Subscriber access provided by - Access paid by the | UCSB Libraries
Process Systems Engineering
Energy Efficient Carbon Fiber Production with Concentrated Solar Power: Process-Design and Techno-Economic Analysis Uwe Arnold, Andreas De Palmenaer, Thomas Bartholomaeus Brück, and Kolja Kuse Ind. Eng. Chem. Res., Just Accepted Manuscript • DOI: 10.1021/acs.iecr.7b04841 • Publication Date (Web): 16 May 2018 Downloaded from http://pubs.acs.org on May 16, 2018
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 43 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Industrial & Engineering Chemistry Research
Energy Efficient Carbon Fiber Production with Concentrated Solar Power: Process-Design and Techno-Economic Analysis Uwe Arnold a,*, Andreas De Palmenaer b,**, Thomas Brück c, Kolja Kuse d a
b
AHP GmbH & Co. KG, Karl-Heinrich-Ulrichs-Str. 11, D-10787 Berlin, Germany
Inst. Textile Technology, RWTH Aachen University, Otto-Blumenthal-Straße 1, 52074 Aachen, Germany
c
Werner Siemens Chair of Synthetic Biotechnology & Director TUM AlgaeTec Center, Dept. of Chemistry, Technical University of Munich (TUM), Lichtenberg Str. 4, 85748 Garching, Germany d
TechnoCarbonTechnologies GbR, Oberföhringer Strasse 175 a, D-81925 München, Germany
1
1 ACS Paragon Plus Environment
Industrial & Engineering Chemistry Research 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 2 of 43
2
ABSTRACT
3
Carbon fibers if generated from
4
anthropogenic CO2 via algae based
5
carbon
fixation
and
subsequent
6
energy
and
cost
efficient
7
carbonization would be a sustainable
8
CO2 sink. They could replace materials, which currently are major GHG-sources, hence
9
contributing significantly to accomplish targets of 2015’s Paris Agreement. For the first time our
10
study presents an integration of concentrated solar power (CSP) technology into a carbonization
11
reactor (CR) for carbon fiber production combined with extensive energy recovery. Based upon a
12
mass and energy flow model of the corresponding CSP-CR concept techno-economic analysis
13
(TEA) was carried out, first with static base case values for broad variation analysis, and in a
14
second step with a dynamic economic model, embedded in a Monte-Carlo simulation, so as to
15
quantify risks from market and modeling uncertainties. First results indicate significant reduction
16
potential of energy consumption and cost. Economic viability perspectives are promising and
17
justify extended research and developments.
18
INTRODUCTION
19
Compliance with 2015’s Paris Agreement requires mitigating further increase of atmospheric
20
greenhouse gas (GHG) concentrations fast and effectively. Sole substitution of fossil energy
21
supplies by renewables, however, will not suffice to meet the Paris goals in time1. Hence, CO2-
22
sinks with lasting GHG-extraction and demobilization effects are to be installed fast and in a
23
significant scale. Solution concepts a) of massive afforestation and reforestation2, b) of
24
combining biomass power plants (BE) with carbon capture and storage (CCS)3,4 equipment ( 2 ACS Paragon Plus Environment
Page 3 of 43 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Industrial & Engineering Chemistry Research
25
BECCS)2, and c) of carbon capture and (sustainable) utilization (CCU)3,4 are rapidly gaining
26
attention worldwide.
27
To date, essential construction materials, such as steel, aluminum, and cement, seem to be
28
irreplaceable in our societies. However, conventional production processes of these materials are
29
highly energy intensive and therefore responsible for up to 21% of the global anthropogenic
30
GHG emissions (see Supporting Information, SI, section 2.1). A substitution by a material
31
derived from CO2 with equivalent performance and cost but reduced energy input would reverse
32
the trend of CO2 emission and generate a value adding, permanent CO2 sink. Carbon fiber (CF)
33
could be an answer to this challenge.
34
Due to their reduced weight and high tensile strength carbon fibers and their composites are
35
rapidly gaining importance in the automotive and aerospace industries5,6,7. Currently, the
36
prevailing CF-precursor polyacrylonitrile fiber (PAN) is generated from petroleum based
37
resources5. Moreover, the conversion of PAN into carbon fiber is extremely energy and cost
38
intensive causing significant CO2 emissions. Cost of CF is currently prohibitive to deploy this
39
advanced material into cost sensitive mass markets, such as the building construction industry.
