Name: VANESSA DAL-BÓ DA SILVA
Type: MSc dissertation
Publication date: 02/08/2016
Advisor:
Name |
Role |
|---|---|
| TAISA SHIMOSAKAI DE LIRA | Co-advisor * |
Examining board:
| Name |
Role |
|---|---|
| TAISA SHIMOSAKAI DE LIRA | Co advisor * |
Summary: In Brazil, the north region of the Espírito Santo stands out as the leading producer of robusta coffee. During the processing of coffee beans, it generates about 50% bark, which most often are disposed of improperly. This study aimed to develop the structural synthesis of technological use of the coffee husk for obtaining energy by means of heuristic and evolutionary methods. First, the structural synthesis for power generation was carried out by state trees. We then carried experimental analysis of the coffee peeling, through characterization, drying and combustion of biomass. For the characterization, they were determined water content, volatile matter, ash and fixed carbon in addition to the calorific value, density and grain size. The coffee husk drying kinetics was held thin layer through a dryer with parallel convective airflow. A factorial design to study the effect of temperature (50 to 80 °C) and speed (0.5 to 2.5 m/s) on the moisture content was prepared. They were analyzed semi-empirical models Lewis, Brooker, Henderson, Page and Overhults, and to determine an equation that best represent the drying kinetics. For combustion, were monitored during the tests, emissions of greenhouse gases such as carbon monoxide, carbon dioxide, sulfur dioxide, nitrogen oxides and hydrocarbons. For structural optimization were applied heuristic method, for identifying the base flowchart and evolutionary method to determine the structural neighbors. The tree states was divided into four technological routes, anaerobic digestion, direct combustion, gasification and pyrolysis. The digestion process was divided into five sub branches 36 branches and the combustion eight subsystems and 936 branches, the gasification and pyrolysis into eight subsystems and 1404 branches each. The characterization of the material indicated high energetic potential and it was useful to define the flow chart of energy recovery. The drying study was important to evaluate the parameters and was helpful in creating the heuristic rules. Combustion, under the conditions used, need larger study for its effective application, since the gaseous emissions exceed the limits established by CONAMA. Based on heuristic rules, the study found of the base flowchart is number 1303, which makes up the dry method, fine mills, without drying, briquetting, pyrolysis in circulating fluidized bed, with energy integration, preceded by the generation of fuel as promising to the use of coffee straw. The evolutionary method identified eleven structural neighbors. This study contributes to sustainable development and encourages the development of new technologies for the utilization of biomass.
