NTPC Ltd plans to set up a 5-10 million-tonnes-per-year coal-to-synthetic natural gas (SNG) facility, according to people familiar with the development. The state-owned power generating company, which is looking to diversify its portfolio, will appoint a technical consultant for drawing up the plan in the ongoing financial year, one of the people cited earlier said, adding that proposals from consultants would be invited soon. The award of the project work may start in the next financial year, the person said. Synthetic natural gas, or syngas, has many uses, including power generation and producing chemicals like methanol, ammonia and fertilisers.