Rescue.asd - Copy

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EXECUTIVE SUMMARY

Hydrogen is a colourless, odourless and lightest gas known and

present in most organic compounds. One of the widely used method of

producing hydrogen is by passing steam through heated metal in the

presence of a metal oxide catalyst. Hydrogen finds application in major

industrial processes and the latest being its application as fuel in

hydrogen powered automobiles. Hence there is need for more efficient,

economical and effective method of production.

PRODUCTION OF HYDROGEN FROM HEAVY OIL FEEDSTOCK

THE PROCESS DESCRIPTION

The major component of the feedstock is carbon, hydrogen andsulphur, which was mixed with preheated air (at 2100C) and steam at

600psig, 251.930C and passed into a combustor. Series of unit

processes and operation were carried out such as sulphur removal,

carbon removal etc (see process description).

OPERATING CONDITIONS OF THE PROCESS.

1 Hydrogen purity 95 percent

2 Heavy fuel oil feed stockrequirement

Viscosity of 900s containing carbon,hydrogen and sulphur

Heat capacity of 42.9m/kg

Specific gravity of 0.9435

3 Oxygen purity 95 percent at a temperature of 200c

and a pressure of 4140kn/m2

4. Steam requirement pressure of 4140kn/m2

5 Cooling water requirement Temperature of 250c

6 Electricity Voltage of 440v at 3-phase 50hz

7 Crude gas 100% volume(dry basis)8 Saturated scrubbed gas Temperature of 350c

MATERIAL OF CONSTRUCTION FOR AN ABSORBER:

The materials for constructing the absorber are as follows:

Stainless Steels Alloy Steels Other Plastic Materials Rubber Lined Steel Plastic Coatings


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There are various types of absorbers depending on whether the components

to be absorbed are in a solid, liquid, or gaseous state. They are:

Open spray towers Packed towers Tray towers

The safety challenge is of two-folds:

1. Address the known risks (e.g. H2 leak) in a way that is compatible

with the operation. The conventional methods used by industry (large

clearance distances, personnel protective equipment) are not easily

applicable here;

2. Discover and address all the new risk factors brought in by the new

elements above and their combination.

Hydrogen gas forms explosive mixture with air if it is 4-74%

concentrated and with chlorine if it is 5-95% concentrated. The mixture

spontaneously explode with spark, heat or sunlight. Pure hydrogen-

oxygen flame emits ultraviolet light and are nearly invisible to the

naked eyes. Hydrogen can react spontaneously and violently at room

temperature with chlorine and fluorine to form the corresponding

hydrogen halides, hydrogen chlorides and hydrogen fluoride which are

also potentially dangerous acids.

ECONOMY

Hydrogen can be used as potential fuel for motor power (including cars

and boats), the energy needs of building and portable

electronics.Hydrogen is an energy carrier (like electricity) not a

primary energy source (like coal).


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INTRODUCTION

Following the new regulation in the last years, defining more stringent

limits for the emissions to the atmosphere, the necessity to find an

alternative use for the fuel oil has created a new challenge for the

refineries. At the same time the need to improve power production has

pushed energy companies, to enter the electricity market. In this frame

we have decided to design a new combined-cycle power plant to produce

20 million standard cubic feet per day of Hydrogen of at least 95 per cent

purity in which the process employed is the partial oxidation of oil

feedstock.

Hydrogen is a naturally occurring gas that is amazingly light it is in fact,

the lightest gas ever found which has no color, no smell and no taste.

Hydrogen is one of the most reactive substances in the world which is

also very flammable. Pure hydrogen gas is very hard to come by, this

means that hydrogen may need to be produced artificially, from either

fossil fuels or water.

The splitting of hydrogen compounds uses a lot of energy, Currently most

hydrogen is made by passing steam through natural gas, creating a

compound of carbon monoxide and hydrogen. The compound is purified by

changing the carbon monoxide to carbon dioxide and then the carbon

dioxide is dissolved in water. Hydrogen is left behind after this process.

