Design of a Mobile Treatment System for Hydraulic Fracturing Waste Chevron Group April 19, 2013

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# Design of a Mobile Wastewater

T reatment System for Hydraulic Fracturing Waste

Marc Panu
Matthew Claussen
Faiz Talib

April 19, 2013Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

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## Table of Contents

Abstract

................................ ................................ ................................ ................................ ................................ ............................... 4
Introduction and Project Charter

................................ ................................ ................................ ................................ ............. 4
Technology Readiness Assessment

................................ ................................ ................................ ................................ ......... 5

Section I: Concept Stage

................................ ................................ ................................ ................................ ............................... 6
Part 1: Market and Competitive Analysis

................................ ................................ ................................ ........................ 6

Part 2: Customer Requirements

................................ ................................ ................................ ................................ .......... 6

Part 3: Preliminary Process Synthesis

................................ ................................ ................................ .............................. 7
Part 4: Assembly of Database

................................ ................................ ................................ ................................ ............... 8

Section II : Feasibility, Development, and Manufacturing

................................ ................................ ........................... 12
Part 1: Process Flow Diagram, Stream Table, and Simulation of Process

................................ ....................... 12

Part 2: Process Description

................................ ................................ ................................ ................................ ................ 14
Part 3: Energy Balance and Utility Requirements

................................ ................................ ................................ ..... 17

Part 4: Equipment List and Unit Descriptions

................................ ................................ ................................ ............ 19

Part 5: Specification Sheets

................................ ................................ ................................ ................................ ............... 22

Part 6: Equipment Cost Summary

................................ ................................ ................................ ................................ .... 29

Part 7: Fixed Capital Investment Summary

................................ ................................ ................................ ................. 29

Part 8: Other Important Considerations

................................ ................................ ................................ ....................... 30

Environmental problems and methods used to eliminate them

................................ ................................ .... 30

Safety and health concerns

- Hazard and Operability Study (HAZOP)

................................ ........................ 30
Process controllability and instrumentation

................................ ................................ ................................ .......... 33
Startup, including additional equipment

................................ ................................ ................................ ................. 33
Plant (trailer) layout

................................ ................................ ................................ ................................ ......................... 33

Par t 9: Operating Cost and Economic Analysis

................................ ................................ ................................ .......... 34

Section III: Conclusions and Recommendations

................................ ................................ ................................ ............. 36
Acknowledgements

................................ ................................ ................................ ................................ ................................ ..... 37
Bibliography

................................ ................................ ................................ ................................ ................................ .................. 38

Appendix

................................ ................................ ................................ ................................ ................................ ......................... 40
Appendix 1: Glossary of Terms

................................ ................................ ................................ ................................ ......... 40
Appendix 2: Design Procedures and Calculations

................................ ................................ ................................ ..... 41

Section 1: Holding Pond

................................ ................................ ................................ ................................ .................. 41

Section 2: Co sting Data

................................ ................................ ................................ ................................ .................... 41

Section 3: DAF compressor pressure sample calculation

................................ ................................ ................. 44Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

3 | P a g e Section 5: Relevant tabulated GE data

................................ ................................ ................................ ....................... 46

Appendix 3: Computer programs developed

................................ ................................ ................................ .............. 49

Section 1: MATLAB

................................ ................................ ................................ ................................ ............................ 49

Section 2: SuperPro D esigner

................................ ................................ ................................ ................................ ....... 53

Section 3: Microsoft Excel Calculator

................................ ................................ ................................ ......................... 53

Section 4: Pertinent printed material

................................ ................................ ................................ ........................ 53Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

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## A bstract
Our team designed a system to treat the contaminated water produced by hyd raulic fracturing
of shale rock for natural gas. We did so by combining and optimizing several current treatment technologies to produce a mobile

- scale process that can treat the flowback at the well site for reuse at
other nearby well sites. The process features an electrochemical oxidation/electrocoagulation unit (EC) that destabilizes small organics, a dissolved air flotation unit (DAF) that removes suspended solids, and a reverse osmosis (RO) unit that treats the dissolved solids.



## Introduction and Project Charter
Hydraulic fracturing (also referred to as hydrofracking or just fracking) is an important technology that has contributed significantly to the boom in domestic pr oduction of natural gas that the United States has seen over the past two decades. Since 1990, the number of actively producing natural gas wells in the United States has more than doubled to over 500,000 1 . The vast majority of
these new wells are stimulat ed using hydraulic fracturing, a technique in which fluid containing mostly water and fine sand is pumped into a well under extreme pressure. This pressurized fluid flows out from the well bore into the gas

- containing formation, causing the formation of sm all fractures. When the fluid is depressurized, the sand acts as a proppant, keeping the fractures open, and gas can flow into the wellbore through the fractures in the formation 1 . This unconventional extraction technique is essential for producing most ne w natural gas wells in an economically efficient way, as most of the natural gas deposits attainable via conventional strategies have been depleted.

However, hydraulic fracturing is controversial due to growing concerns over the environmental impacts of t reating the fluid that returns to the surface once fracturing is complete. Rising regulation of the disposal of this fluid, commonly called flowback, has forced fracturing operators to ship flowback from well sites to stationary water treatment plants. How ever, most active drilling sites are located far away from a stationary wastewater treatment plant, meaning the well owner must invest in transporting the spent fluid long distances for treatment. This in turn has led to a
demand for a mobile treatment sol ution that could be deployed to treat flowback at well sites.

The goal of our project was to design a mobile treatment solution geared specifically to treatment of fracking wastewater at a well site. Several potential technologies and engineering strategie s were considered to achieve this goal. The scope of the project consisted of a detailed conceptual design of the treatment process, an economic analysis of operating and capital costs, and an estimation of the expected return on investment. The design wor k was completed over a one semester period with progress reports generated on a weekly basis. Throughout the design process, our team developed simulation tools and other programs to generate custom models and calculators that would be useful for planning deployments to individual wells. The process design goals emphasized safety, effectiveness of the treatment, and economic benefit to both our company and our clients.Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

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## Technology Readiness Assessment
Our treatment scheme relies on three core technologies to effectively remove contaminants from the flowback. The first process unit is an electrochemical oxidation reactor used to flocculate suspended solids and organic species found in the flowback. The next unit is a dissolved air flotation
chamber which re moves the flocculated suspended solids and organics. Finally, a reverse osmosis unit removes the dissolved solids in the flowback, rendering the water clean enough to be re

- used to
fracture another well.

Electrocoagulation/Electrochemical Oxidation is a ne w and emerging technology that has been extensively researched on a lab scale. There are some EC units being used in industrial sett ings, so we
know it can be done. H owever, the details of these operations are scarce. Implementing this technology
on an ind ustrial level will require further research 2 . Specifically, studies will need to be conducted to fine tune the electrode material and specifications and determine if there is a need for any additional
chemicals to adjust the pH and electrical conductivity. If a business were to be launched based on our design, a significant amount of money would need to be invested in research and development of the

EC unit.

