Component 96: Extended Coal-Gasifier

In This Topic

Component 96: Extended Coal-Gasifier

Specifications

Line connections
1	Oxidizing fluid inlet
2	Crude gas outlet
3	Water-/Steam inlet
4	Coal inlet
5	Ash subtraction
6	Oil inlet
7	Gas inlet
8	Heat extraction (to be specified)
9	Control input (for degree of coal gasification, if FGASN=2)

General User Input Values Characteristic Lines Physics Used Displays Example

General

This component maps a coal gasifier. As compared to the existing Component 50 the component 96 has the following extensions:

Additional fuel inlets for oil and gas
Consideration of the formation of NH3 and Benzene (via characteristics)
For CH4, H2S, NH3 and Benzene the reaction rates or the outlet concentrations (mass or volume percentage) can be specified alternatively.
The degree of coal gasification can be specified either as a specification value, via a pseudo- measurement value or through a reference input.
The water-gas reaction can be determined either from the thermodynamic equilibrium or by specifying an outlet component (H2, CO, H2O or CO2).
Typical application cases:
Specification of coal, air and steam mass flows,

- Calculation of raw gas temperature, composition and residual carbon

- Specification of carbon mass flow, residual carbon and raw gas outlet temperature, calculation of air and steam mass flow and the raw gas composition

- Distribution of sulfur on slag and fly dust, specification of the percentage of S, which is not converted in H2S, but instead lands up in the slag.

Specification of a heat loss (constant or relative to furnace heat output, constant in part-load) and of a gasifier cooling as fixed value (logic connection).

User Input Values

FSPEC	Handling the water-gas reaction Like in Parent Profile (Sub Profile option only) Expression =0: Calculation of the outlet concentrations of H2, H2O, CO and CO2 from the water-gas reaction =1: Specification of the H2-concentration in XOUT, calculation of the remaining from the element balances =2: Specification of the H2O-concentration in XOUT, calculation of the remaining from the element balances =3: Specification of the CO-concentration in XOUT, calculation of the remaining from the element balances =4: Specification of the CO2-concentration in XOUT, calculation of the remaining from the element balances
XOUT	Outlet concentration (content by mass) as per the setting of FSPEC
FOUT	Handling of the formation of CH4, H2S, NH3 and Benzene Like in Parent Profile (Sub Profile option only) Expression =0: RCH4N, RH2SN, RNH3 and RBENZN are interpreted as reaction rates =1: RCH4N, RH2SN, RNH3 and RBENZN are interpreted as content by mass in the exhaust gas =2: RCH4N, RH2SN, RNH3 and RBENZN are interpreted as mole fraction in the exhaust gas
RCH4N	CH4 to C - ratio (at FOUT=0) or CH4-concentration in the exhaust gas (as per FOUT)
RH2SN	H2S to S - ratio (at FOUT=0) or H2S-concentration in the exhaust gas (as per FOUT)
RNH3N	NH3 to N - ratio (at FOUT=0) or NH3-concentration in the exhaust gas (as per FOUT)
RBENZN	Benzol to C - ratio (at FOUT=0) or Benzene-concentration in the exhaust gas (as per FOUT)
FGASN	Type of specification of the degree of coal gasification: Like in Parent Profile (Sub Profile option only) Expression =0: Specification through the specification value RGASN =1: Specification through a pseudo-measurement point, to which the specification value IPSGASN points =2: Specification through the control input 9 (to be specified as enthalpy on the logic line)
RGASN	Degree of coal gasification (if FGASN=0)
IPSGASN	Index of the pseudo-measurement point for the degree of coal gasification (if FGASN=1)
FSPECM	Type of specification of the mass flows Like in Parent Profile (Sub Profile option only) Expression =1: Only one mass flow is specified and the remaining are calculated =2: All the inlet mass flows are specified
M6MF	Share of the oil mass flow in the total fuel mass flow
M7MF	Share of the gas mass flow in the total fuel mass flow
FSFT	Type of specification of the shift-reaction Like in Parent Profile (Sub Profile option only) Expression =1: Use of the temperature of the exhaust gas as the reaction temperature =2: Specification of the reaction temperature in the specified value TFRE =3: specification of the reaction constants in the specified value CWGS (for definition of CWGS see the explanations under "Explanations for the constant CWGS" in Component 50)
CWGS	Reaction constant for the shift reaction (Water-gas shift constants), if FSFT=3
TFRE	Freezing temperature for the shift-reaction, if FSFT=2
ROCN	Ratio of oxygen to carbon: Molar ratio of the whole O (including O in the fuel and in the steam) to the whole C, The value must lie between 1 (CO) and 2 (CO2)
RWM4N	Ratio of water/steam to fuel: Mass ratio between line 3 (steam inlet) and the sum of the lines 4, 6, 7 (fuel inlets)
RFLAS	Fly-ash ratio: Distribution of ash on the raw-gas outlet and ash extraction RFLAS specifies the percentage of ash, which goes in the raw-gas Outlet.
RCFA	Distribution of the (ungased) carbon on the raw-gas outlet and ash extraction RCFA specifies the percentage of carbon, which goes in the raw- gas outlet
FQLOSS	Type of specification of the heat loss: Like in Parent Profile (Sub Profile option only) Expression =0: User entry for value QLOSS contains the absolute heat loss =1: User entry for value QLOSS contains the relative heat loss, with reference to the fuel heat brought in (mass flow * calorific value)
QLOSS	Heat loss (as per FQLOSS)
DP12N	Absolute pressure drop (nominal)
TASHE	Slag temperature (line 5)
FMODE	Calculation mode Like in Parent Profile (Sub Profile option only) Expression =0: global (as set for the entire cycle) =1: local partial load (always partial load, even when the design mode is set for the cycle)
M1N	Mass flow of the oxidation agent (nominal)

