Natural Gas to Hydrogen (H) - Revision history

Msl333 at 00:03, 14 March 2015

2015-03-14T00:03:04Z

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	Team H Final Report		Team H Final Report

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	Instructors: Fengqi You, David Wegerer		Instructors: Fengqi You, David Wegerer

	March 13, 2015

	__TOC__		__TOC__

Msl333 at 00:02, 14 March 2015

2015-03-14T00:02:49Z

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	Authors: Nick Dotzenrod, Samson Fong, Vince Kenny, Matthew Leung, Matthew Nathal, John Plaxco, Spencer Saldaña, Micah Zuckerman, Erik Zuehlke		Authors: Nick Dotzenrod, Samson Fong, Vince Kenny, Matthew Leung, Matthew Nathal, John Plaxco, Spencer Saldaña, Micah Zuckerman, Erik Zuehlke

	Instructors: Fengqi You, David Wegerer,		Instructors: Fengqi You, David Wegerer

	March 13, 2015		March 13, 2015

Msl333: /* Process Alternatives */

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Process Alternatives

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	::Disadvantages: high process temperatures, process has high a degree of complexity, poor hydrogen to carbon monoxide ratio		::Disadvantages: high process temperatures, process has high a degree of complexity, poor hydrogen to carbon monoxide ratio


	Steam reforming is the most appropriate technique for the proposed design due to its high degree of industrial maturity and safe operating conditions. Although partial oxidation and autothermal reforming each have distinct advantages, the lack of maturity for both of these processes would add a high degree of risk to the overall plant design. Furthermore, the lower operation temperature of steam reforming will result in a safer process (Holiday et al. 2007).		Steam reforming is the most appropriate technique for the proposed design due to its high degree of industrial maturity and safe operating conditions. Although partial oxidation and autothermal reforming each have distinct advantages, the lack of maturity for both of these processes would add a high degree of risk to the overall plant design. Furthermore, the lower operation temperature of steam reforming will result in a safer process (Holiday et al. 2007).


	The five methods of steam reforming that would provide the necessary purity for hydrogen cars are the conventional box method, conventional can method, the compact steam methane reformers, plate-type steam methane reformers, and membrane reactor steam reforming.		The five methods of steam reforming that would provide the necessary purity for hydrogen cars are the conventional box method, conventional can method, the compact steam methane reformers, plate-type steam methane reformers, and membrane reactor steam reforming.
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	::Disadvantages: Membrane reactors require temperatures 200 °C greater than conventional methods and does not work effectively at the large scale desired (Ogden, 2002).		::Disadvantages: Membrane reactors require temperatures 200 °C greater than conventional methods and does not work effectively at the large scale desired (Ogden, 2002).

		⚫	After taking all the processes into consideration, the conventional box steam reformer is the most appropriate choice for the plant being designed as it will yield the desired purity and can produce the 100 MMscfd desired.

⚫	After taking all the processes into consideration, the conventional box steam reformer is the most appropriate choice for the plant being designed as it will yield the desired purity and can produce the 100 MMscfd desired.

	==Technology Options==		==Technology Options==

Msl333: /* Carbon Monoxide Removal Alternatives */

2015-03-14T00:02:01Z

Carbon Monoxide Removal Alternatives

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	===Carbon Monoxide Removal Alternatives===		===Carbon Monoxide Removal Alternatives===


	The steam reforming process produces approximately 5% of carbon monoxide in the product stream. Water-gas shift and methanation are two most common method to improve purity (Song, 2002). Water-gas shift reacts carbon monoxide and water to form hydrogen and carbon dioxide. In order to prevent the oxidation of hydrogen, precise control of air input is needed. Conventionally, the product stream is passed through a high temperature reactor because the reaction is substantially faster at higher temperature, but it is then passed through a low temperature reactor to improve hydrogen production (Hoogers, 2003). TeGrotenhuis et al. (2002) have demonstrated that a single reactor with a gradient temperature that spans both ends of the temperature extremes can be used in order to reduce the utility used. While copper catalysts are most prevalent, increased selectivity can be achieved with higher cost molybdenum carbide or platinum-based catalysts (Patt et al. 2000; Chandler et al. 200).		The steam reforming process produces approximately 5% of carbon monoxide in the product stream. Water-gas shift and methanation are two most common method to improve purity (Song, 2002). Water-gas shift reacts carbon monoxide and water to form hydrogen and carbon dioxide. In order to prevent the oxidation of hydrogen, precise control of air input is needed. Conventionally, the product stream is passed through a high temperature reactor because the reaction is substantially faster at higher temperature, but it is then passed through a low temperature reactor to improve hydrogen production (Hoogers, 2003). TeGrotenhuis et al. (2002) have demonstrated that a single reactor with a gradient temperature that spans both ends of the temperature extremes can be used in order to reduce the utility used. While copper catalysts are most prevalent, increased selectivity can be achieved with higher cost molybdenum carbide or platinum-based catalysts (Patt et al. 2000; Chandler et al. 200).