Dissolved air flotation is a widely used technology in many process industries for removing suspende d solids from solutions where sedimentation is slow or does not occur at all in the case of suspended emulsions 3 . Because it is a well understood and widely used technology, there will be few barriers in the R & D stage of building the required DAF unit. Based on DAF design equations and normal operating parameter ranges, our DAF unit could be scaled to a mobile size 4 . Additionally, several companies such as Ecologix have already begun using mobile DAF units to treat fracking flowback, indicating that dis solved air flotation could readily be adapted to the intended application of removing suspended solids from flowback 5

.
Reverse osmosis is also widely used in the wastewater processing industry for desalination operations similar to the one we intend to perform. The main technological obstacle to the use of an RO unit in our design is the selection of an appropriate membrane. However, many companies manufacture and sell membrane materials by area. We believe the most effective membrane for our process wil l be an asymmetric cellulose acetate based membrane, but further R & D will be required to select a specific type and vendor 6 . Companies such as GE Wastewater are already using mobile scale reverse osmosis systems to treat flowback for re

- use, so it is rea sonable to expect a reverse osmosis unit could be scaled to meet our needs for the process 7

.Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

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## Section I: Concept Stage

Part 1: Market and Competitive Analysis
There are approximately 35,000 wells actively being fracked for natural gas in the United

Stat es. Typical wells take between 3 and 9 million gallons of water to frack, and on average, about one
third of that water returns to the surface as flowback. This means that most wells have 1 to 3 million gallons of water return to the surface as flowback 1

. Right now, the majority of wells either have to dispose of the flowback (usually through deep well injection or evaporation ponds), or ship the water to a remote water treatment facility. Neither of these are particularly good options. Environmentalists

ar e also putting pressure on frackers to treat the flowback more stringently. Both deep well injection and evaporation ponds are liabilities to the environment. Shipping water to stationary treatment facilities is more environmentally friendly, but this meth od is expensive. Additionally, the high volume of flowback being produced is pushing these stationary water treatment facilities to their maximum capacity. Once this water is treated, it can either be reintroduced to the environment, or reused in
other fra cking wells.

A mobile treatment option will mitigate all of these concerns if executed properly. First, a mobile treatment option will reduce the concern from environmentalists because it can reduce the amount of waste water by more than 80%. A mob ile tre atment system will also significantly reduce costs for frackers. Due to the huge volume of water that comes back from the well, a large part of the cost is transportation. If the water is treated on site, that will save the well the cost of transporting th e water to a treatment facility. It will also likely reduce costs due to the fact that most of the water reservoirs are far from the wells, while transporting water from one well to another in close proximity is much cheaper.



### Part 2: Customer Requirements Frackers are actively seeking more economically efficient and environmentally friendly ways to handle the flowback from fracking operations. Thus, essentially the only customer requirements are that we offer an economical and environmentally friendly mob ile system that does not have major barriers to entry. One key requirement of the mobile process is that it treats flowback to the acceptable standards for re

- use of the flowback for further fracturing. While these standards vary widely depending on the de ployment region and the operator conducting the fracturing job, table 1 shows the most widely used specifications that our product reusable water must meet 8

.

Table 1

. Treatment Specifications for Reusable Flowback 8

Parameter Units Re

- use specification

TD S mg/L 20,000

Alkilinity mg/L 600Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

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### P art 3: Preliminary Process Synthesis
Figu re 1 shows the first process flow diagram we generated during the preliminary design phase.

Figure 1

. Preliminary process flow diagram for SuperPro simulation

In general, the main components of the flowback that we have to remove are organics, suspended solid s , and dissolved solid s . Suspended solid s can be removed using either a sedimentation
tank or a flotation tank. However, a sedimentation tank would require a longer residence time and thus a large tank, which is not suitable for a mobile treatment sy stem. This led us to the conclusion that dissolved air flotation is the best technology to separate the suspended solid s from the water.

Total dissolved solid s (TDS) is a term used for the combination of all ions present in the water.
Dissolved solid s cou ld be removed either using reverse osmosis (RO) or an evaporator. The main advantage of using RO is that it can handle high throughput

, but its economic efficiency decreases rapidly as the concentration of TDS increases to above 45,000 ppm. The main advant age of an evaporator is it s ability to operate on a wide range of TDS concentration s . However, an evaporator can only handle low throughput in order to be mobile. Hardness as CaCO3 mg/L 2,000

TSS mg/L 50

Chloride mg/L 12,500

Iron mg/L 10

Oil and soluble organics mg/L 50

Sulfate mg/L 25

pH range 6.5

- 8.5Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

8 | P a g e Based on GE data 7 , flowback from the well typically has a high flowrate with low concentrat ion
of TDS during the first few days and this phase is followed by a low flowrate with high concentration of TDS. In order to optimize the treatment process, we separate d the process into two phases: 1) using RO to treat high volumetric flow of wastewater with low TDS concentration; 2) using evaporator to treat low volumetric flow of wastewater with high TDS concentration. The process would start by removing the organics using activated carbon. DAF would then be used to remove suspended solid s

. Finally, the RO or evaporator would be used to remove dissolved solid s, depending on TDS level

.
For the first phase of the process, we use d RO to remove TDS because RO can handle high throughput but has a n economically imposed TDS concentration limit (below 45,000 ppm ) that it can
operate on 6

. Inlet flowrate was set to be at 100 gal/min with TDS concentration at 40,000 ppm. When TDS concentration increases to be above 45,000 ppm, we would switch to the second phase of the process where the evaporator is used to remove TDS

. For the evaporator, i nlet flowrate was set to be at 10 gal/min with TDS concentration at 100,000 ppm.

However, several changes were made to this preliminary process based on furthe r research
results. We discovered that using activated carbon to remo ve the organics would not be very effective
due to the fact that most of the organics are either long chain polymer s which could not penetrate the porous surface of the activated carbon or have a high solubility in water , rendering activated carbon
ineffe ctive for absorbing them.

Additionaly , the result s from the MATLAB simulation based on the GE data 7 as shown in Figure s 2 through 4 revealed that the highest TDS concentration that could be reached is 70,000 ppm.

We thus decide d to eliminate the use of t he evaporator in order to reduce the capital cost of purchasing the equipment and operating cost due to the evaporator’s high energy demand. We are able to reduce the TDS concentration to be below 45,000 ppm by recycling some of the clean water to
dilute t he effluent coming out of the DAF.



### Part 4: Assembly of Database
One early challenge we faced in our design project was a lack of data concerning the composition of flowback. Many articles mentioned general ranges and variances base d on the shale region, b ut few provided hard data. Eventually we discovered a data set collected by GE Wastewater that showed time variance of the flowback composition, density, and flowrate over time ( See Appendix 2, section 5 for relevant tabulated data ) 7

. Figures 2, 3, and 4 s how the GE database information in graphical form.Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

9 | P a g e Figure 2

. Flowback flow rate from well is initially high, then sharply declines after a few days 7

Figure 3

. Flowback density increases steadily as the flowback period elapses 7

0 50 100 150 200 250 300

0 5 10 15 20 25 30 35 Flowback Flow Rate (thousand gpd)

Time (days)

8.2 8.4 8.6 8.8 9 9.2 9.4 9.6

0 5 10 15 20 25 30 35 Flowback Density (lbs/gal)

Time (days)Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

10 | P a g e Figure 4

. TDS concen tration in the flowback increases steadily as the flowback period elapses 7

From the database, we concluded that our process would not be able to handle the wide range of flow rates coming from the well directly and thus decided to have the operators pump the flowback into a holding pond before we begin treatment 1 day after flowback commences. F igure 5 shows a scheme of this setup, along with differential material balances on the total flowback mass and on the

t otal dissolved solids.

