Hydrocarbon Processing - December 2020 - 24

Plant Design, Engineering and Construction
autothermal-only reforming plant. The plant-which originally
required a feedstock provided by nearby conventional steam re-

A plant originally dependent on a
hydrogen-rich feed from a nearby steam
methane reforming facility can now
operate independently through minimal
investment modification.
forming facilities (an imported hydrogen-rich stream) and fresh
natural gas-is now capable of operating in a standalone condition; specifically, this plant has become independent of any
feedstock from the nearby conventional reforming facility, and
the design change applied is unique among plants of this kind.
Chile 4 original design. Chile 4 is a 2,400-metric-tpd, oxygen-based methanol plant at Cabo Negro, Punta Arenas, Chile.
The plant has four main processing units, including:
* Natural gas preparation and reforming: Natural gas
compression, feed gas hydrogenation and desulfurization,
saturation and reforming (via an oxygen-fed autothermal
reformer)
* Methanol synthesis: Makeup and recycle compression,
methanol reactors and outlet gas cooling
* Methanol distillation: Degassing, topping column and
refining distillation columns
* Air separation unit: A 1,600-metric-tpd (99.5% purity)
oxygen plant.
In the reforming unit, synthesis gas is produced from natural
gas and purge gas from the adjacent Chile 1-3 methanol plants
(hydrogen-rich stream). The availability of external purge gas as
additional process feed allows the application of a single autothermal reformer-only reforming step to produce the synthesis
gas (FIG. 2).
Oxygen

Natural gas

Synthesis
gas

Reforming

Synthesis

Crude
methanol

Distillation

Methanol
product

Imported purge gas from
Chile 1, 2 and 3 methanol plants

FIG. 2. Integrated methanol production in Chile 4 (original design).

Natural gas

Hydrogen

Synthesis
gas

Reforming
Tail
gas

Synthesis
gas

Synthesis

Crude
methanol

Distillation

Methanol
product

Purge
gas

Pressure swing
adsorption

FIG. 3. Chile 4 standalone methanol production (adapted) block flow
diagram.

24

DECEMBER 2020 | HydrocarbonProcessing.com

Chile 4 plant modification. This plant incorporates design

features that result in a very efficient plant in terms of natural
gas consumption, but it does require additional feedstock imported from a nearby conventional steam
reforming plant (i.e., Chile 1). This extra feedstock
is a portion of the synthesis loop purge gas, which
is a hydrogen-rich stream. This additional hydrogen
allows the Chile 4 plant to achieve a stoichiometric
ratio higher than (and close to) a value of 2. This
characteristic of the Chile 4 plant made it unable to
operate in an autonomous manner.
However, the modification in FIG. 3 was applied,
which enabled the Chile 4 plant to operate in a standalone condition. This was achieved by purifying two streams from its own
process, namely:
* The purge gas stream coming from the synthesis loop
unit of Chile 4
* A portion of the reformed gas stream coming from the
exit of the reforming unit of the Chile 4 plant.
The solution (added to the Chile 4 flowsheet/plant), which
allowed standalone operation, incorporated a pressure swing
adsorption (PSA) package. The PSA separates hydrogen from
carbon compounds in the purge gas and reformed gas streams.
This high-purity hydrogen stream produced from the PSA
unit can then be fed to the front-end reforming section of the
Chile 4 plant, creating a synthesis gas that complies with the
stoichiometric design requirement of the synthesis loop and
eliminates the need for imported (hydrogen-rich) purge gas
from the Chile 1 plant.
The most interesting aspect of this project is related to the
modification of an existing plant that was not designed to operate with a PSA unit. Although some plants operate using their
own purge gas, Chile 4 purge gas had insufficient hydrogen to
reach the required stoichiometric ratio for methanol synthesis.
Therefore, an extra supply of " impure hydrogen " was required
to feed the PSA and to bridge the shortfall of hydrogen required to achieve the necessary stoichiometry ratio of feed gas
to the methanol synthesis unit. The synthesis gas stream (i.e.,
feed or makeup gas to the methanol synthesis unit) became the
solution to provide the additional hydrogen required for the
methanol synthesis unit. Feeding a certain percentage of the
synthesis gas stream, in addition to the synthesis loop purge
stream, to the PSA unit enabled the production of sufficient
extra hydrogen to meet the design stoichiometry target (> 2)
in the feed stream to the methanol synthesis unit.
The project also managed to recover compounds rejected
by the PSA after the hydrogen-rich stream was returned to the
process. The rejected stream (noted as tail gas in FIG. 3) is a carbon-rich stream and is returned as a fuel source to the existing
heating furnace. As such, no stream was wasted in this design,
and returning the tail gas as a fuel source allowed the plant to
maintain a high overall process efficiency level. When operating
in standalone mode, the efficiency level achieved on the Chile 4
plant was comparable and competitive with the efficiency level
of most of Methanex's remaining plants around the world.
Startup modification of the redesigned plant. In addition to the installation and connections required to install a PSA
package, a minor modification of the Chile 4 plant's startup was