40
The development of new production processes that aim at a conversion of anthropogenic CO2 to
41
carbon fiber with minimal energy and cost input would offer a significant CCU solution and may
42
enable a disruptive transition in the construction, vehicle, and other producing industries. To that
43
end processes that convert CO2 into carbon fiber by electrolysis8 and by algae based biochemical
44
methods9 are evaluated technologically. In our previous manuscript9 we have delineated and
45
analyzed a process route for the conversion of anthropogenic CO2 to PAN fiber via generation of
46
algae biomass for the first time. In this study, we complete the process path by disclosing an
47
energy-efficient method for the thermal conversion of PAN into carbon fiber using concentrated 3 ACS Paragon Plus Environment
Industrial & Engineering Chemistry Research 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 4 of 43
48
solar power (CSP) technologies in combination with extensive internal energy recovery for the
49
first time.
50
After wet spinning into PAN fiber in the conventional CF production process, PAN precursor
51
is thermo-chemically converted into CF. Specifically, the PAN precursor is first stabilized
52
(oxidized) under air atmosphere at temperatures up to 300 °C and then carbonized
53
(denitrogenated) under nitrogen inter gas atmosphere and temperatures in excess of 1,500 °C.
54
These processes including downstream exhaust gas treatment are highly energy intensive.
55
Depending on the local energy prices, these processes comprise up to 33 % of the CF production
56
cost (SI, section 6.1). In that regard, the typical energy demand amounts to about 340 MJ/kg
57
without precursor production10. Hence, the high energy consumption is a main cost driver and
58
environmental burden of CF production. Industry requires cost reductions of about 50% for a
59
diversified application of suitable high quality carbon fiber11. Consequently, lowering cost and
60
specific energy demand of CF production is a major target of numerous CF related recent
61
investigations6,7,11,12,13,14.
62
To achieve both, reduced cost and energy demand, without losing material quality, the present
63
study suggests integrating concentrated solar power (CSP) technology into a carbonization
64
reactor (CR) in combination with extensive internal energy recovery. This new technology
65
platform is termed CSP-CR. The principle feasibility of carbonizing PAN fiber by means of
66
concentrated light was demonstrated by Fraunhofer-Institute ILT at RWTH Aachen University,
67
which treated oxidized PAN precursors with a laser beam as a concentrated light source15. These
68
experiments enabled quantitative PAN carbonization. The second prerequisite of high quality
69
carbon fibers are sufficiently high temperatures in the focal zone of the CSP setup. The 1 MW
70
solar furnace at Odeillo in Southern France is reported to create temperatures up to 3,200°C16. 4 ACS Paragon Plus Environment
Page 5 of 43 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Industrial & Engineering Chemistry Research
71
Hence, a temperature of 1,200-1,400 °C should be achievable given sufficient collector aperture
72
area and focusing quality. While multiple research on optimizing CSP for power production has
73
been reported e.g. 17,18, an investigation of viability perspectives of CSP for CF production has not
74
been disclosed to the authors’ knowledge.
75
The data reported in this study present a primary feasibility analysis of the CSP-CR-concept,
76
The system boundaries of our study encompass process design, static techno-economic analysis
77
(TEA) with average values for broad sensitivity analysis, and dynamic TEA embedded in a
78
Monte-Carlo simulation for assessment of risk from market, design, and modeling uncertainties.
79
The related work is reported as an early stage contribution to mandatory CCU technology
80
developments. Our study applies a reverse engineering approach by initially analyzing the
81
required conditions for economic viability of the investigated technology prior to proceeding
82
towards more detailed and resource consuming developments.
83
MATERIALS AND METHODS
84
CSP-CR Process, Mass and Energy Flow Model. For analysis of the CSP-CR technology, a
85
concise process concept (see figure 1) and a simplified mass and energy balancing model was
86
developed. The predominantly integral CSP-CR-model was configured to enable sufficient
87
differentiation for comparison with the conventional CF production process. Moreover, the model
88
had to be appropriately simplified for early stage TEA and the reverse engineering approach.
