Sensex Today | Stock Market LIVE Updates: Indraprastha Gas Limited (IGL), the nation's biggest city gas operator, is looking to set up as many as 19 compressed biogas plants in four states as part of its efforts to expand business beyond natural gas and embrace cleaner forms of energy. The firm has signed Memorandum of Understanding (MoU) with two technology partners to set up compressed biogas plants in Delhi, Haryana, Rajasthan and Uttar Pradesh, it said.