Preparation of New Eco-Friendly Gel Foam Based on Biomass Pectin Material for Fire Prevention of Coal

The traditional gel foam materials have achieved certain effects in preventing coal fire. However, the traditional gel foam materials commonly use chemical compounds which cause harm to the environment. Therefore, based on biomass materials such as low methoxyl pectin (LMP), calcium L-lactate (Ca-L), and biomass compound foaming agent (BF), a new eco-friendly gel foam (LMP-Ca) was prepared. The foaming performance, gelling time, stability, coal oxidation inhibition and fire extinguishing performances of LMP-Ca were systematically studied. The study shows that the gelling time of LMP-Ca with 1.2 wt% LMP, 0.075 wt% Ca-L and 0.03 wt% BF is 10 min and the half-life is up to 216 h. Moreover, the LMP-Ca has excellent film-forming performance, and the isolation film with thickness up to 2.5 mm can be formed on the surface. The coal oxidation inhibition experiment shows that LMP-Ca can effectively delay the oxidation rate of coal with the temperature rising, and the inhibition rate of CO is 72.1% at 180°C. The fire extinguishing experiment shows that the temperature of the coal treated by LMP-Ca decreases rapidly from 960 to 60°C in 20 min and to 30°C in the following 110 min without the reignition phenomenon. The result indicates that LMP-Ca has excellent fire extinguishing performance. This study is helpful to develop eco-friendly coal fire prevention and control technology, and overcome the shortcomings of traditional gel foam on environmental pollutions.