89
Some comprehensive system characteristics were covered by means of empirical mass or energy
90
specific coefficients and calibrated by means of the “MegaCarbon”-model of the Institute of
91
Textile Technology (ITA) at RWTH Aachen University, which is a granular physics-based
92
simulation model and process cost accounting tool of the comprehensive conventional carbon
93
fiber production process19,20,21,22,23. 5 ACS Paragon Plus Environment
Industrial & Engineering Chemistry Research 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 6 of 43
94
The MegaCarbon model was developed 2010-2013 in a joint R&D project of ITA Institute of
95
Textile Technology at RWTH Aachen University and industrial partners22,23. The model consists
96
of 46 interlinked modules (see figure S13 in SI) which model mass and energy flows and cost of
97
the different production steps of PAN-precursor production, carbon fiber production, and
98
preparation and supply of operation media such as nitrogen, steam and other. Included are
99
separate model components of cost accounting, factor input balancing and scenario analyses.
100
Differentiated for the single elements of the process-chain including steam and nitrogen
101
generation and waste gas abatement, the model calculates annual capital and operation cost,
102
energy and media consumptions depending on plant capacity and carbon fiber quality input
103
values. The specifics of investment and operation expenses were derived from data provided by
104
industrial producers and plant operators. Additional details of the ITA MegaCarbon model
105
including the model structure are presented in SI, section 4.2.
106 107
The model was modified to serve as a reference case (exclusion of the precursor production section, confinement to comparable system boundaries and related boundary conditions).
6 ACS Paragon Plus Environment
Page 7 of 43 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Industrial & Engineering Chemistry Research
108 109
Figure 1. Simplified process flow chart of the CSP-CR process for PAN precursor carbonization
110
to carbon fiber. Roving flow connection through the interface between oxidation and
111
carbonization zone can be both continuous and decoupled. The power block scheme (here for
112
simplification 1-stage process) is symbolic and can represent a multi-stage process with
113
intermediate storage capacities as well.
114
The sequence of basic treatment steps of the CSP-CR is identical with that of the conventional
115
process of PAN fiber oxidation and carbonization: pre-treatment, oxidation, carbonization, post-
116
treatment, (see figure 1). Instead of electric furnaces and in analogy to a solar field of a CSP
117
plant, the carbonization step takes place in a field of parallel solar heated carbonization reactors
118
with parabolic trough reflectors, which focus sunlight upon transparent carbonization tubes in
119
their focal axis. Each carbonization reactor tube comprises a heating zone (collector) and a heat7 ACS Paragon Plus Environment
Industrial & Engineering Chemistry Research 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 8 of 43
120
insulated extension zone (non-transparent, internally coated with reflecting surface) necessary to
121
ensure sufficient reaction time of the moving carbon roving inside. With the reported heat
122
demand for carbonization, the determined average area specific normal irradiation (DNI) of the
123
sun, and an assumed efficiency ηSF of the energy conversion form irradiation to heat a required
124
minimum collector aperture area ASF is calculated. With this area and a design-specific (pre-
125
selected) collector height hSC, a number of collector elements nSC, which is a function of the
126
required production capacity, a necessary minimum collector length lSC can be determined. The
127
total length of the carbonization reactor tube lCR needs to exceed the minimum transfer path
128
length of the roving in order to match with the minimum carbonization time of the roving (due to
129
reaction dynamics). This path length is a function of the average longitudinal roving velocity.
130
Figure 1 illustrates the related geometric parameters. The related formulae and additional details
131
are presented in section 4.1.4 of SI. The length of the zones and the geometry of the collectors are
132
results of the mass and energy flow model. Effective building ground demand of the plant is
133
derived by multiplying the total aperture area of the solar field with an empirical factor of 3.924,
134
whose delineation is described in the SI (SI, section 4.3, equation number 30).
135
Nitrogen serves as protective gas to enable the pyrolysis process inside the carbonization tubes.
136
The “exhaust gas” flow at the reactor’s exit has to be purified from gaseous products of the
137
carbonization reaction, i.e. from HCN, CH4, CO, NH3, C2H4, C2H6 and other by means of a state-
138
of-the-art RTO-component (regenerative thermal oxidation)25, which is a purpose-specific
139
combustion-chamber fueled with natural gas. The major energy recovery unit of the CSP-CR-
140
system is the power block, which may include an indirect Rankine or Brayton power cycle or a
141
classic small CHP-plant if the combustion unit is integrated. Due to the high temperature level at
142
the entrance of the power block’s primary side, a multi-stepped process may be required. The 8 ACS Paragon Plus Environment
Page 9 of 43 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Industrial & Engineering Chemistry Research
143
final selection of the power block’s energy conversion process is depending on the results of a
144
future techno-economic system comparison on a higher level of detail. At present, a Rankine-
145
process was assumed. The electric power generated by the power block contributes significantly
146
to covering the electric power consumption of the CSP-CR-process.