The parameters marked in blue are reference quantities for the off-design mode. The actual off-design values refer to these quantities in the equations used.

Generally, all inputs that are visible are required. But, often default values are provided.

For more information on colour of the input fields and their descriptions see Edit Component\Specification values

For more information on design vs. off-design and nominal values see General\Accept Nominal values

Result values

ROC	Oxygen to carbon ratio
RWM4	Steam to coal ratio
RCWGS	Calculated water gas shift constant
RGAS	Carbon gasification
RCCH4	CH4-production (C in CH4 / C total)
RSH2S	H2S-production (S in H2S / S total)
NCVCG	Crude gas-Net calorific value at 0°C
NCVFUEL	Net calorific value of natural gas at 0°C (average)
RQCGC	Energy ratio of natural gas to coal
RTEQ	Calculated equilibrium temperature
RQLOSS	Calculated heat loss
TR1	Equilibr. T for CO+H2O=CO2+H2
TR2	Equilibr. T for C+CO2=2 CO
TR3	Equilibr. T for C+H2O=CO+H2
TR4	Equilibr. T for CO+3 H2=CH4+H2O
TR5	Equilibr. T for C+2 H2=CH4
RFA	ratio of fuel mass flow to air mass flow
RFAST	stoichiometric ratio of fuel mass flow to air mass flow (i.e. the ratio required for complete combustion)
EQRAT	equivalence ratio = RFA / RFAST (according to https://www.sciencedirect.com/topics/engineering/equivalence-ratio). An equivalence ratio EQRAT greater than 1 always indicates a fuel excess in the fuel-oxidant mixture, i.e. more fuel than required for a complete combustion (stoichiometric reaction), irrespective of which fuel and which oxidant are used, whereas ratios smaller than 1 indicate a lack of fuel or an equivalent oxidant excess in the mixture. Please note that the equivalence ratio relates to the air number λ as follows: λ = 1 / EQRAT.

