Design 1

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Team BAT Final Report

Authors: Anne Disabato, Tim Hanrahan, Brian Merkle

Instructors: Fengqi You, David Wegerer, David Chen

Date Presented: March 14, 2014


Executive Summary

In an effort to build a new bio-product facility for Evanston Chemical, Team BAT is considering producing 99.7% propylene glycol solution. Team BAT designed a small-scale process to use the crude glycerin waste from an up-steam biodiesel facility. It was assumed that capital is available at 12%.

Research on an industrially available propylene glycol manufacturing process, patented by GTC Technology, and a universal process for purifying crude glycerin were used guided the final design [1], [2]. The facility is divided into two sub-processes: pre-treatment of crude glycerin and continuous hydrogenolysis of glycerin to propylene glycol. Microsoft Visio and Aspen HYSYS were used to design the process flow diagram and simulate the production. All other calculations were performed in Microsoft Excel. The plant was designed to operate safely, and have minimal environmental impact.

Team BAT’s plant produces 18.6 tonnes per year of 99.7% propylene glycol. Economic analysis predicts a net present value of - $4.2 million on a twenty-year basis. Based on this analysis, the proposed propylene glycol production facility would be not be economically viable without considerable scale-up and optimization.

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.

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 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.

Design Basis

Project Economics

Plant Location

Process Overview

Production Schedule

Design Considerations

Batch Purification

Raw Materials

Modeling and Sizing the Batch Process

Batch Process Assumptions and Limitations

Batch Optimization

Continuous Conversion to Propylene Glycol

Raw Materials

Reactor

Modeling and Sizing
Catalyst

Design of Heat Transfer Equipment

E-201: Heating Reactor Feed
E-202: Cooling Reactor Effluent

Product Purification

Liquid-Gas Separator
C-201 Distillation Column
C-202 Distillation Column
C-203 Distillation Column

Assumptions and Limitations

Sensitivity Analysis

Safety and Environment

Conclusion

References

Appendix I: Equipment Costs

Appendix II: Economic Analysis

Appendix III: Process Flow Diagrams

Appendix IV: Mass Balances

Appendix V: Equipment Specification

Appendix VI: Batch Process Gantt Chart