煤制油与煤气化制甲醇技术的比较与选择

煤炭液化制油技术投资大、煤耗高、耗水多、污染严重,以目前的技术水平,生产1t油往往需要4～5t煤,折算其热能利用率为50%,若按南非的煤耗（6t）计,其热能利用率仅为33.3%。改用煤炭气化制甲醇技术,采用6MPa纯氧高压气化制合成气（CO＋H2）,合成气可产双倍的甲醇,则1t甲醇的煤耗仅为1.3～1.5t,甲醇用作汽车发动机燃料时,以1.3～1.5t甲醇相当于1t汽油作功计算,则煤炭的热能利用率可以达到66%～76%。如果配套水电解制氢技术,还可以实现CO2的零排放。中国每年有20×10^8t的煤炭产量,如果将其中的12×10^8t纳入煤炭气化制甲醇产业链,可每年创造产值约2.67万亿元,可减排CO2约30×10^8t。

Comparison between Coal Liquefaction and Coal-to-methanol Technologies and Selection

Coal liquefaction has many disadvantages such as large investment,high coal and water consump tion and serious pollution.With technologies currently available,the production of It of oil typically requires 4-5t of coal,equivalent to a heat utilization rate of 50%.If calculated using South Africa＇s conversion efficiency of 6t of coal for It of oil,the heat utilization rate is only 33.3%.If using coal gasification technology to produce methanol,in which pure oxygen is used to produce syngas（CO＋H2） under a pressure of 6MPa,the syngas produced in the process could produce twice as much methanol and producing It of methanol requires only 1.3-1.5t of coal.When methanol is used as auto fuel,assuming 1.3-1.5t of methanol does the same amount of work as It of gasoline does the heat utilization rate of coal is 66%-76%.If water electrolysis hydrogen production technology is adopted,no CO2 would be emitted.China produces 20×10^8t of coal annually.If 12×10^8t of coal is gasified to produce methanol,annual output value could reach around 2.67 trillion yuan and CO2 emissions could drop by about 30×10^8t.