Figure 5

. Flowback flows from the well to a holding pond, where it is stored until treatment. N otation: All F variables are flowrates in gpm, all ρ are densities in lbs/gal, and all x are TDS concentrations in lbs/gal. The w subscripts indicate that variable refers to the well, and the p subscripts refer to the pond. V p (t) refers to the volume of fl owback stored in the pond at time t.

0 20 40 60 80 100 120 140 160 180

0 5 10 15 20 25 30 35 Flowback TDS Concentration (thousand ppm)

Time (days)Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

11 | P a g e Using figure 5 , we derived the shown material balances. To simplify the system of differential mass balances to a point where both could be solved as ODE’s, we made the simplifying assumption that the pond’s density, ρ p , was a constant 8.49 lbs/gal. While the density of the flowback from the well did increase significantly late in the flowback period, the effects of this increase on the overall pond density were negligible owing to the sharply decreasing flowrate from the well after a few days.

To solve the system of ODE’s, we turned to MATLAB’s ode45 differential equation simulator. We created a MATLAB file based on the GE data to represent the system of differential equations. The file uses the GE data in a piecewis e manner to select values for the well outlet density, flowrate, and TDS concentration ( See Appendix 3, section 1 for ODE file ). We set the F p , or the flowrate from the pond to the unit at approximately 45 gpm in order to simulate the process withdrawing t he very last of the water from the pond. This allowed us to approximate the highest TDS concentration we would
observe. Figure 6 shows how the volume of flowback stored in the pond varies over the treatment period, while figure 7 shows the variation of TDS concentration

.

Figure 6. The volume of flowback stored in the pond increases rapidly for several days until the flowrate from the well drops off and the process intake flowrate begins to dominate

0 200 400 600 800 1000 1200 1400

0 5 10 15 20 25 30 35 Flowback Volume in Pond (thousand gal)

Time (days)Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

12 | P a g e Figure 7. The TDS concentration in the pond steadily increases, levels off near 40,000 ppm, and then spikes as the pond volume reaches zero

The simulation results led to the very important finding that even though the last portions of flowback have TDS concentrations well over 100,000 ppm, the maximum conc entration we would ever treat is closer to 70,000 ppm due to the dilution effects of the pond’s large volume. This finding lead us to remove the evaporator unit we had previously considered to treat high TDS content portions . We instead implement ed a recyc le stream around the RO unit that allowed us to keep the TDS concentration in the stream entering it below the economics influenced limit of 45,000 ppm for

reverse osmosis.

It should also be noted that the ODE file has been developed so that with minimal modification, it can be used to calculate the above plots for any well site. All that would be required is a data set similar to the one this simulation was developed from. We expect this data to be readily available from operators in the deployment area , as fracturing flowback has been monitored in virtually every region fracking occurs.



## Section II: Feasibility, Development
, and Manufacturing

Part 1: Process Flow Diagram, Stream Table, and Simulation of Process
One key step in moving from a conceptual to a more detailed process design was to use a process simulation tool to help determine actual operating conditions and the feasibility of using our selected technologies in a mobile setting. Because our design dealt with wastewater treatment, we
chose to u se SuperPro for our simulation. SuperPro’s focus on wastewater processing allowed us to more easily simulate the reverse osmosis and dissolved air flotation processes than would have been possible using Aspen. Figure 8 shows a simplified process flow diagr am drawn in SuperPro and used to simulate the process.

0 10,000 20,000 30,000 40,000 50,000 60,000 70,000 80,000

0 5 10 15 20 25 30 35 TDS Concentration (ppm)

Time (days)Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

13 | P a g e Figure 8. Final process flow diagram for SuperPro simulation

Due to the lack of a process model and usable design data for the EC unit, all design of the electrocoagulation unit was done manually ba sed on data acquired from a report describing the operation of a comparably sized EC unit being used by a company in Australia 9 . SuperPro was used to solve the material and energy balances for the DAF and RO units, allowing a more rigorous design of
these units. The TDS in the flowback was modeled using NaCl and CaCl 2 , and the TSS was modeled using octane (SuperPro allows the user to specify whether a component is a dissolved or suspended solid). The SuperPro simulation is available as an electronic file. S ee Appendix 3, Section 2 for more
information. The stream table shown in table 2 gives the results of the SuperPro simulation

.Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

14 | P a g e Table 2. SuperPro simulation stream table for mobile treatment process

Time Ref: min Post EC Suspende d Waste Post

DAF Recycl

e RO Pre RO Post RO Treate d
Water Dissolve

d Waste

Type Raw

Material

Total
Flow kg
253.654 3.543 250.11

1 161.16

2 411.27

4 322.325 161.162 88.959

Temp. °C 25 25 25 26.61 25.64 26.61 26.61 26.61

Pressur

e bar

1.013 1.013 1.013 1.013 1.013 1.013 1.013 1.013

Liq/Sol
Flow kg
253.6545 3.5431 250.11

1 161.16 411.27 322.325 161.16 88.9597

Liq/Sol
Vol Flow gal
65 0.9247 64.075

3 42.744 106.81 85.488 42.744 21.3717

Total

Content

s mas

s frac 1 1 1 1 1 1 1 1

CaChlori
de 0.0135 0.013 0.0135 0.0019 0.0 09 0.0019 0.0019 0.0346

Octane 0.0006 0.0395 0 0.0001 0.0001 0.0001 0.0001 0

Sodium
Chloride 0.0565 0.0543 0.0565 0.0017 0.035 0.0017 0.0017 0.1558

Water 0.9294 0.8932 0.9299 0.9963 0.9559 0.9963 0.9963 0.8096



### Part 2: Process Description
By chaini ng the EC, DAF, and RO units together, we were able to design an overall process that can address each of the main pollutants in the flowback to the accepted reuse standards. At the conceptual level, we also carefully considered the sequencing of the units to achieve the most efficient solution, eliminating unnecessary maintenance. Figure 9 shows a conceptual block diagram of the

process.

Electrocoagulation

(EC) Dissolved Air Flotation (DAF) Reverse Osmosis (RO)Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

15 | P a g e Figure 9. Conceptual block diagram of the treatment process

Two important steps occur in the EC unit. The f irst is the electrochemical oxidation of small organics from the flowback, typically measured as chemical oxygen demand (COD). While the presence of organics in the flowback is not necessarily a major concern in further reuse of the flowback, the

reverse o smosis unit employed to remove dissolved solids will become easily fouled if exposed to these small organics. Thus, to reduce membrane replacement costs to an acceptable level, we need to
remove the COD from the feed. Electrochemical oxidation allows for t he effective removal of organics.