http://www.HydrocarbonProcessing.com

Hydrocarbon Processing - December 2020

Table of Contents for the Digital Edition of Hydrocarbon Processing - December 2020

Contents
Hydrocarbon Processing - December 2020 - Intro
Hydrocarbon Processing - December 2020 - Cover1
Hydrocarbon Processing - December 2020 - Cover2
Hydrocarbon Processing - December 2020 - Contents
Hydrocarbon Processing - December 2020 - 4
Hydrocarbon Processing - December 2020 - 5
Hydrocarbon Processing - December 2020 - 6
Hydrocarbon Processing - December 2020 - 7
Hydrocarbon Processing - December 2020 - 8
Hydrocarbon Processing - December 2020 - 9
Hydrocarbon Processing - December 2020 - 10
Hydrocarbon Processing - December 2020 - 11
Hydrocarbon Processing - December 2020 - 12
Hydrocarbon Processing - December 2020 - 13
Hydrocarbon Processing - December 2020 - 14
Hydrocarbon Processing - December 2020 - 15
Hydrocarbon Processing - December 2020 - 16
Hydrocarbon Processing - December 2020 - 17
Hydrocarbon Processing - December 2020 - 18
Hydrocarbon Processing - December 2020 - 19
Hydrocarbon Processing - December 2020 - 20
Hydrocarbon Processing - December 2020 - 21
Hydrocarbon Processing - December 2020 - 22
Hydrocarbon Processing - December 2020 - 23
Hydrocarbon Processing - December 2020 - 24
Hydrocarbon Processing - December 2020 - 25
Hydrocarbon Processing - December 2020 - 26
Hydrocarbon Processing - December 2020 - 27
Hydrocarbon Processing - December 2020 - 28
Hydrocarbon Processing - December 2020 - 29
Hydrocarbon Processing - December 2020 - 30
Hydrocarbon Processing - December 2020 - 31
Hydrocarbon Processing - December 2020 - 32
Hydrocarbon Processing - December 2020 - 33
Hydrocarbon Processing - December 2020 - 34
Hydrocarbon Processing - December 2020 - 35
Hydrocarbon Processing - December 2020 - 36
Hydrocarbon Processing - December 2020 - 37
Hydrocarbon Processing - December 2020 - 38
Hydrocarbon Processing - December 2020 - 39
Hydrocarbon Processing - December 2020 - 40
Hydrocarbon Processing - December 2020 - 41
Hydrocarbon Processing - December 2020 - 42
Hydrocarbon Processing - December 2020 - 43
Hydrocarbon Processing - December 2020 - 44
Hydrocarbon Processing - December 2020 - 45
Hydrocarbon Processing - December 2020 - 46
Hydrocarbon Processing - December 2020 - 47
Hydrocarbon Processing - December 2020 - 48
Hydrocarbon Processing - December 2020 - 49
Hydrocarbon Processing - December 2020 - 50
Hydrocarbon Processing - December 2020 - 51
Hydrocarbon Processing - December 2020 - 52
Hydrocarbon Processing - December 2020 - 53
Hydrocarbon Processing - December 2020 - 54
Hydrocarbon Processing - December 2020 - 55
Hydrocarbon Processing - December 2020 - 56
Hydrocarbon Processing - December 2020 - 57
Hydrocarbon Processing - December 2020 - 58
Hydrocarbon Processing - December 2020 - 59
Hydrocarbon Processing - December 2020 - 60
Hydrocarbon Processing - December 2020 - 61
Hydrocarbon Processing - December 2020 - 62
Hydrocarbon Processing - December 2020 - 63
Hydrocarbon Processing - December 2020 - 64
Hydrocarbon Processing - December 2020 - 65
Hydrocarbon Processing - December 2020 - 66
Hydrocarbon Processing - December 2020 - 67
Hydrocarbon Processing - December 2020 - 68
Hydrocarbon Processing - December 2020 - 69
Hydrocarbon Processing - December 2020 - 70
Hydrocarbon Processing - December 2020 - 71
Hydrocarbon Processing - December 2020 - 72
Hydrocarbon Processing - December 2020 - 73
Hydrocarbon Processing - December 2020 - 74
Hydrocarbon Processing - December 2020 - 75
Hydrocarbon Processing - December 2020 - 76
Hydrocarbon Processing - December 2020 - 77
Hydrocarbon Processing - December 2020 - 78
Hydrocarbon Processing - December 2020 - 79
Hydrocarbon Processing - December 2020 - 80
Hydrocarbon Processing - December 2020 - 80A
Hydrocarbon Processing - December 2020 - 80B
Hydrocarbon Processing - December 2020 - 81
Hydrocarbon Processing - December 2020 - 82
Hydrocarbon Processing - December 2020 - Cover3
Hydrocarbon Processing - December 2020 - Cover4
Hydrocarbon Processing - December 2020 - GP-1
Hydrocarbon Processing - December 2020 - GP-2
Hydrocarbon Processing - December 2020 - GP-3
Hydrocarbon Processing - December 2020 - GP-4
Hydrocarbon Processing - December 2020 - GP-5
Hydrocarbon Processing - December 2020 - GP-6
Hydrocarbon Processing - December 2020 - GP-7
Hydrocarbon Processing - December 2020 - GP-8
Hydrocarbon Processing - December 2020 - GP-9
Hydrocarbon Processing - December 2020 - GP-10
Hydrocarbon Processing - December 2020 - GP-11
Hydrocarbon Processing - December 2020 - GP-12
Hydrocarbon Processing - December 2020 - GP-13
Hydrocarbon Processing - December 2020 - GP-14
Hydrocarbon Processing - December 2020 - GP-15
Hydrocarbon Processing - December 2020 - GP-16
Hydrocarbon Processing - December 2020 - GP-17
Hydrocarbon Processing - December 2020 - GP-18
Hydrocarbon Processing - December 2020 - GP-19
Hydrocarbon Processing - December 2020 - GP-20
Hydrocarbon Processing - December 2020 - GP-21
Hydrocarbon Processing - December 2020 - GP-22
Hydrocarbon Processing - December 2020 - GP-23
Hydrocarbon Processing - December 2020 - GP-24
Hydrocarbon Processing - December 2020 - GP-25
Hydrocarbon Processing - December 2020 - GP-26
Hydrocarbon Processing - December 2020 - GP-27
Hydrocarbon Processing - December 2020 - GP-28
Hydrocarbon Processing - December 2020 - GP-29
Hydrocarbon Processing - December 2020 - GP-30
Hydrocarbon Processing - December 2020 - GP-31
Hydrocarbon Processing - December 2020 - GP-32
Hydrocarbon Processing - December 2020 - GP-33
Hydrocarbon Processing - December 2020 - GP-34
Hydrocarbon Processing - December 2020 - GP-35
Hydrocarbon Processing - December 2020 - GP-36
Hydrocarbon Processing - December 2020 - GP-37
Hydrocarbon Processing - December 2020 - GP-38
Hydrocarbon Processing - December 2020 - GP-39
Hydrocarbon Processing - December 2020 - GP-40
Hydrocarbon Processing - December 2020 - GP-41
Hydrocarbon Processing - December 2020 - GP-42
Hydrocarbon Processing - December 2020 - GP-43
Hydrocarbon Processing - December 2020 - GP-44
https://www.nxtbook.com/gulfenergyinfo/gulfpub/hpi-market-data-2024-v2
https://www.nxtbook.com/gulfenergyinfo/gulfpub/hpi-market-data-2024
