The production of nitrogen fertilizers in China started
in 1930s when the highest total output was only 226kt/a.
After new China was founded, the Chinese government attached
great importance to the development of nitrogenous fertilizer
industry. By the end of 1965, 15 medium-sized nitrogenous
fertilizer plants had been put into operation in the country,
with the total output of synthetic ammonia reaching 1,300kt/a
and above. In 1964~1966, preparation was made for the construction
of Sichuan Luzhou Natural Gas Chemical Plant and Shanxi
Xingping Fertilizer Plant using imported technology, which
were successively put into production in 1970. In the following
one decade and more, on the basis of continuously summarizing
the construction and production experience with medium-sized
nitrogenous fertilizer plants, a number of other medium-sized
nitrogenous fertilizer production plants were built. After
1978, China carried out an all-round rectification of medium-sized
nitrogenous fertilizer plants in terms of organization,
management and technology, and conducted gap filling and
potential tapping of the existing enterprises targeting
energy saving and consumption reduction, which increased
the productivity of the existing plants. As of 1983, the
number of medium-sized nitrogenous fertilizer plants in
the country amounted to 56, and the raw materials used by
the plants reflected the policy of making use of coal, oil
and gas simultaneously with coal as the main raw material.
As a result, the nitrogenous fertilizer production series
in the country came into being.
To meet the increasing demand of agriculture
for nitrogenous fertilizer and with the large-scale development
of petroleum and natural gas in the country, China introduced
13 sets of complete production plants from the United States,
Holland, Japan and France in 1973, each having a capacity
of 1000t/d of synthetic ammonia and 1620~1740 t/d of urea,
of which 10 sets used natural gas as raw material and 3
sets use light oil as raw material. With the joint efforts
made by the provinces and cities concerned, these large-scale
nitrogen fertilizer plants were completed with high speed,
high quality and high level and were put into operation
one after another between May 1976 and Sep. 1979. Although
the output of these large-scale nitrogenous fertilizer plants
accounts for 20% only of the total output of nitrogenous
fertilizer in the country, they have played a significant
role in enhancing the technical level and management level
of the country's nitrogenous fertilizer industry. Since
1983, the nitrogenous fertilizer output of the country ranked
the second in the world, only next to that of the former
Soviet Union.
After ECEC was established, the first project
it undertook was the design of the phase I project (including
basic engineering design and detail engineering design)
of Huainan Chemical Fertilizer Plant (the present Huainan
Chemical Group). This project was one of the medium-sized
nitrogenous fertilizer enterprises built up during the "Second
Five-Year Plan" period of the country, the design capacity
of which was 50kt/a of synthetic ammonia and 110kt/a of
ammonium nitrate. The first system of the project was completed
and successfully commissioned in one stroke on Sept. 23,
1965, and the second system was completed and put into operation
on Dec. 30, 1965.
In 1966, ECEC implemented a new process
flow for synthetic ammonia-methanol combined production
(known as medium-pressure co-production of methanol) in
the design of phase II expansion project of Huainan Chemical
Fertilizer Plant. To explore the production conditions and
process flow for the industrialization of the co-production
of methanol, ECEC carried out the design and industrial
test of a pilot plant in Danyang Chemical Fertilizer Plant,
Jiangsu Province during 1967~1968 and finally made a success
of the new process flow test of co-production of methanol.
On such a basis, ECEC accomplished the design of the co-production
of methanol project of Huainan Chemical Fertilizer Plant
for 20,000t/a of fine methanol in 1969, which was successfully
commissioned in one stroke in July 1973. This engineering
design won the excellent design prize of the former Ministry
of Chemical Industry in 1981.
In 1973, ECEC organized and participated
in the negotiations with foreign companies for the import
into China of 3 out of the 13 sets of large chemical fertilizer
plants and specifically implemented the chemical fertilizer
plant of Anqing Petrochemical Complex, which uses naphtha
or refinery gas as raw material to produce 300,000/a of
synthetic ammonia and 520,000t/a of urea.
In the past 40 years, ECEC has accomplished
dozens of new construction and technical revamping projects
of small, medium and large-sized nitrogenous fertilizer
projects in China, all of which have been completed and
put into production and the productive capacities and product
quality of which have all met the design figures. The productive
capacities (as synthetic ammonia) of these projects are
2~300kt/a. The raw materials for their production include
coke, anthracite, bituminous, naphtha, refinery gas and
coke oven gas, etc. The product variety includes synthetic
ammonia, ammonium bicarbonate, ammonium nitrate, urea as
well as nitric acid, methanol, formaldehyde etc. Typical
projects completed by ECEC include:
The phase I project of Huainan
Chemical Fertilizer Plant, whose design capacity
is 50kt/a of synthetic ammonia and 110kt/a of ammonium nitrate.
The synthetic ammonia system uses a process with lump coal
or coke as raw material, which consists of fixed-bed, atmospheric-pressure,
intermittent gasification, atmospheric pressure conversion,
1.8MPa water wash decarbonization, 13MPa copper and alkali
wash purification and 32MPa ammonia synthesis.
The phase II project of Huainan
Chemical Fertilizer Plant, which mainly includes:
two sets of side-fed, tamped coking furnace and associated
coking recovery system, which use Huainan coal as raw material
and have a total capacity for 560kt/a of coke; an ammonia
synthetic gas production unit with a design capacity for
45kt/a of synthetic ammonia, which uses coke oven gas as
raw material and pressurized catalytic partial oxidation
process; a 25kt/a crude methanol production unit using the
process of co-production of methanol and associated methanol
rectifying unit; a 110kt/a urea plant using an aqueous solution
total circulating process; a 40kt/a concentrated nitric
acid plant; a 50kt/a crude tar and 15kt/a crude benzol purification
plant as well as utility and auxiliary facilities corresponding
to the second-phase expansion project.
