By V. M. Kulkarni November 10 – 13, 2012 6 th International Sugar Conference Aswan, Egypt

1. Spent wash Treatment to Reduce Pollution and to earn profits to help sugar industry & in particular fermentation industry to totally avoid Pollution By V. M. Kulkarni November 10 – 13, 2012 6th International Sugar Conference Aswan, Egypt

2. Spent wash facts in India • India has more than 550 sugar factories • Crushing about 160 – 220 million tones cane • Produces about 15 – 24 million tones sugar • Or produces 6.4 – 8.8 million MT pressed mud • Or 7.2 – 10 million MT molasses • Average cane crushing is about 120 – 180 days • Distilleries operate for about 250 – 300 days VM BIOTECH, Pune, INDIA

3. Spent wash facts in India • There are more than 250 distilleries attached to sugar mills • Capacity varies 30, 45, 60 and 90 KLPD alcohol • The average capacity can be 50 KLPD • Thus average spent wash production would be 600 m3 per day • Or 2 million m3 spent wash per year considering only 200 days of operation consuming 1.4 million MT molasses only! VM BIOTECH, Pune, INDIA

4. Spent wash facts in India • There is plenty of molasses left untreated • In other wards there is potential to increase alcohol production by at least 7 times! • The greatest limiting factor that hinders the growth of alcohol industry is POLLUTION! • And there is no economically viable SOLUTION for this POLLUTION • This is not limited to India only; it’s a Global Problem without appropriate solution VM BIOTECH, Pune, INDIA

5. Spent wash facts …. • COD - 110000 - 120000 mg/lit • BOD - 55000 - 60000 mg/lit • Highly toxic. • It is an Environmental hazard. • Very difficult to treat. • Globally no one has come closer to solve the menace, economically. VM BIOTECH, Pune, INDIA

6. Present treatment(?) process.. • Biomethanation to produce biogas. • Outlet of treated spent wash has following properties: • COD - 30000 - 35000 mg/lit • BOD - 5000 - 8000 mg/lit • Total solids 45000 mg/lit • Color 750000 IU • This is further taken for evaporation! VM BIOTECH, Pune, INDIA

7. Why Evaporation? • spraying spent wash to pressed mud for composting is allowed by pollution control board and is found to be the legal way to dispose spent wash. • One factory, as an example produces 45000 MT pressed mud by crushing about 10 lac MT cane • It has 60 KLPD distillery producing 800 m3 spent wash per day for 300 days! • 1kg pressed mud can absorb 2.5 liter spent wash, thus volume must be reduced to less than 200 m3 from 800 m3 per day VM BIOTECH, Pune, INDIA

8. Present process,unsolved issues: • The problem of color is not solved, in fact it is aggravated by concentration • Such compost, when used in the field, is likely to leach the color contaminating water bodies • Huge amount of precious energy is wasted for concentrating the problem • Spent wash is highly corrosive; equipment used for concentrating will have to be replaced in few years VM BIOTECH, Pune, INDIA

9. VM Biotech technology for spent wash • Spent wash after treating in biogas digester is feed to this Novel system. • The technology will produce water with parameters as follows.. • COD less than 10000 mg/lit • BOD less than 1000 mg/lit • Color less than 100 000 IU (Transparent yellow to brown/red) • And 0.3% solids having about 3100 calorific value VM BIOTECH, Pune, INDIA

11. VM BIOTECH, Pune, INDIA

12. VM Biotech technology for spent wash • Treated spent wash can be safely used for composting pressed mud that can absorb about 8 – 10 liter treated spent wash per kg pressed mud • Thus entire quantity of treated spent wash is used for composting, no evaporation. • The composting will be complete as there are no inhibitors present and will be of International standard and can be sold at more than INR 8000 per MT VM BIOTECH, Pune, INDIA

13. VM Biotech technology for spent wash • Capital cost to treat 800 m3 spent wash is about INR 3.80 Cr • Cost of treatment of entire spent wash for year is about INR 2.40 Cr • Color problem solved completely • No evaporation, thus Saves more than INR 20 Cr per year • Separated solid can generate 4 MW Power every day • High Quality compost is bonus! VM BIOTECH, Pune, INDIA

14. VM BIOTECH Technology .. Advantages. • Most enviro-friendly treatment process. • Low cost, yielding huge profits! • No water pollution from distillery • No evaporation, saves about INR 20 Cr • Good grade of treated water output. • It can be directly used for making international grade compost fertilizer. • Problem of color solved completely. • The process generates significant profit to treat pollution! VM BIOTECH, Pune, INDIA

15. VM Biotech technology, flexibility • Treated spent wash can be concentrated using MEV or RO system to recover water • Finally solids, rich in potash can be recovered as value added product • Or concentrated liquid can be used for composting VM BIOTECH, Pune, INDIA