In the electrochemical oxidation reaction, a current is passed through the wastewater using two iron electrodes. The anode acts as a sacrificial electrode, degrading overtime as the current causes
it to disso lve into posit ively charged iron ions. These ions are strong oxidizers, and react with the small organics in solution to oxidize them to CO 2 gas and other compounds which do not inhibit reuse or further processing of the water 10

.
The second major step that happens in t he EC unit is the electrocoagulation of suspended solids in the flowback. One of the main suspended solids in the flowback is emulsified oil and grease 11

. While dissolved air flotation can remove the emulsified oil, the efficiency of the removal is vastly increased if the emulsion is first broken and the suspended solids coagulated. A side effect of the current that passes through the EC is that it destabilizes the charges that hold the oil in the emulsion state. The charge destabilization causes both the normal suspended solids and the emulsified oil to flocculate into much larger grouped particles, commonly called flocs 12 . The reaction also causes the formation of hydrogen gas bubbles, which serve to further increase the efficiency of the DAF unit. For
fu rther information on the specifications of the EC, see page 17.

After passing through the EC, the flowback enters a dissolved air flotation (DAF) unit. The DAF functions to remove suspended solids from the flowback. In the dissolved air flotation unit, the flowback enters a flotation tank open to the air. A recycle stream exits the other end of the tank and re

enters it at the same end as the influent wastewater. Air bubbles are dissolved in the recycle stream of the process water at high pressure by a comp ressor. The pressure is then reduced with a valve at the point where the recycle stream enters the flotation tank. When the pressure decreases, the solubility of air rapidly falls, causing the formation of micron sized bubbles 4 . These tiny bubbles attach t o the flocculated suspended solids in the effluent from the EC, and cause the flocs to float to the surface,Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

16 | P a g e where the sludge can be removed using a mechanical skimmer. For further information on the specifications of the DAF, see page 18.

Once the DAF has removed the suspended solids, the wastewater stream’s main remaining contaminants are dissolved solids, mostly CaCl 2 , NaCl, and other chloride salts. The third and final main unit of our process is a reverse osmosis unit that uses a polymer membrane to re ject salt and produce clean, reusable frack water. The reverse osmosis unit is placed last in the separation train because of its fouling sensitivity to organic chemicals and suspended solids. Osmosis is the process by
which molecules of a solvent will nat urally diffuse across a semipermeable membrane towards an area of high solute concentration from an area of low solute concentration 6 . In our RO unit, we apply pressure on the high concentration solution side of the membrane using a pump, allowing us to

re verse the osmosis process. The pressure applied to the wastewater forces clean water through the membrane, which rejects the salt ions present in the pre

- treated flowback. The resulting exiting streams are (1) a concentrated waste stream that can be dispos ed of by deep well injection, and (2) a stream of treated flowback that can be shipped to a new well site to be reused on the next fracking job. For further information on the specifications of the RO unit, see page 19.Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

17 | P a g e Figure 10 presents a more detail ed flow sheet that shows intermediate processing including pumps and compressors.

Figure 10. Detailed process flow diagram for mobile treatment unit



### Part 3: Energy Balance and Utility Requirements
Finding a way to power a large scale operation in a remo te area was one of the important considerations for our process. Most fracking well sites will have a power converter that has the capability to convert natural gas to electricity. Each of our units will be powered by electricity generated on site. Usually these operatio ns are typically between 40

- 60% Efficient in converting natural gas energy into electrical energy, so we calculated our costs based on 50% efficiency 13 . Electric motors also have a drop off in energy efficiency (78.8% for <5 hp and 90.2% for 50

- 99 hp motors) 13

. Considering these factors, we were able to estimate the power usage and cost of electricity for the
motors. Based on the EC unit’s design, the expected electricity requirements of the EC unit will be about 0.006 KWh/gallon of water tr eated. Sample calculations to demonstrate the precise derivation can be found in Appendix 2, Section 2.Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

18 | P a g e Table 3 shows a summary of the energy requirements of each unit.

Table 3. Equipment electricity requirement summary

Operation Time 720 hours

Wate r Treated 2.83E+06 Gallons

Power Source

(Natural Gas) $ 0.0123 $/KWh

Usage Units Usage (KW) Usage

(KWh) Cost

($/KWh) Cost ($)

Unit Operations

EC 0.006 KWh/gallo

n 17,000 $ 0.0246 $ 417.84

Pump

- motors

1 1.30 hp 0.969 698 $ 0.0312 $ 21.78

2 1.30 hp 0.969 698 $ 0.0312 $ 21.78

3 1.30 hp 0.969 698 $ 0.0312 $ 21.78

4 85.38 hp 63.667 45,840 $ 0.0273 $ 1,250.20

5 1.30 hp 0.969 698 $ 0.0312 $ 21.78

6 0.94 hp 0.700 504 $ 0.0312 $ 15.73

7 0.58 hp 0.433 312 $ 0.0312 $ 9.74

Compressor

8 4.25 hp 3.169 2,281 $ 0.0312 $ 71.24

TOTAL $ 1,851.86

TOTAL (per gallon) $ 0.0006542Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

19 | P a g e 

### Part 4: Equipment List and Unit Descriptions
Electrocoagulation (V

- 100):

As previously mentioned, we were unable to simulate the electrocoagulation reactor due to the lack of a process model and usable design data. Thus, the design was done manually based on data acquired from a report describing the operation of a similar EC unit being used by a company in
Australia 9 . The electrode s used in the unit will be made of Iron metal. Despite the higher cost of replacement for Iron electrodes, they are more efficient than aluminum electrodes for natural gas

based wastewaters 14 . The influent total COD of the wastewater is approximately 742 p pm, and based on several sources, it appears that we could reasonably assume a 95% oxidation of the organics in the
flowback 10, 11 . This results in the EC unit effectively treating the COD to below acceptable standards. The electricity requirements for the EC are estimated to be 0.006 kwh/gal treated, and the costs for replacement electrodes are estimated as $0.00015/gal treated 9 . The EC reactor chamber itself will be constructed from stainless steel to provide resistance to corrosive components of the flow back.

Dissolved Air Flotation (V

- 101, P

- 101, C

- 100)

The DAF unit and associated equipment (recycle pump and compressor) were simulated in SuperPro. SuperPro allowed us to manipulate several input parameters to the DAF process model,
which allowed for a r igorous design of the unit. The DAF will be operated with a solids loading of 1 gal/ft 2

- min, a typical value for many small DAF units. The first parameter we sought to optimize for the operation was the air

- to

- solids ratio. Given our desired total suspende d solids effluent concentration of <50 mg/L, we used the optimization chart presented figure 11 to select an air

- to

- solids ratio of 0.02 mL/mg.

Figure 11. Air

- to

- solids opt imization chart for the DAF unit 3



## Desired Effluent TSS concentration (mg/L)Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

20 | P a g e After selecting the air to solids ratio, th e last critical parameter to be optimized was the recycle ratio. This optimization was done on a total capital cost basis. A lower recycle ratio reduces the required cost of the pump and the flotation tank, but increases the required air pressure from the compressor. This lead to a need to balance the competing effects of the recycle ratio on capital cost. The required air compressor pressure was calculated using the DAF design equation 4 :

(1)

Where R is recycle ratio, S out is concentration of dissolved air in outgoing wastewater (20.36 mg/L),

f accounts for non

- saturation of air in water (65%), P is the required air pressure in atm, and X 0 is the TSS concentration in the influent (608.5 mg/L). This pre ssure was calculated for each recycle ratio we simulated ( see appendix 2, section 3 for sample calculation ). Once the compressor pressure and recycle flow rate were known, the total capital cost for all three pieces of equipment included in the DAF analysi s (flotation tank V

- 101, compressor C

- 100, and pump P

- 101) were calculated for each recycle ratio. The results of these calculations are graphed in figure 12

.

