Bioprocess Optimization for Enhanced Biogas Production from Grape Pulp Waste

India ranks as one of the largest producer of fruits and vegetables in the world. Grapes with an annual production of 2.48 million tonnes, is cultivated in an area of approximately 34, 000 hectares in India, of which approximately 30-35 % is wasted due to improper cold storage facilities, transportation, lack of appropriate post harvest technologies and damage caused due to pests and diseases. In the grape processing industry, the major product is grape juice. Huge quantities of grape pomace (grape pulp) is accumulated which cause environmental pollution. Since grapes are rich in nutrients, these can be channelized through biomethanogenic pathway for the production of value added products like biomethane. The grape pulp contains more of carbon and less of nitrogen, supplementation of urea improves the biogas production. Similarly, the effect of various metal ions had a positive effect in enhancing the biogas production. The unique combination of metal ions was found to be stimulatory in boosting the production of biogas from this abundant raw material.