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Pirólise de agulhas de pinheiro: resultados preliminares

Publication . Nascimento, M.; Silva, F.; Pilão, R.; Neto, M.P.; Ribeiro, A.M.

(Introdução) As florestas em Portugal ocupam uma área aproximada de 3 224 200 ha, apresentando como espécies predominantes o sobreiro, o pinheiro e o eucalipto (ICNF, 2021). Os pinheiros ocupam cerca de 28 % desta área e geram diversos resíduos, entre os quais as agulhas, que se não forem retiradas das florestas podem agravar o problema dos incêndios florestais (Omvesh et al., 2023). A energia proveniente de resíduos florestais pode ser transformada em combustíveis ou em outros produtos químicos através de processos termoquímicos, como a pirólise, onde há a formação de três fases distintas: o carbonizado, o bio-óleo e o gás (Basu, 2018).

2024Conference object

Open access

Gasification of crude glycerol after salt removal

Publication . Almeida, Ana; Pilão, Rosa; Ribeiro, A.M.; Ramalho, Elisa; Pinho, Carlos

The increase in the amount of crude glycerol available on the market, as well as the decrease in its purity due to the use of waste materials in the production of biodiesel, has forced producers to look for alternative ways of valuing this byproduct. In this research work, crude glycerol of a Portuguese biodiesel producer was pretreated using an ion exchange process in order to reduce its salt content. The gasification process was performed using steam as the oxidizing agent in a down-flow fixed-bed reactor using alumina particles as bed material. After the gasification process, the producer gas flowed through a condensing and cleaning system, in order to remove the condensable fraction. Dry gas samples were collected and analyzed by GC in order to quantify the CO, CO2, CH4, and H2 content. Three different feed mixtures were studied with 35%, 39%, and 59% (w/w) water, and the tests were performed at 850, 900, and 950 °C. The results showed that the increase of the water content in the feed mixture led to higher values of H2 and CO2, and lower values for CO and CH4, on the producer gas composition. A slight increase of dry gas yield and hydrogen conversion efficiency with the increase of water content in the feed was observed, while the lower heating value of producer gas decreased. No significant influence of water content was detected in the carbon conversion efficiency and cold gas efficiency. The increase of temperature resulted in the increase of four gasification parameters with maximum mean values of 90% for carbon conversion efficiency, 100% for hydrogen conversion efficiency, 107% for cold gas efficiency, and 1.3 m3/kg raw material. The maximum lower heating value of 14.5 MJ/m3 was obtained at 850 °C.

2019Journal article

Restricted access