With continuous increase in the global population, the energy consumption has increased tremendously which has primarily increased our dependence on fossil fuels, in tum causing great environmental problems. Depleting fossil fuels reserves and increased emission of toxic gases in our atmosphere is a big environmental hazard. Also in India, each year billions of dollars are spent for the import of these conventional fuels which further devaluates the currency there by causing a big setback to national economy.Biogas is an environment friendly fuel which has the capabilities to be used as fuel in future vehicles thereby, reducing the import of conventional fuels. The current biogas generation technologies available gives less yield in more days, with high percentage of impurities. The presence of incombustible gases such as CO2, H2S and water vapour reduces its calorific value and makes it difficult to transport and compress. Biogas with more than 90% methane can be obtained using processes like adsorption, absorption, cryogenic and membrane separation. Carbon emission between base CNG and purified biogas is the same.This review provides summary of biowaste materials like cattle dung, spoiled food, chicken manure, vegetable waste and rice husk. It has been seen that a substrate of Cow-Dung mixed with other biowastes like rice husk or vegetable peelings can satisfactorily achieve a yield hike of 44% under mesophilic(30–40 °C) condition with the pH of 4–7. Presence of certain catalyst like NaOH also positively affects the biogas generation. Biogas digesters fed with a substrate profile of 25% cow-dung and 75% food-waste give 80% higher yield within 10 days of loading with minimal impurities. Results of using this biogas mixed with CNG in engines is also elaborated.