147
Behind the power block, treated exhaust gas of the carbonization reactor flows through heat
148
exchangers (e.g. double wall, shell exchanger or other) of the oxidation ovens. In closed N2-cycle
149
mode, the N2-stream is mixed with refill N2 behind the oxidation ovens to compensate for gas
150
losses and reduce the concentration of residual products of the combustion processes.
151
Subsequently, the gas stream is fed into the carbonization tube. Switch S in figure 1 denotes the
152
possibility of an open or semi-open N2 cycle where between zero and 100% of the N2-inflow to
153
the CR-tube are fed from an N2- supply (tank or attached air-splitting facility). The exiting part of
154
the N2-effluent from the oxidation ovens encompasses heat recovery and cleaning units to be
155
released to the atmosphere. This simplified model covers the gross effects of the different
156
operation modes for N2 mass flows and energy balances by means of related parameters. At
157
present, details of the stabilization gas cleaning process and of heat recovery for pre-heating the
158
N2-feed are not modelled in-detail.
159
Due to the exothermal reaction of the precursor oxidation, the temperature inside the oxidation
160
ovens has to be controlled very precisely. This is achieved by control of the hot N2-flow through
161
the oven system (by means of a bypass valve) and by control of the cool air inflow and heat
162
exchange between air in- and outflow. Behind the oxidation ovens, the gas flow exiting from
163
inside has to be cleaned from gaseous products of the stabilization reaction i.e. most importantly
164
from HCN and CO. Natural gas is required for this treatment by combustion and electric power is
165
consumed by the air fans and auxiliary devices of the oxidation/stabilization steps. 9 ACS Paragon Plus Environment
Industrial & Engineering Chemistry Research 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 10 of 43
166
In the process model, sophisticated heat recovery is generally assumed. The total demands of
167
electrical power (12.07 MJ/kg CF) and natural gas (118.30 MJ/kg CF) are determined empirically
168
by means of mass specific factors which were calibrated by the ITA MegaCarbon-model.
169
The CSP-CR-model allows for both a continuous 24h-operation of the plant and an intermittent
170
“Sun-day”-mode with decoupled operation of the oxidation ovens and the carbonization tubes.
171
The intermittent mode is governed by the varying daily sunshine period and requires extra thread
172
spools at the oxidation/carbonization-interface and additional electric heating equipment for pre-
173
heating the oxidation ovens. Intermittent operation is associated with significant additional
174
control and organization efforts because of the daily variation and the seasonal sunshine
175
differences. The model requires selection of a geographic plant location to determine local DNI
176
(direct normal irradiance) and average hours of sunshine from underlying meteorological data.
177
The CSP-CR process model is a simplified integral balance of mass and energy flows of the
178
following CSP-CR main components: stabilization & oxidation ovens, carbonization reactors,
179
waste gas abatement and power-block, auxiliary elements including roving pre- and post-
180
processing. The basic quantity is the carbon fiber mass flow, which is identical with the plant
181
production capacity. Precursor mass flow, nitrogen demand and number of required parallel
182
carbonization reactors are derived from the carbon fiber mass flow in combination with average
183
roving velocity, roving strength, material properties, and empirical specific precursor and
184
nitrogen demands per mass unit of carbon fiber. Material properties of carbon fiber and nitrogen
185
are computed by means of empirical formulae from literature. The required heat input to the
186
carbonization reactor is the sum of heating the roving from reactor entrance to exit temperature,
187
heating of nitrogen flow, and coverage of the pyrolysis-enthalpy of the endothermal
188
carbonization reaction. 10 ACS Paragon Plus Environment
Page 11 of 43 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Industrial & Engineering Chemistry Research
189
The mass specific pyrolysis enthalpy was derived from literature data under the assumption of
190
approaching a practical optimum as elaborated by Liddell et al.10 and U.S. Dept. Energy12 leading
191
to an estimate of 65 MJ/kg CF. The carbon fiber specific demand of natural gas required for
192
waste gas abatement was calibrated by means of the MegaCarbon model at 2.99 m3N/kg CF. The
193
calculation of electric power produced from heat recovery and a Rankine cycle applies moderate
194
assumptions of 90% and 31% for the energy conversion coefficients of heat recovery and of the
195
heat-power-cycle. On the power demand side the process related consumption of electricity per
196
carbon fiber mass unit (without heating) was calibrated by means of the MegaCarbon model
197
leading to a specific value of 12.07 kWhel/kg CF.
