# Numerical Simulations of Gasification of Low-Grade Coal and Lignocellulosic Biomasses in Two-Stage Multi-Opposite Burner Gasifier

^{1}

^{2}

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## Abstract

**:**

_{2}composition in syngas. The maximum CO value was observed to be 57.59% at a 1.0 O/C ratio with a 0.005 kg/s feed rate, and the maximum H

_{2}value was observed to be 16.58% in the same conditions for Lakhra coal samples. In summary, Lakhra coal exhibited better performance than other biomass samples due to its better fixed carbon and volatiles in its composition.

## 1. Introduction

_{x}, and NO

_{x}. Owing to these problems, though coal is used for energy generation, it has become extremely important to develop a method to utilize coal in a cleaner way.

_{2}[11,12]. Considering the industrial demands for fuel, raw biomasses undergo conversion via biochemical, thermochemical, and extraction methodologies to yield a more adaptable fuel [13,14]. The syngas produced through thermochemical conversion processes is a more versatile fuel than the original raw material used for numerous applications such as electricity production, H

_{2}production, and heat generation [15].

## 2. Numerical Method

#### 2.1. CFD Model Development

#### 2.2. Computational Domain

^{®}19.1 and the meshing was performed in Ansys Meshing

^{®}19.1. The gasifier consisted of two nozzles on each level with central and tangential orientation. Biomass/coal as a feedstock was injected from the central nozzles, whereas oxygen as a gasifying medium was injected through tangential nozzles. Initially, meshes of four different sizes were developed; the details are presented in Table 2. The mesh independence test was performed by comparing the temperature profile along the central axis for all mesh sizes as shown in Figure 3. It has been observed that finer and finest meshes show almost similar temperature results. Hence, the finer mesh was considered the optimized mesh and beyond this density of grid, the solution become independent of the result.

#### 2.3. Governing Equations and Assumptions

_{2}, HCN, NH

_{3}, and H

_{2}S during gasification process were ignored. (3) The body force of the flow and the thermal radiation in the reactor were omitted. (4) The gasifier wall was deemed adiabatic. The Navier–Stokes equations coupled with the energy and species equations in both steady-state and time-averaged forms were resolved alongside the conventional k-epsilon turbulence model. Detailed information about the governing equations and their associated constants is provided in Table 3, following the strategies of previous research [42,43,44].

#### 2.4. Chemical Reactions

_{P}signifies the temperature of the feed particles, V represents the fraction of mass consisting of volatiles, A corresponds to the pre-exponential factor, k denotes the reaction rate constant, and Ea signifies the activation energy for the reactions. The ${E}_{h},{E}_{l},{Y}_{h},{Y}_{l},{K}_{h},{\mathrm{a}\mathrm{n}\mathrm{d}K}_{l}$ values are given in Table 4 [32,47].

_{2}during its gasification. Different researchers have selected various reactions to define the gasification reaction mechanism [32,48,49,50]. The gasification process starts with the breakup of feedstock into different species as per Equation (10). Later, several homogeneous and heterogeneous reactions occur due to the availability of appropriate species and thermodynamic conditions. Table 5 describes all these reactions along with their kinetic information. In this work, preliminary simulations were carried out with different reaction plans (from A to F per Table 3) to find the best reaction plan based on the comparison with previous experimental research conducted by Ambatipudi and Varunkumar [41].

_{f}, in the equation above was derived according to the Arrhenius law. In this context, ‘A’ represents the pre-exponential factor, while ‘E’ signifies the activation energy. Detailed values for ‘A’ and ‘E’ pertaining to various reactions can be found in Table 5.

#### 2.5. Feedstock Composition, Operating Parameters, and Performance Indicators

_{2}concentrations, while the cold gas efficiency was ascertained by examining the levels of H

_{2}and CO concentrations.

#### 2.6. Conditions at Boundary Zones and Solution Strategies

^{®}19.0 software. The SIMPLE algorithm was employed to solve the governing equations and manage the boundary conditions within these simulations. Meanwhile, for the calculation of diffusion fluxes and convection, a first-order upwind scheme was utilized. The feedstock type, feedstock flowrate (feeding rate) and O/C ratio were the varying parameters. Total 27 cases were simulated, whose parametric information is given in Table 7. A Core i7 PC with 1.30 GHz and 1.50 GHz processing speed was used, having 16 GB RAM along with a 4 GB graphics card. Each simulation took about 3 to 4 h to be solved.

^{−6}. The energy and P-1 radiation equations are most the sensitive in terms of solving for gasification cases.

