Design G1 - Revision history

Jian: /* References */

2015-02-28T22:13:34Z

References

Jian: /* References */

2015-02-28T17:03:46Z

References

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	=References=		=References=
			:Cityofchicago.org. Water Sewer Rates [Internet]. Chicago: City of Chicago; c2010-15 [cited 2015 Feb 26]. Available from: http://www.cityofchicago.org/city/en/depts/water/provdrs/cust_serv/svcs/know_my_water_sewerrates.html.

			:Dailyfinance.com [Internet]. New York: AOL Inc.; c2015 [cited 2015 Feb 26]. Available from: http://www.dailyfinance.com/.

	:Ding Z, Chiu J, Jin W, inventor; GTC Technology US LLC, assignee. Process for converting glycerin into propylene glycol. US Patent 08394999 B2. 2013 Mar 12.		:Ding Z, Chiu J, Jin W, inventor; GTC Technology US LLC, assignee. Process for converting glycerin into propylene glycol. US Patent 08394999 B2. 2013 Mar 12.

	:~~Xiao Y, Xiao G, Varma A~~. ~~A universal procedure for crude glycerol purification~~ from ~~different feedstocks in biodiesel production~~: ~~experimental and simulation study~~. ~~Ind Eng Chem Res~~. ~~2013;52(39):14291-6~~.		:Dow.com. About propylene glycols [Internet]. Midland: The Dow Chemical Company; c1995-2015a [cited 2015 Feb 26]. Available from: http://www.dow.com/propyleneglycol/about/.

	:~~Propylene-glycol~~.com [Internet]. ~~Brussels~~: ~~PO/PG Sector group of Cefic~~ [cited 2015 Feb 26]. Available from: http://~~www~~.~~propylene-glycol~~.com/.		:Dow.com. Product Safety Assessment [Internet]. Midland: The Dow Chemical Company; c1995-2015b [cited 2015 Feb 26]. Available from: http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_091a/0901b8038091a41a.pdf?filepath=productsafety/pdfs/noreg/233-00490.pdf&fromPage=GetDoc.

	:~~Dow~~.com~~. About propylene glycols~~ [Internet]. ~~Midland: The Dow Chemical~~ Company; ~~c1995-2015~~ [cited 2015 Feb 26]. Available from: http://www.~~dow~~.com/~~propyleneglycol/about/.~~		:Globalindustrial.com [Internet]. Global Equipment Company Inc.; c2015 [cited 2015 Feb 26]. Available from: http://www.globalindustrial.com/.

	~~:Tuck MWM, inventor; Davy Process Technology Limited, assignee. Process for the hydrogenation of glycerol to propylene glycol. US patent 08227646 B2. 2012 Jul 24~~.

	:Northerntool.com [Internet]. Burnsville: Northern Tool + Equipment [cited 2015 Feb 26]. Available from: http://www.northerntool.com/.		:Northerntool.com [Internet]. Burnsville: Northern Tool + Equipment [cited 2015 Feb 26]. Available from: http://www.northerntool.com/.

	~~:Globalindustrial.com [Internet]. Global Equipment Company Inc.; c2015 [cited 2015 Feb 26]. Available from: http://www.globalindustrial.com/.~~

	:Pkgequipment.com [Internet]. Rochester: PKG Equipment Inc.; c2013 - [cited 2015 Feb 26]. Available from: http://www.pkgequipment.com/index.html.		:Pkgequipment.com [Internet]. Rochester: PKG Equipment Inc.; c2013 - [cited 2015 Feb 26]. Available from: http://www.pkgequipment.com/index.html.

	:~~Cityofchicago~~.~~org. Water Sewer Rates~~ [Internet]. ~~Chicago~~: ~~City of Chicago~~; ~~c2010~~-15 [cited 2015 Feb 26]. Available from: http://www.~~cityofchicago~~.~~org/city/en/depts/water~~/~~provdrs/cust_serv/svcs/know_my_water_sewerrates.html~~.		:Praxair.com [Internet]. Danbury: Praxair Technology, Inc.; c2013-15 [cited 2015 Feb 26]. Available from: http://www.praxair.com/.

	:~~Dailyfinance~~.com [Internet]. ~~New York~~: ~~AOL Inc.; c2015~~ [cited 2015 Feb 26]. Available from: http://www.~~dailyfinance~~.com/.		:Propylene-glycol.com [Internet]. Brussels: PO/PG Sector group of Cefic [cited 2015 Feb 26]. Available from: http://www.propylene-glycol.com/.

