Introduction

This report presents the results of the heat integration simulation of a methanol production plant using coelectrolysis. Each run will generate an output json file stored in the “Rosmose/result” folder and a “frontend.html” file is stored in “Rosmose” folder.

Once your models and units are ready you can run the rsomose simulation by pressing the “Preview” button in the top right corner or using the command line “quarto preview” in the terminal at the correct directory location.

A ready example is given to demonstrate extraction of data from an Aspen flowsheet, changing the process parameters in Aspen through your Rmd file and displaying your integration results.

All Aspen related files are found in this folder “model/AspenModel/.”

The “Aspen_methanol_process.rmd” file is coupled with the “methanol_process_PD1.bkp” file. The same example Aspen process flowsheet used in all tutorials throughout the course.

Methanol process in Aspen model

MODEL Methanol
Software	Location	Comment
ASPEN	model_process_PD1.bkp

MODEL INPUTS Methanol
Name	Path	Value	Units	Comments
Electrolyzer_size	/Data/Streams/POWER/Input/POWER	-30000	kW

MODEL OUTPUTS Methanol
Name	Path	Units
T_AIR_1	/Data/Streams/AIR1/Output/TEMP_OUT/MIXED	C
T_AIR_2	/Data/Streams/AIR2/Output/TEMP_OUT/MIXED	C
heater_1	/Data/Blocks/HEATER1/Output/QCALC	kW
T_FUEL_1	/Data/Streams/FUEL1/Output/TEMP_OUT/MIXED	C
T_FUEL_2	/Data/Streams/FUEL2/Output/TEMP_OUT/MIXED	C
heater_3	/Data/Blocks/HEATER3/Output/QCALC	kW
T_FUEL_3	/Data/Streams/FUEL3/Output/TEMP_OUT/MIXED	C
heater_4	/Data/Blocks/HEATER4/Output/QCALC	kW
T_FUEL_4	/Data/Streams/FUEL4/Output/TEMP_OUT/MIXED	C
heater_5	/Data/Blocks/HEATER5/Output/QCALC	kW
T_AIR_OUT	/Data/Streams/AIROUT/Output/TEMP_OUT/MIXED	C
T_AIR_4	/Data/Streams/AIR4/Output/TEMP_OUT/MIXED	C
cooler_1	/Data/Blocks/COOLER1/Output/QCALC	kW
T_FUEL_OUT	/Data/Streams/FUELOUT/Output/TEMP_OUT/MIXED	C
T_LTFUEL	/Data/Streams/LTFUEL/Output/TEMP_OUT/MIXED	C
cooler_2	/Data/Blocks/COOLER2/Output/QCALC	kW
MSC_cooler_1_Tin	/Data/Blocks/C1/Output/B_TEMP/1	C
MSC_cooler_1_Tout	/Data/Blocks/C1/Output/COOL_TEMP/1	C
MSC_cooler_1_Duty	/Data/Blocks/C1/Output/QCALC/1	kW
MSC_cooler_2_Tin	/Data/Blocks/C1/Output/B_TEMP/2	C
MSC_cooler_2_Tout	/Data/Blocks/C1/Output/COOL_TEMP/2	C
MSC_cooler_2_Duty	/Data/Blocks/C1/Output/QCALC/2	kW
MSC_power_tot	/Data/Blocks/C1/Output/WNET	kW
T_S1	/Data/Streams/S1/Output/TEMP_OUT/MIXED	C
T_S2	/Data/Streams/S2/Output/TEMP_OUT/MIXED	C
HX1_Duty	/Data/Blocks/HX1/Output/QCALC	kW
T_S4	/Data/Streams/S4/Output/TEMP_OUT/MIXED	C
T_S5	/Data/Streams/S5/Output/TEMP_OUT/MIXED	C
HX2_Duty	/Data/Blocks/HX2/Output/QCALC	kW
T_S7	/Data/Streams/S7/Output/TEMP_OUT/MIXED	C
T_S8	/Data/Streams/S8/Output/TEMP_OUT/MIXED	C
HX3_Duty	/Data/Blocks/HX3/Output/QCALC	kW
T_S3	/Data/Streams/S3/Output/TEMP_OUT/MIXED	C
R1	/Data/Blocks/R1/Output/QCALC	kW
cond_ti	/Data/Blocks/T1/Output/B_TEMP/2	C
cond_to	/Data/Blocks/T1/Output/B_TEMP/1	C
cond_Q	/Data/Blocks/T1/Output/COND_DUTY	kW
reb_ti	/Data/Blocks/T1/Output/B_TEMP/23	C
reb_to	/Data/Blocks/T1/Output/B_TEMP/24	C
reb_Q	/Data/Blocks/T1/Output/REB_DUTY	kW
V_R1	/Data/Streams/S3/Output/VOLFLMX2	cum/hr
Q_R1	/Data/Blocks/R1/Output/QCALC	kW
V_T1	/Data/Streams/S12/Output/VOLFLMX2	cum/hr

Next we define the Energy Technology (ET) we want to solve.

