Coal-to-oil vs. methanol fuel: Who do you favor?

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Coal-to-oil vs. methanol fuel: Who do you favor? Author/Source: Date: 2016-07-27 Clicks: 12 I. Comparison of Process Routes Indirect coal liquefaction for oil production: First, the raw coal is reacted with oxygen and steam to gasify it completely; the resulting crude gas is then processed through shift reaction, desulfurization, and decarburization to produce clean syngas (CO+H2). This syngas enters a synthesis reactor, where, under certain temperature, pressure conditions and in the presence of catalysts, H2 and CO are converted into straight-chain hydrocarbons, water, and small amounts of oxygen-containing organic compounds. The product is subjected to three-phase separation, with the aqueous phase being used to extract chemicals such as alcohols, ketones, and aldehydes ； The oil phase is processed using conventional petroleum refining methods such as atmospheric and vacuum distillation; the desired product fractions are separated from it, and further processing steps such as hydrorefining, hydrodewaxing, catalytic reforming, and hydrocracking are carried out to obtain qualified oil products or intermediate products ； The gas phase is subjected to cryogenic separation and olefin conversion to yield LPG, polymer-grade propylene, polymer-grade ethylene, and medium calorific value fuel gas. Coal-to-methanol for producing high-purity fuels: Raw coal is converted into water-coal slurry, which then reacts with oxygen and steam to gasify the coal completely. Energy is recovered efficiently to generate heat and electricity. The resulting raw gas is processed through conversion, desulfurization, and decarburization to produce clean syngas (CO+H2), which is then fed into a synthesizer to be converted into methanol. Methanol is further processed in a mixed-bed reactor to yield high-purity fuels with high efficiency and selectivity, while heat is recovered once again. The essential difference between the two is as follows: first, the utilization of matter and energy differs; the former has a low energy utilization rate, while the latter can not only make full use of energy but also recover water. Second, the Fischer-Tropsch synthesis route of the former has a long process sequence, low selectivity, and many by-products. II. Comparison of investment costs: Indirect coal liquefaction for oil production: Based on recent media reports regarding Shenhua Ningmei’s investment, 55 billion yuan was invested to produce 4 million tons of oil products, with the by-products accounting for no less than one-third of that amount. Coal-to-methanol for high-clean fuels: 4 million tons of methanol are used to produce high-clean fuels, with almost no by-products. The investment required is 8 billion yuan. To produce 4 million tons of such fuels, 10 million tons of methanol are needed, and the investment for 10 million tons of methanol is 40 billion yuan. III. Comparison of investment returns: Since coal indirect liquefaction produces oil primarily in the form of heavy-duty diesel, while the light components are mainly liquefied gas. Methanol-based high-clean fuel is essentially equivalent to National V 95 gasoline. Therefore, with the same 4 million tons of fuel, producing highly clean fuels from methanol is much more efficient. IV. Comparison of environmental impacts: The new system for producing high-purity clean fuels from coal via methanol synthesis adheres to principles of efficient use of materials and energy, as well as cleanliness and low carbon emissions, whereas indirect coal liquefaction fails to take energy utilization into sufficient account. V. Comparison in terms of consumption: For oil production through the indirect liquefaction of coal (including by-products such as gas), reports indicate that 4–5 tons of standard coal are required per ton of oil produced, with an overall energy efficiency of 44%–47%. In practice, the new system for producing high-purity fuels from coal methanol reaches around 80%.