	:~~Praxair~~.com [Internet]. ~~Danbury~~: ~~Praxair Technology~~, Inc.; ~~c2013~~-15 [cited 2015 Feb 26]. Available from: ~~http~~://www.~~praxair~~.com/.		:Sciencelab.com. Material Safety Data Sheet Propylene glycol MSDS [Internet]. Houston: ScienceLab.com, Inc.; c1997-2005 [cited 2015 Feb 26]. Available from: https://www.sciencelab.com/msds.php?msdsId=9927239.

	:~~Zhou Z~~, ~~Li X, Zeng T, Hong W~~, ~~Cheng Z, Yuan W~~. ~~Kinetics of hydrogenolysis~~ of glycerol to propylene glycol ~~over Cu-ZnO-Al2O3 catalysts~~. ~~Chin J Chem Eng~~. ~~2010;18(3);384-90~~.		:Tuck MWM, inventor; Davy Process Technology Limited, assignee. Process for the hydrogenation of glycerol to propylene glycol. US patent 08227646 B2. 2012 Jul 24.

	:~~Dow~~.~~com~~. ~~Product Safety Assessment [Internet]~~. ~~Midland: The Dow Chemical Company~~; ~~c1995-2015 [cited 2015 Feb 26]. Available from~~: ~~http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_091a/0901b8038091a41a.pdf?filepath=productsafety/pdfs/noreg/233~~-~~00490.pdf&fromPage=GetDoc~~.		:Xiao Y, Xiao G, Varma A. A universal procedure for crude glycerol purification from different feedstocks in biodiesel production: experimental and simulation study. Ind Eng Chem Res. 2013;52(39):14291-6.

	:~~Sciencelab.com~~. ~~Material Safety Data Sheet Propylene~~ glycol ~~MSDS [Internet]~~. ~~Houston: ScienceLab.com, Inc~~.; ~~c1997~~-~~2005 [cited 2015 Feb 26]. Available from: https://www.sciencelab.com/msds.php?msdsId=9927239~~.		:Zhou Z, Li X, Zeng T, Hong W, Cheng Z, Yuan W. Kinetics of hydrogenolysis of glycerol to propylene glycol over Cu-ZnO-Al2O3 catalysts. Chin J Chem Eng. 2010;18(3);384-90.

	=Appendix I: Equipment Costs=		=Appendix I: Equipment Costs=

Jian: /* Introduction */

2015-02-28T16:59:07Z

Introduction

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	In food and beverage products, propylene glycol is mainly used as a solvent and carrier of flavor and color, or as a thickener, clarifier, and stabilizer in items such as beer, salad dressing, and baking mixtures. It provides lipstick with its consistent texture, preserves the homogenous consistency of body lotions containing both oil and water, and ensures that shampoos foam nicely. In the pharmaceuticals industry, propylene glycol is used to solubilize and provide equal distribution of the active ingredient in the formulation.		In food and beverage products, propylene glycol is mainly used as a solvent and carrier of flavor and color, or as a thickener, clarifier, and stabilizer in items such as beer, salad dressing, and baking mixtures. It provides lipstick with its consistent texture, preserves the homogenous consistency of body lotions containing both oil and water, and ensures that shampoos foam nicely. In the pharmaceuticals industry, propylene glycol is used to solubilize and provide equal distribution of the active ingredient in the formulation.

	The market for propylene glycol is currently dominated by Dow Chemical and BASF, with 1.8 million tonnes produced globally in 2011 (Dow.com). Assuming a price of $1.16 per lb, the current market value is $3.97 billion per year (Propylene-glycol.com). Evanston Chemical Technology Division challenged their employees to design a bioproducts facility in Blue Island, IL capable of taking advantage of a small fraction of this market.		The market for propylene glycol is currently dominated by Dow Chemical and BASF, with 1.8 million tonnes produced globally in 2011 (Dow.com, a). Assuming a price of $1.16 per lb, the current market value is $3.97 billion per year (Propylene-glycol.com). Evanston Chemical Technology Division challenged their employees to design a bioproducts facility in Blue Island, IL capable of taking advantage of a small fraction of this market.

