Sim Eng Tong
Biomax founder Sim Eng Tong, posed near a Biomax aerobic digestion unit.
Photo courtesy of Biomax and Coco PR Agency.

Time may be right for more aerobics

The founder of an aerobic digestion technology firm says a global fertilizer shortage has drawn the world’s attention to the waste treatment technique.


The side effects of Russia’s invasion of Ukraine have been numerous in the commodities market, and among them has been a global shortage of fertilizer.

With a key fertilizer ingredient produced in Ukraine (and shipments from Russia off-limits in much of the world) there has been a scramble to seek new sources of fertilizer.

Sim Eng Tong, the founder and CEO of Singapore-based Biomax, says the aerobic digestion waste treatment technology made by his firm is playing a role in that hectic market. In early May, he answered several questions from Waste Today Senior Editor Brian Taylor about his company’s role in the fast-paced market.

Waste Today (WT): What types of materials are the best candidates for aerobic digestion?

Sim Eng Tong (SET): Organic wastes such as human feces, all animal feces, food waste—which includes expired food and waste from food processing plants—sludge and biodegradable plastic products are the best candidates for aerobic digestion. Any other organic wastes would also be good candidates for this process.

WT: What end products will result from the process?

SET: Biomax has developed a breakthrough technology that converts organic wastes into 100 percent premium grade organic fertilizer at a high temperature (80 to 85 degrees Celsius, or 175 to 185 degrees Fahrenheit) within 24 hours. The technology, called the Rapid Thermophilic Digestion System, is the fastest process so far in the organic waste treatment industry. Based in Singapore, we are highly committed in our research and development [of] various enzyme-based solutions to support sustainable business operations. The end products (the output) will be a high-nutrient organic fertilizer, virus-free and with no foul odor.

WT: Why might an economy where fertilizer has become in short supply aid the spread of aerobic digestion technology? How long does it take to install a new system?

SET: Our breakthrough technology allows the organic waste to be converted to organic fertilizers in just 24 hours with a high temperature of 175 to 185 degrees Fahrenheit to kill off viruses and bacteria present in the organic waste.

Our digester machines do not use up too much space. In just 24 hours, a small digester can produce an output of 10 metric tons of organic fertilizers. Whereas a big digester can produce an output of 35 metric tons of organic fertilizers.

 With our technology, we are confident that we are able to meet the supply for the shortage in demand.


The installation of the digester only takes five days upon the machine’s arrival at the client’s end, and thereafter it can officially start to operate.

WT: How would you describe current aerobic digestion capacity (globally), and how much potential for growth is there?

SET: Based on Biomax’s growth in the past 10 years, personally I feel the idea of going green has been rapidly spreading globally in recent years. First off, here in Singapore, the government is encouraging the green movement and starting to educate the public on how to convert waste into useful resources.

Our company also collaborated with many overseas companies that have come forth to Biomax to further understand our technology and how we can potentially aid them in the process of waste conversion.

Based on my own personal views, the growth and market for our technology will be fast growing and it will continue this way for a long time. Additionally, considering how many are starting to see the issue with existing waste management methods such as landfills—which are overflowing and have high carbon emissions—and incineration—which is extremely harmful for the environment and also releases high carbon emissions—we foresee that in the future more countries will be made aware of the waste problems and will be looking into resolving it by tapping into biotechnological methods such as aerobic digestion. 

WT: What is the timeframe of the aerobic digestion process [materials in/end products out], and how does it differ from anaerobic digestion or other treatment methods?

SET: The timeframe for our whole process of converting organic waste (input) into organic fertilizers (output) will be 24 hours.

The process will be a one-input and one-output system, with a high processing temperature of 175 to 185 degrees Fahrenheit to kill off the bacteria and viruses present in the waste.

For an input of 15 metric tons of organic waste, you simply add 15 kilograms (33 pounds) of our BM1 enzymes to break down wastes such as animal bones, lamb heads, chicken corpses, etc. For a 15 metric ton input, the output will be approximately 70 percent of the input, which is about 10 to 10.5 metric tons of organic fertilizers.

The output will be hot, so once it is cooled down, it can be packaged and sold on the market.

Biomax’s treatment process differs from other treatments as we depend on our BM1 enzymes to break down the wastes (again, such as animal bones, lamb heads and chicken corpses). There is no further crushing or grinding needed, as our BM1 enzymes will be able to break down the waste as it is.

Both aerobic and anaerobic digestion are methods of processing biodegradable materials, mainly organic waste and involves the process of decomposition by biological organisms.

Aerobic digestion occurs in the presence of oxygen and can be a batch-fed process (to input waste only once, and the moisture requirement is 40 percent. Anaerobic digestion occurs in the absence of oxygen, and it is a continuous-fed process (to input waste material from time to time) and the moisture requirement is 100 percent.

Aerobic digestion produces compost, water, volatilized gas (ammonia, carbon dioxide) and the end product is called compost. Whereas anaerobic digestion produces digestate, biogas (methane, carbon dioxide and hydrogen sulfide). The end product is called digestate.

Aerobic digestion also has a shorter process (often eight to 10 days), but Biomax’s process is way faster with just 24 hours, as our aerobic digestion happens in a controlled environment (in-vessel). The breakdown process is also simpler, involving hydrolysis. Heat generated in the process is also sufficient to kill pathogens.

Anaerobic digestion has a longer processing time (it can be from 60 to 90 days), with a complex breakdown process involving hydrolysis, acidogenesis and acetogenesis. Heat generated in the process is not [always] sufficient to kill pathogens.

WT: At what stage in the process should a company like Biomax be consulted by a government or company considering aerobic digestion?

SET: In addition to the technological capabilities of our technology, for companies like Biomax to be consulted, we would require more data and feedback from our users to generate proven track records as good reference points for government bodies or companies who are considering aerobic digestion as a waste management method. On this note, I hope that more countries can be made aware and start using our technology internationally to create a greener planet such that this cyclical process can be kick-started.