## 3. Results and Discussion

#### 3.1. Validation of Reaction Schemes

_{2}–48% CO

_{2}and 23% O

_{2}–59% CO

_{2}, respectively. The estimated mole fractions of the important components (CO, H

_{2}and CO

_{2}) of simulated syngas with different reaction schemes are compared with experimental data [38] in Figure 4a,b for the gasification of coal and groundnut shell feedstocks, respectively.

_{2}, and CO

_{2}with the error in the range of 1–5% using both feedstocks; it was observed that scheme E predicted the results well, per previous research [32,44]. Therefore, the rest of the simulations were performed by taking scheme E as the base reaction scheme.

#### 3.2. Syngas Composition

_{2}, and CO

_{2}have primary importance in gasification. Following the trends of previous researchers, the CO, H

_{2}, and CO

_{2}mole fractions were estimated from all the cases. Their compositions were plotted against an O/C ratio at different feed rates for LC, RH and WS in Figure 5a–c respectively. It was observed that CO and H

_{2}showed their maximum values at O/C ratio = 1.0, which is consistent to the trend obtained in previous studies [32,53]. After 1.0, the combustion scenario dominated, as observed by the increasing CO

_{2}concentration. The maximum mole fractions of CO were observed to be 57.59%, 36.57%, and 47.54% for the LC, RH, and WS feedstocks, respectively. Similarly, the maximum mole fractions of H

_{2}were observed to be 16.58%, 23.54%, and 13.47% for the LC, RH, and WS feedstocks, respectively. It was seen that higher CO mole fraction values were achieved with coal as feedstock as compared to biomass feedstocks due to higher fixed carbon in coal. On the other hands, the higher H

_{2}mole fraction was achieved with biomass feedstocks as compared to coal due to higher amount of moisture in biomass samples.

_{2}, and H

_{2}are illustrated by mole fraction profiles in Figure 6a–c for selected feedstocks. The findings suggest that combustion prevails in the upper region of the gasifier due to higher amounts of CO

_{2}production. However, near the gasifier bottom, the gasification reactions play their role, exhibiting higher conversion of CO and H

_{2}.

#### 3.3. Temperature of Gasification

#### 3.4. Quality of Produced Syngas

_{2}. The quality of produced syngas was evaluated by estimating its HHV. The HHV was estimated for all the cases at O/C ratio = 1.0 (as this gave maximum CO and H

_{2}composition). The HHV was estimated using an Aspen HYSYS V11 simulator through the Peng–Robbinson Fluid Package. Figure 9 illustrates the extracted results for HHV estimation for syngas produced from selected feedstocks at varying feed rates. It was observed that the HHV of syngas was decreased by increasing the feeding rate of feedstock, keeping a constant O/C ratio. The reason for this behavior is a decreasing trend in CO and H

_{2}production at higher feed rates due to the dominancy of combustion reactions at elevated feed rates, as also explained by previous research [32,48,55]. The maximum HHVs for LC, RH, and WS were estimated as 11,412.47 kJ/kg, 9732.29 kJ/kg, and 8779.2 kJ/kg, respectively.

#### 3.5. Conversion of Char and Volatiles

#### 3.6. Conversion Efficiencies

_{2}, whereas the cold conversion efficiency expresses the conversion of fixed carbon into CO and H

_{2}. Both the CCE and CGE were estimated using Equations (21) and (22), respectively. Figure 11 presents the efficiencies for coal and biomass samples at the 1.0 O/C ratio. It was observed that the CCE for all the feedstocks was above 90% at the investigated feeding rates. This shows the high performance of the gasification system and also confirms the char conversion data of the previous section. The highest CCE was observed in the range of 98% for WS due to higher amounts of CO

_{2}production from this particular feedstock. Conversely, the CGE was higher at low feeding rates and decreased with increasing feeding rate. The maximum CGE was observed for LC 92.9% at 0.005 kg/s, whereas the most minimum CGE was observed for WS 59.57% at a 0.015 kg/s feeding rate.

#### 3.7. Flow Visualization

#### 3.8. Comparison of Simulated Results with Published Work

_{2}, and H

_{2}mole fraction of syngas were compared with those reported in previously published work [29,41,45,53,54,55,56,57,58,59,60] as depicted in Figure 13. It can be seen that results of most of the literature are closer, apart from a few exceptional cases. A more rigorous comparison can be performed with the RH and SW cases presented by Maitlo, Unar [45], in which CO is in closer ranges. However, CO

_{2}is a little lower and H

_{2}is a little higher for the current study, which could be due to the use of different technology. In these studies, a concentric tube gasifier was used, which is different from the presently modeled MOB gasifier, which is based on a flameless strategy.

