Jet fuel mercaptan oxidation treating - PFD

This PFD of jet fuel mercaptan oxidation treating was redrawn from Wikipedia file: ConvLPGMerox.png. [en.wikipedia.org/ wiki/ File:ConvKeroMerox.png]
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported icense. [creativecommons.org/ licenses/ by-sa/ 3.0/ deed.en]
"Merox is an acronym for mercaptan oxidation. It is a proprietary catalytic chemical process developed by UOP used in oil refineries and natural gas processing plants to remove mercaptans from LPG, propane, butanes, light naphthas, kerosene and jet fuel by converting them to liquid hydrocarbon disulfides.
The Merox process requires an alkaline environment which, in some of the process versions, is provided by an aqueous solution of sodium hydroxide (NaOH), a strong base, commonly referred to as caustic. In other versions of the process, the alkalinity is provided by ammonia, which is a weak base.
The catalyst in some versions of the process is a water-soluble liquid. In other versions, the catalyst is impregnated onto charcoal granules.
Processes within oil refineries or natural gas processing plants that remove mercaptans and/ or hydrogen sulfide (H2S) are commonly referred to as sweetening processes because they results in products which no longer have the sour, foul odors of mercaptans and hydrogen sulfide. The liquid hydrocarbon disulfides may remain in the sweetened products, they may be used as part of the refinery or natural gas processing plant fuel, or they may be processed further.
The Merox process is usually more economical than using a catalytic hydrodesulfurization process for much the same purpose." [en.wikipedia.org/ wiki/ Merox]
The process flow diagram (PFD) example "Jet fuel mercaptan oxidation treating" was drawn using the ConceptDraw PRO software extended with the Chemical and Process Engineering solution from the Chemical and Process Engineering area of ConceptDraw Solution Park.

The vector stencils library "Citric acid cycle (TCA cycle)" contains 26 symbols of metabolites for drawing metabolic pathway maps and biochemical shematic diagrams of the citric acid cycle (TCA cycle, tricarboxylic acid cycle, Krebs cycle) and diagrams of metabolism processes.
"The citric acid cycle - also known as the tricarboxylic acid cycle (TCA cycle), or the Krebs cycle, - is a series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetate derived from carbohydrates, fats and proteins into carbon dioxide and chemical energy in the form of adenosine triphosphate (ATP). In addition, the cycle provides precursors of certain amino acids as well as the reducing agent NADH that is used in numerous other biochemical reactions. Its central importance to many biochemical pathways suggests that it was one of the earliest established components of cellular metabolism and may have originated abiogenically.
The name of this metabolic pathway is derived from citric acid (a type of tricarboxylic acid) that is consumed and then regenerated by this sequence of reactions to complete the cycle. In addition, the cycle consumes acetate (in the form of acetyl-CoA) and water, reduces NAD+ to NADH, and produces carbon dioxide as a waste byproduct. The NADH generated by the TCA cycle is fed into the oxidative phosphorylation (electron transport) pathway. The net result of these two closely linked pathways is the oxidation of nutrients to produce usable chemical energy in the form of ATP." [Citric acid cycle. Wikipedia]
The shapes example "Design elements - TCA cycle" is included in the Biology solution from the Science and Education area of ConceptDraw Solution Park.