The partial oxidation of heavy fuel oil feedstock is as an integral building

block for hydrogen production in the refining scheme whereby a feed

consisting of Carbon, Hydrogen and Sulphur are fed to a reactor with

Oxygen and Steam to give products which undergo three major stages to

obtain hydrogen in a pure form of at least 95% purity. The three major

stages are:

CO conversion H2S removal CO2 removal


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Our objective is therefore to accomplish these tasks using a maximum of

proven technology to produce a marketable product slate. Apart from the

partial oxidation method, oxygen can also be prepared in other various

processes such as, the haber process in fertilizers industries (from

ammonia), steam reforming (burning natural gas), direct water splitting

with high energy input, electrolysis and thermolysis under high

temperature(this is the most expensive processes), coal carbonization,

reduction of metal oxide,

In spite of all this various processes of hydrogen production, the partial

oxidation method is widely used in the industries and refineries because it

has some advantages over other process which are:

(1) It is the cheapest method

(2) It minimizes the rate of environmental pollution such as;

reducing sulphur, carbon(iv)oxide and nitrogen(iv)oxide

emissions.

(3) Low energy input

USES OF HYDROGEN.

Production of electricity in power stations Production of paints Fertilizer production Petrochemical industries (hydro-treating processes). Steel production.

Even with all these processes more research are still on for a more

efficient, economical and environmental friendly methods for the

production of hydrogen.


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LITERATURE REVIEW

Hydrogen is a major gas which is widely used in almost every sector of

production in the industry for producing gases, power, and several other

components for mans utilization. As earlier stated in the introduction,

there are various method of hydrogen production, but our case study

which is the partial oxidation of heavy fuel oil is one of the most wide

spread method of hydrogen production. It involves the conversion of

steam, oxygen and hydrocarbons to hydrogen and carbon oxides with or

without catalyst. The catalytic process which was used in this plant

design included two stages of catalytic conversion at a temperature of

370C and pressure of 4140KN/m2.

Generally, it is first necessary to prepare the fuel for feeding to the

reactor in the presence of preheated oxygen and steam whereby reaction

takes place and the product (gas) is treated to remove particulates and

other components that may be detrimental to the downstream processes.

From a process perspective, partial oxidation of gases and liquids is very

similar to the gasification of solids. The term gasification is used to refer

to all the applications of the various unit operations carried out in this

design process. A wide variety of feed stocks can be considered for

gasification, ranging from solids to liquids to gaseous streams. Although

when the feed is a gas or liquid, the operation is frequently referred to as

partial oxidation (POX). The major requirement for a suitable feedstock is

that it contains a significant content of carbon and hydrogen.

Oxygen at 99.5%v purity will be supplied from an air separation unit and

will be preheated prior to being introduced into the reactor (combustor).

The heat required to heat the feed streams and the extent of complete

combustion which occurs is a function of the amount of oxygen co-fed to

the combustor. Gasification temperature is controlled by the addition of

water or steam and for slurry feed stocks, the slurry water accomplishes

this control. For other feed stocks, such as heavy oils as used in this


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process, steam is injected with the feedstock to control temperature.

This steam injection may also be used to adjust the composition of the

product from the combustor (mixture of crude gas and carbon particles.

The following reaction take place in the oil mixture;

CnHm + n/2CO2 nCO + m/2H2

CnHm + H2O nCO + (n+m)/2H2

CO + H2O CO2 + H2

The cleaned gas is then sent to the column where the hydrogen content is

increased and fed to a purification section where it is upgraded to meet

the end use requirements of hydrogen of at least 95 per cent purity.

The optimal design of a hydrogen production and purification system is

based on the following set of criteria:

hydrogen demand required hydrogen delivery purity and pressure hydrogen recovery efficiency total plant integration opportunities system reliability, availability and maintenance requirements capital and operating costs

The choice of method employed for hydrogen prodution will depend on

feedstock availability, the physical characteristics of the feed, the

temperature and pressure needed to optimize the desired product yields.

If ultra pure hydrogen is required i.e. hydrogen of at least 95 percent

purity, either pressure swing adsorption or cryogenic separation will

probably have to be employed but if hydrogen purity is to be below 95

percent, membrane separation can be used to purify the gas.

In the selection of the process units in the cleanup section which

comprises of the quencher, scrubber, the saturator and desaturator, the

various absorbers, and measures applied for the final hydrogen

purification, is dependent on the quality of the raw gas from the reaction

and the ultimate end-use of the product hydrogen. In this case, filters

were used for particulate removal of gases such as carbon from the


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quencher. Also, the sulphides and ammonia can be removed with the use

of a variety of commercial processes which include both regenerable and

non-regenerable solid adsorption and liquid absorption processes. The

carbon dioxide in the gas may be removed or absorbed by utilizing one of

the commercial liquid absorption processes that employ either a physical

solvent or a regenerated chemical solvent such as an amine or hot

potassium carbonate.