Figure 12. Total c apital costs of the DAF system passes through a minimum with a recycle ratio of 0.8

The results of this optimization led us to select a recycle ratio of 0.8 or 80%, which resulted in an estimated total capital cost of about $420,000 for the three components of the DAF system. The DAF

$0 $100,000 $200,000 $300,000 $400,000 $500,000 $600,000 $700,000

0 0.5 1 1.5 2 Capital Costs (USD)

Recycle Ratio Air Compressor

Flotation Tank and Recycle Pump

Total DAF Capital
CostDesign of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

21 | P a g e tank will be constructed from stainless steel to provide resistance to corrosive components of the
flowback.

Reverse Osmosis (V

- 102 ):

Reverse Osmosis (RO) is used to remove dissolved solid from the flowback. The operating pressure is calculated to be about 1000 psi, which is approximately twice the o smotic pressure of the 45,000 ppm dissolved solid flowback solution ( See Appendix 2, section 4 ) 15

. Increasing operating pressure would increase percent recovery and rejection coefficient. The operating temperature is
determined to be at 25 o C. Increasing o perating temperature would increase percent recovery but decrease rejection coefficient 16 . A membrane with rejection coefficient of 0.99 and 0.95 for NaCl and
CaCl 2 , respectively and percent recovery of 80% 16 are required for the process. The size of a RO module is determined to be about 40 inch in length and 16 inch in diameter which can hold up to

160m 2 of membrane 17

.

Pumps

Each of our material streams will be pushed through the system by electric powered centrifugal pumps. The pumps used for the simulat ion are constructed from stainless steel because there will be copious amounts of dissolved solids passing though. The flow rates they will handle range from 30 to 65 gallons per minute, and they are rated to handle head loss up to 45 feet.Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

22 | P a g e 

### Part 5: Speci fication SheetsDesign of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

23 | P a g eDesign of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

24 | P a g eDesign of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

25 | P a g eDesign of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

26 | P a g eDesign of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

27 | P a g eDesign of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

28 | P a g eDesign of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

29 | P a g e 

### Part 6: Equipment Cost Summary

Table 4. Equipment cost b reakdown

Equipment Cost

Electric Motors $ 29,448.52

Centrifugal Pumps $ 154,206.36

Compressors $ 36,849.74

DAF $ 311,817.63

RO (housing) $ 380,800.00

RO (membrane) $ 15,000.00

Electrocoagulation $ 155,000.00

Recycle Tank $ 5,000.00

Truck $ 50,000.00

TOTAL EQUIPMENT COST $ 1,123,122.25

*See Appendix 2, Section 2 for complete derivation of each cost



### Part 7: Fixed Capital Investment Summary
Costing for each unit was conducted using the process equipment cost equations presented in Chapter
22 of Product and Process Design Principles 13 . These equations allowed us to est imate the expected capital cost of process equipment based on a sizing factor related to the unit’s size or throughput. Once the capital cost was calculated and adjusted to 2013 dollars using the CE Index, we had a reasonably good approximation of the capi tal cost of each unit. Where appropriate, construction material correction factors were used to adjust the cost based on a non

- standard material of construction (stainless steel flotation tank, pumps, etc.). Sample calculations of the capital cost for some units are
shown in Appendix 2, section 2. Table 5 gives the sizing parameter and its units used to calculate cost of each piece of process equipment.

Table 5. Equipment c ost equation p arameters and construction material factors 13

Equipment Cost Eqn. Para meter [units] Material Material factor

Electric Motors P c [hp] N/A N/A

Centrifugal Pumps S = Q(H) 0.5 [(gpm)*(ft 0.5 )] Stainless steel 2.00Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

30 | P a g e Compressors P c [hp] Stainless steel 2.5

DAF Q [gpm] N/A N/A

RO (housing) Q [gpm] Cast iron 1.0

RO (membrane) A [ ft 2 ] N/A N/A

Electrocoagulation N/A (estimated from analysis of similar unit) N/A N/A

Recycle Tank V (gal) N/A N/A

Truck N/A (estimated from typical estimates for mobile process trucks)



### Part 8: Other Important Considerations

Environmental problems and methods used to eliminate them

The goal of this system is to minimize the effect that fracking has on the environment by treating the noxious wastewater so that it can be reused in other wells and not be reintroduced directly into the environment. How ever, there will still be an environmental impact. The treatment process will reduce the waste from the well to about 15% of the original volume. In the case of most wells, this will still result in tens of thousands of gallons of concentrated waste. This sludge is typically taken to a landfill or injected deep underground into a well that is no longer active. This does pose a slight risk to the environment, but it is greatly reduced from the risk that is present without a treatment
system.

Safety and heal th concerns

- Hazard and Operability Study (HAZOP)



### Node: Pump Intention: Flows
Guide
Word Parameter Cause Consequence Action

NO FLOW Line is blocked Pump could break due
to overheat of electric

motor. Check for bends/blocks

Line is leaking Visual in spectionDesign of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

31 | P a g e No power to pump Have backup power

source

MORE FLOW Pump spinning too fast Overflow of flowback
and membrane could be damaged Monitor pump speed regularly

Error in pump setting Monitor pump setting regularly



### Node: Compressor Intention: Provides compressed air to the Dissolved Air Floatation (DAF)
Guide
Word Parameter Cause Consequence Action

NO PRESSURE Line is blocked Tank could be
overflown due to presence of excessive
solid in the DAF Check for bends/blocks

Line is leaking Line i nspection using
soap water

No power Have backup power

source

MORE PRESSURE Error in compressor setting Pipe could burst Monitor compressor setting regularlyDesign of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

32 | P a g e 

### Node: Electrocoagulation (EC) Intention: Destabilizes the organics and suspended solid

Gu ide
Word Parameter Cause Consequence Action

NO CURRENT No power More suspended solid and organics get through to cause membrane fouling Have backup power

source

Electrode depleted Monitor electrode regularly

MORE CURRENT Error in EC setting Possible electrocution Monitor EC setting regularly



### Node: Dissolved Air Flotation (DAF) Intention: Separates organics and suspended solid from water
Guide
Word Parameter Cause Consequence Action

NO FLOW Line is blocked Compressed air
released to atmosphere dir ectly Check for bends/blocks

Line is leaking Visual inspection

MORE FLOW Pump spinning too
fast Tank could be

overflown which causes spill of
flowback Monitor pump speed regularly

Error in pump setting Monitor pump setting regularly



### Node: Revers e Osmosis Intention: Separated dissolved solid from water
Guide
Word Parameter Cause Consequence Action

NO PRESSURE Pump is broken Minimal or no separation occurs Troubleshoot pump regularly

Line is leaking Visual inspection

MORE PRESSURE Pump spinni ng too fast Membrane could be

damaged and module
could burst which causes spill of Monitor pump speed regularly

Error in pump setting Monitor pump setting regularlyDesign of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

33 | P a g e Narrow line being
used flowback Line inspection

MORE COMPOSITION Error in sensor

r eading Membrane could be

fouled and inefficient separation Online and offline

measurement

Error in control

action Monitor control process

Process controllability and instrumentation

Since there are no major effects from changes in flow rates, we wil l use direct acting feedback controllers to control all our valves. There are no heating or cooling elements in the process, so there will not be any heat control equipment necessary. We will also have to monitor the COD and control the valves accordingly.

