Production cost of methanol from abundant and cheap coke oven gas (COG) is about 800—1000 CNY·t-1 lower than that from coal or natural gas. With expansion of international methanol production capacity and production scale

methanol market competition becomes more intense and cost advantage of coke oven gas to methanol is reduced evidently. It is significant to improve technology and extend industrial chains to use coke oven gas and obtain maximal benefits on the basis of coke oven gas to methanol production. One technical solution is combining coke oven gas with coal gasified gas (CGG) to produce methanol. CH4/CO2 reforming technology is used to convert CO2 + CH4 into H2+CO

and adjust H2/CO ratio of syngas in this scheme. With this scheme

methanol production can increase by 30%. Another option is to extend methanol industrial chain to obtain high-value-added downstream products

such as vinyl acetate

polyvinyl alcohol

and 1

4-butanediol. In this design

CH4 is separated from COG to make acetylene

which is used to synthesize methanol downstream products by methane partial oxidation technology. However

0.07 billion m3 H2 surplus and small scale of methanol production are the disadvantage of this design. Concerning scale effect and industrial chain extension simultaneously

to make full use of the unused H2 resource

dual-gas (COG and CGG)-acetylene-methanol system is proposed based on the above scheme. In this solution

an appropriate proportion of the CGG is supplied to mix with surplus H2 to obtain syngas with H2:CO = 2:1

which is used to synthesize methanol. With the scale of 2 million ton coke per year

gross profits of the above three systems are 2.421

1.892 and 2.874 billion CNY

respectively

and the internal rates of return for these schemes are 28.29%

24.34% and 27.11% accordingly. The dual-gas-acetylene-methanol system is found to be the highest profitable system. Meanwhile

dual-gas-acetylene-methanol system is highly flexible; methanol and methanol downstream product production

as well as production technology can be adjusted according to market requirement

production capacity and resource distribution.