 2 is the most marketable product and Pressure Swing Adsorption ( PSA ) purification systems work better at higher pressures . The product mixture is known as " synthesis gas " because it is often used directly for the production of methanol and related compounds . Hydrocarbons other than methane can be used to produce synthesis gas with varying product ratios . One of the many complications to this highly optimized technology is the formation of coke or carbon : 