https://www.nxtbook.com/gulfenergyinfo/gulfpub/gas-processes-handbook-2022_v2
https://www.nxtbook.com/gulfenergyinfo/gulfpub/gas-processes-handbook-2022
https://www.nxtbook.com/gulfenergyinfo/gulfpub/hp_202212
https://www.nxtbook.com/gulfenergyinfo/gulfpub/hpi-market-data-2023-v2
https://www.nxtbook.com/gulfenergyinfo/gulfpub/hpi-market-data-2023
https://www.nxtbook.com/gulfenergyinfo/gulfpub/hp_202211
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202210
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202209
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202208
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202207_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202207
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202206_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202206
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202205_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202205
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202204_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202204
https://www.nxtbook.com/nxtbooks/gulfpub/hp_032022
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202203
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202202
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202201
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202112
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202111
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202110
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2022_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2022
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202109
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202108
https://www.nxtbook.com/nxtbooks/gulfpub/petrochemical_processes_handbook_2021_v2
https://www.nxtbook.com/nxtbooks/gulfpub/petrochemical_processes_handbook_2021
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202107
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202106
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202105
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202104
https://www.nxtbook.com/nxtbooks/gulfpub/hp_ebooks
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202103
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202102
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202101
https://www.nxtbook.com/nxtbooks/gulfpub/catalyst_handbook_2020_v2
https://www.nxtbook.com/nxtbooks/gulfpub/catalyst_handbook_2020
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202012
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202011
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202010
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2021
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202009
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202008
https://www.nxtbook.com/nxtbooks/gulfpub/refining_processes_handbook_2020
https://www.nxtbook.com/nxtbooks/gulfpub/refining_processes_handbook_2020_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202007
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202006
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202005
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202004
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202003
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202002
https://www.nxtbook.com/nxtbooks/gulfpub/hp_202001
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201912
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201911
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2020_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2020
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201910
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201909
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201908
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201907
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201906
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201905
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201904
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201903
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201902
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201901
https://www.nxtbook.com/nxtbooks/gulfpub/petrochemical_2018_v2
https://www.nxtbook.com/nxtbooks/gulfpub/petrochemical_2018
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201812
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2019_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hpimarket_2019
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201811
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201810
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201809
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201808
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201807
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201806
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201805
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201804
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201803
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201802
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201801
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201712
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201711
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201710
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201709
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201708
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201707
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201706
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201705
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201704
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201703
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201702
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201701
https://www.nxtbook.com/nxtbooks/gulfpub/hp_2017mediaplanner
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201612
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201611
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201610
