hrvatski

Prirodni plin – izvor petrokemijskih proizvoda i ekološki čistih kapljevitih goriva

Prirodni plin najviše se upotrebljava izravno kao energent, a manji dio, u obliku čistog metana, prevodi se u sintezni plin, smjesu ugljikovog monoksida i vodika, od kojega se zatim dobiva veliki broj petrokemijskih proizvoda, kao i kapljevita, ekološki prihvatljiva ugljikovodična motorna goriva (engl. gas-to-liquid, GTL). Takva se goriva proizvode procesima temeljenim na Fischer-Tropschovoj sintezi (FTS), pretežito dieselska goriva, ili pretvorbom sinteznog plina prvo u metanol, a zatim njegovom dehidratacijom u prisutnosti posebnih vrsta djelotvornih zeolitnih katalizatora izravno u benzinske ugljiko-vodike (engl. methanol-to-gasoline, MTG). U zadnje vrijeme u razvitku su i procesi izravne pretvorbe metana u metanol, kao i u olefinske i aromatske ugljikovodike (engl. methanol-to-olefine, MTO). U ovom preglednom radu, opisani su petrokemijski proizvodi na temelju prirodnog plina, kao i GTL, MTG i MTO procesi proizvodnje ekološki čistih kapljevitih goriva, prvenstveno benzina i dieselskog goriva, te njihov predvidivi razvitak u 21. stoljeću. / Extensive research efforts in the past two decades have been focused on the utilization of methane, a principal component of natural gas, as a source for ultra-clean transportation fuels. Most of the natural gas is currently being used directly as a source of energy, and a part of it, mostly as pure methane is converted to synthetic gas, a mixture of carbon monoxide and hydrogen. From syngas a number of petrochemical products and highly ecologically acceptable liquid fuels (gas-to-liquids, GTL), under the conditions of Fischer-Tropsch synthesis (FTS) can be produced. Two general processes producing synthetic gas: by catalytic steam reforming of methane or lower hydrocarbons and by partial oxidation of petroleum residues or coal (water gas). The capital cost of syngas plant based on methane is much lower than others, therefore is preferred process. The main petrochemical intermediate and products from syngas, besides hydrogen and carbon monoxide, are methanol, ammonia and their derivatives. Beside, FTS process the syngas could be converted to gasoline over methanol, so called MTG process, using a special type of zeolite catalyst. The hydrocarbons obtained are in the gasoline range. Two other potential large scale petrochemical products from methane via methanol under development, are olefin hydrocarbons as ethylene and propylene by oxidative coupling reaction, so called methanol-to-olefin (MTO) process, as well as direct conversion of methane to aromatics. In this paper, the review of current status and development predictions of FTS, GTL, MTG and MTO petrochemical processes and products have been presented.

prirodni plin; metan; Fischer-Tropschova sinteza; vodik; sintetička goriva; GTL procesi; MTG procesi

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