Poha Production: What are problems associated with it’s manufacturing?

Understanding the Scale of Poha Production

Though concrete production data isn’t readily available, it’s estimate that around 10% of India’s total rice production is used to make flaked, popped, and expanded rice. Major poha manufacturing hubs are like Orissa, Maharashtra, Madhya Pradesh, and Chhattisgarh.

Despite its popularity, poha manufacturing has been flagged as a major polluter, especially during roasting production. The question is: why is poha production so harmful to the environment?

The process of poha production is below:

1. How Does Poha Production Generate Pollution?

During roasting, rice is heated in hot sand or another suitable heating medium, depending on the process and equipment design. The heat may come from natural gas or solid biomass fuels such as rice husk, wood, and sawdust.

When a furnace burns solid fuel, it produces combustion gases and may generate particulate matter. The quantity and composition of emissions depend on the fuel, its moisture content, the combustion system, the operating conditions, and the effectiveness of emission controls.

Three common concerns are:

• Smoke and particulate matter: These can increase when fuel burns incompletely.
• Excessive fuel consumption: Poor insulation and inefficient combustion can waste useful heat.
• Unstable roasting temperatures: Inconsistent heat input can affect product quality and production consistency.

2. Incomplete Combustion and Excess Smoke

Incomplete combustion occurs when fuel doesn’t burn completely. This may happen when the furnace receives insufficient air, fuel and air don’t mix properly, temperatures are too low, or the fuel supply changes faster than the combustion system can respond.

Solid biomass fuels can be especially challenging when they vary in size, moisture, and composition. Poor combustion may produce visible smoke, carbon monoxide, and unburned carbon particles.

How can manufacturers improve combustion?

Start by checking the fuel-feeding system, air supply, furnace temperature, and condition of the combustion chamber. The goal is to maintain proper combustion conditions rather than simply increasing the air supply.

Too little air can cause incomplete combustion, while too much air can carry extra heat out through the exhaust. The correct operating range depends on the furnace and fuel.

Where appropriate, manufacturers can consider controlled air distribution, improved fuel feeding, regular burner maintenance, and monitoring of flue-gas conditions. These measures should be evaluated against actual operating data rather than assumed to deliver a fixed reduction in emissions.

3. Furnace Insulation and Heat Loss

Traditional brick furnaces may lose heat through walls, doors, gaps, and other poorly insulated surfaces. When heat escapes before it can be used for roasting, the furnace may require more fuel to maintain the desired temperature.

Insulation can reduce heat transfer through the furnace structure. However, the right insulation material and thickness depend on operating temperature, construction, abrasion exposure, and maintenance requirements.

Manufacturers should inspect the furnace for damaged lining, cracks, unsealed openings, and deteriorated insulation. Repairs may improve temperature stability and reduce unnecessary heat loss for poha production.

It’s also important to distinguish between heat escaping through the furnace structure and heat leaving through the exhaust. Both can matter, but they require different solutions.

4. Fuel Quality and Moisture Content

Biomass fuel quality has a direct influence on combustion performance. Wet fuel uses part of the available heat to evaporate its moisture, leaving less energy available for the roasting process.

Fuel with inconsistent particle sizes can also create feeding and airflow problems. Ash content matters because excessive ash may increase residue handling, obstruct airflow, or contribute to operational difficulties, depending on the fuel and equipment.