This project will use the Methanol ET.

Methanol ET

This ET will use the following Layers

OSMOSE LAYERS Methanol
Layer	Display name	shortname	Unit	Color
ELEC	Electricity	elec	kW	yellow

The methanol ET contains the following units

OSMOSE UNIT Methanol
unit name	type
Methanol	Process

Methanol Unit

cost1	cost2	cinv1	cinv2	imp1	imp2	fmin	fmax
0	0	0	0	0	0	1	1

Methanol Unit Streams

After importing the powers of your compressors and pumps in your Aspen model. you can use this ET to sum up everything and report your net electricity consumption.

layer	direction	value
ELEC	in	32025.86471

Heat Streams

name	Tin	Tout	Hout	DT min/2	alpha
heater_1	25.0	700.0	9662.79484	2.5	1
heater_3	25.0	33.7975644	114.016569	2.5	1
heater_4	33.7975644	94.9629521	5166.04347	2.5	1
heater_5	94.9629521	700.0	3332.57776	2.5	1
cooler_1	700.021398	25.0	-10945.0531	2.5	1
cooler_2	700.021398	25.0	-3445.01521	2.5	1
MSC_cooler_1	207.329046	25.0	-672.664443	2.5	1
MSC_cooler_2	207.401247	25.0	-675.120921	2.5	1
HX_1	207.656056	250.0	159.335927	2.5	1
HX_2	250.011953	50.0	-3802.07109	2.5	1
HX_3	52.5239904	250.0	2233.05923	2.5	1
R_1	250.011953	250.011953	-2523.17368	2.5	1
reb	77.3036885	91.2973447	1879.57604	2.5	1
cond	63.9245458	58.7832494	-1802.74722	2.5	1

Utility systems models

We will then define the utility systems, starting by the cooling technology.

Cooling Tower

Layers of the Cooling Tower ET

OSMOSE LAYERS coolingtower
Layer	Display name	shortname	Unit	Color
ELEC	Electricity	elec	kW	yellow
WATER	Water	water	kg/h	blue

Cooling tower unit of the Cooling Tower ET

OSMOSE UNIT coolingtower
unit name	type
CoolTower	Utility

Parameters of the Cooling Tower unit

cost1	cost2	cinv1	cinv2	imp1	imp2	fmin	fmax
0	0	0	11411.988413145207	0	0	0	100000

Cooling Tower Streams

Defining the resource streams, in this case electricity to the Cooling Tower

Resource Streams

layer	direction	value
ELEC	in	21.0
WATER	in	731.751592356688

Heat Streams

name	Tin	Tout	Hin	Hout	DT min/2	alpha
cooltowerheat	15	30	0	1000	5	1

Next, the refrigeration system

Refrigerator

Layers of the Refrigerator ET

OSMOSE LAYERS refrigerator
Layer	Display name	shortname	Unit	Color
ELEC	Electricity	elec	kW	yellow

Refrigerator unit of the Refrigerator ET

OSMOSE UNIT refrigerator
unit name	type
Refrigerator	Utility

Parameters of the Refrigerator unit

cost1	cost2	cinv1	cinv2	imp1	imp2	fmin	fmax
0	0	0	125590.17081620239	0	0	0	10

Refrigerator Streams

Resource Streams Defining the resource streams, in this case electricity to the refrigerator

layer	direction	value
ELEC	in	1079.1366906474818

Heat Streams

name	Tin	Tout	Hin	Hout	DT min/2	alpha
evaporation	5	5	0	5000	2	1
condensation	35	35	6079.136690647481	0	2	1

We also need to define a furnace Technology.

Furnace

Layers of the Furnace ET

OSMOSE LAYERS furnace
Layer	Display name	shortname	Unit	Color
NATGAS	Gas	ng	kW	green

Furnace unit of the Furnace ET

OSMOSE UNIT furnace
unit name	type
Furnace	Utility

Parameters of the Furnace unit

cost1	cost2	cinv1	cinv2	imp1	imp2	fmin	fmax
0	0	0	13772.807687141723	0	0	0	100

Furnace Streams

Resource Streams Defining the resource streams, in this case natural gas to the furnace

layer	direction	value
NATGAS	in	1030.9278350515465

Heat Streams

name	Tin	Tout	Hin	Hout	DT min/2	alpha
radiation	1050	1050	480.26584125000005	0	2	1
convection	1050	100	482.04866749999997	0	8	1
preheating	25	26	0	0.37098249999999994	8	1