From the various methods of hydrogen production, steam reforming is the

method that has a close relationship with the partial oxidation of heavy

fuel oil as it involves the burning of natural gas. Steam reforming or partial

oxidation is used to maximize hydrogen content of the gas. Steam

reforming has the advantage of being a well-established process. Its

disadvantage is it requires steam and a separate heating source to

provide the heat of reaction. In contrast, partial oxidation is an emerging

technology and the heat of reaction is generated in the reactor by

combustion of some of the feed.


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DESCRIPTION OF THE PROCESS

Heavy fuel oil feedstock is delivered into the suction of metering-type ram

pumps which feed it via-a steam preheater into the combustor of a

refractory-lined flame reactor. The feedstock must be healed to 200C in

the preheater to ensure efficient atomization in the combustor. A mixture

of oxygen and steam is also fed to the combustor, the oxygen being

preheated in a separate steam preheater to 210C before being mixed with

the reactant steam. The crude gas, which will contain some carbon

particles, leaves the reactor at approximately 1300C and passes

immediately into a special waste-heat boiler where steam at 600 psig

(4140 kN/m2 gauge) is generated. The crude gas leaves the waste heat

boiler at 250C and is further cooled to 50C by direct quenching with

water, , which also serves to remove the carbon as a suspension. The

analysis of the quenched crude gas is as follows:

H2 47.6 percent vol (dry basis)

CO2 8.3 percent vol (dry basis)

CO 42.1 percent vol (dry basis)

CH4 0.I percent vol (dry basis)

H2S 0.5 percent vol (dry basis)

N2 1.40 percent vol (dry basis)

100.0 per cent vol (dry basis)

For the primary flame reaction steam and oxygen arc fed to the reactor at

the following rales:

Steam 0.75 kg/kg of heavy fuel oil feedstock Oxygen 1.16 kg/kg of heavy

fuel oil feedstock. The carbon produced in the flame reaction, and which

is subsequently removed as carbon suspension in water, amounts to 1.5

per cent by weight of the fuel oil feedstock charge. Some I-I2S present in

the crude gas is removed by contact with the quench water. The

quenched gas passes to an H2S removal stage where it may be assumed

that H2S is selectively scrubbed down to 15 parts per million with


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substantially nil removal of CO2. Solution regeneration in this process is

undertaken using the waste low-pressure steam from another process.

The scrubbed gas, at 35C and saturated, has then to undergo CO

conversion, final H2S removal, and CO2 removal to allow it to meet the

product specification.

CO conversion is carried out over chromium-promoted iron oxide catalyst

employing two stages of catalytic conversion; the plant also incorporates

a saturator and desaturator operating with a hot water circuit.

Incoming gas is introduced into the saturator (a packed column) where it

is contacted with hot water pumped from the base of the desaturator; this

process serves to preheat the gas and to introduce into it some of the

water vapour required as reactant. The gas then passes to two heat

exchangers in series. In the first, the unconverted gas is heated, against

the converted gas from the second stage of catalytic conversion; in the

second heat exchanger the unconverted gas is further healed against the

converted gas from the first stage of catalytic conversion. The remaining

water required as reactant is then introduced into the unconverted gas as

steam at 000 psig (4140 kN/m2 gauge) saturated and the gas/steam

mixture passes to the catalyst vessel at a temperature of 3700C. The-

catalyst vessel is a single shell with a dividing plate separating the two

catalyst beds which constitute the two stages of conversion.

The converted gas from each stage passes to the heat exchangers

previously described and thence to the desaturator, which is a further

packed column. In this column the converted gas is contacted

countercurrent with hot water pumped from the saturator base; the

temperature of the gas is reduced and the deposited water is absorbed in

the hot-water circuit. An air-cooled heat exchanger then reduces the

.temperature of the converted gas to 40C for final H2S removal. Final H2S

removal takes place in four vertical vessels each approximately 60 feet

(18.3 m) in height and 8 feet (2.4 m) in diameter and equipped with five


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trays of iron oxide absorbent. Each vessel is provided with a locking lid of

the autoclave type. The total pressure drop across these vessels is 5 psi

(35 kN/m2). Gas leaving this .section of the plant contains less than 1ppm

of H2S and passes to the CO2 removal stage at a temperature of 35C. CO2

removal is accomplished employing high-pressure potassium carbonate

wash with solution regeneration.