	The goal of this report is to evaluate Team BAT’s design of a propylene glycol plant, to determine if Evanston Chemical should invest in independent production. The design of our plant was driven by current manufacturing processes found in literature. The design is split into two sections for simplicity: batch purification of crude glycerin and continuous hydrogenolysis of glycerin to propylene glycol. The facility, project economics, and process flow diagram were modeled on Aspen, Aspen Process Economic Analyzer, and Microsoft Visio, respectively.		The goal of this report is to evaluate Team BAT’s design of a propylene glycol plant, to determine if Evanston Chemical should invest in independent production. The design of our plant was driven by current manufacturing processes found in literature. The design is split into two sections for simplicity: batch purification of crude glycerin and continuous hydrogenolysis of glycerin to propylene glycol. The facility, project economics, and process flow diagram were modeled on Aspen, Aspen Process Economic Analyzer, and Microsoft Visio, respectively.

Jian: /* Safety and Environment */

2015-02-28T16:58:12Z

Safety and Environment

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	Chemical plant safety is one of the primary requirements in process design at Evanston Chemical. From the delivery of raw materials to final product transport, the employees of Evanston Chemical have the right to a safe workplace. All OSHA standards for exposure, personal protective equipment, and operation control will be strictly followed. Pressures are kept low and should not constitute a major hazard; moreover, vessel wall thickness exceeds ASME BPV code requirements for maximum safety. All process equipment will be fitted with pressure relief valves for safety. The highest temperature is 275 °C, found in the second distillation column bottoms. In the event of a sudden temperature increase, the valves can be shut off.		Chemical plant safety is one of the primary requirements in process design at Evanston Chemical. From the delivery of raw materials to final product transport, the employees of Evanston Chemical have the right to a safe workplace. All OSHA standards for exposure, personal protective equipment, and operation control will be strictly followed. Pressures are kept low and should not constitute a major hazard; moreover, vessel wall thickness exceeds ASME BPV code requirements for maximum safety. All process equipment will be fitted with pressure relief valves for safety. The highest temperature is 275 °C, found in the second distillation column bottoms. In the event of a sudden temperature increase, the valves can be shut off.

	Neither glycerin nor propylene glycol constitutes a major threat to safety. As additives to consumer products, the chemicals are only slightly dangerous in large quantities ~~[13]~~. Eye contact may result in temporary irritation; corneal injury is unlikely. Prolonged skin contact is unlikely to cause irritation. Inhalation of vapors appears to present no significant hazard in ordinary applications, and this is reflected in the fact that OSHA has not found it necessary to establish a permissible exposure level in the workplace.		Neither glycerin nor propylene glycol constitutes a major threat to safety. As additives to consumer products, the chemicals are only slightly dangerous in large quantities (Dow.com, b). Eye contact may result in temporary irritation; corneal injury is unlikely. Prolonged skin contact is unlikely to cause irritation. Inhalation of vapors appears to present no significant hazard in ordinary applications, and this is reflected in the fact that OSHA has not found it necessary to establish a permissible exposure level in the workplace.

	The lifecycle of propylene glycol production is relatively environmentally friendly. The fundamental raw material, glycerin, is obtained from a up-stream facility which converts local restaurant vegetable oil into biodiesel. The environmental cost of transportation is minimized.		The lifecycle of propylene glycol production is relatively environmentally friendly. The fundamental raw material, glycerin, is obtained from a up-stream facility which converts local restaurant vegetable oil into biodiesel. The environmental cost of transportation is minimized.

	The product, propylene glycol, is considered to be practically nontoxic to fish on an acute basis (LC50 > 100 mg/L) and practically nontoxic to aquatic invertebrates ~~[13]~~. Additionally, the products of PG degradation are less toxic than the product itself.		The product, propylene glycol, is considered to be practically nontoxic to fish on an acute basis (LC50 > 100 mg/L) and practically nontoxic to aquatic invertebrates (Dow.com, b). Additionally, the products of PG degradation are less toxic than the product itself.

