Diesel from gas and coal

---

A Fischer Tropsch plant in China

Rezwan Amin Khan
The technology will allow Bangladesh to produce diesel out of natural gas or coal. There would be no need to import crude oil. The technology would help save expenditure on fuel imports and better utilise the country's natural gas and coal reserves.
The Fischer Tropsch Process, developed by Germany during the Second World War, was recently put into commercial use to solve global crude shortage. Small-scale Fischer Tropsch plants, set up recently, could be used to exploit remote and small gas reserves, previously considered uneconomic to develop.
Shell operates a commercial plant in Malaysia to produce low-sulphur diesel and naptha out of natural gas. Shell is building a large plant in Qatar. In South Africa, a plant of SASOL uses coal as feedstock to produce diesel and a number of chemicals. Besides, there are a number of small-scale commercial demonstration plants around the world.
The World War-time German technology staged a comeback a decade ago to make direct conversion possible. First, coal or natural gas is burned in a controlled way to generate syngas, a mixture of carbon mono oxide and hydrogen. Syngas is converted to diesel in the next step. It is done at a heat of 250 degree C in the presence of a suitable catalyst such as Nickel or Fe.
Called Fischer Tropsch fuel or synthetic fuel, the fuel produced is much cleaner in terms of emissions. In quality, the fuel is considered much better than ultra-low sulphur diesel.
An advantage of the newly upgraded technology is that it converts natural gas to diesel using a very small plant at the gas field. The liquid fuel is more convenient and economic to transport than natural gas, which requires pipelines. The technology could possibly be used to make unprofitable gas fields like Begumganj and Semutang commercially profitable. It could cut down the cost of gas supply by making pipelines unnecessary. It could be particularly useful for the small gas fields in remote areas of the country. The new technology has the potential to revolutionise the country's gas sector.
The technology can convert coal of Bangladesh into diesel. The Barapukuria colliery has an estimated reserve of 1.0 million tons.
The technology would enable the government to overcome Bangladesh's energy shortage.
(The writer, who served international oil and gas companies, is now a researcher with the Petroleum Division of CSIRO, an Australian National Research Organisation, can be reached at e-mail: rezwanakbd@yahoo.com)