THE HYSIS PROCESS FLOW DIAGRAM:


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MATERIAL BALANCE

BASIS: HYDROGEN

PRODUCT: Hydrogen

SPECIFICATION: 6.424m3/sec

CONDITION: Temperature=308k, pressure=172.42*103N/m2

Hydrogen is quench crude gas

C0NDITION: Temperature=323k, pressure=206.9*103N/m3

P1*V1/T1=P2*V2/T2

P1=206.9*103N/m2

T1=323K

P2=172.42*103N/m2

T2=308K

V2=6.424m3/sec

V1=

V1=P2*V2*T1/(P1*T2)

=172.42*6.424*323/(206.9*308)

V1=5.614m3/sec

COMPONENT OF QUENCH CRUDE GAS

H2=47.6%v

CO=42.1%v

CO2=8.3%v

CH4-0.1%v

H2S-0.5%v

N2-1.4%v

Let the total volume of quench gas be P, where volume of Hydrogen inquench crude gas is 5.614m3/sec


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47.6*P/100=5.614

P=11.794m3/sec

Component of quench crude gas in volume

H2=5.614m3/sec

CO=42.1*11.794/100

=0.978m3/sec

Co2 =(8.3/100)*11.794

= 0.978m3/sec

CH4=(0.1/100)*11.794

=0.0118m3/sec

H2S=(0.5/100)*11.794

=0.0589m3/sec

N=(1.4/100)*11.794

=0.165m3/sec

NB: N2 feed into the reactor at 483k, pressure-206.9*103N/m2

Recall from Charles law; V1/T1=V2/T2

V1=V2*T1/T2

=483*0.165/323

=0.247m3/sec

NB; moles of N2 entering the reactor=moles of N2 leaving the reactor

From ideal gas law, PV=nRT

n=PV/RT

=(206.9*103*0.247)/8.314*483

=12.73mol/sec

Converting to mass;

mass=moles*molar mass

12.73*(14*2)


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=0.356Kg/sec

Since air is 95% of oxygen and 5% nitrogen

Air supplied= (5/100)*Air=0.356

Air= (0.3559*100)/5

Air=7.127kg/sec

Oxygen supplied=(95/100)*7.127

=6.7704kg

1.16kg of oxygen----------------------------------------------------1kg of heavy fuel oil

6.7704kg----------------------------------------------------------------x

Therefore; x=1kg of heavy fuel oil*6.7704kg of oxygen/1.6kg of oxygen

=5.84kg of heavy fuel oil at 483k

Therefore moles of heavy fuel oil at 483k and 206.9*103N/m

Also, mass of heavy fuel oil supplied=5.84kg of heavy fuel oil

Carbon=(85/100)*5.84

=4.964kg/12kg/kmoles

=413.667moles

Hydrogen=(11/100)*5.84

=0.6424/kg/1kg/kmole

=642.4mole

Sulphur=(4/100)*5.84

=0.2336kg/32kg/kmole

=7.3moles

Amount of carbon suspension removed is (1.5/100)*5.84

=0.0876kg of carbon suspension

H2S removed of saturated scrubber gas

H2S at 323k=0.0589m3/sec

At 308k; from Charles law,

V1/T1=V2/T2


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Therefore, 0.0589/323=v2/308

V2==0.05616m3/sec at 308k

If 15ppm of H2S removed =0.0562-(15*10-6)*0.056

=0.0561m3/sec removed

Amount of H2S left=8.424*10-7m3/sec

Conversion of CO to CO2

Therefore CO+1/2O2-------CO2

CO : CO2

1 : 1

4.965M3/S : 4.965M3/S

Total CO2 formed=4.95+0.978=5.943m3/sec

Amount of H2 Removed finally at 308k

=8.424*10-7 m3/sec-

Product out of the process

H2 - 6.424 m3/secs

CH4 -

H2O - 1 x 10-6 m3/secs

Nv - at 350C - 308k

V1T2 = V2T1

For T1 =323k = SS

V1 =0.165 1 m3/s

0.1651 x 307 = V2 x 323

N2 = 0.1574 m3/s

CH4 at 350C = 308k

For T1 = 323k, V1 = 0.0118 m3/s

V2 = (0.0118 x 308)/323

CH4 = 0.0113 m3/s


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ENERGY BALANCE AROUND THE REACTOR:

Assumptions: Flow rate of air and steam is constant

Cp of air (T-T1) = Cp of steam (252.31T)

25.67 (T-210) = 2799.57 (252.31T)

T = 251.93oC

Energy balance within and out of the reactor:

From the reaction;