	Another process to reduce carbon monoxide is methanation. Similar to water-gas shift, methanation reacts carbon monoxide and hydrogen to form methane and water. Methanation reactors are generally simpler without the need for a precise air stream. However, the reaction fundamentally consumes hydrogen at a very high rate (3 moles of hydrogen are consumed for 1 mole of carbon monoxide consumed) (Hoogers, 2003). A combination of both methods is generally used for high purity hydrogen production, which is appropriate for the proposed design. As such, both a water-gas shift as well as methanation will be utilized.		Another process to reduce carbon monoxide is methanation. Similar to water-gas shift, methanation reacts carbon monoxide and hydrogen to form methane and water. Methanation reactors are generally simpler without the need for a precise air stream. However, the reaction fundamentally consumes hydrogen at a very high rate (3 moles of hydrogen are consumed for 1 mole of carbon monoxide consumed) (Hoogers, 2003). A combination of both methods is generally used for high purity hydrogen production, which is appropriate for the proposed design. As such, both a water-gas shift as well as methanation will be utilized.


	===Acid Gas Removal===		===Acid Gas Removal===

Msl333: /* Reactor and Catalyst Alternatives */

2015-03-14T00:01:48Z

Reactor and Catalyst Alternatives

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	Of the several process alternatives described above, steam reforming is the most developed technology for hydrogen production. However, there are different ways to carry out the process of steam reforming. The alternatives focus on the choice of catalyst and the configuration of the catalyst in the reactor.		Of the several process alternatives described above, steam reforming is the most developed technology for hydrogen production. However, there are different ways to carry out the process of steam reforming. The alternatives focus on the choice of catalyst and the configuration of the catalyst in the reactor.


	Generally, catalysts can be categorized as non-precious metal (such as nickel) and precious metal (such as platinum and rhodium). The cost of non-precious metal catalysts is substantially lower, but the catalyst is also far less effective. Nevertheless, conventional steam reforming plants usually use nickel catalysts because heat and mass transfer effects generally dominate the reaction kinetics with an effectiveness factor as low as 5% (Adris and Pruden, 1996).		Generally, catalysts can be categorized as non-precious metal (such as nickel) and precious metal (such as platinum and rhodium). The cost of non-precious metal catalysts is substantially lower, but the catalyst is also far less effective. Nevertheless, conventional steam reforming plants usually use nickel catalysts because heat and mass transfer effects generally dominate the reaction kinetics with an effectiveness factor as low as 5% (Adris and Pruden, 1996).


	To reduce the heat and mass transfer effects, some processes attempt to reduce the particle size of catalysts and increase the reaction area by using microchannel-based reactors (Wang et al. 2004). As the size of the catalyst particle decreases, the apparent kinetics of reaction converge to the intrinsic kinetic of the catalyst. As a result, the more expensive precious metal catalysts are favored (Rostrup-Nielsen, 2003). Currently, researchers are developing cobalt-based catalysts to mitigate the cost of rhodium based catalysts (Song et al. 2007).		To reduce the heat and mass transfer effects, some processes attempt to reduce the particle size of catalysts and increase the reaction area by using microchannel-based reactors (Wang et al. 2004). As the size of the catalyst particle decreases, the apparent kinetics of reaction converge to the intrinsic kinetic of the catalyst. As a result, the more expensive precious metal catalysts are favored (Rostrup-Nielsen, 2003). Currently, researchers are developing cobalt-based catalysts to mitigate the cost of rhodium based catalysts (Song et al. 2007).


	===Carbon Monoxide Removal Alternatives===		===Carbon Monoxide Removal Alternatives===

Msl333: /* Appendix D: Cost Estimation Details */

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Appendix D: Cost Estimation Details

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	<u>Yearly Revenue: </u> $747,619,200/yr. Calculated by multiplying the cost of hydrogen per kilogram by the plant’s yearly output of hydrogen in kilograms (O’dell, 2015).		<u>Yearly Revenue: </u> $747,619,200/yr. Calculated by multiplying the cost of hydrogen per kilogram by the plant’s yearly output of hydrogen in kilograms (O’dell, 2015).








	==Appendix E: Economic Calculations==		==Appendix E: Economic Calculations==

Msl333: /* Site Conditions */

2015-03-13T23:59:59Z

Site Conditions

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	==Site Conditions ==		==Site Conditions ==

	The proposed plant will be located in Freeport, Texas, a port city in Brazoria County. Texas was chosen as the site for the plant because of its lack of corporate and individual income taxes as well as its low sales and property taxes.12 The sales tax rate in Freeport is 8.25% and the property tax rate is approximately 0.5%.13 Furthermore, the presence of the Dow Chemical Company’s Texas Operations facility in Freeport ensures that the proper utilities infrastructure will be available. Texas was rated as the best state for business in 2014, which further motivated the decision to locate the plant there.4 The climate of Freeport is classified as humid subtropical. This ensures continuous production with little climate effects on the plant.		The proposed plant will be located in Freeport, Texas, a port city in Brazoria County. Texas was chosen as the site for the plant because of its lack of corporate and individual income taxes as well as its low sales and property taxes. The sales tax rate in Freeport is 8.25% and the property tax rate is approximately 0.5%. Furthermore, the presence of the Dow Chemical Company’s Texas Operations facility in Freeport ensures that the proper utilities infrastructure will be available. Texas was rated as the best state for business in 2014, which further motivated the decision to locate the plant there. The climate of Freeport is classified as humid subtropical. This ensures continuous production with little climate effects on the plant.

