Comparing hydrogen absorption kinetics of the samples of intermetallic compound and metal hydride compact on its basis

This work is devoted to an experimental study and comparison of the kinetics of hydrogen absorption by an intermetallic compound LaNi4.4Al0.3Fe0.3 in form of pure intermetallic compound free backfill and a compact based on it obtained by cold pressing with a spiral matrix of nickel-foam. To calculate the kinetic parameters of the hydrogen absorption reaction, the initial rates method is used. The PCT absorption isotherms are measured at temperatures of 313, 333, and 353 K. The experimental data are described with quite high confidence by the chosen model, which assumes that the reaction rate controlling step is the dissociative absorption of hydrogen on the surface of the a-phase. The rate of hydrogen absorption increases with increasing pressure drop and temperature. It is shown that the rate of hydrogen absorption by the sample of pure IMC is significantly less dependent on temperature compared to the compact sample. In addition, the reaction rate at temperatures of 313 and 333 K is higher for the free backfill sample, and at 353 K it is higher for the metal hydride compact. The values of the absorption constant and the activation energy of the hydrogen absorption reaction are determined for both samples.

Recruitment Neutralizers of Hydrogen Sulfide to Produce a Fuel Oil of Astrakhan Gas Processing Plant

The content of hydrogen sulfide in the gas condensate of the Astrakhan gas condensate field, which is the raw material of the Astrakhan gas processing plant (Astrakhan GPP), is about 26% by volume. The high content of sulfur compounds in the reservoir mixture leads to an increased content in the fraction of >350°C, which is obtained during the primary fractionation of stable condensate. The selection of an effective reagent for the absorption of hydrogen sulfide and mercaptans from fuel oil is a very urgent task that is important for the company’s economy. The results of laboratory tests of reagents-neutralizers are the first stage of admission to industrial use at the Astrakhan GPP. This article is devoted to the search for analogs of reagents-neutralizers for reducing hydrogen sulfide and mercaptans in the fuel oil of the Astrakhan GPP.

Absorption removal of hydrogen sulfide from recirculated biogas

This study is focused on the effect of biogas recirculation with hydrogen sulfide removal on anaerobic treatment of sulfur-enriched synthetic wastewater in a UASB reactor. The presence of hydrogen sulfide in biogas causes problems in its further energy recovery while sulfides inhibit the anaerobic process. The reactor was gradually loaded with sulfates and their effect on the reactor operation was monitored. At the same time, external absorption of hydrogen sulfide from biogas with absorbent regeneration was operated. The results show that low concentrations of added sulfates support biogas production. At the sulfate concentration of 125 mg l−1, biogas production increased by approximately 2 l d−1. However, further increasing of the amount of sulfates in the substrate led to the opposite effect. At twice the amount of sulfates, the biogas production decrease by 1 l d−1 and its adverse effects on the removal of N-NH4, NC and P-PO4 were observed. Biogas recirculation through the absorption column ensured a decrease in the hydrogen sulfide concentration from 19 960 ppm to 4 030 ppm and an increase in the methane content from 59.2 % to 83 % and also a decrease in the sulfides concentration in the reactor. From the measured data it can be concluded that this method reduces sulfides inhibition.