Different gasification fuels
Gasification process converts a carbon based fuel into a gaseous product with a useful heating value. A range of different gasification fuels can be used for this for example - coal, biomass, residual oil and even natural gas.
1. Coal Gasification
There are various types of coal and each type of coal has its own properties which are important forcoal gasification. Some of those important aspects of coal to be used in gasification are:
- 煤的年龄
- Caking properties
- Water content
- Ash properties
Coal analysisis done to find out suitability of different samples of coals based on these properties. Coal is mostly classified based on fixed carbon, volatile matter and their heating values.
| Class | Volatile Matter(wt%) | Fixed Carbon(wt%) | Heating Value(MJ/kg) |
| Anthracite | <8 | > 92 | 36-37 |
| Bituminous | 8-22 | 78-92 | 32-36 |
| Sub-bituminous | 22-27 | 73-78 | 28-32 |
| 褐煤 | 27-35 | 65-73 | 26-28 |
Heating Value of coal
Heating valueis generally determined by combustion inside a热量计. Both lower and higher heating values are used for thermodynamic calculation. The lower heating value popularly known as LHV takes into account the amount of water vapor lost in the exhaust stream. For determination of HHV, one needs to condense out the water vapour present in the exhaust stream to calculate steam heat.
There are two different methods to calculate heating values:
Dulong Formula
MJ/kg中的HHV 33.86×C + 144.4×（H -O/8） + 9.428×S
其中C，H，O和S是从最终分析获得的质量分数。
Channiwala formula
HHV in MJ/kg ═ 34.91×C+117.83×H‐10.34×O‐1.51×N+10.05×S ‐ 2.11×Ash
These formulas and experiments together are used to calculate heating value of coal.
2.液体和气体燃料用于气化
Liquid feedstock is another type of fuel for gasification process. In 2002, around 154 million NM3使用液体燃料的部分氧化产生合成气体。气体饲料不需要气化，并且它们在很小的规模上用于生产大量石化物。
3. Biomass Gasification
广泛的生物质资源基础包括农作物残留物，能源农场生产的原料，受到约束牲畜和家禽业务的肥料，主要木材产品制造厂的木材和树皮磨坊残留物，木浆行业的树皮残留物，从木浆中记录木材残留物，收获操作，站立森林的非商业组成部分以及市政固体废物的有机部分。总体生物质可以分为两类。
Woody Biomass
Woody biomass is characterized by high bulk density, less voidage, low ash content, low moisture content, high calorific value. Because of the multitude of advantages of woody biomass its cost is higher, but supply is limited.
Non-Woody biomass
The various agricultural crop residues resulting after harvest, organic fraction of municipal solid wastes, manure from confined livestock and poultry operations constitute non-woody biomass. Non-woody biomass is characterized by lower bulk density, higher voidage, higher ash content, higher moisture content, and lower calorific value.
4. Wastes
废物作为气化原料覆盖了广泛的材料。由于其异质性，很难提供对废物的明确特性描述。物理特性和废物的组成以及不同成分的存在，例如硫，氯化物或金属，都会影响其利用。
实际使用废物作为原料需要持续调整操作条件，以防止损失和产生不良的出口气体。
Biomass Properties relevant to gasification
Bulk Chemical Analysis
In evaluating gasification feedstocks, it is generally useful to have proximate and ultimate analyses, heat of combustion analysis and sometimes ash analysis. These provide information about volatility of the feedstock, elemental composition and heat content.
物理特性Analysis
Major physical data necessary for predicting thermal response of biomass materials under pyrolysis, gasification and combustion reactions are shape, size, voidage, thermal conductivity, heat capacity, diffusion coefficient and densities viz. bulk density, apparent particle density and true density.
Properties of different type of Biomass are given in following Table-1
| Biomass | HHV（MJ/kg） | Moisture (wt%) | Ash (wt%) | Sulfur (wt%dry) | Chlorine (wt%dry) |
| charcoal | 25-32 | 1-10 | 0.5-6 | ||
| Wood | 10-20 | 10-60 | 0.25-1.7 | 0.01 | 0.01 |
| coconut shell | 18-19 | 8-10 | 1-4 | ||
| straw | 14-16 | 10 | 4-5 | 0.07 | 0.49 |
| 地螺母壳 | 17 | 2-3 | 10 | ||
| coffee husks | 16 | 10 | 0.6 | ||
| 棉花残留物(圣alks) | 16 | 10-20 | 0.1 | ||
| cocoa husks | 13-16 | 7-9 | 7-14 | ||
| palm oil residues (shells) | 15 | 15 | |||
| rice husk | 13-14 | 9-15 | 15-20 | ||
| soya straw | 15-16 | 8-9 | 5-6 | ||
| 棉花残留物（杜松子酒垃圾） | 14 | 9 | 12 | ||
| maize | 13-15 | 10-20 | 2 | 0.05 | 1.48 |
| palm oil residues (fibres) | 11 | 40 | |||
| 锯末 | 11 | 35 | 2 | ||
| bagasse | 8-10 | 40-60 | 1-4 | ||
| palm oil residues (fruit stems) | 5 | 63 | 5 | ||
| bark | 0.07 | 0.49 |
生物质的表1特性 - 源自Quaak等，1999;Arbon，2002。
