Experimental study on kinetic characteristics of oil sludge gasification

Abstract

Oil sludge (OS) is a typical dangerous waste in petroleum industry, which also contains abundant energy. The purpose of this study was to recover resources from OS gasification. To figure out the gasification process, a thermal analyzer was used to carry out OS gasification experiments under steam/nitrogen atmosphere with different heating rates. Results showed that the OS gasification reaction could be divided into five stages: free water volatilization, the escape of light components, the cracking of heavy components and steam reforming, the charring process and water gas shift (WGS) reactions, and inorganic mineral decomposition. The activation energy (E), pre‐exponential factor (A), enthalpy change (ΔH), Gibbs free energy change (ΔG), and entropy change (ΔS) of three main reaction stages (Stages 2–4) were analyzed through kinetic and thermodynamic analysis. From Stage 2 to Stage 4, E, ΔH, and ΔS decreased from 118.80 kJ·mol−1, 113.92 kJ·mol−1, and −4.09 J·(K mol)−1 to 13.19 kJ·mol−1, 5.92 kJ·mol−1, and −234.06 J·(K mol)−1, respectively. Nevertheless, ΔG increased from 116.01 to 210.04 kJ·mol−1. From these parameters, it could be found that the decrease of E was beneficial to the reaction. However, the values of ΔG were always positive and the reaction could not happen spontaneously.

An Overview of the Current State and Prospects for Oil Recovery from Oily Sludge

“…According to the physicochemical composition and method of formation, oil sludge is divided into five groups [32][33][34]: (iv) Tank oil sludge is waste generated throughout the transportation and storage of oil in various tanks. (v) Ground oil sludge -is a product of the combination of soil and oil spilled on it; the reason for this can be both a technological process and an accident.…”

Steam Pyrolysis of Oil Sludge for Energy-Valuable Products

“…Oil is one of the most abundant energy resources worldwide [1]; its extraction, transportation, storage, and processing are associated with the formation of a significant amount of waste, including oil sludge (OS) [2][3][4][5][6][7]. This type of high-hazard waste comprises water, oil, mineral impurities, and different deposits (sand, clay, silt, etc.)…”

“…A similar trend was described by Motlang et al [25] based on numerical studies of the effect of water vapor added in OS thermal conversion. In turn, Chu et al [5] revealed five stages of steam pyrolysis of OS proceeding in the temperature range of 30-669 • C: drying of external moisture, volatilization of light components, cracking of heavy components and steam reforming, the coking process, and the subsequent inorganic mineral decomposition.…”

Углеродистый Остаток От Термической Переработки Нефтешлама Как Основа Для Био-Топливной Композиции

“…В настоящее время нефть является одним из наиболее востребованных видов энергоносителей в мире [1]. Её добыча, транспортировка, хранение и переработка сопровождаются образованием значительного количества нефтешламовых отходов [2][3][4], имеющих высокий класс опасности [3]. Состав нефтешламовых отходов зависит от своего технологического происхождения.…”

“…Одним из современных подходов переработки нефтешламовых отходов является их термическое преобразование методами пиролиза или газификации [2][3][4]7] с получением полезных продуктов в виде жидких углеводородов, синтез-газа и углеродистого остатка. Перечисленные процессы относятся, как правило, к аллотермическому типу [8], по причине чего образующийся углеродистый остаток используют в качестве вторичного энергоресурса для компенсации энергетических затрат.…”