Ahmed Al Shoaibi

Health care and health professions education are becoming increasingly global, yet no formal international accrediting body exists for medical education. Among the challenges in developing internat...

Benzene is one of the aromatic hydrocarbons that are co‐absorbed with the acid gases during amine scrubbing and are carried over to the catalytic reactors in the sulfur recovery unit where they crack and deactivate the catalyst. As a solution, adsorption of benzene using porous adsorbents is being considered as a suitable process for removal. The present work considers carbon based porous adsorbents as potential adsorbents and attempts to screen the large pool of adsorbents. Preliminary screening was made using information in open literature and structural characteristics, before the adsorbents were subjected to gas phase benzene adsorption. The pool of porous carbons screened included highly acidic sulfonated carbons, ordered mesoporous carbons (OMCs) and various commercial activated carbons (ACs). Among the pool of porous carbons, mesoporous carbon identified as AC1, was found to possess the highest adsorption capacity for benzene with heat of adsorption capacity of 20–32 KJ/mol. It was found that it is possible to regenerate the benzene adsorption capacity of AC1 and a benzene adsorption capacity of about 14 mmol/g for the mesoporous carbon was found to be far superior to the adsorption capacities reported in literature. © 2018 American Institute of Chemical Engineers Environ Prog, 38: S93–S99, 2019

Pyrolysis of hydrogen sulfide, as an alternative treatment method to Claus process, with simultaneous hydrogen production and sulfur recovery is an energy intensive process. The high energy demand of the process remains a hindrance to its application. Production of hydrogen via hydrogen sulfide oxidation at very high equivalence ratios, compared to the high equivalence ratio of 3 employed in Claus reactor, has been studied experimentally. The objective of this approach is to alleviate the energy load requirement of hydrogen production from hydrogen sulfide stream. Since combustion of hydrogen sulfide cannot be sustained at such high equivalence ratios, partial oxidation reaction was examined in a heated quartz tubular reactor that was placed inside an electrical furnace. Oxygen concentration of 1% or 2 % in 10% H₂S (called the 10%H₂S/O₂ mixture) were injected into the reactor with the remaining 90% nitrogen gas. These results were compared to the case of decomposing H₂S alone. Experimental data showed that destruction of hydrogen sulfide increased with oxygen injection and that it increased with increase in oxygen concentration. Injection of oxygen at increased concentration consumed hydrogen constituent in hydrogen sulfide to water to result in dramatic decrease in hydrogen production. Formation of sulfur dioxide was absent over the examined temperature range of 1273–1673 K. These results provide the potential of hydrogen production from hydrogen sulfide oxidation, define the favorable operational conditions and outline the potential future developments for treatment of hydrogen sulfide.

It still remains a challenge to the recycling industry to develop an efficient and economical large-scale plastic waste recycling system, in spite of growing environmental concerns in waste disposal. Selective dissolution and precipitation (SDP) is a mechanical recycling technique that eliminates pre-sorting of mixed waste plastics and recycling polymer of high-grade quality. In this preliminary investigation, recycling of a comingled post-consumer waste plastic mixture of low-density polyethylene (LDPE), polystyrene (PS), high-density polyethylene (HDPE), and polyethylene terephthalate (PETE) using a lab-scale SDP setup was examined. A few experimental runs performed on the representative samples using Xylene/Toluene as solvents and acetone/2-propanol as anti-solvents demonstrated the sorting and recycling efficiency of this technique. FT-IR analysis of the reclaimed products revealed that the structural properties being very similar to virgin materials.