## 4. Conclusions

_{2}in produced syngas. The feed rate exhibited an inverse relationship with the overall gasifier performance. Increasing the feed rate decreased the CO and H

_{2}composition in the syngas.

_{2}percentages were 57.59% and 16.58%, respectively, for Lakhra coal at a 1.0 O/C ratio and 0.005 kg/s feed rate. Rice husk achieved maximum CO and H

_{2}percentages of 36.57% and 23.54%, while sawdust reached 47.54% and 13.47% under the same conditions. The syngas exit temperatures were highest for Lakhra coal at 1478 K, compared to 1034 K and 1045 K for rice husk and sawdust. The temperature profiles indicate that the impinging and tangential nozzles favored gasification at a 1.0 O/C ratio, resulting in a flameless scenario. The flow streams show the development of a strong vortex due to impinging and tangential multi-opposite injectors.

_{2}and H

_{2}were generally within similar ranges, with a few exceptions.

## Author Contributions

## Funding

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

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**Figure 4.**Mole fraction of important components of syngas from the gasification of various feedstocks at different reaction schemes.

**Figure 5.**Syngas composition at varying O/C ratios and feedstock feeding rate with Lakhra coal as feedstock.

**Figure 11.**Carbon conversion efficiency and cold gas efficiency for selected feedstock at 1.0 O/C ratio.

Sr. No | Specification | Value |
---|---|---|

1 | Diameter of main gasifier body | 350 mm |

2 | Height | 1200 mm |

3 | Diameter of inlet nozzles | 10 mm |

4 | Outlet diameter | 230 mm |

Sr. No | Grid Name | No. of Elements |
---|---|---|

1 | Coarser mesh | 78,457 |

2 | Fine mesh | 89,748 |

3 | Finer mesh | 112,185 |

4 | Finest mesh | 185,850 |

Physics | Governing Equations | Equation No. |
---|---|---|

Continuity | $\frac{\mathsf{\partial}}{\mathsf{\partial}{x}_{i}}\left(\rho {u}_{ij}\right)=\frac{{\u2206m}_{p}}{{m}_{p,0}}{\dot{m}}_{p,0}$ | (1) |

Momentum | $\frac{\mathsf{\partial}}{\mathsf{\partial}{x}_{i}}\left(\rho {u}_{i}{u}_{j}\right)=-\frac{\mathsf{\partial}p}{{\mathsf{\partial}x}_{j}}+\frac{\mathsf{\partial}}{{\mathsf{\partial}x}_{i}}\left({\tau}_{ij}-\overline{{{pu}^{\prime}}_{i}{{u}^{\prime}}_{j}}\right)+\sum \left[\frac{{18\mu C}_{D}Re}{{\rho}_{p}{d}_{p}^{2}24}\left({u}_{p}-u\right)\right]{\dot{m}}_{p}\u2206t$ | (2) |

Energy | $\frac{\mathsf{\partial}}{\mathsf{\partial}{x}_{i}}\left(\rho {c}_{p}{u}_{i}T\right)=\frac{\mathsf{\partial}}{\mathsf{\partial}{x}_{i}}\left(\lambda \frac{\mathsf{\partial}T}{{\mathsf{\partial}x}_{i}}-\rho {c}_{p}\overline{{{u}^{\prime}}_{i}{T}^{\prime}}\right)-{\sum}_{j}\frac{{\u2206H}_{j}^{0}}{{M}_{j}}\overline{{R}_{j}}$ | (3) |

Species transport model | $\frac{\mathsf{\partial}}{\mathsf{\partial}{x}_{i}}\left(\rho {c}_{p}{u}_{i}T\right)=\frac{\mathsf{\partial}}{\mathsf{\partial}{x}_{i}}\left(\lambda \frac{\mathsf{\partial}T}{{\mathsf{\partial}x}_{i}}-\rho {c}_{p}\overline{{{u}^{\prime}}_{i}{T}^{\prime}}\right)-{\sum}_{j}\frac{{\u2206H}_{j}^{0}}{{M}_{j}}\overline{{R}_{j}}$ | (4) |