Visualization of Furnace

To finally provide a Market

Market

Layers of the Market ET

OSMOSE LAYERS market
Layer	Display name	shortname	Unit	Color
NATGAS	Gas	ng	kW	green
ELEC	Electricity	elec	kW	yellow
WATER	Water	water	kg/h	blue

Units of the Market ET

OSMOSE UNIT market
unit name	type
ElecSell	Utility
NatgasSell	Utility
WaterSell	Utility

Electricity Selling Unit

Electricity sold by the grid to the process

Parameters of the Electricity Selling unit

cost1	cost2	cinv1	cinv2	imp1	imp2	fmin	fmax
0	250.0	0	0	0	0	0	100000

Electricity Selling Streams

Resource Streams

Electricity sold from the market to the process and the indirect CO₂ emissions from the electricity generated by the grid.

layer	direction	value
ELEC	out	1000

Natural Gas Selling Unit

Parameters of the Natural Gas Selling unit

cost1	cost2	cinv1	cinv2	imp1	imp2	fmin	fmax
0	119.0	0	0	0	0	0	1000

Natural Gas Selling Streams

Resource Streams

Natural gas sold from the market to the process. In addition to total CO₂ emissions (direct and indirect) from the use of natural gas

layer	direction	value
NATGAS	out	1000

Water Selling Unit

Water from the market to the process

Parameters of the Water Selling unit

cost1	cost2	cinv1	cinv2	imp1	imp2	fmin	fmax
0	2.5	0	0	0	0	0	10000

Water Selling Streams

Resource Streams

Water sold from the market to the process

layer	direction	value
WATER	out	1000

Complete the heat integration using Steam Network

STEAM NETWORK SUPERSTRUCTURE

Define the supestructure as STEAMNETWORK and provide a name for the ET.

======================================================================================================================================

Fluid selection

Define the fluids list from which Osmose can choose the fluid during the optimization process.

Fluids: ‘water’,‘R141b’,‘R123’,‘n-Butane’,‘IsoButane’,‘Ammonia’,‘R12’,‘R134a’,‘n-Propane’,‘R22’,‘R1234yf’,‘Propylene’,‘R115’,‘R32’,‘Ethane’,‘CarbonDioxide’,‘R13’,‘Ethylene’,‘Methane’

: OSMOSE FLUID steamnetwork_ss

fluid >> water [-] # Fluid selected from the fluid list

====================================================================================================================================== ## Levels of pressure and layers of pressure and draw off {-}

Define the related levels and layers of pressure and layers of draw off.

Pressure [bar]: Pressure levels of all units (headers, drawoffs, and condensation) in decreasing order, the last pressure level is considered as the condenser layerofpressure [-]: Layers of pressure defined for each pressure level. Temperatures [C]: Temperature levels of saturation (valid only for subcritical conditions), if pressures are not defined. isturbine [-]: Binary variable specifying if a pressure level is also an inlet of a turbine, the first element of the table must always be 1. issteam [-]: Binary variable specifying whether at the specified pressure level the steam can be produced, the first element of the table must always be 1. superheatdT [C]: Superheating temperature above saturation. Last element of the table is the condenser and it is always 1. layerdrawoff [-]: Layers of drawoff in case that steam is consumed as “mass” rather than “heat”.

OSMOSE LEVELS steamnetwork_ss
Parameter	L1	L2	L3	L4	Unit	Comment
Pressure	30	3	1	0.04	bar	Pressure levels defined for the rankine cycle in decreasing order
layerofpressure	p1	p2	p3	p4	-	Layer of pressure
Temperature	1	1	1	1	C	Temperature level, only if pressure is not defined (Optional)
isturbine	1	0	0	0	-	Activate turbine at the respective level, for last level is zero
issteam	1	0	0	0	-	Activate steam generation at the respective level
superheatdT	200	2	2	2	K	Superheating temperature difference
layerofdrawoff	droffp1	droffp2	droffp3	droffp4	-	Layer of draw off for steam straction

======================================================================================================================================

Minimum temperature difference contribution and heat transfer coefficient of fluids

DT[C]: Minimum temperature difference contribution (dtmin/2), which depends on the fluid state.