The nitrogenous fertilizer plant
of Anqing Petrochemical Complex, which uses naphtha
or refinery gas as raw material to produce 300,000t/a of
synthetic ammonia and 520,000t/a of urea. The ammonia unit
consists of naphtha desulfurization, steam reforming, high-temperature
conversion, hot potash decarbonization, centrifugal steam
turbine-driven compression and TOPS§ĥE S-200 ammonia converter,
while the urea unit uses CO2 stripping process
for urea production. In 1996, ECEC completed the revamping
of raw material route of Anqing Petrochemical Complex, substituting
refinery gas instead of 50% of naphtha to produce synthetic
ammonia. The engineering design of the revamping project
of the said unit was completed by the end of 1996, and the
unit was successfully commissioned in 1997.
The technical revamping project
of the nitrogenous fertilizer plant of Guangzhou Petrochemical
Complex, the 300,000t/a synthetic ammonia and 520,000t/a
urea unit of Guangzhou Petrochemical Complex used naphtha
as raw material. In 1999, ECEC completed the revamping of
raw material route of the plant for synthetic ammonia in
order to replace naphtha with partial refinery gas in the
production of synthetic ammonia, and later, by cooperating
with TOPS§ĥE, completed the expansion and energy saving retrofitting
for 10% increase of production capacity.
The revamping and expansion project
of Huainan Chemical General Works, for detail,
please refer to Sample Project.
ECEC has accumulated 40 years' engineering
experience in the aspect of nitrogenous fertilizer field.
In order to maintain the technical superiority in this field,
ECEC maintains long-term cooperative relations with a number
of Chinese companies engaged in the technical research of
nitrogenous fertilizer and, at the same time, keeps good
cooperative relationships with world-known licensors, such
as TOPS§ĥE, TEXACO, STAMICARBON, SNAMPROGETTI, LINDE, etc.
Sample project:
China is a country with coal as its main
energy resources. The synthetic ammonia industry of China
has been constructed and developed with coal as the main
raw material. The productive capacity of synthetic ammonia
plants with coal as raw material accounts for 80% and above
of the total domestic synthetic ammonia production capacity.
The revamping and expansion project for 180,000t/a of synthetic
ammonia and 270,000t/a of urea of Huainan Chemical General
Works,which was undertaken by ECEC,is a typical synthetic
ammonia plant with coal as raw material.
The revamping and expansion project of
Huainan Chemical General Works is a key construction project
of Anhui Province during the "Ninth Five-Year Plan"
period. The feasibility study report was approved in Jan.
1994. The preliminary design of the project was approved
in December of the same year.The construction of the project
was completed and the plant was put into production in Sept.
2000. On-spec products were produced in Oct. 2000. Then,
the plant passed performance test and the capacity, product
quality and consumption of the plant all reached the design
figures.
This plant consists of following main units:
Gasification unit: Including raw coal handling,
coal slurry preparation, water-coal slurry gasification,
crude synthetic gas scrubbing and slag/water treatment.
The operating pressure of the gasification
unit is 4.0Mpa, and 3 sets of Texaco gasification furnaces
are provided, 2 in operation and 1 standby. For the gasification
unit, Texaco Development Inc. provided the process package
design.
Purification unit: Including crude synthetic
gas conversion, desulfurization/decarbonization, methanation
and sulfur recovery.
Synthetic gas conversion uses a domestic
sulfur-resistant conversion catalyst. The conversion section
is provided with 3 shift converters to make full use of
the steam contained in the crude synthetic gas from the
Texaco water-coal slurry gasification section and make sure
that the CO content in the synthetic gas leaving the conversion
section meets the requirement of the synthetic ammonia plant
(ĦÜ0.35% mol). The heat generated during the reactions is
recovered by the methods of producing medium and low-pressure
steam and heating boiler feed water and demineralized water,
etc.
The desulfurization/decarbonization uses
the domestic NHD technology.to remove the CO2
and H2S in the synthetic gas. The desulfurization/decarbonization
section uses packed absorption tower.
The methanation section uses domestic catalyst
and adiabatic reactor.
The sulfur recovery section uses the German
Linde AG's CLINSULF-Do technology, with which air is used
to directly oxidize the H2S in the acidic gas
to form sulfur under the action of Ti catalyst. NaOH solution
is used to absorb the gas from which sulfur is separated
to further remove the SO2 and H2S
contained in it so a to make sure that the off gas reaches
standard before emitted. The process package for the sulfur
recovery section was provided by the German Linde AG.
Synthesizer: Including synthetic gas compression
(circulating section is included), ammonia synthesis and
hydrogen recovery.
The synthetic gas compression uses the
domestically designed and manufactured steam-driven centrifugal
compressor. In the compression section, on-spec synthetic
gas and circulating gas are pressurized to 14.0Mpa to meet
the needs of ammonia synthesis. The ammonia synthesizing
section uses TOPS§ĥE Ammonia synthesizing process and the
synthetic tower uses the TOPS§ĥE S-200 internals.
The hydrogen recovery section uses the
American PERMEA company's membrane separating technology
and equipment.
The urea unit uses the Italian Snamprogetti
company's ammonia stripping process.
The air separation unit uses the French
Air Liquid company's proprietary technology and key equipment
for air separation, with which an internal-compression,
two-pump flow is used to directly produce high-pressure
oxygen and nitrogen. The productive capacity of the air
separation plant is 28,000 Nm3/h of oxygen. ECEC
completed the associated engineering design of civil works
for the air separation unit.
Plant control system: The entire synthetic
ammonia and urea production system uses the America Rosemount
and Honeywell's DCS operating system to realize the automation
of production control and detection.