Kinematic viscosity | ${\mu}_{t}={\rho C}_{\mu}{k}^{2}/\epsilon $ | (5) |

Kinetic energy | $\frac{\mathsf{\partial}}{\mathsf{\partial}{x}_{i}}\left(\rho {u}_{i}k\right)=\frac{\mathsf{\partial}}{\mathsf{\partial}{x}_{i}}\left[\left(\mu +\frac{{\mu}_{t}}{{\sigma}_{k}}\right)\frac{\mathsf{\partial}k}{\mathsf{\partial}{x}_{i}}\right]+{G}_{k}-\rho \epsilon $ | (6) |

Dissipation rate | $\frac{\mathsf{\partial}}{\mathsf{\partial}{x}_{i}}\left(\rho {u}_{i}k\right)=\frac{\mathsf{\partial}}{\mathsf{\partial}{x}_{i}}\left[\left(\mu +\frac{{\mu}_{t}}{{\sigma}_{k}}\right)\frac{\mathsf{\partial}k}{\mathsf{\partial}{x}_{i}}\right]+{G}_{k}-\rho \epsilon $ | (7) |

Heat conductivity | $\rho {c}_{p}\overline{{{u}^{\prime}}_{i}{T}^{\prime}}=-\lambda \frac{\mathsf{\partial}T}{{\mathsf{\partial}x}_{i}}=-{C}_{p}\frac{{\mu}_{t}}{{Pr}_{t}}\frac{\mathsf{\partial}T}{{\mathsf{\partial}x}_{i}}$ | (8) |

Diffusion coefficient | $\rho {{u}^{\prime}}_{i}\overline{{{Y}^{\prime}}_{j}}=-\rho D\frac{\mathsf{\partial}Y}{{\mathsf{\partial}x}_{i}}=-\frac{{\mu}_{t}}{{SC}_{t}}\frac{\mathsf{\partial}Y}{{\mathsf{\partial}x}_{i}}$ | (9) |

Discrete phase model | ||

Change in velocity of a particle | $Fd=\frac{{m}_{p}{dV}_{P}}{dt}$ | (10) |

Drag force | ${F}_{D}=\frac{{\rho A}_{p,c}{C}_{D}{v}_{r}^{2}}{2}$ | (11) |

Constants | ${C}_{\mu}$ = 0.09 ${C}_{1\mathsf{\u0511}}$ = 1.44 ${C}_{2\mathrm{\u0511}}$ = 1.92 ${\sigma}_{k}$ = 1.0 ${\sigma}_{\mathsf{\u0511}}$ = 1.3 ${Pr}_{t}$ = 0.85 ${Sc}_{t}$ = 0.7 |

Parameter | Value |
---|---|

${K}_{h}{s}^{-1}$ | 1.28 × 10^{7} |

${K}_{l}{s}^{-1}$ | 200,000 |

${Y}_{h}$ | 1 |

${Y}_{l}$ | 0.29 |

${E}_{h}\left(\mathrm{K}{\mathrm{J}\mathrm{m}\mathrm{o}\mathrm{l}}^{-1}\right)$ | 165.3 |

${E}_{l}\left(\mathrm{K}{\mathrm{J}\mathrm{m}\mathrm{o}\mathrm{l}}^{-1}\right)$ | 106.9 |

Sr. No | Reactions | Schemes | Kinetic Parameters | ||||||
---|---|---|---|---|---|---|---|---|---|

A | B | C | D | E | F | A (Pre-Exponent Factor) | E (Activation Energy) | ||

Homogeneous Reactions | |||||||||

1 * | Vol + X O_{2} → A CO_{2} + B H_{2}O + C N2 + D SO_{2}(Volatiles complete combustion) | 2.119 × 10^{11} | 2.03 × 10^{8} | ||||||

2 * | Vol + X’ O_{2} → A’ CO + B H_{2}O + C N2 + D SO_{2}(Volatiles partial combustion) | 2.12 × 10^{11} | 2.20 × 10^{11} | ||||||

3 | $\mathrm{C}\mathrm{O}+0.5{\mathrm{O}}_{2}\to {\mathrm{C}\mathrm{O}}_{2}\hspace{1em}\u2206{\mathrm{H}}^{0}=-283\mathrm{M}\mathrm{J}{\mathrm{k}\mathrm{m}\mathrm{o}\mathrm{l}}^{-1}$ (CO combustion) | 2.239 × 10^{12} | 1.70 × 10^{8} | ||||||