OSMOSE DT steamnetwork_ss
Parameter	DT	Unit	Comment
gas	15	K	Minimum temperature difference contribution related to the gas phase stream
liquid	5	K	Minimum temperature difference contribution related to the liquid phase stream
phasechange	2	K	Minimum temperature difference contribution related to the phasechange stream
global	10	K	Minimum temperature difference contribution for the global scope

htc [kW/m2K]: Heat transfer coefficients for each fluid state. It follows the relation $DT=112.14/htc^{0.4913}$

OSMOSE HTCOEFF steamnetwork_ss
Type	htc	Unit	Comment
gas	0.06	kW/m2K	Heat transfer coefficient related to the gas phase stream
liquid	0.56	kW/m2K	Heat transfer coefficient related to the liquid phase stream
condensing	1.6	kW/m2K	Heat transfer coefficient related to the condensing stream
vaporising	3.6	kW/m2K	Heat transfer coefficient related to the vaporasing stream

======================================================================================================================================

Efficiency of the rotary machines

eff_backpr_turb [-]: isentropic efficiency of backpressure turbine. eff_cond_turb [-]: isentropic efficiency of condesing turbine. eff_pump [-]: isentropic efficiency of pump.

OSMOSE EFFICIENCY steamnetwork_ss
Efficiency	Value
eff_backpr_turb	0.90
eff_cond_turb	0.95
eff_pump	0.80

======================================================================================================================================

Size constraints and costing of the steam network units

Fmin [-]: Minimum load factors of the units of the superstructure provided in kW. Fmax [-]: Maximum load factors of the units of the superstructure provided in kW.

OSMOSE SIZING steamnetwork_ss
Equipment	Fmin	Fmax
header	0	100000
drawoff	0	100000
turbine_drawoff	0	100000
turbine_ext	0	100000
pump	0	100000

======================================================================================================================================

Investment of the components of the steam network

Inv1 [Eur/yr]: Fixed annualized investment cost of the units of the superstructure Inv2 [Eur/yr/kW]: Variable annualized investment cost of the units of the superstructure

For pump it can be approximated by the cost function of centrifugal pump given by Turton et al. (2012) after linearized. For turbine, if steam turbine, use Bruno et al. (1998), else radial expander function by Turton et al. (2012).

15000.08 = 120 1000.08 = 8

OSMOSE COST steamnetwork_ss
Equipment	Inv1	Inv2
turbine	150	120
pump	50	8

======================================================================================================================================

Additional parameters of the superstructure

layerofelec [-]: Define the layer of electricity. layerofheat [-]: Define the layer of heat. layerofmakeup [-]: Define the layer of makeup fluid. Add it in the Resource ET. subcooldT [C]: Negative value indicating the subcooling in the condenser add_ext_turbine [-]: Binary variable to add extraction turbine

: OSMOSE PARAMS steamnetwork_ss

layerofelec >> ELEC [-] # Layer of electricity layerofheat >> DefaultHeatCascade [-] # Layer of heat subcooldT >> -1.1 [K] # Subcooling temperature difference in the condenser, must be <= 0 add_ext_turbine >> 0 [-] # Binary variable to add extraction turbine

======================================================================================================================================

Layer type

Define the layer type. It can be used as shown below by default CAUTION: THESE TABLE NEED TO BE DEFINED IN THE LUA FILE BUT CAN BE OMITTED FROM THESE RMD FILE NAMELY IT CAN BE GIVEN BY DEFAULT

OSMOSE LAYERTYPE steamnetwork_ss
LayerType	BalanceType
electricity	ResourceBalance
pressure	ResourceBalanceQuality
drawoff	ResourceBalance
condensate	ResourceBalance
makeup	ResourceBalance

====================================================================================================================================== ## Visualization of SteamNetwork Superstructure {-}

Process integration and Optimization problem definition

The objective function can be either MER (Minimum energy requirement) or TotalCost. To run in MER mode you need to specify only the process-type ET you want to solve. However to run in TotalCost mode, sufficient utilities must be supplied for the optimization problem to be feasible.

When running in MER mode it can be displayed the cc and gcc curves with the minimum energy requirements chunk. However when solving for TotalCost it should reported the CAPEX/OPEX chunk and display the icc and carnot plots to analyze the utility integration.

The following code chuncks can be used to serialize the project and the models to generate the OSMOSE lua files that enable debugging the system.

Optimization Results

In this section, the optimization results are summarized.

Capital and Operational Expenditures

CAPEX (EUR/Y): 705024

OPEX (EUR/Y): 68177309

Graphical representation of the energy integrated solution

Hot and cold Composite curves

Grand Composite Curve

Integrated Composite Curve

Carnot Plot

Heat Exchanger Network

The heat exchanger network area required to attain the minimum energy requirement is extracted from OSMOSE optimization results. The minimum number of heat exchangers for the network and average area per heat exchanger can also be calculated from the simulation outputs. Next the cost of this heat exchanger network can be computed based on the equations published in Turton 1998 and corrected by the chemical engineering plant cost index (CEPCI) for 2023.

Heat exchanger network area: 10260.2045 m².

Minimum number of heat exchangers: 58.

Average area per heat exchanger: 176.9001 m².

Annualized cost of heat exchanger network: 654761.1681 $/y.

Annualization factor: 0.0963.