Startup, including additional equipment

This process is designed as a mobile service for frackers. Inherent in this design is the minimization of startup barriers for the on

- site operations. The entire process will fit on a
standard 8.5’ x48’ trailer. Thi s is so that the startup for the system is limited to setting up pipes and a pump that drain the holding pond. There will also be additional costs to the frackers, as they will need to dig a second well so that the clean water can be stored
somewhere befor e being transported to the next fracking location. The majority of our startup costs will be related to the assembly of the unit operations as well as mounting everything onto our trailer.

Plant (trailer) layout

Figure 13

. Schematic showing proposed p hysical arrangement of process on truckDesign of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

34 | P a g e 

### Part 9: Operating Cost and Economic Analysis

Table 6. ROI summary for us



## US
EQUIPMENT COST (1 time cost) $ 1,126303.58

OPERATING COST (per well) $ 102,532.35

Revenue (per well) $ 297,467.65

Revenue (per year) $ 1,665,818.84

Payback period 3 years

Return on Investment 326.5 %Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

35 | P a g e Table 7. ROI summary for frackers



## Frackers

TOTAL COST (per well) $ 400,000.00

TOTAL SAVINGS (per well) $ 483,282.72

Return on Investment (%saving s) 21%

Cost per Gallon Treated $ 0.14

The full cost sheet is available as an electronic file. S ee Appendix 3, Section 3 for more information

. We
have an unrealistically high ROI and this is based on the way we calculated the savings to t he well. The

savi ngs that we considered were 1) treated water that can be used at a nearby well without having to
draw fresh water and 2) the cost of disposal of dirty water. We have a reliable source indicating that $0.12 /gal is the average cost to draw and transp ort fresh water to a well site 18

. Since we were unable

to accurate ly estimate the cost to transport treated water to a nearby well

, w e assumed these costs to be much lower than the cost of transporting fresh water to the well site, and based our calculations on
the $0.12/gal rate for clean water . H owever, if we bring this number to $ 0 .00 ( implying that it would
cost the same to t ransport our treated water to a nearby well as it would to draw and transport the
same amount of clean water from a rem ote source)

, we will still have a profitable operation.

Table 8. ROI summary for us, savings from fresh water ignored



## US
EQUIPMENT COST (1 time cost) $ 1,126,303.58

OPERATING COST (per well) $ 102,532.35

Revenue (per well) $ 82,467.65

Revenue (p er year) $ 461,818.84

Payback period 3 yearsDesign of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

36 | P a g e Return on Investment 18.2%

Table 9. ROI summary for frackers, savings from fresh water ignored



## Frackers

TOTAL COST (per well) $ 185,000.00

TOTAL SAVINGS (per well) $ 198,162.72

Return on Invest ment (%savings) 7.1%

Cost per Gallon Treated $ 0.065/gal



## Section III: Conclusions and Recommendations
Hydraulic fracturing is a growing industry, and will almost certainly be a key part of the energy
market for the foreseeable future. The rising en vironmental regulations of frac turing’s impacts are a challenge to the development of the technology, but also provide an opportunity for chemical engineering compani es to design novel solutions for the problem of flowback management. The
market for a mobi le treatment solution for flowback is very large, and is only projected to grow

. Based on our study, we concluded that a mobile sy stem to treat the flowback at well sites is a viable business development op portunity

. The key to our process design’s success lies in the synergy between the electrocoagulator, the dissolved air flotation unit, and the reverse osmosis modules. By correctly sequencing these units, we were able to design an overall process capable of treating the most problematic contaminants from fracking flowback.

Our design centered on creating a safe, functional, and economic method for reusing flowback, a goal which we achieved. The high return on i nvestment for both our company and the well operators indicates that with our process, operator s can realize a significant savings over current disposal
methods in the Marcellus Shale and that our company also stands to profit significantly from this operation. In addition to the economic benefits, our mobile treatment process will address several

e nvironmental issues surrounding fracturing. By reusing flowback, operators avoid withdrawing extra water from rivers and lakes. The mobile aspect of the design also significantly reduces greenhouse gas emissions from trucking the flowback to deep well inje ction sites.

During the design process, our team designed the process for a single specific well in the Marcellus Shale region. However, as our design evolved, we developed simulation tools, designed calculators, and gathered data that would allow us to g eneralize our solution to a wide range of well sites. The versatility offered by these tools will provide a competitive advan tage in allowing us to optimize the operation for each well site based on its unique chemistry and flow profile. WeDesign of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

37 | P a g e recommend that our com pany engage in further R & D to further explore the potential benefits of this design.



## Acknowledgements

We would like to thank Dr. Russell F. Dunn, Dr. Kenneth A. Debelak and Dr. John Roth from the Vanderbilt University Chemical Engineering Depart ment for their advice throughout the entirety of the design process. We would also like to thank Dr. Alan Bowers from the Vanderbilt University Civil Engineering Department for his comments and recommendations. And finally , we would like to thank
Vanderbil t University for th e financial support and provisions of computer software.Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

38 | P a g e 

## Bibliography

1. Sourcewatch. “Fracking” Sourcewatch.org. Web. 12 February 2013. <http://www.sourcewatch.org/index.php/Fracking>.

2. Sequiera, C. et. Al. “Mediated and non

- mediated elec trochemical oxidation of isopropanol” Applied Surface Science. Web. 13 April 2013. <http://www.sciencedirect.com/science/article/pii/S0169433205015680>.

3. GE Water & Process Technologies. “Wastewater Solids Flotation Techniques” World Water

Tour . Web. 5 Febr uary 2013. <http://www.gewater.com/pdf/watertour/wwtchi/breakout_session/Flotation_Technology.p
df>.

4. Armenante, Piero M. “Flotation”; Web. March 17, 2013. <http://cpe.njit.edu/dlnotes/CHE685/Cls05

- 1.pdf>.
5. Ecologix Environmental Systems. “Integrated Treatmen t System for Fracking Flowback” Ecologix Wastewater Treatment Solutions . Web. 15 April 2013. <http://www.ecologixsystems.com/system

- its.php>.

6. Water Quality Association. “Technical Briefs: Reverse Osmosis” Web. April 16, 2013.

<http://www.wqa.org/sitelogic. cfm?ID=872>.

