Odour Control in Starch Processing Plants: A Practical Guide

Starch processing plants smell because their by-products release foul gases (like a rotten-egg hydrogen sulfide smell and sharp ammonia) during processes such as steeping, drying, and wastewater treatment. These gases come from decomposing organic material and chemicals used in production, creating the sour or "rotten egg" odours around starch factories.

Odour control in starch processing plants is the practice of capturing and treating the foul air emissions from starch production so that bad smells are neutralized before they can affect workers or nearby communities. It involves engineering systems to contain smelly gases and technologies to scrub or break down those odorous compounds.

Odour control in starch processing plants is important because it prevents constant bad smells from bothering nearby residents and workers. By controlling odours, a plant maintains community trust, complies with environmental regulations (avoiding fines or shutdowns), ensures a more comfortable workplace, and protects its reputation from being known as a polluter.

The first step is to capture the odour at its source. This means enclosing smelly tanks and wastewater lagoons, installing hoods and ducts over odor-producing equipment like dryers, and keeping certain areas under negative air pressure. By sealing and capturing odorous air before it escapes, the plant can then direct these collected gases to treatment systems.

Odour control in starch processing plants typically uses a combination of proven technologies. Common solutions include wet scrubbers (which use chemicals or water to neutralize acidic gases and ammonia), biofilters or biotrickling filters (which use microbes to consume and break down odorous compounds), activated carbon filters (to adsorb any remaining smell-causing molecules), and thermal oxidisers (which burn off volatile organic compounds from dryers at high temperatures). Often, multiple technologies are combined for the best result.

Starch plants can reduce wastewater odours by covering or enclosing their wastewater lagoons and tanks so the smelly gases are trapped and treated instead of vented to the open air. Many plants use anaerobic digestion (sealed tanks that break down waste without oxygen) to prevent odour formation and even capture biogas for energy. Improving the wastewater treatment process with proper aeration, pH control, and equalization tanks (to avoid sudden surges of waste) also helps prevent the formation of foul-smelling compounds in the first place.

The typical odorous gases from starch processing include hydrogen sulfide (H₂S) – which gives a rotten egg smell, ammonia (NH₃) – a sharp, pungent odour that can irritate, sulfur dioxide (SO₂) – an acidic, burnt-match smell from corn steeping, and various volatile organic compounds (VOCs) (like aldehydes and amines) that add sour or pungent notes. Even at low concentrations, these substances can be very noticeable and unpleasant.

Starch processing plants monitor odour by using gas sensors and detectors around the facility. These sensors continuously check for specific gases like H₂S, NH₃, and SO₂, as well as overall VOC levels. Many plants also set up fence-line monitoring stations at the property boundary to detect any odours leaving the site. Additionally, regular odour surveys or inspections are conducted. All this data helps operators ensure their odour control systems are working and that they remain in compliance with environmental odour limits.

Effective odour control in starch processing plants drastically reduces foul smells (often by over 90% with the right systems in place). This leads to fewer complaints from neighbors and a better relationship with the community. It also ensures the plant meets environmental regulations, avoiding fines or forced shutdowns. In some cases, odour control improvements (like anaerobic digestion of waste) even allow the plant to generate renewable energy from captured biogas. Overall, investing in good odour control means a safer, more sustainable operation and an improved public image for the plant.

Amalgam Biotech specializes in custom odour control solutions for starch processing plants. They design and implement systems that combine technologies like wet scrubbers, biofilters/biotrickling filters, activated carbon units, and chemical treatments tailored to a plant’s specific sources of odour. By taking a comprehensive approach – including improving on-site wastewater treatment and capturing all odorous emissions – Amalgam Biotech helps starch factories effectively eliminate bad smells and stay compliant with regulations, all while keeping the operation running smoothly.