	=Conclusion=		=Conclusion=

Jian: /* Catalyst */

2015-02-28T16:44:25Z

Catalyst

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	=====Catalyst=====		=====Catalyst=====
	Team BAT decided to use a Cu-ZnO-Al2O3 catalyst with a Cu: ZnO: Al2O3 molar ratio of 1: 1: 0.5. This catalyst was chosen because of its relatively high conversion of glycerol (81.5%) and extremely high selectivity towards propylene glycol (93%) ~~[12]~~. The catalyst was modeled as a collection of spherical particles, each with a diameter of 0.34 millimeters. Using a void fraction in the reactor of 0.5, the total amount of catalyst needed is 467 kg.		Team BAT decided to use a Cu-ZnO-Al2O3 catalyst with a Cu: ZnO: Al2O3 molar ratio of 1: 1: 0.5. This catalyst was chosen because of its relatively high conversion of glycerol (81.5%) and extremely high selectivity towards propylene glycol (93%) (Zhou et al., 2010). The catalyst was modeled as a collection of spherical particles, each with a diameter of 0.34 millimeters. Using a void fraction in the reactor of 0.5, the total amount of catalyst needed is 467 kg.

	====Design of Heat Transfer Equipment====		====Design of Heat Transfer Equipment====

Jian: /* Modeling and Sizing */

2015-02-28T16:43:52Z

Modeling and Sizing

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	====Reactor====		====Reactor====
	=====Modeling and Sizing=====		=====Modeling and Sizing=====
	The reactor used to convert glycerol to propylene glycol is modeled from the GTC Technology patent (Ding et al., 2013). The reactor is a fixed-bed reactor packed with catalyst, and operates at 190 °C and 30 atmospheres. The reactor was modeled in HYSYS as a generic conversion reactor using conversion and selectivity data from the article “Kinetics of Hydrogenolysis of Glycerol to Propylene Glycol over Cu-ZnO-Al2O3 Catalysts” by Zhou et al ~~[12]~~. The reactor is able to achieve 81.5% conversion of glycerol with selectivity towards propylene glycol of 93%.		The reactor used to convert glycerol to propylene glycol is modeled from the GTC Technology patent (Ding et al., 2013). The reactor is a fixed-bed reactor packed with catalyst, and operates at 190 °C and 30 atmospheres. The reactor was modeled in HYSYS as a generic conversion reactor using conversion and selectivity data from the article “Kinetics of Hydrogenolysis of Glycerol to Propylene Glycol over Cu-ZnO-Al2O3 Catalysts” by Zhou et al. (2010). The reactor is able to achieve 81.5% conversion of glycerol with selectivity towards propylene glycol of 93%.

	Using a LHSV of 4.6 hr-1 and a reactant feed of just under 5 kg / hour, Team BAT determined the size of the reactor to be 0.39 meters in diameter with a tangent length of 1.17 meters, resulting in a total volume of 0.141 cubic meters. The reactor was designed as a stainless steel 304 pressure vessel according to ASME standards, giving a shell thickness of 13 millimeters.		Using a LHSV of 4.6 hr-1 and a reactant feed of just under 5 kg / hour, Team BAT determined the size of the reactor to be 0.39 meters in diameter with a tangent length of 1.17 meters, resulting in a total volume of 0.141 cubic meters. The reactor was designed as a stainless steel 304 pressure vessel according to ASME standards, giving a shell thickness of 13 millimeters.

Jian: /* Raw Materials */

2015-02-28T16:42:36Z

Raw Materials

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	====Raw Materials====		====Raw Materials====
	The raw material inputs to the second part of the process, the conversion of purified glycerol to propylene glycol, include purified glycerol and hydrogen gas. The purified glycerol is produced from the batch process described earlier, and is pumped in from a large storage tank. The hydrogen gas, supplied at a pressure of 30 atmospheres, is fed in excess at a rate of 1 kg / hour and is supplied by Praxair at $7 / kg ~~[10]~~.		The raw material inputs to the second part of the process, the conversion of purified glycerol to propylene glycol, include purified glycerol and hydrogen gas. The purified glycerol is produced from the batch process described earlier, and is pumped in from a large storage tank. The hydrogen gas, supplied at a pressure of 30 atmospheres, is fed in excess at a rate of 1 kg / hour and is supplied by Praxair at $7 / kg (Dailyfinance.com).

	====Reactor====		====Reactor====

Jian: /* Project Economics */

2015-02-28T16:41:44Z

Project Economics

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	Using a 10 year MACRS depreciation method, a tax rate of 28% and capital available at 12%, the project is not economically feasible, with the 10 and 20 year NPV coming in at -$3.2 MM and -$4.2 MM, respectively.		Using a 10 year MACRS depreciation method, a tax rate of 28% and capital available at 12%, the project is not economically feasible, with the 10 and 20 year NPV coming in at -$3.2 MM and -$4.2 MM, respectively.