	==Steam Reforming Process==		==Steam Reforming Process==

Msl333: /* Technical Approach Taken */

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Technical Approach Taken

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	The Peng-Robinson fluid package was chosen for use in the HYSYS simulation because it is ideal for describing hydrocarbon systems such as the steam methane reforming plant, where most components are gases or are nonpolar. Furthermore, Peng-Robinson is reliable over a large range of operating temperatures and pressures, which encompass those within our system. The amine plant portion of the simulation uses the amine package. This package is based on the Kent-Eisenberg model specifically designed for modeling removal of CO<sub>2</sub> and H<sub>2</sub>S by amines.		The Peng-Robinson fluid package was chosen for use in the HYSYS simulation because it is ideal for describing hydrocarbon systems such as the steam methane reforming plant, where most components are gases or are nonpolar. Furthermore, Peng-Robinson is reliable over a large range of operating temperatures and pressures, which encompass those within our system. The amine plant portion of the simulation uses the amine package. This package is based on the Kent-Eisenberg model specifically designed for modeling removal of CO<sub>2</sub> and H<sub>2</sub>S by amines.
	Difficulties encountered modeling adsorption processes in HYSYS lead to the use of component splitters to model the feed pretreatment and pressure swing adsorption (PSA) steps.		Difficulties encountered modeling adsorption processes in HYSYS lead to the use of component splitters to model the feed pretreatment and pressure swing adsorption (PSA) steps.

			==Site Conditions ==

			The proposed plant will be located in Freeport, Texas, a port city in Brazoria County. Texas was chosen as the site for the plant because of its lack of corporate and individual income taxes as well as its low sales and property taxes.12 The sales tax rate in Freeport is 8.25% and the property tax rate is approximately 0.5%.13 Furthermore, the presence of the Dow Chemical Company’s Texas Operations facility in Freeport ensures that the proper utilities infrastructure will be available. Texas was rated as the best state for business in 2014, which further motivated the decision to locate the plant there.4 The climate of Freeport is classified as humid subtropical. This ensures continuous production with little climate effects on the plant.

	==Steam Reforming Process==		==Steam Reforming Process==

Sfong at 21:05, 13 March 2015

2015-03-13T21:05:10Z

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	==Executive Summary==		==Executive Summary==

			As environmental concerns lead many automobile makers to use alternative fuel source, hydrogen fuel cell is increasingly attractive. However, the hydrogen needed to be used in a fuel cell requires a purity of 99.999% which is purer than most applications. As a result, there is an opportunity to produce high purity hydrogen to support this potential market. In addition, the recent natural gas boom will provide a cheap feedstock for a traditional method for hydrogen production: steam reforming.

			The plant is proposed to be located in Freeport, Texas to be near the East Texas Basin natural gas feedstock. It will be able to produce the hydrogen at 100 MMscfd (Million standard cubic feet per day), a relatively high capacity plant especially for such high purity hydrogen. In addition to the feedstock, the location also has a low corporate tax rate reducing annual costs.

			The steam reforming process, after desulfurization, utilizes the natural gas feed by combining it with steam. The mixture is then passed through a reactor filled with catalysts, resulting in a mixture of carbon monoxide, carbon dioxide, and hydrogen. The subsequent water gas shift and separation units (amine plant) remove the impurity to result in highly pure hydrogen. Any wastewater produced will be sent for off-site treatment. The steam reforming process is industrially mature. As a result, there is no unknowns in the process as it is very well characterized. This reduces down time and risk and ensure the safety of the workers.

			In order to make this process as efficient as possible, several key parameters are optimized. For instance, a large part of the operating cost is due to utility costs. As a result, heat exchangers were included and placed optimally to take advantage of the heat produced to reduce the necessary heating by a furnace. In addition, to reduce the need to treat the impure unconverted gases, they are burned as fuel. Finally, the size of the amine plant and the specific amine used are also optimized for this application of high purity hydrogen production.
			In addition to optimizing the process, an optimization to the process equipment has also been done. The design goal is generally to use the most industrially mature process to reduce risk of failure and maximize uptime. In addition, when there are several competing technologies, the cheapest, high-throughput capable option is selected.

			The total capital cost of this proposed plant is $62.6 million. Annually, the plant is predicted to have a revenue of $748 million (assuming 360 days operation to allow for holiday vacations). In addition, the plant will cost $359 million to operate, resulting in $2.11 billion of profit after 10 years. The simple payback period is 0.161 years with a return on investment of 6.21. Financially, the cheap feedstock and process make this project highly profitable. While the economic analysis is only done for the first ten years, the plant is expected to remain in operation for 25 to 50 years.

	==Introduction==		==Introduction==

Mzuckerman at 20:29, 13 March 2015

2015-03-13T20:29:42Z

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