Dehydration of cloudy-diesel using poly(acrylamide-co-sodium polyacrylate) hydrogel grafted onto cellulose

Abstract

This article discusses the synthesis and application of poly(sodium acrylate-co-acrylamide) grafted onto cellulose hydrogel to remove water from diesel. The synthesis of the hydrogel was evaluated using a 2³ factorial design with two initiation methods (redox or thermal), two cellulose types (cellulose nanocrystal − CNC or hydroxyethyl cellulose − HEC), and two cellulose loadings (4 % or 10 %). The hydrogel swelling degree and final water concentration on diesel were used as responses. The best-performing hydrogel was made with CNC using the redox initiation system, and the cellulose loading was not significant. This hydrogel swelled less but presented significantly higher mechanical properties, with Young’s modulus and toughness increased by 132 % and 31 % compared to the ungrafted formulations, respectively. Additionally, the cellulose-grafted hydrogels presented a faster water removal from diesel, reducing its water content from 5,000 to 150 mg.kg⁻¹ in just 2 h. The material proves capable of being reused in more than one cycle of oil treatment, maintaining higher dehydration efficiency (up to 97 %). Cellulose-grafted hydrogels also reduce the turbidity of fuel and make it more compatible with standard requirements. Thus, this study presents the optimum conditions for synthesizing a highly promising material for oil dehydration.