7. Wilson, Mark “Flowback and Produced Water Treatment Overview” GE Water & Process Technologies. Web. February 16, 2013. <http://www.makingwaterconnections.com/wp

content/uploads/2012/05/Wilson_Flowback

- and

- Produced

- Water

- Treatment

- Overview.pdf>

. 8. Acharya, Harish R. “Cost Effective Recovery of Low

- TDS Frac Flowback Water for Re

- use” GE Water & Process Technologies . Web. February 27, 2013. <http://www.gwpc.org/sites/default/files/event

- sessions/3Acharya_Haris.pdf>.

9. Tetreault, Alena “Electrocoagulat ion Process for Wastewater Treatment.” Web. April 8, 2013. < http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CD8QFjAB&ur l=http%3A%2F%2Fwww.redmeatinnovation.com.au%2Fproject

- reports%2Freport

categories%2Fenvironment%2Felectrocoagulation

- process

- for

- wastewater

treatment%2Fmla

- report

- prenv011

- 1&ei=zQljUaHhLJLW8gTi2ID4Bg&usg=AFQjCNHfIBMws2DnYRvkjhoD19l0Yjazrw&sig2=Nd9M gRk2iIcO6Hhetqat6Q&bvm=bv.44770516,d.eWU>.

10. Hardik, Shah. “Electrochemical Oxidation of Organic Pollutants” Sarvajanik Colle ge of Engineering and Technology . Web. April 16, 2013. <http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CDoQFjAB&u rl=http%3A%2F%2Fwww.environmental

expert.com%2FFiles%2F0%2Farticles%2F2980%2Farticle1363.doc&ei=cVhtUd7VMYS28wT W7IGgAw&usg =AFQjCNEPzkKIPmy0hET

eykLjs7UhLEEgg&sig2=l_ZnyeLndRB5UbMDRExWiQ&bvm=bv.45175338,d.eWU>.

11. Wolford, Robert. “Characterization of Organics in the Marcellus Shale Flowback and Produced
Waters” Pennsylvania State Library . Web. March 3, 2013.

< https://etda.librar ies.psu.edu/paper/12343/7626 >.
12. Holt, Peter et. Al. “Electrocoagulation as a wastewater Treatment” Australian Environmental Engineering Research . Web. April 2, 2013. <http://www.isf.uts.edu.au/publications/PH_GP_CM_1999.pdf>.Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

39 | P a g e 13. Seider, Warren et. Al. Product and Process Design Principles . Third Ed. John Wiley and Sons: Hoboken, NJ. 2009.

14. Vepsäläinen, Mikko. “Electrocoagulation in the treatment of industrial waters and
wastewaters” VTT Science 19 . Web. April 7, 2013. <http://www.vtt.fi/inf/pdf/science/2012/S19. pdf>.
15. Applied Membranes. “Reverse Osmosis RO Systems” Water Treatment Guide. Web. April 10, 2013. <http://www.appliedmembranes.com/Reverse_Osmosis_Systems.htm>.

16. Applied Membranes. “Factors Affecting RO Membrane Performance” Water Treatment Guide. April 9, 2013. <http://www.watertreatmentguide.com/factors_affecting_membrane_performance.htm>.

17. Johnson, Jon and Busch, Markus. “Engineering Aspects of Reverse Osmosis Module Design.”
Dow Water & Process Solutions . Web. March 27, 2013. < http://gwri

ic.technion.ac. il/pdf/IDS/380.pdf>.

18. Sider, Alison. “Drillers Begin Reusing Frac Water” Wall Street Journal. Web. April 8, 2013. <http://online.wsj.com/article/SB10001424052970203937004578077183112409260.html>.Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

40 | P a g e 

## Appendix

Appendix 1: Glossary of Terms

– mass flow rate of the water leaving the well

– density of the water leaving the well

– concentration of TDS in the water leaving the well

– volume of the water in the holding pond

– density of the water in the hold ing pond

– concentration of the water in the pond

– mass flow rate of the water leaving the pond

– density of the water in the pond

– concentration of the water in the pondDesign of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

41 | P a g e 

### Appendix 2: Design Procedures and Calculations

Section 1: Holding Pond Component Balance (TDS):

Overall Material Balance:

Section 2: Costing Data

CE = 550

Motors:

Define Q (gpm), P (psi), H (ft), (lb/gal)

(table 22.22)Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

42 | P a g e Pumps :

Define Q (GPM) and H (feet)

( table 22.20 in design book)

(table 22.21) (stainless steel)

Compressor :

(based on an electric powered motor)

(based on a stainless steel compressor)

Utilities:

Natural Gas:

Heating value (approximated as methane)Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

43 | P a g e Cos t of energy from natural gas

Cost of electricity

On site turbines will harness approximately half of the energy in the natural gas as usable

electri city

Cost of powering a motor

Motors will convert approximately 80

- 95% of the electricity to usable power

For this example 90.2% (50

- 99 hp motor minimum efficiency) 13

For a 85.38 hp motor, operating for 720 hours (30 days)

DAF :

Q = 117 gpm

C BM = 14,800*Q 0.64 = $311,817Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

44 | P a g e RO:

Q = 144,000 gp d

C BM = 2.7*Q = $388,800

EC: capital cost was assumed to be c omparable to cost of Australian unit 9 , which is $155,000. Non

rigorous design prevented a more accurate estimation.

Section 3: DAF compressor pressure sample calculation For a recycle ratio of 0.8 (the designed value), the required compression pressure was calculated as 4 :

= 13.03 atm = 191.5 psi

Section 4 : TDS model and operating pressure calculation

TDS was modeled by combination of sodium chloride (NaCl) and calcium chloride (CaCl 2 ) which are significant com ponents based on GE data 7 where 80.7% of TDS was modeled by NaCl and 19.3% of TDS was modeled by CaCl 3

.

Osmotic pressure of NaCl and CaCl 2 were calculated to be 413.9 psi and 71.1 psi, respectively from
known data 15 :

For NaCl:

For CaCl 2 :Design of a Mobile Treatment System for Hydraulic Fracturing Wa ste Chevron Group April 19, 2013

45 | P a g e Thus, the osmotic pressure of the solution is 486.1 psi. Operating pressure of a reverse osmosis is usually doubled the osmotic pressure 17 , in our case it would be 972.1 psi which is approximately close to 1000 psi.Design of a Mobile Treatment System for Hydraulic Fracturing Waste Chevron Group April 19, 2013

46 | P a g e Section 5: Relevant tabulated GE data

Table S5.1. Flowback composition

Day Density

(lbs/gal) TDS

(mg/L) TDS ppm Ca (mg/L) Mg (mg/L) TH (CaCO3) (mg/L) Na (mg/L) K (mg/L) Fe (mg/L) Ba

(mg/L) Sr (mg/L)

1 8.36 559 558 40 4 118 137 6 39 0 3

1.5 8.39 6438 6405 380 31 1171 1900 104 27 11 74

2 8.42 12773 12658 935 77 2899 4639 264 16 26 196

3 8.49 23818 23419 1313 102 4087 5943 284 8 38 315

4 8.58 40803 39690 2447 191 7817 11040 457 22 106 734

5 8.60 45759 44381 2680 209 85 90 12122 481 28 126 821

12 8.68 59634 57337 4395 381 13644 15740 546 47 210 818

15 8.78 78682 74789 4462 372 14402 19562 713 15 240 1351

21 9.20 156570 142071 10528 872 33122 40017 1750 67 336 2599

25 9.27 170014 153021 12085 1013 38039 41390 1926 39 3 85 2959

31 9.36 185729 165673Design of a Mobile Treatment System for Hydraulic Fracturing Waste Chevr on Group April 19, 2013