2C + O2 = 2CO

C + O2=CO2

H2 + S= H2S

Calculating the various enthalpies from the relations: a + bT + Ct 2= cp

Cp for carbon = specific heat capacity

From carbon

Cp= 11.18 + 1.095*10-2(473)-4.89*10-5(473)-2 =16.359

2 Cp of carbon =2*16.359

=32.7187

Cp of O2 =29.10 +1.158*10-2(200)0.6076*10-5*(200)-2

=31.416

Cp of sulphur = 2.68

Cp of H = 28.84 + 0.00765*10 -2(200) + 0.3288*10-5(200)-2

=28.85

Cp of N2=29.44

NB; heat loss= heat gained around reactor

Heat losses from the fuel gases, air, and steam are

CARBON

m CpT =32.718*(1300-200)*0.6424


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=23119.7475j/gmole/k

HYDROGEN

4.964*(1300-200)*28.85

=157532.54j/gmolek

SULPHUR

0.2336*(1300-200)*2.68

=688.6528j/gmole.k

AIR

Cp of air=28.94+0.4147(210) +0.319*10-2(210)-2

=116.027

M Cp air* T =7.127*116.027(1300-210)

=901347.63j/gmolek

STEAM

Cp =4140

M=7.127(same with air)

H = mcpT

=7.127*4140(1300-251.93)

=30924122.84j/gmolek

Therefore

Total energy inlet= total energy outlet

n=ii=1Hn=2311908475+157532054+688.6528+901347.63+30924122.84

=32006811.51j/gmolek

=32006811j/gmole.k


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CHEMICAL ENGINEERING DESIGN FOR THE PROCESS

There are six (6) stages which describes this partial oxidation process in

details, they are;

(1) REACTION OF FEED: The heavy fuel oil fed to the combustorreacts with the input preheated oxygen and steam in which the

product consisting of crude gas and carbon particles leaves at

approximately 1300C to a waste heat boiler where steam is

generated at 4140KN/m2.

(2) REMOVAL OF CARBON: The product from the waste boiler entersthe quencher which removes the carbon particles as a suspension

at 50C. Some H2S in the crude was also removed at this stage while

some more were selectively scrubbed down when the quenched gas

was passed into the scrubber.

(3) CONVERSION OF CARBONMONOXIDE: This was carried out overchromium-promoted ironoxide catalyst where the catalytic

conversion took place in two stages involving the saturator, two

heat exchangers in series and a desaturator. The converted gas was

cooled at 40C and transferred to four (4) absorbers.

(4) REMOVAL OF HYDROGEN SULPHIDE: The absorbers absorbs theH2S in the presence of iron oxide absorbent whereby the gas leaving

this section contained H2S less than 1ppm at a total pressure drop

of 35KN/m2 across the four vessels.

(5)

REMOVAL OF CARBON(IV)OXIDE: At a temperature of 35C, in the

presence of a high-pressure potassium carbonate wash with

solution regeneration, the CO2 is absorbed in the absorber to

produce hydrogen with impurities.

(6)PURIFICATION OF HYDROGEN: The gas produced after CO2removal, is sent to this section where the specification is made to

meet up the end requirement of hydrogen at 95 percent purity.


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OPERATING CONDITIONS OF THE PROCESS.

1 Hydrogen purity 95 percent

2 Heavy fuel oil feed stock

requirement

Viscosity of 900s containing

carbon, hydrogen and sulphur

Heat capacity of 42.9m/kg

Specific gravity of 0.9435

3 Oxygen purity 95 percent at a temperature of

200c and a pressure of

4140kn/m2

4. Steam requirement pressure of 4140kn/m2

5 Cooling water requirement Temperature of 250c

6 Electricity Voltage of 440v at 3-phase 50hz

7 Crude gas 100% volume(dry basis)

8 Saturated scrubbed gas Temperature of 350c

MATERIAL OF CONSTRUCTION FOR AN ABSORBER:

The materials for constructing the absorber are as follows:

Stainless Steels Alloy Steels FRP Other Plastic Materials Rubber Lined Steel Plastic Coatings

There are various types of absorbers depending on whether the

components to be absorbed are in a solid, liquid, or gaseous state. They

are:

Open spray towers Packed towers Tray towers


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SAFETY MEASURES

ENVIRONMENTAL IMPACT

Hydrogen is widely used today as a chemical product in various industries

(petrochemical, food, electronics, metallurgical processing etc.). So far,

the only significant energy application has been space programs.