Characteristic Lines

Characteristic 1, CCSL: Degree of gasification RGAS/RGASN = f (M1/M1N)
C-gasification

     X-axis         1         M1/M1N                      1^st point
                        2          M1/M1N                     2^nd point
                        .
                      N         M1/M1N                      last point

     Y- axis         1          RGAS/RGASN              1^st point
                        2          RGAS/RGASN              2^nd point
                        .
                        N         RGAS/RGASN               last point

Characteristic 2, CCH4: CH4-conversion characteristic RCH4/RCH4N = f (M1/M1N)
CH4 production

     X- axis         1          M1/M1N                   1^st point
                        2          M1/M1N                     2^nd point
                        .
                      N         M1/M1N                      last point

     Y- axis         1          RCH4/RCH4N             1^st point
                        2          RCH4/RCH4N             2^nd point
                        .
                        N         RCH4/RCH4N              last point

Characteristic 3, CH2S: H2S-conversion characteristic RH2S/RH2SN = f (M1/M1N)
H2S production

     X- axis         1         M1/M1N                      1^st point
                        2          M1/M1N                     2^nd point
                        .
                      N         M1/M1N                     last point

     Y- axis        1          RH2S/RH2SN               1^st point
                        2          RH2S/RH2SN              2^nd point
                        .
                        N         RH2S/RH2SN               last point

Characteristic 4, CNH3: NH3-conversion characteristic RNH3/RNH3N = f (M1/M1N)
NH3 production

     X- axis         1         M1/M1N                     1^st point
                        2          M1/M1N                    2^nd point
                        .
                      N         M1/M1N                     last point

     Y- axis         1          RNH3/RNH3N          1^st point
                        2          RNH3/RNH3N            2^nd point
                        .
                        N         RNH3/RNH3N             last point

Characteristic 5, CBENZ: Benzene conversion characteristic RBENZ/RBENZN = f (M1/M1N)
Benzene production

     X- axis         1          M1/M1N                  1^st point
                        2          M1/M1N                    2^nd point
                        .
                      N         M1/M1N                     last point

     Y- axis       1          RBENZ/RBENZN         1^st point
                        2          RBENZ/RBENZN         2^nd point
                        .
                        N         RBENZ/RBENZN          last point

Physics Used

Equations

All Cases

Mass flows

--------------------

M1MF from gasification balance

M2MF from gasification balance

M3MF from gasification balance

M4MF = 1-M6MF-M7MF (user input values)

M5MF from gasification balance

If FSPECM = 1:

M4 - M4MF/M1MF * M1 = 0

M6 - M6MF/M1MF * M1 = 0

M7 - M7MF/M1MF * M1 = 0

M2 - M2MF*M4 - M2MF*M6 - M2MF*M7 = 0

M3 - M3MF*M4 - M3MF*M6 - M3MF*M7 = 0

M5 - M5MF*M4 - M5MF*M6 - M5MF*M7 = 0

If FSPECM = 2:

M5 - M5MF*M4 - M5MF*M6 - M5MF*M7 = 0

M1 - M2 + M3 + M4 - M5 + M6 + M7

Pressures

----------

Design: P1 - P2 = DP12N

Partial load: M1R=M1/M1N

P1 - P2 = DP12N*M1R*M1R

P4 - P5 = 0

P6 - P5 = 0

P7 - P5 = 0

P1 - P4 = 0

P1 - P3 = 0

Enthalpies

--------------

T5 = TASHE

H5 = f(P5,T5)

If FQLOSS = 1:

QL = QLOSS

If FQLOSS = 2:

QL = QLOSS*(M4*NCV4+M6*NCV6+M7*NCV7)

M2*H2 - M1*H1 - M3*H3 - M4*H4 + M5*H5

- M6*H6 - M7*H7 + M8*H8 =

M4*NCV4-M2*NCV2-M5*NCV5+M6*NCV6

+M7*NCV7-QL

Component Displays

Display Option 1

Example

Click here >> Component 96 Demo << to load an example.