	See Appendix I and II for the equipment costs and full economic analysis, respectively. The majority of equipment costing was done on ASPEN Economic Evaluation, with some smaller equipment costs found on Northern Tool & Equipment, Global Industrial, and PKG Equipment ~~[6], [7], [8]~~. Utility costs for water and steam were estimated from the City of Chicago website and DailyFinance.com, respectively~~, [9], [10]~~.		See Appendix I and II for the equipment costs and full economic analysis, respectively. The majority of equipment costing was done on ASPEN Economic Evaluation, with some smaller equipment costs found on Northern Tool & Equipment, Global Industrial, and PKG Equipment (Northerntool.com; Globalindustrial.com; Pkgequipment.com). Utility costs for water and steam were estimated from the City of Chicago website and DailyFinance.com, respectively (Cityofchicago.org; Dailyfinance.com).

	=Plant Location=		=Plant Location=

Jian: /* Design Basis */

2015-02-28T16:39:34Z

Design Basis

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	=Design Basis=		=Design Basis=
	As a part of Evanston Chemicals, Team BAT studied an industrial method of producing propylene glycol through continuous hydrogenolysis as described in the GTC Technology 2013 patent. Evanston Chemicals corresponding biodiesel facility produces 4,700 lbs / week crude glycerin as a byproduct. With crude glycerin being a commodity in excess, the option of selling crude glycerin will be ignored and the available 4,700 lbs / week will be considered free. Our process was designed to increase biodiesel facility profits by taking advantage of the unwanted crude glycerin byproduct.		As a part of Evanston Chemicals, Team BAT studied an industrial method of producing propylene glycol through continuous hydrogenolysis as described in the GTC Technology 2013 patent (Ding et al., 2013). Evanston Chemicals corresponding biodiesel facility produces 4,700 lbs / week crude glycerin as a byproduct. With crude glycerin being a commodity in excess, the option of selling crude glycerin will be ignored and the available 4,700 lbs / week will be considered free. Our process was designed to increase biodiesel facility profits by taking advantage of the unwanted crude glycerin byproduct.

	Team BAT also considered the Davy Process Technology Limited patent, which uses minimal hydrogen and carried out the reaction in multiple stages ~~[5]~~. After careful process and market considerations, the GTC process was chosen based on low capital-costs, possible reduced operating costs due to multiple energy integration options, high selectivity in a one-step reaction, and relatively low temperatures.		Team BAT also considered the Davy Process Technology Limited patent, which uses minimal hydrogen and carried out the reaction in multiple stages (Tuck, 2012). After careful process and market considerations, the GTC process was chosen based on low capital-costs, possible reduced operating costs due to multiple energy integration options, high selectivity in a one-step reaction, and relatively low temperatures.

	If the GTC style facility produces the maximum possible 18.6 tonnes per year of propylene glycol, Evanston Chemical will account for less than 0.01% of the market. Team BAT decided not to produce and market additional propylene glycol because it is not the primary objective of the larger biodiesel facility.		If the GTC style facility produces the maximum possible 18.6 tonnes per year of propylene glycol, Evanston Chemical will account for less than 0.01% of the market. Team BAT decided not to produce and market additional propylene glycol because it is not the primary objective of the larger biodiesel facility.

Jian: /* Introduction */

2015-02-28T16:37:48Z

Introduction

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	=Introduction=		=Introduction=
	Propylene glycol, C3H8O2, is a non-corrosive, non-toxic, low volatility liquid, used as chemical feedstock for the production of unsaturated polyester resins, and in the food, beverage, cosmetic, and pharmaceutical industry ~~[3]~~. The freezing point of water is lowered when mixed with propylene glycol, and the latter is therefore used as an anti-freeze and de-icing fluid. Propylene glycol also lowers vapor pressure, making it an ideal burst protection fluid in pipes and vessels. As a cleaning product additive, propylene glycol acts as a stabilizer for the dirt-removing ingredients and helps retain their function at low temperatures.		Propylene glycol, C3H8O2, is a non-corrosive, non-toxic, low volatility liquid, used as chemical feedstock for the production of unsaturated polyester resins, and in the food, beverage, cosmetic, and pharmaceutical industry (Propylene-glycol.com). The freezing point of water is lowered when mixed with propylene glycol, and the latter is therefore used as an anti-freeze and de-icing fluid. Propylene glycol also lowers vapor pressure, making it an ideal burst protection fluid in pipes and vessels. As a cleaning product additive, propylene glycol acts as a stabilizer for the dirt-removing ingredients and helps retain their function at low temperatures.

