Experimental study of the hydrothermal reactivity of oxalic acid under high pressure

• Published in: IOP conference series. Earth and environmental science 2020-11, Vol.600 (1), p.12003
• Main Authors: Chen, Kefei, Li, Yuanju, Zhang, Chen, Zhou, Shixin, Li, Jing, Li, Pengpeng, Sun, Zexiang, Meng, Bingkun, Fu, Deliang
• Format: Article
• Language: English
• Subjects: Acids; Decarboxylation; Decomposition; Dissolution; High pressure; Organic acids; Oxalic acid; Thermal stability
• ISSN: 1755-1307; 1755-1315
• DOI: 10.1088/1755-1315/600/1/012003

The thermal stability of organic acids has a close relationship with the formation mechanism of secondary pores in deep reservoirs. Experiments were conducted to investigate the thermal stability of oxalic acid under high pressure and the influence of K-feldspar on oxalic acid decomposition. The experiment temperatures were set in the range of 130-330°C and each experiment was performed for 72h under 60MPa. Results show that both temperature and K-feldspar have significant influence on the decomposition of oxalic acid. The oxalic acid decomposed slowly at temperatures less than 180°C, and most of the oxalic acid decomposed at temperatures between 180°C and 230°C. Besides, the decarboxylation reaction proceeded more slowly in the presence of K-feldspar than the mineral-free experiments, which is most likely attributed to the increasing pH caused by dissolution. In addition, because the decomposition rate of oxalic acid was low, the K-feldspar dissolution was not affected at temperatures lower than 230°C.