α-cellulose.

Biomass photochemistry. IX: Photochemical pretreatment of cellulose and its effect on cellulase efficiency

Abstract Cellulose derivatives were irradiated by UV light at λ > 254 nm and λ > 300 nm. The degradation of cellulose derivatives was followed by fluorescence, viscosimetry, weight loss and thermogravimetry measurements. An attempt was made to correlate the changes in degree of polymerization and weight of the irradiated materials with the hydrolysis of cellulosic materials to glucose by cellulase under different conditions. The crystallinity and probably the specific surface area are the most important parameters for the enzymatic hydrolysis of cellulose. These results and the relative quantum yields showed that λ > 300 nm is excellent for the pretreatment of cellulose.