{"id":1975,"date":"2015-09-16T12:11:33","date_gmt":"2015-09-16T12:11:33","guid":{"rendered":"http:\/\/hydrogen.wsu.edu\/?page_id=1975"},"modified":"2016-01-06T15:30:55","modified_gmt":"2016-01-06T23:30:55","slug":"purification","status":"publish","type":"page","link":"https:\/\/hub.wsu.edu\/ise\/design\/purification\/","title":{"rendered":"Purification"},"content":{"rendered":"
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Meet the WSU H2-Refuel Purification Team!<\/h2>\n<\/header>\n

\"Purification<\/a>Derek Johnson, Zachary Gilvey, Daniel Barnes, Ryan Fish & Ryan Brown<\/p>\n

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Purification, one small step for hydrogen fuel, one giant leap towards a cleaner future.<\/strong><\/p>\n<\/blockquote><\/div>\n<\/section>\n

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Our Objective<\/h2>\n<\/header>\n

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In Spring 2016 everyone will be racing to Pullman to check out the innovative modular hydrogen fueling station designed by WSU Engineering students! <\/span>The purification team is tasked with the goal of allowing our design to output a gas that is 99.999% pure hydrogen gas.<\/span> To put our goal into perspective \u00a0let’s relate it to our famous WSU Martin Stadium. \u00a0The capacity of Martin Stadium is approximately 35,000 people, if each one of those people represented a molecule of our output gas only 3 of those people could not be hydrogen molecules for us to succeed. \u00a0<\/span>Our challenge is to output pure hydrogen with less than one hundred parts per million of impurities as required by SAE J2719.<\/span><\/p>\n

During the design process the Hydrogen Source and Purification teams have worked closely together. We finalized and submitted a design to the H2-Refuel Competition that utilizes electrolysis to separate hydrogen from water or methane.<\/p>\n

What makes our design so innovative is the modularity. Electrolysis was determined to be the best option for the competition design due to the input of the system. We have also researched ideal design alternatives if Syn-Gas is inputted instead.<\/p>\n

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Input:<\/strong> Methane, Water, Electricity<\/td>\nInput:<\/strong> Syn-Gas (Hydrogen, Carbon Monoxide & Carbon Dioxide)<\/td>\n<\/tr>\n
Output:<\/strong> Gaseous Hydrogen and Waste Gases<\/td>\n<\/tr>\n
Musts:<\/strong> Reach a purity of 99.995% or greater<\/td>\n<\/tr>\n
Should:<\/strong> Generate Power, Output at high pressure, Easily Accessible<\/td>\n<\/tr>\n<\/tbody>\n<\/table><\/div>\n<\/section>\n
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Background<\/h2>\n<\/header>\n

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There are many different commercially available ways to purify a gas. Our challenge is to find the right method that meets all of the system needs and links well with the other subsystems.\u00a0The following processes are the most commercially available and proven hydrogen purification technologies today:<\/p>\n

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Palladium Membrane Diffusion<\/strong>:<\/em> As the name suggests, this method uses the chemical element palladium (Pd) and typically a silver alloy. Together they posses the ability to only allow hydrogen to pass through when subjected to temperatures of approximately 300 <\/span>\u00b0C.\u00a0<\/span><\/p>\n

Palladium Membrane advantages include exceeding hydrogen purity standards, unlimited lifetime (no vessel replacement), low power consumption, customizable by flow rate.\u00a0The purifier does not require replacement\u00a0since the inlet impurities are trapped on the inlet side of the palladium and vented continuously.<\/p>\n

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Cryogenic Separation<\/strong>: Is the process of selectively purifying gases by boiling them in liquified states at various boiling temperatures. The process would possibly require small heat exchangers to turn any liquid input into a gas before it went through separation.<\/span><\/p>\n

The Cryogenic Separation system separates impurities by cryogenic adsorption. A pressurized hydrogen gas is inputed into the system and enters a series of heat exchangers and adsorbent beds to produce a 99.99% pure hydrogen gas. Silica gel is the main adsorbent material used, which is submerged in liquid nitrogen during the process. Some of the key benefits of utilizing this technology are ease of on-site maintenance, small footprint, low operational cost, output meets hydrogen fuel purification standards.<\/p>\n

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Pressure Swing Adsorption (PSA):\u00a0Pressure swing adsorption is when components of a gas mixture are adsorbed on a solid material matrix using high pressure, such as active carbon and zeolite. These different components are then desorbed at a low pressure and can then be siphoned off. <\/span><\/b><\/p>\n

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Chemical Adsorption<\/strong>:<\/strong> A method of separating gas components through specific adsorption zones. The most prominent method in use is carbon nanotubes, carbon is well known for being porous and being able to absorb gases. Difficult to find commercially available units, typically this method is found in large scale industrial operations.<\/span><\/p>\n

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Physical Absorption: <\/b>Is a puriificaiton method\u00a0where either liquid absorbs a gas or solid absorbs a liquid.\u00a0<\/span>Unwanted molecules attach themselves to a substance of volume and the desired\u00a0molecules, will still be in the same state. For our application, this method w<\/span>ould\u00a0consume to much space.\u00a0<\/span><\/p>\n<\/p><\/div>\n

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Palladium Membrane Diffusion Diagram<\/b><\/p>\n

\"Palladium\"<\/a><\/p>\n

Cryogenic Separation Diagram<\/b><\/p>\n

\"Screen<\/a><\/p>\n

Pressure Swing Adsorption Diagram<\/strong><\/p>\n

\"Screen<\/a><\/p>\n

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Design Specifications<\/h2>\n<\/header>\n

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A House of Quality ranks the relationship between system requirements and different design options. As we research and develop our purification system these relationships will help us optimize our design.<\/span><\/p>\n

\"simplified<\/a><\/p>\n

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Ranking System:<\/strong> Each\u00a0purification\u00a0process\u00a0was given a rank of 1-4 for each quality characteristic.<\/p>\n

1-Bad \u00a0 2-Good \u00a0 3-Great \u00a0 4-Ideal<\/p>\n

Manufacturing cost, Safety & Modularity were all multiplied by 3 because they are most relevant and important requirements to our sub system. Reliability is also multiplied by 2 due to its relevance of meeting hydrogen fuel purification standards.<\/p>\n

As you can see purification is critical to the system because it is highly related to many important requirements such as, cost, power usage, reliability, ease of maintenance, hydrogen output, contamination & modularity<\/p>\n<\/p><\/div>\n<\/section>\n

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Design Alternatives<\/h2>\n<\/header>\n

Palladium Diffusion Membrane –<\/strong><\/p>\n

Necessary Input:<\/span><\/p>\n