4 | ${\mathrm{H}}_{2}+0.5{\mathrm{O}}_{2}\to {\mathrm{H}}_{2}\mathrm{O}\hspace{1em}\u2206{\mathrm{H}}^{0}=-242\mathrm{M}\mathrm{J}{\mathrm{k}\mathrm{m}\mathrm{o}\mathrm{l}}^{-1}$ (H _{2} combustion) | 6.800 × 10^{15} | 1.68 × 10^{8} | ||||||

5 | $\mathrm{C}\mathrm{O}+{\mathrm{H}}_{2}\mathrm{O}\to {\mathrm{C}\mathrm{O}}_{2}+{\mathrm{H}}_{2}\u2206{\mathrm{H}}^{0}=-41.1\mathrm{M}\mathrm{J}{\mathrm{k}\mathrm{m}\mathrm{o}\mathrm{l}}^{-1}$ (Water shift reaction) (f) | 2.750 × 10^{10} | 8.38 × 10^{7} | ||||||

6 | ${\mathrm{C}\mathrm{O}}_{2}+{\mathrm{H}}_{2}\to \mathrm{C}\mathrm{O}+{\mathrm{H}}_{2}\mathrm{O}\u2206{\mathrm{H}}^{0}=41.1\mathrm{M}\mathrm{J}{\mathrm{k}\mathrm{m}\mathrm{o}\mathrm{l}}^{-1}$ (Water shift reaction) (b) | 0.0265 | 3960 | ||||||

Heterogeneous Reactions | |||||||||

7 | $\mathrm{C}+\frac{1}{2}{\mathrm{O}}_{2}\to \mathrm{C}\mathrm{O}\hspace{1em}\u2206{\mathrm{H}}^{0}=-111\mathrm{M}\mathrm{J}{\mathrm{k}\mathrm{m}\mathrm{o}\mathrm{l}}^{-1}$ (Char partial combustion) | 0.052 | 6.10 × 10^{7} | ||||||

8 | $\mathrm{C}+{\mathrm{O}}_{2}\to \mathrm{C}{\mathrm{O}}_{2}\hspace{1em}\u2206{\mathrm{H}}^{0}=-393\mathrm{M}\mathrm{J}{\mathrm{k}\mathrm{m}\mathrm{o}\mathrm{l}}^{-1}$ (Char complete combustion) | 415.7 | 9.04 × 10^{7} | ||||||

9 | $\mathrm{C}+{\mathrm{C}\mathrm{O}}_{2}\to 2\mathrm{C}\mathrm{O}\hspace{1em}\u2206{\mathrm{H}}^{0}=+111\mathrm{M}\mathrm{J}{\mathrm{k}\mathrm{m}\mathrm{o}\mathrm{l}}^{-1}$ (Gasification, Boudourad reaction) | 107,800 | 2.44 × 10^{7} | ||||||

10 | $\mathrm{C}+{\mathrm{H}}_{2}\mathrm{O}\to \mathrm{C}\mathrm{O}+{\mathrm{H}}_{2}\hspace{1em}\u2206{\mathrm{H}}^{0}=+131\mathrm{M}\mathrm{J}{\mathrm{k}\mathrm{m}\mathrm{o}\mathrm{l}}^{-1}$ (Gasification) | 97,540 | 2.02 × 10^{8} |

Biomass Type | Lakhra Coal | Rice Husk | Wood Sawdust |
---|---|---|---|

Proximate analysis (wt.%, dry basis) | |||

M | 9.93 | 4.83 | 5.53 |

VM | 43.69 | 61.86 | 72.60 |

FC | 31.96 | 15.30 | 14.55 |

Ash | 14.42 | 18.01 | 7.32 |

Ultimate analysis (wt. %, dry basis) | |||

C | 67.84 | 45.8 | 44.1 |

H | 7.9 | 6 | 5.96 |

N | 1.43 | 0.3 | 0.36 |

O | 13.81 | 47.9 | 49.39 |

S | 9.02 | 0 | 0.19 |

HHV (J kg^{−1}) | 1.89 × 10^{7} | 1.33 × 10^{7} | 1.88 × 10^{7} |

Sr. No | Case Name | Feedstock | Feeding Rate | O/C Ratio | Oxidant Flowrate | Oxidant Distribution (kg/s) | |
---|---|---|---|---|---|---|---|

