Citation:

Huang, X. AND T. Tolaymat. Gas Quantity and Composition from the Hydrolysis of Salt Cake from Secondary Aluminum Processing. Majid Abbaspour (ed.), International Journal of Environmental Science and Technology. Springer, Heidelburg, Germany, 16(4):1955-1966, (2019). https://doi.org/10.1007/s13762-018-1820-x

Impact/Purpose:

Salt Cake is a byproduct of the secondary aluminum processing industry that can undergo reaction with water to generate heat and gas. Data regarding the potential for gas generation and temperature increase from SC hydrolysis are not readily available. Thus, to provide better end-of-life management for SC, a systematic study on heat and gas production potential due to the hydrolysis of SC was conducted [6-8]. The purpose of this manuscript is to present the first part of the study focusing on the gas generation, composition, and productivity from the hydrolysis. The relations between the gas production and the abundance of mineral phase in SC will also be presented.

Description:

A systematic approach to understanding the hydrolysis of salt cake from secondary aluminum production in municipal solid waste landfill environment was conducted. Thirty-nine (39) samples from 10 Aluminum recycling facilities throughout the USA were collected. A laboratory procedure to assess the gas productivity of SC from SAP under anaerobic conditions at 50 ^oC to simulate a landfill environment was developed. Gas quantity and composition data indicate that on average 1400 µmol g^-1 (35 mL g^-1) of gas resulted from the hydrolysis of SC. Hydrogen was the dominant gas generated (79% by volume) followed by methane with an average of 190 µmol g^-1 (21% by volume). N₂O was detected at a much lower concentration (1.2 ppmv). The total ammonia released was 680 µmol g^-1, and because of the closed system nature of the experimental setup, the vast majority of ammonia was present in the liquid phase (570 mg L^-1). In general, the productivity of both hydrogen and total ammonia (the sum of gas and liquid forms ammonia) was a fraction of that expected by stoichiometry indicating an incomplete hydrolysis and a potential for re-hydrolysis when conditions are more favorable. The result provides substantial evidence that SC can be hydrolyzed to generate gas with relative long-lasting implications for municipal solid waste landfill operations.

URLs/Downloads:

Record Details: