Nitrogen transformation during pyrolysis of oilfield sludge with high polymer content

Gong

Environmental Engineering Research

et al. 2020

With the enhancement of public awareness of environmental protection, the harm of oily sludge has gradually been paid attention to. As a kind of dangerous solid waste, the arbitrary disposal of oily sludge will cause quite serious harm to both the environment and human beings. Research on the treatment methods of oily sludge has become a hot spot recently. At present, treatment methods of oily sludge are various, mainly including pyrolysis, direct combustion, freeze-thaw treatment, biological treatment, solvent extraction, thermochemical cleaning, ultrasound-assisted treatment or joint technology, etc. Based on the consideration of economic benefits, social benefits and treatment difficulties, pyrolysis has been considered to be the most appropriate method for oily sludge treatment. Syngas, liquid oil and char can be obtained from pyrolysis of oily sludge, which can meet different needs. In this paper, the pyrolysis technology of oily sludge is reported in detail, including pyrolysis methods, operational parameters and pyrolysis products of oily sludge. On the basis, the advantages and limitations of oily sludge pyrolysis technology are discussed, together with the report of feasibility of pyrolysis technology of oily sludge. Moreover, the development trend of pyrolysis technology of oily sludge is prospected for the future work.

Section: Formation and Release Of Nitrogen/sulfur Compoundsmentioning

confidence: 99%

Application and development of pyrolysis technology in petroleum oily sludge treatment

Gong

Environmental Engineering Research

et al. 2020

Environ. Sci.: Water Res. Technol.

“…Many approaches have been developed to improve the production of combustible gas/tar, including solvent extraction, ultrasonic de-oiling, freeze/thaw, bioconversion, surfactant washing, gasification, and pyrolysis. 4,5,[7][8][9][10][11][12][13][14][15] Among these approaches, pyrolysis has the merits of recovering energy in situ and to yielding combustible gas/tar without the emission of pollutants. 8,9 During pyrolysis, some additives, e.g., vapor, 11 KOH, 16 urea, 7 CO 2 , 10 and solid organics, 12 were added into the scum, where the following evaporation, cracking and decomposition reactions occurred on the additive surface 1,17 to accelerate the decomposition of heavy oil in the oil scum as combustible gas/tar.…”

Section: Introductionmentioning

confidence: 99%

“…4,5,[7][8][9][10][11][12][13][14][15] Among these approaches, pyrolysis has the merits of recovering energy in situ and to yielding combustible gas/tar without the emission of pollutants. 8,9 During pyrolysis, some additives, e.g., vapor, 11 KOH, 16 urea, 7 CO 2 , 10 and solid organics, 12 were added into the scum, where the following evaporation, cracking and decomposition reactions occurred on the additive surface 1,17 to accelerate the decomposition of heavy oil in the oil scum as combustible gas/tar. Given that the Fe oxides have strong redox performance with organics, they served as an additive to accelerate the decomposition of heavy oil in oil sludge.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Transformation of oil scum as magnetic char for effective recovery of Cu and Ni from EDTA-bearing wastewater

Guo²,

Hong

et al. 2023

“…influence the pyrolysis performance of the biomass. Researchers investigated the migration course of nitrogen elements in raw biomass, proteins, and N-containing compounds (formed by protein mixed with hemicellulose, cellulose, and lignin) under various operating conditions [9][10][11]. With the increase of temperature, NO x precursors are primarily formed by the following three ways: the pyrolysis of unstable fuel-N, secondary decomposition of char, and tar products [12].…”

Section: Introductionmentioning

confidence: 99%

Nitrogen Migration during Pyrolysis of Raw and Acid Leached Maize Straw

Mou

Zou

et al. 2021

Sustainability

Solid biofuel is considered as a possible substitute for coal in household heat production because of the available and sustainable raw materials, while NOx emissions from its combustion have become a serious problem. Nitrogen-containing compounds in pyrolysis products have important effects on the conversion of fuel-N into NOx-N. Understanding these converting pathways is important for the environmentally friendly use of biomass fuels. The nitrogen migration during pyrolysis of raw and acid leached maize straw at various temperatures was investigated in this study. Thermal gravimetric analysis and X-ray photoelectron spectroscopy were used to investigate the performances of thermal decomposition and pyrolysis products from samples. The main nitrogen functional groups in biomass and biochar products were N-A (amine-N/amide-N/protein-N), pyridine-N, and pyrrole-N, according to the findings. The most common gaseous NOx precursor was NH3, which was produced primarily during the conversion of N-A to pyridine-N and pyrrole-N. The formation of HCN mainly came from the secondary decomposition of heterocyclic-N at high temperatures. Before the pyrolysis temperature increased to 650 °C, more than half of the fuel-N was stored in the biochar. At the same pyrolysis temperature, acid-leached maize straw yielded more gas-N and char-N than the raw biomass. The highest char-N yield of 76.39 wt% was obtained from acid-leached maize straw (AMS) pyrolysis at 350 °C. Low pyrolysis temperature and acid-leaching treatment can help to decrease nitrogen release from stable char structure, providing support for reducing nitrogenous pollutant emissions from straw fuel.