(kg/s) | (kg/s) | Up-Nozzles (60%) | Down-Nozzles (40%) | ||||

1 | LC_0.005_0.9 | LC | 0.005 | 0.9 | 0.0024 | 0.00072 | 0.00048 |

2 | LC_0.005_1.0 | LC | 0.005 | 1.0 | 0.0027 | 0.00081 | 0.00054 |

3 | LC_0.005_1.1 | LC | 0.005 | 1.1 | 0.003 | 0.0009 | 0.0006 |

4 | LC_0.01_0.9 | LC | 0.01 | 0.9 | 0.0047 | 0.00141 | 0.00094 |

5 | LC_0.01_1.0 | LC | 0.01 | 1.0 | 0.0054 | 0.00162 | 0.00108 |

6 | LC_0.01_1.1 | LC | 0.01 | 1.1 | 0.0061 | 0.00183 | 0.00122 |

7 | LC_0.015_0.9 | LC | 0.015 | 0.9 | 0.0071 | 0.00213 | 0.00142 |

8 | LC_0.015_1.0 | LC | 0.015 | 1.0 | 0.0081 | 0.00243 | 0.00162 |

9 | LC_0.015_1.1 | LC | 0.015 | 1.1 | 0.0091 | 0.00273 | 0.00182 |

10 | RH_0.005_0.9 | RH | 0.005 | 0.9 | 0.0206 | 0.00618 | 0.00412 |

11 | RH_0.005_1.0 | RH | 0.005 | 1.0 | 0.0229 | 0.00687 | 0.00458 |

12 | RH_0.005_1.1 | RH | 0.005 | 1.1 | 0.0252 | 0.00756 | 0.00504 |

13 | RH_0.01_0.9 | RH | 0.01 | 0.9 | 0.0041 | 0.00123 | 0.00082 |

14 | RH_0.01_1.0 | RH | 0.01 | 1.0 | 0.0458 | 0.01374 | 0.00916 |

15 | RH_0.01_1.1 | RH | 0.01 | 1.1 | 0.0504 | 0.01512 | 0.01008 |

16 | RH_0.015_0.9 | RH | 0.015 | 0.9 | 0.0618 | 0.01854 | 0.01236 |

17 | RH_0.015_1.0 | RH | 0.015 | 1.0 | 0.0687 | 0.02061 | 0.01374 |

18 | RH_0.015_1.1 | RH | 0.015 | 1.1 | 0.0756 | 0.02268 | 0.01512 |

19 | WS_0.005_0.9 | WS | 0.005 | 0.9 | 0.002 | 0.0006 | 0.0004 |

20 | WS_0.005_1.0 | WS | 0.005 | 1.0 | 0.0022 | 0.00066 | 0.00044 |

21 | WS_0.005_1.1 | WS | 0.005 | 1.1 | 0.0024 | 0.00072 | 0.00048 |

22 | WS_0.01_0.9 | WS | 0.01 | 0.9 | 0.004 | 0.0012 | 0.0008 |

23 | WS_0.01_1.0 | WS | 0.01 | 1.0 | 0.0044 | 0.00132 | 0.00088 |

24 | WS_0.01_1.1 | WS | 0.01 | 1.1 | 0.0049 | 0.00147 | 0.00098 |

25 | WS_0.015_0.9 | WS | 0.015 | 0.9 | 0.006 | 0.0018 | 0.0012 |

26 | WS_0.015_1.0 | WS | 0.015 | 1.0 | 0.0066 | 0.00198 | 0.00132 |

27 | WS_0.015_1.1 | WS | 0.015 | 1.1 | 0.0073 | 0.00219 | 0.00146 |

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## Share and Cite

**MDPI and ACS Style**

Rehman, A.u.; Unar, I.N.; Abro, M.; Qureshi, K.; Almani, S.; Jatoi, A.S.
Numerical Simulations of Gasification of Low-Grade Coal and Lignocellulosic Biomasses in Two-Stage Multi-Opposite Burner Gasifier. *Processes* **2023**, *11*, 3451.
https://doi.org/10.3390/pr11123451

**AMA Style**

Rehman Au, Unar IN, Abro M, Qureshi K, Almani S, Jatoi AS.
Numerical Simulations of Gasification of Low-Grade Coal and Lignocellulosic Biomasses in Two-Stage Multi-Opposite Burner Gasifier. *Processes*. 2023; 11(12):3451.
https://doi.org/10.3390/pr11123451

**Chicago/Turabian Style**

Rehman, Anees u, Imran Nazir Unar, Masroor Abro, Khadija Qureshi, Sikandar Almani, and Abdul Sattar Jatoi.
2023. "Numerical Simulations of Gasification of Low-Grade Coal and Lignocellulosic Biomasses in Two-Stage Multi-Opposite Burner Gasifier" *Processes* 11, no. 12: 3451.
https://doi.org/10.3390/pr11123451