Process Heating and Control for Hemp Drying and Hemp Oil Processing

Process Heating and Control for Hemp Drying and Hemp Oil Processing

Hemp is experiencing a renaissance in popularity due to increased demand for CBD oil and commercial items such as paper, textiles, clothing, biodegradable plastics, paint, insulation, biofuel, food, and animal feed. By 2025, the global industrial hemp market could be worth more than $10 billion. 

Hemp was legalized as part of the 2018 Farm Bill, transforming it from a controlled substance to an agricultural commodity. Farmers whose tariff increases have impacted certain crops find hemp cultivation appealing. Consumer demand, combined with higher farm profits, is driving explosive growth. Hemp cultivation occurs for seed, fiber, or floral biomass. 

After harvest, the hemp needs to be immediately transported to a drying facility to remove the moisture content. Hemp harvesting and drying are critical steps in CBD production. Molds and mildews associated with moisture reduce the value of floral hemp biomass, so the harvest needs stabilization before mold, mildew, or decomposition can occur. 

Air drying small batches of hemp in a barn makes sense despite its inefficiency and slowness, but more modern and systematic approaches to drying are required to meet consumer demand for large batches. New industrial dryers with capacities ranging from 1000 to 4000 pounds of biomass per hour and total drying control are available to meet this skyrocketing demand. 

Batch dryers have drying chambers that typically include a dehumidifier, an aerator, and a heat source. The energy-efficient dehydration systems for drying hemp are closed systems that operate independently of ambient conditions. Combining the heat-driven dehumidification unit, a programmable controller, and airflow equipment result in consistent drying conditions inside the chamber. 

Belt dryers include a conveyor that leads into a large drying chamber. Mesh-belt hemp dryers continuously dry large quantities of biomass in a short time without requiring a large production footprint. Belt dryers enable an operator to fine-tune the hemp dryer's thermal energy to evaporate moisture without over-drying or overheating the hemp. Belt dryers use propane or natural gas as their heat source with high BTU output. Belt dryers also use electronic controls for precise biomass drying and optimize combustion efficiency. 

Rotary dryers have been the workhorse of industrial dryers for many years. They also work well for drying hemp and typically use natural gas as their heat source. The biomass goes in a heated cylinder, which rotates and tumbles the material in the presence of hot, dry air. Plates on the inside of the cylinder, or drum, move the hemp through the drum, and sophisticated electronic combustion controls regulate temperature and time for the drying process.

Legacy custom oven and furnace manufacturers are finding a new, lucrative market for hemp dryers and hemp oil processing, considering the technology and fabrication process are nearly identical to the custom furnace and kiln development. Burners, controls, and gas valves are all standard components. A critical piece for success in developing a successful hemp drying strategy is to work closely with an expert in process heating, combustion, and control systems. Their breadth of experience and engineering skills will contribute to positive outcomes.

For expert advice on process heating and control systems specifically for hemp oil processing and hemp drying, contact Combustion Technology, LLC. Their experience in combustion optimization, thermal profiling, and temperature measurement is premier. They have equipment and instrumentation ready to provide the high-level performance required for the hemp processing industry, such as:

  • Wide turndown burners with precise temperature control. 
  • Modulating gas control valves with .1 of a degree positioning accuracy. 
  • Process controllers and indicators are accurate to .25% of span.
  • 508A listed electrical panels, NFPA 86 compliant
  • Secure digital recording of temperature and other critical variables for contract drying.

Headquartered in the Pacific Northwest, reach them by calling 800-327-1831 or visiting their website at