Context: India has become the top sugar producer globally, surpassing Brazil. It is also the second-largest sugar exporter. The growth of the ethanol biofuel sector has contributed to the improvement of the sugar industry and the financial well-being of sugar mills.
What is Pressmud?
- Pressmud, also referred to as filter cake or press cake, is a byproduct of sugar production that is derived from agricultural waste.
- This substance is obtained through the repetitive filtration process of cane juice prior to extracting sugar.
- On average, around 3-4 percent of press mud is generated per metric ton of crushed cane.
- Traditionally, pressmud is recycled and transformed into manure through composting, which is then distributed to local farmers for agricultural purposes.
- However, pressmud has also gained recognition as a valuable source of green energy.
- Specifically, it can be utilised to produce biogas through the process of anaerobic digestion, ultimately resulting in the creation of compressed biogas (CBG).
- This renewable energy source not only has environmental benefits but also serves as a rich source of micronutrients for crops and horticulture.
Difficulties associated with pressmud:
- There are two major concerns related to pressmud – storage issues and price increase.
- Firstly, pressmud has a tendency to decompose gradually, which poses challenges for its long-term storage.
- This decomposition process not only complicates the storage process but also leads to increased production costs.
- Secondly, due to the recognition of its potential benefits, there has been a significant surge in pressmud prices.
- This increase in demand has driven up the prices, making pressmud more expensive for consumers.
Using pressmud as a feedstock for CBG production:
- The utilisation of pressmud offers a solution to the difficulties often encountered in managing agricultural residue supply chains.
- In contrast to municipal solid waste, pressmud boasts a consistent quality and does not contain lignin, thereby reducing the expenses associated with pre-treatment.
- Moreover, when it comes to the production of CBG, pressmud proves to be a more efficient and cost-effective feedstock compared to cattle dung and other forms of agricultural residue.
- However, it is important to note that the rising cost of pressmud and the growing competition for its utilisation in fertilisers and bio-composting present considerable challenges.
India has various regional production and sugar mills scattered across the country:
- The two primary states in India that make significant contributions to the cultivation of sugarcane are Uttar Pradesh and Maharashtra.
- In terms of operational sugar mills, as of the 2022-23 period, India had a total of 531 mills actively functioning.
- Furthermore, during this time, the country produced a substantial amount of sugar, reaching 32.74 million tonnes, along with approximately 11.4 million tonnes of pressmud.
- The potential for generating CBG from the pressmud is considerable and can lead to significant economic gains.
- To fully utilise this potential, it is necessary for states to enact bioenergy policies, regulate pressmud prices, and establish enduring agreements with sugar mills.
- Additionally, it is vital to invest in research and training initiatives that focus on developing efficient storage technologies for pressmud and providing adequate training for CBG plant operators.