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:

The Pollution Problem: Why Poha Production is Under Scrutiny

One critical process in poha production is roasting, which gives the flakes their crispy texture and distinctive color. Most manufacturers today rely on continuous cylindrical roasters to roast paddy. In this process, sand is heated to temperatures between 170°C and 220°C using natural gas or biomass fuels like sawdust, rice husk, and wood.

Unfortunately, using biomass fuels in inefficient combustion chambers contributes significantly to pollution. Let’s break down some common problems in poha roasting facilities, particularly in regions like Bhatapara (Chhattisgarh) and Ujjain (Madhya Pradesh).

1. Convective Heat Loss
The furnaces in most poha mills are made with regular construction bricks and lack proper insulation. This design flaw leads to significant heat loss during roasting.

2. Radiative Heat Loss
These furnaces have openings for ash removal, which are often left uncovered. Operators manually remove hot ash from these openings, allowing much heat to escape.

3. Flue Gas Loss
The ash removal openings also allow excess air to enter the furnace, causing more heat to be lost through the flue gases. This inefficient combustion results in black smoke pouring out of chimneys, further polluting the environment.

4. Inappropriate Fuel Choices
Many poha manufacturers opt for cheap, locally available biomass fuels like rice husk, sawdust, and wood. While these fuels are affordable, their high moisture and ash content make them inefficient, leading to more fuel being burned to maintain the required temperature. It not only increases pollution but also raises monthly fuel costs.

5. Manual Operation of Furnaces
Plant operators often rely on manual judgment to control furnace temperatures by inspecting the combustion chamber through an open hole. This manual process is far from precise and frequently leads to over or under-feeding the furnace with fuel. The result? Unstable temperatures that affect both poha quality and emissions.