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201609
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201608
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201607
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201606
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201605
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201604
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201603
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201602
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201601
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201512
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201511
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201510
https://www.nxtbook.com/nxtbooks/gulfpub/hp_2016mediaplanner
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201509
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201508
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201507
https://www.nxtbook.com/nxtbooks/gulfpub/hp_2015tmsd
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201506
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201505
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201504
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201503
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201502
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201501
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201412
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201411
https://www.nxtbook.com/nxtbooks/gulfpub/hp_2015mediaplanner
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201410
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201409
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201408
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201407
https://www.nxtbook.com/nxtbooks/gulfpub/hp_2014petrochemicalprocesses_v2
https://www.nxtbook.com/nxtbooks/gulfpub/hp_2014petrochemicalprocesses
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201406
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201405
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201404
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201403
https://www.nxtbook.com/nxtbooks/gulfpub/hp_2014calendar
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201402
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201401
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201312
https://www.nxtbook.com/nxtbooks/gulfpub/hp_2014mediaplanner
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201311
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201310
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201309
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201308
https://www.nxtbook.com/nxtbooks/gulfpub/hp_srsguide2013
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201307
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201306
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201305
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201304
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201303
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201302
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201301
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201212
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201211
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201210
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201209
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201208
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201207
https://www.nxtbook.com/nxtbooks/gulfpub/hp_srsguide2012
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201206
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201205
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201204
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201203
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201202
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201201
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201112
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201111
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201110
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201109
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201108
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201107_srsguide
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201107
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201106
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201105
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201104
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201103
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201102
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201101
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201012
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201011
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201010
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201009
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201008
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201007
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201006
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201005
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201004
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201003
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201002
https://www.nxtbook.com/nxtbooks/gulfpub/hp_201001
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200912
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200911
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200910
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200909
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200908
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200907
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200906
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200905
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200904
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200903
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200902
https://www.nxtbook.com/nxtbooks/gulfpub/hp_200901
https://www.nxtbookmedia.com