0086-138 3838 9622Osaka’s morning tofu production starts before dawn, the steam rising from cooking vats as soybeans transform into milk and then curds. By mid-morning, the okara—soy pulp—accumulates in bins, a byproduct that historically went to animal feed or disposal. Now some of it goes to cat litter.
Market Background
Japan’s pet market has evolved rapidly. Pet owners, particularly cat owners, seek products that are convenient, effective, and environmentally responsible. Traditional clay litter requires mining, produces dust, and fills landfills. Tofu-based litter offers an alternative: biodegradable, flushable, and made from a renewable resource.
The okara feedstock is abundant in Japan, where tofu consumption remains high. It’s food-grade material, clean and consistent, with properties that make it suitable for litter after processing.
Raw Material and Processing Challenges
Fresh okara contains 70 to 80 percent moisture—far too wet for direct pelleting. It spoils quickly without preservation. And its protein and fiber content affect how it absorbs moisture and controls odor.
The process must address all these factors. Drying reduces moisture to pelletizing range. Additives control odor and improve absorption. And the pellet mill must form durable pellets without over-compressing the material—over-compression reduces absorbency and makes pellets too hard for cats to cover.
Production Line Design
The Osaka line incorporates lessons from previous installations:
- Raw material receiving and pre-mixing with additives and preservatives
- Hammer mill for particle size adjustment
- Rotary dryer with temperature control to prevent protein degradation
- Pellet mill with specialized die for soft-but-durable pellets
- Counterflow cooler for gentle temperature reduction
- Screening system for fines removal
- Automatic bagging with dust control
The cat litter pellet machine uses dies with compression ratios specific to soy-based materials—different from paper or wood because the protein and fiber content affect binding.
Installation and Timeline
Mechanical assembly at the Osaka site is complete. Electrical integration continues, with commissioning scheduled for March. The customer plans initial production focused on the domestic Japanese market, where tofu litter commands premium prices.
Environmental and Market Benefits
For the tofu manufacturers supplying okara, the plant provides a disposal channel for a material that has low value. For the litter producer, it creates a product with growing demand. For Japanese cat owners, it offers a litter option that reduces environmental impact compared to clay.
For RICHI, the project demonstrates adaptation to yet another specialized feedstock—the kind of application-specific engineering that distinguishes the company from competitors offering standardized solutions.