198
The required aperture area of the solar field of the carbonization reactors is a function of the
199
required heat input to cover the energy demand of heating and pyrolysis of the carbonization
200
reactors, the collector geometry (height, length), the location specific solar irradiation (DNI), the
201
number of required parallel carbonization reactors and an average energy conversion efficiency
202
coefficient of the solar field. Based upon operating CSP-plants this coefficient was approximated
203
by 50%, which is a target value and needs validation in follow-up studies.
204
Supporting Information SI contains the complete equation set of the CSP-CR-process model
205
applied by the authors including the simplifying model assumptions, and the derivation of
206
empirical design factors (SI, section 4.1). Details of the model calibration by the MegaCarbon-
207
model are presented in SI-section 4.2.2.
208
Static Techno-Economic Analysis Method. The economic model applied to static TEA uses
209
time averaged values for the calculation of product sales revenues, capital and operation cost in
210
order to determine a break-even-price of the carbon fiber product which is defined by line 36 of
211
table S4 in SI (sum of direct and indirect annual cost plus venture & profit surcharge divided by 11 ACS Paragon Plus Environment
Industrial & Engineering Chemistry Research 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
212
annual production capacity). The simple model was applied, which compares the CSP-CR with
213
conventional CF production plants for selected case scenarios and in a broad variation analysis.
214
Primarily, fixed capital investment, usually consisting of ISBL (inside battery limits) plant cost,
215
OSBL (outside battery limits) plant cost, engineering cost and contingency surcharges is
216
determined so as to calculate capital cost. In the static cost-model ISBL plant cost consists of four
217
components: 1 carbonization reactors and solar field, 2 power block, 3 oxidation ovens, 4 sum of
218
all other plant components and aggregates. The following scale functions for ISBL plant cost
219
components were derived by means of regression analysis from anchor values of real plant
220
investments or were calibrated by means of the ITA MegaCarbon-model (for derivation of the
221
scale functions see SI, section 4.3):
222
CSP-CR-carbonization reactor:
223
, = 353.92 ∗
224
with
225
KInv,CR:
.
∗ 1 + κ!"#!$ % € (1)
ISBL investment demand of the carbonization reactor field in €, cost year: 2017
226 227
'()
aperture area of solar collector field in m2
228
κ(*
empirical investment cost coefficient for CSP-CR specific additional
229
technical effort and cost, initial estimate: + 100%
230
'() is provided by the CSP-CR process model. The coefficients and the exponent of the scale
231
function (1) were derived from known data of two CSP-plants, which is a relatively poor data
232
base and needs additional empirical input. Compared with the established cost structure of a
233
standard CSP-power plant solar field, the empirical cost-coefficient κCSPCR represents the
234
additional cost in % which is caused by transparent absorber tubes instead of simple metallic 12 ACS Paragon Plus Environment
Page 12 of 43
Page 13 of 43 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Industrial & Engineering Chemistry Research
235
ones, additional sensors and control devices, roving entry and exit gas locks, roving transport and
236
positioning elements and sturdier mechanical construction of the reflector, its framework and
237
foundation and other additional technical equipment. As an initial estimate and cost target for the
238
CSP-CR design a value of 100% was selected, assuming that the CSP-CR-specific features of the
239
collector/reactor field lead to a duplication of investment demand. This “duplication-assumption”
240
is a working-hypothesis and was the object of broad variation analysis within the study presented
241
here.
242
Power block:
243
-.,// ,** = 9,949.57 ∗ 01
244
with
*
.234
€ (2)
245
KInv,PP:
ISBL investment demand of the power block in €, cost year: 2017
246
5 67,**
installed power generation capacity of power block in kW
247
567,** is provided by the energy balance of the CSP-CR process model. The coefficients and
248
the exponent of the scale function (2) were derived by means of regression analysis with 23
249
anchor points (square of the Pearson correlation coefficient r2 = 0.993).
250
Oxidation ovens:
251
,89 = 77,360 ∗ 0>= ⁄
252
with