	In food and beverage products, propylene glycol is mainly used as a solvent and carrier of flavor and color, or as a thickener, clarifier, and stabilizer in items such as beer, salad dressing, and baking mixtures. It provides lipstick with its consistent texture, preserves the homogenous consistency of body lotions containing both oil and water, and ensures that shampoos foam nicely. In the pharmaceuticals industry, propylene glycol is used to solubilize and provide equal distribution of the active ingredient in the formulation.		In food and beverage products, propylene glycol is mainly used as a solvent and carrier of flavor and color, or as a thickener, clarifier, and stabilizer in items such as beer, salad dressing, and baking mixtures. It provides lipstick with its consistent texture, preserves the homogenous consistency of body lotions containing both oil and water, and ensures that shampoos foam nicely. In the pharmaceuticals industry, propylene glycol is used to solubilize and provide equal distribution of the active ingredient in the formulation.

	The market for propylene glycol is currently dominated by Dow Chemical and BASF, with 1.8 million tonnes produced globally in 2011 ~~[4]~~. Assuming a price of $1.16 per lb, the current market value is $3.97 billion per year ~~[3]~~. Evanston Chemical Technology Division challenged their employees to design a bioproducts facility in Blue Island, IL capable of taking advantage of a small fraction of this market.		The market for propylene glycol is currently dominated by Dow Chemical and BASF, with 1.8 million tonnes produced globally in 2011 (Dow.com). Assuming a price of $1.16 per lb, the current market value is $3.97 billion per year (Propylene-glycol.com). Evanston Chemical Technology Division challenged their employees to design a bioproducts facility in Blue Island, IL capable of taking advantage of a small fraction of this market.

	The goal of this report is to evaluate Team BAT’s design of a propylene glycol plant, to determine if Evanston Chemical should invest in independent production. The design of our plant was driven by current manufacturing processes found in literature. The design is split into two sections for simplicity: batch purification of crude glycerin and continuous hydrogenolysis of glycerin to propylene glycol. The facility, project economics, and process flow diagram were modeled on Aspen, Aspen Process Economic Analyzer, and Microsoft Visio, respectively.		The goal of this report is to evaluate Team BAT’s design of a propylene glycol plant, to determine if Evanston Chemical should invest in independent production. The design of our plant was driven by current manufacturing processes found in literature. The design is split into two sections for simplicity: batch purification of crude glycerin and continuous hydrogenolysis of glycerin to propylene glycol. The facility, project economics, and process flow diagram were modeled on Aspen, Aspen Process Economic Analyzer, and Microsoft Visio, respectively.

← Older revision		Revision as of 22:13, 28 February 2015
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	=References=		=References=
	:Cityofchicago.org. Water Sewer Rates [Internet]. Chicago: City of Chicago; c2010-15 [cited 2015 Feb 26]. Available from: http://www.cityofchicago.org/city/en/depts/water/provdrs/cust_serv/svcs/know_my_water_sewerrates.html.		Cityofchicago.org. Water Sewer Rates [Internet]. Chicago: City of Chicago; c2010-15 [cited 2015 Feb 26]. Available from: http://www.cityofchicago.org/city/en/depts/water/provdrs/cust_serv/svcs/know_my_water_sewerrates.html.

	:Dailyfinance.com [Internet]. New York: AOL Inc.; c2015 [cited 2015 Feb 26]. Available from: http://www.dailyfinance.com/.		Dailyfinance.com [Internet]. New York: AOL Inc.; c2015 [cited 2015 Feb 26]. Available from: http://www.dailyfinance.com/.

	:Ding Z, Chiu J, Jin W, inventor; GTC Technology US LLC, assignee. Process for converting glycerin into propylene glycol. US Patent 08394999 B2. 2013 Mar 12.		Ding Z, Chiu J, Jin W, inventor; GTC Technology US LLC, assignee. Process for converting glycerin into propylene glycol. US Patent 08394999 B2. 2013 Mar 12.

	:Dow.com. About propylene glycols [Internet]. Midland: The Dow Chemical Company; c1995-2015a [cited 2015 Feb 26]. Available from: http://www.dow.com/propyleneglycol/about/.		Dow.com. About propylene glycols [Internet]. Midland: The Dow Chemical Company; c1995-2015a [cited 2015 Feb 26]. Available from: http://www.dow.com/propyleneglycol/about/.