Hydrogen is however emerging as a major component for a future

sustainable energy economy where hydrogen and electricity are foreseen

to be complimentary sustainable energy carriers1 with hydrogen

especially valid for movable or portable applications.

Hydrogen offers a unique method of reducing the fossil fuel dependency

while increasing the usage of renewable energy sources.

The main driving forces to introduce hydrogen as an energy carrier are

based on the limited fossil fuel resources in general, and the implicit

political dependencies creating a widespread and high level political need

to secure and diversify national energy supplies2. Environmental concerns

on urban pollution and the greenhouse effect are also important drivers

concerns over environmental impacts of continued fossil fuel use are

leading to development of decarbonisation technologies. In the short term,

it is believed that such technologies will be a source for low-cost

hydrogen production. Currently about 90 percent of the worlds hydrogen

production is based on fossil fuels and mainly natural gas4. In the long

term, the production needs to be based on the renewable energy sources

in order to reduce the pollution problem in a sustainable way. In the mean

time hydrogen production might be based on fossil fuels (natural gas

reforming, coal gasification) with CO2 sequestration and H2 production at

nuclear installations.

The safety challenges result not only from the implementation of hydrogen

technology for use directly by the public in a non-industrial context and for


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a completely new application. It lies also in the demanding performance

and cost targets imposed by the applications leading to:

the excursion to new domains of service conditions the introduction of new physical processes the use of new materials

The safety challenge is of two-folds:

1. Address the known risks (e.g. H2 leak) in a way that is compatible with

the operation. The conventional methods used by industry (large

clearance distances, personnel protecttive equipment) are not easily

applicable here;

2. Discover and address all the new risk factors brought in by the new

elements above and their combination.

Hydrogen gas forms explosive mixture with air if it is 4-74% concentrated

and with chlorine if it is 5-95% concentrated. The mixture spontaneously

explode with spark, heat or sunlight. Pure hydrogen-oxygen flame emits

ultraviolet light and are nearly invisible to the naked eyes. Hydrogen can

react spontaneously and violently at room temperature with chlorine and

fluorine to form the corresponding hydrogen halides, hydrogen chlorides

and hydrogen fluoride which are also potentially dangerous acids.

ECONOMY

Hydrogen can be used as potential fuel for motor power (including cars

and boats), the energy needs of building and portable electronics.

Hydrogen is an energy carrier (like electricity) not a primary energy source

(like coal). The utility of a hydrogen economy depends on issues of energy

sourcing, including fossil fuel use, climate change and sustainable energy

generation.


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CONCLUSION

From the process description, energy, material balance and process

design, the method of producing hydrogen from heavy oil feedstock is an

efficient and effective one.

From the energy balance carried out around the reactor mixer system, a

total energy of 32006.811kJ/gmol0c will be needed to produce 20 x 106

standard cubic feet of hydrogen per day of 95% purity.


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REFERENCES

A. Eucken, PhysikZ. 14, 324 (1913).

A. Eucken, PhysikZ. 14, 324 (1913).

C. Higman & G. Grnfelder, "Clean Power Generation from Heavy

Residues", Inst. Mech. Eng., Nov 1990.

C. R. Wilke, J . Chem. Phys. 17, 550 (1949).

C. R. Wilke, J . Chem. Phys. 17, 550 (1949).

E. J. Owens and G. Thodos, AIChE J. 3, 454 (1957).

E. J. Owens and G. Thodos, AIChE J. 3, 454 (1957).

E. Stldt, "Concepts for Zero Residue Refineries", Interpec China '91,

Beijing, Sept 1991.

E. Stldt, "Concepts for Zero Residue Refineries", Interpec China '91,

Beijing, Sept. 1991.

F. Fesharaki & D. Isaak, "Crisis means changes for oil market, OPEC", Oil

& Gas Journal, Nov 1990.

F. Fesharaki & D. Isaak, "Crisis means changes for oil market, OPEC", Oil

& Gas Journal, Nov 1990.

G. Heinrich, M. Valais, M. Passot and B. Chapotel, "Mutations of World

Refining: Challenges and Answers", Ptrol et Techniques, April/May 1992.

G. Heinrich, M. Valais, M. Passot and B. Chapotel, "Mutations of World

Refining: Challenges and Answers", Ptrol et Techniques, April/May 1992.

G. Wiedemann and R. Franz, Annu. Phys. Chem. 89, 530 (1853).

G. Wiedemann and R. Franz, Annu. Phys. Chem. 89, 530 (1853).

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Rescue.asd - Copy