Produção de sabão usando cinzas de madeira e óleo residual de fritura

Abstract

The growing environmental concern and the need to give a sustainable destination to solid waste are driving the search for reuse alternatives. This work proposes the production of soap from wood ash and residual frying oil, two waste products with high domestic and industrial generation in Mozambique. The main objective is to develop soap using these materials as raw materials, as well as to characterize their physical and chemical properties. The methodology was based on the formulation of 9 mixtures with different proportions (10% to 90% ash and complementary oil) and the performance of physical and chemical tests. The saponification index, pH, humidity, free alkalinity, glycerin content, softening and foaming capacity are the parameters evaluated in this work. The results showed that the quality of the oil directly influences the efficiency of saponification, and that formulations with balanced proportions between wood ash and waste oil presented better physical-chemical properties. The soap obtained showed an adequate pH (between 9 and 11), low humidity (<1%), controlled free alkalinity, significant presence of glycerin and good durability, demonstrating itself as a viable, economical and environmentally sustainable alternative. After analysis, the optimal mixture remains sufficient for soap production, with the optimal mixture observed being VI (IS=261.1 mg KOH/g; pH=10.07; Humidity=0.25% < 1%; Free Alkalinity=0.00085% NaO; Glycerol= 2.457 g and Stable foam stability 10 min after agitation) because it presents a performance comparable to Maëva commercial soap, and can give a suitable destination to Residual Oil and Wood Ash waste for soap production, contributing to the reduction of environmental impacts, promoting recycling practices and developing the circular economy. (NOSSA TRADUÇÃO)