	:Dow.com. Product Safety Assessment [Internet]. Midland: The Dow Chemical Company; c1995-2015b [cited 2015 Feb 26]. Available from: http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_091a/0901b8038091a41a.pdf?filepath=productsafety/pdfs/noreg/233-00490.pdf&fromPage=GetDoc.		Dow.com. Product Safety Assessment [Internet]. Midland: The Dow Chemical Company; c1995-2015b [cited 2015 Feb 26]. Available from: http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_091a/0901b8038091a41a.pdf?filepath=productsafety/pdfs/noreg/233-00490.pdf&fromPage=GetDoc.

	:Globalindustrial.com [Internet]. Global Equipment Company Inc.; c2015 [cited 2015 Feb 26]. Available from: http://www.globalindustrial.com/.		Globalindustrial.com [Internet]. Global Equipment Company Inc.; c2015 [cited 2015 Feb 26]. Available from: http://www.globalindustrial.com/.

	:Northerntool.com [Internet]. Burnsville: Northern Tool + Equipment [cited 2015 Feb 26]. Available from: http://www.northerntool.com/.		Northerntool.com [Internet]. Burnsville: Northern Tool + Equipment [cited 2015 Feb 26]. Available from: http://www.northerntool.com/.

	:Pkgequipment.com [Internet]. Rochester: PKG Equipment Inc.; c2013 - [cited 2015 Feb 26]. Available from: http://www.pkgequipment.com/index.html.		Pkgequipment.com [Internet]. Rochester: PKG Equipment Inc.; c2013 - [cited 2015 Feb 26]. Available from: http://www.pkgequipment.com/index.html.

	:Praxair.com [Internet]. Danbury: Praxair Technology, Inc.; c2013-15 [cited 2015 Feb 26]. Available from: http://www.praxair.com/.		Praxair.com [Internet]. Danbury: Praxair Technology, Inc.; c2013-15 [cited 2015 Feb 26]. Available from: http://www.praxair.com/.

	:Propylene-glycol.com [Internet]. Brussels: PO/PG Sector group of Cefic [cited 2015 Feb 26]. Available from: http://www.propylene-glycol.com/.		Propylene-glycol.com [Internet]. Brussels: PO/PG Sector group of Cefic [cited 2015 Feb 26]. Available from: http://www.propylene-glycol.com/.

	:Sciencelab.com. Material Safety Data Sheet Propylene glycol MSDS [Internet]. Houston: ScienceLab.com, Inc.; c1997-2005 [cited 2015 Feb 26]. Available from: https://www.sciencelab.com/msds.php?msdsId=9927239.		Sciencelab.com. Material Safety Data Sheet Propylene glycol MSDS [Internet]. Houston: ScienceLab.com, Inc.; c1997-2005 [cited 2015 Feb 26]. Available from: https://www.sciencelab.com/msds.php?msdsId=9927239.

	:Tuck MWM, inventor; Davy Process Technology Limited, assignee. Process for the hydrogenation of glycerol to propylene glycol. US patent 08227646 B2. 2012 Jul 24.		Tuck MWM, inventor; Davy Process Technology Limited, assignee. Process for the hydrogenation of glycerol to propylene glycol. US patent 08227646 B2. 2012 Jul 24.

	:Xiao Y, Xiao G, Varma A. A universal procedure for crude glycerol purification from different feedstocks in biodiesel production: experimental and simulation study. Ind Eng Chem Res. 2013;52(39):14291-6.		Xiao Y, Xiao G, Varma A. A universal procedure for crude glycerol purification from different feedstocks in biodiesel production: experimental and simulation study. Ind Eng Chem Res. 2013;52(39):14291-6.

	:Zhou Z, Li X, Zeng T, Hong W, Cheng Z, Yuan W. Kinetics of hydrogenolysis of glycerol to propylene glycol over Cu-ZnO-Al2O3 catalysts. Chin J Chem Eng. 2010;18(3);384-90.		Zhou Z, Li X, Zeng T, Hong W, Cheng Z, Yuan W. Kinetics of hydrogenolysis of glycerol to propylene glycol over Cu-ZnO-Al2O3 catalysts. Chin J Chem Eng. 2010;18(3);384-90.

	=Appendix I: Equipment Costs=		=Appendix I: Equipment Costs=