47 | P a g e Table S5.2. Flowback flowrate

Day Percent of

Fracture Barrels gallons/day gal/min

1 7.56% 6124 257208 178.62

2 7.56% 6119 256998 178.47

3 7.50% 6071.4 254998.8 177.08

4 7.44% 6023.8 252999.6 175.69

5 7.26% 5881 247002 171.53

6 4.56% 3690.5 155001 107.64

7 2.88% 2333.3 97998.6 68.05

8 1.21% 976.2 41000.4 28.47

9 0.88% 714.3 30000.6 20.83

10 0.65% 523.8 21999.6 15.28

11 0.44% 357.1 14998.2 10.42

12 0.35% 285.7 11999.4 8.33

13 0.26% 214.3 9000.6 6 .25

14 0.18% 142.9 6001.8 4.17

15 0.12% 95.2 3998.4 2.78

16 0.07% 57.1 2398.2 1.67

17 0.04% 28.6 1201.2 0.83

18 0.04% 33.3 1398.6 0.97

19 0.03% 23.8 999.6 0.69

20 0.03% 26.2 1100.4 0.76

21 0.04% 28.6 1201.2 0.83

22 0.04% 29.8 1251.6 0.87Desig n of a Mobile Treatment System for Hydraulic Fracturing Waste Chevron Group April 19, 2013

48 | P a g e 23 0.03% 27.4 1150.8 0.80

24 0.03% 27.1 1138.2 0.79

25 0.04% 30.5 1281 0.89

26 0.04% 28.6 1201.2 0.83

27 0.04% 33.3 1398.6 0.97

28 0.03% 23.8 999.6 0.69

29 0.08% 61.9 2599.8 1.81

30 0.04% 28.6 1201.2 0.83

31 0.04% 29.8 1251.6 0.87Desig n of a Mobile Treatment System for Hydraulic Fracturing Waste Chevron Group April 19, 2013

49 | P a g e 

### Appendix 3: Computer programs developed

Section 1: MATLAB
MATLAB ODE file :

Can be used to model or predict incoming TDS concentration at a particular well site by solving differential balances on holding pond

function xdot = Flowback_Blending_Simulator( t,x)

% INPUTS

% t = time in days

% x(1) = Vp (volume in pond, gal)

% x(2) = Xp (TDS concentration in pond, lbs/gal)

% PARAMETERS

% rhoP = density of flowback in pond (lbs/gal)

% rhoW = density of flowback coming out of the well (lbs/gal)

% Fw = volumetric flowrate from well (gal/day)

% Xw = TDS concentration in flowback coming out of well (lbs/gal)

% Fout = volumetric flow rate from pond to seperation units (gal/day)

% OUTPUTS

% xdot(1) = d(Vp)dt (gal/min)

% xdot(2) = d(Xp)dt (lbs/gal * min)

% xdot(3) = can be used to plot TDS concentration in ppm format instead of

% lbs/gal

% Vp= x(1) (gal)

% Xp= x(2) (lbs/gal)

%rhoPDesig n of a Mobile Treatment System for Hydraulic Fracturing Waste Chevron Group April 19, 2013

50 | P a g e rhoP = 8.49; % assume constant, weighted average of the well flow density

measurements from GE data

%rhoW

if (t <= 1)

rhoW = 8.362;

elseif (t<= 1.5)

rhoW = 8.387;

elseif (t<= 2)

rhoW = 8.421;

elseif (t<= 3)

rhoW = 8.487;

elseif (t<= 4)

rhoW = 8.579;

elseif (t<= 5)

rhoW = 8.604;

elseif (t<= 12)

rhoW = 8.679;

elseif (t<= 15)

rhoW = 8.779;

elseif (t<= 21)

rhoW = 9 .197;

elseif (t<= 25)

rhoW = 9.272;

else

rhoW = 9.355;

end

%FwDesig n of a Mobile Treatment System for Hydraulic Fracturing Waste Chevron Group April 19, 2013

51 | P a g e Fvals = [257208 256998 254998.8 252999.6 247002 155001 97998.6 41000.4

30000.6 21999.6 14998.2 11999.4 9000.6 6001.8 3998.4 2398.2 1201.2 1398.6

999.6 1100.4 1201.2 1251.6 1150.8 1138.2 1281 1201.2 1398.6 999.6
2599.8 1201.2 1251.6];

tpicked = floor(t);

Fw = Fvals(tpicked);

%Xw

if (t <= 1)

Xw = .0046;

elseif (t<= 1.5)

Xw = .053;

elseif (t<= 2)

Xw = .1065;

elseif (t<= 3)

Xw = .1987 ;

elseif (t<= 4)

Xw = .3405;

elseif (t<= 5)

Xw = .3819;

elseif (t<= 12)

Xw = .4976;

elseif (t<= 15)

Xw = .6565;

elseif (t<= 21)

Xw = 1.3065;

elseif (t<= 25)Desig n of a Mobile Treatment System for Hydraulic Fracturing Waste Chevron Group April 19, 2013

52 | P a g e Xw = 1.4187;

else

Xw = 1.5499;

end

Fp= 44.7997*24*60; % Fp chosen t o bring simulation to near completion, volume is very close to zero

xdot(1)= (Fw*rhoW)/rhoP

- Fp;

xdot(2)= (Fw*Xw

- Fp*x(2)

- x(2)*xdot(1))/x(1);

xdot(3)= (xdot(2)/rhoP) * 1000000;

xdot=[xdot(1);xdot(2);xdot(3)];

% to Run the simulation at the Matlab Prompt:

%trange = [1 31]

%ic = [257208, .00467, 557.94];

%[t,y]=ode45('Flowback_Blending_Simulator',trange,ic);

%to Plot

% plot(t,y(:,1)) %Vp(t)

% plot(t,y(:,2)) %Xp(t) in lbs/gal

% plot(t,y(:,3)) %Xp(t) in ppm

endDesig n of a Mobile Treatment System for Hydraulic Fracturing Waste Chevron Group April 19, 2013

53 | P a g e Section 2: SuperPro Desi gner SuperPro Process Simulation:

An easy to edit process simulation was created in SuperPro. The file can be easily applied to design custom units for different regions or well sizes. This file is available as an electronic file (contact Matthew Claussen at matthew.w.claussen@vanderbilt.edu for access).

Section 3: Microsoft Excel Calculator Process Costing and Pricing Calculator:

An easy to edit economics calculator was created in Microsoft excel. This extensive spreadsheet allows for easy addition or modification of process costs, and calculates expected return on investment for the design. Due to its large size, the file will not be included here. This file is available as an electronic file (con tact Marc Panu at marc - daniel.m.panu@vanderbilt.edu for access).

Section 4 : Pertinent printed material See design notebook