Characteristic of the Volatile Arsenic in Natural Gas and its Novel Determination Method

Abstract

The occurrence of volatile arsenic in natural gas, could lead to the poisoning of catalyst in processing equipment, and pose a serious threat to human health. In order to detect the total volatile arsenic in natural gas, this paper analyzed the characteristic and original mechanism of the volatile arsenic first, then a novel method was carried out by using silver nitrate solution, saturated potassium persulfate solution and concentrated nitric acid solution as sorption solution, followed by volatile arsenic determination with ICP-MS .The result showed that 2% silver nitrate solution had a good adsorption effect to volatile arsenic, and the recoveries of arsenic ranged from 87%~103%, which basically met the demand for the rapid detection of volatile arsenic in natural gas.

Arsenic Analysis in the Petroleum Industry: A Review

“…Pressurized cylinders can be used to sample gases at high pressures directly on the production system or in the well under initial pressure . Although natural gas sampling with pressurized cylinders is a fast and easy-to-handle method, arsenic depletion has been observed in natural gas samples stored in steel cylinders. To overcome this problem, a special coating (Silcosteel or Sulfinert) has been designed to create an inert internal surface in these cylinders to limit the interactions between arsenic and the cylinder walls.…”

“…). 4 Concentrated nitric acid (HNO 3 ) can be used as a trapping solution. 2,14,19 However, it has been shown that a 2% aqueous silver nitrate (AgNO 3 ) solution provides better TMA trapping efficiency than a concentrated nitric acid solution.…”

“…It was later demonstrated that different organic and inorganic forms of As are present, , with a dominance of trimethylarsine (TMA, (CH 3 ) 3 As), triethylarsine ((C 2 H 5 ) 3 As), triphenylarsine ((C 6 H 5 ) 3 As). and arsine (AsH 3 ). ,,, TMA is the most abundant volatile As species in natural gas (55–80% of the total As in natural gas) . The dominance of TMA is thought to be related to its higher stability over time compared to that of other As compounds …”

“…and arsine (AsH 3 ). ,,, TMA is the most abundant volatile As species in natural gas (55–80% of the total As in natural gas) . The dominance of TMA is thought to be related to its higher stability over time compared to that of other As compounds …”

“…5 The dominance of TMA is thought to be related to its higher stability over time compared to that of other As compounds. 4 Few articles mention the total amount of As in crude oil; only Olsen et al 15 and Stigter et al 16 were able to identify a concentration range from <10 to 26.2 μg kg −1 of As in real crude oil samples. The main forms of arsenic in these matrices are TMA, which is predominant, dimethylated arsenic ((CH 3 ) 2 As), and monomethylated arsenic ((CH 3 )As).…”