GASIFIERS – Applications

Gasifiers can cater to almost all applications needing solid, liquid or gaseous fuels.

The utility of gasifiers arises from the fact that they convert low cost solid fuels (coal or biomass) into clean combustible gas. Then, the produced gas can easily substitute costlier liquid fuels (such as diesel, LDO, furnace oil, kerosene, etc.) or gaseous fuels (such as LPG, natural gas, etc.). Thus, gasifiers offer great opportunity of reduction in energy costs.

When gasifiers are retrofitted where solid fuels are already in use, then generally pollution decreases and efficiency increases due to the use of cleaner gaseous fuel.

Gasifiers can also be used in applications requiring process gas for synthesis or downstream chemical processes.

So far, in India, gasifiers have been widely used for industrial heating (thermal) and power (electricity) generation applications.


THERMAL APPLICATIONS


Gasifiers can be used for almost any industrial heating (thermal) application. With appropriate design of burners and combustion system, temperatures up to  15000C can be reached. Some of the applications that can be thought of are:

Metal reheating furnaces  Metal melting furnaces  Dryers  Hot air generators
Rotary kilns  Heat treatment furnaces Glass melting   Boilers
Galvanizing furnaces Chemical reactors heating  Vertical shaft kilns  Tunnel kilns

The above list is not is not exhaustive. If you have any thermal application, just get in touch with us. We will explore the benefits that you may get by using gasifiers.

Capacity range: 120 kWth to 30,000 kWth (10 litres/hour to 2500 litres/hour oil equivalent) with single reactor modules, any larger scale is feasible with parallel installation of multiple gasifiers.


POWER(ELECTRICITY GENERATION) APPLICATIONS


Generating power using producer gas from coal or biomass is one of the potential applications of gasifiers. This application could take one of the following forms:

Substitution of Diesel in Existing DG sets: If the local power availability situation warrants use of DG sets, then gasifiers offer great opportunity of savings. Producer gas generated from coal or biomass through gasifiers can substitute 60-80% diesel.

Standalone Power Generating Unit with 100% Gas Engines: The gasifier – gas engine combination can generate power with 100% gas produced from coal or biomass.

Combined Heat & Power: While power is produced from producer gas fired engine, waste heat from the engine could be used for a thermal application or refrigeration.

Capacity Range: 100 kW to 5 MW with single reactor module


SELECTION OF GASIFIERS - UPDRAFT OR DOWNDRAFT


The selection of updraft or downdraft gasifier depends upon:

  -   Availability of specified fuel & need for fuel flexibility
  -   Scale of application
  -   Type of application

One of the myths about gasification technology is that clean gas (such as required for power generation) cannot be produced by updraft gasifiers. The fact is that producing clean gas using updraft gasifier requires more complex equipment & processes.

Downdraft gasifier is more stringent regarding type and quality of fuel while updraft gasifier is more forgiving in this respect. Further, updraft gasifier is more efficient than downdraft. The calorific value of gas is also higher in case of updraft.

Where gas cleanliness (for most of the thermal applications) is not a major issue, updraft gasifier would be the natural choice.

For small / medium clean gas applications (such as power generation), where fuel type & quality can be strictly maintained, downdraft would make a better choice.

For large clean gas applications (including power generation) or at sites where strict adherence to type / quality of fuel could be difficult, updraft would make a better choice.