METHANOL CHAIN AUTHORED BY MICHAEL SUMEY STEFAN WIERSGALLA

METHANOL CHAIN AUTHORED BY: MICHAEL SUMEY & STEFAN WIERSGALLA

HISTORY & OVERVIEW • THE FIRST USE OF METHANOL WAS IN THE ANCIENT EGYPTIAN EMBALMING PROCESS. IT WAS PRODUCED PRIMARILY FROM THE DESTRUCTIVE DISTILLATION OF WOOD WHICH IS WHY METHANOL IS FREQUENTLY CALLED WOOD ALCOHOL. • METHANOL IS A POLAR LIQUID AT ROOM TEMPERATURE THAT IS COLORLESS, VOLATILE, FLAMMABLE, AND POISONOUS. ITS PRINCIPAL USES ARE IN FUELS, ORGANIC SYNTHESIS, SOLVENTS, AND ANTIFREEZE. • PURE METHANOL WASN’T ISOLATED UNTIL 1661 BY ROBERT BOYLE. THE FRENCH CHEMISTS JEAN-BAPTISTE DUMAS AND EUGENE PELIGOT DETERMINED ITS ELEMENTAL COMPOSITION IN 1834. • IN 1923, THE GERMAN CHEMISTS ALWIN MITTASCH AND MATHIAS PIER DEVELOPED A MEANS TO CONVERT A MIXTURE OF CARBON MONOXIDE, CARBON DIOXIDE, AND HYDROGEN INTO METHANOL. THE FIRST NOTED PATENT WAS FILED 12 JANUARY 1926. • IN 1970 S MONSANTO INTRODUCED ACETIC ACID PROCESSED BY METHANOCARBOXYLATION AND MOBIL INTRODUCED METHANOL TO GASOLINE SYNTHESES. • IN 2006 ASTRONOMERS USING THE MERLIN ARRAY OF RADIO TELESCOPES, DISCOVERED A LARGE CLOUD OF METHANOL IN SPACE, 300 BILLION MILES ACROSS.

PRECURSORS • NATURAL GAS IS THE MOST ECONOMICAL AND WIDELY USED FEEDSTOCK FOR METHANOL PRODUCTION. HOWEVER, COAL IS INCREASING IN POPULARITY AS A FEEDSTOCK FOR METHANOL PRODUCTION IN CHINA. • CURRENTLY THREE METHODS ARE COMMONLY USED TO PRODUCE THE PRECURSOR SYNTHESIS GAS FROM THE METHANE COMPONENT IN NATURAL GAS. THE METHODS ARE STEAM-METHANE, PARTIAL OXIDATION WITH MOLECULAR OXYGEN, AND A COMBINATION OF THE TWO, AUTOTHERMAL REFORMING. (THECHEMCO) • ORIGINALLY ONE-STEP REFORMING WAS THE MOST POPULAR INDUSTRIAL SYNTHESIS OF METHANOL USING SYNTHESIS GAS. THIS TECHNIQUE OF METHANOL MANUFACTURING WOULD EMIT ABOUT 1 METRIC TON OF CARBON DIOXIDE FOR EVERY TON OF METHANOL PRODUCED. NEW TECHNOLOGIES HAVE BEEN IMPLEMENTED THAT HAVE REDUCED CO 2 EMISSIONS. (METHANOL INSTITUTE) • IN MANY PLANTS TODAY EITHER TUBULAR STEAM REFORMING OR TWO-STEP REFORMING IS USED FOR THE PRODUCTION OF SYNTHESIS GAS. HOWEVER, STAND-ALONE AUTOTHERMAL REFORMING AT A LOW STEAM TO CARBON RATIO IS THE PREFERRED TECHNOLOGY. • CATALYSTS SUCH AS COPPER OXIDE ARE CAPABLE OF OPERATING AT LOWER TEMPERATURES AND ARE USED TO EFFICIENTLY PRODUCE MODERN METHANOL. (LIU) • THE SYNTHESIS GAS PREPARATION AND COMPRESSION TYPICALLY ACCOUNTS FOR ABOUT 60% OF THE INVESTMENT, AND ALMOST ALL ENERGY IS CONSUMED IN THIS PROCESS. (LIU)

INDUSTRIAL CHEMISTRY One-step reforming: synthesis gas is produced by tubular steam reforming alone (without the use of oxygen). It is primarily used where CO 2 is contained in the natural gas or available at low cost from other sources. Even though less popular a methanol plant based on CO 2 reforming was started up in Iran in 2004 CO 2 + 3 H 2 → CH 3 OH + H 2 O (-ΔH 298 K, 50 Bar = 40. 9 k. J/mol) . Two-step reforming: is the process of a combination of fired tubular reforming (primary reforming) followed by oxygen-fired adiabatic reforming (secondary reforming). The primary reforming produces excess H 2 while secondary reforming has can use the excess hydrogen during combustion during its reforming. The combination of the two types of reforming create a energy efficient creation of synthesis gas. CO 2 + H 2 → CO + H 2 O CO + 2 H 2 → CH 3 OH Figure 1: Methanol production by two-step reforming. (-ΔH 298 K, 50 Bar = 90. 7 k. J/mol)

INDUSTRIAL CHEMISTRY CONT’D AUTOTHERMAL REFORMING (ATR). ATR IS A STAND-ALONE, OXYGEN-FIRED REFORMER. THE AUTOTHERMAL REFORMER DESIGN INCLUDES A BURNER, A COMBUSTION ZONE, AND A CATALYST BED IN A REFRACTORY LINED PRESSURE VESSEL. THE BURNER MIXES THE FEED AND THE OXIDANT. IN THE COMBUSTION ZONE, THE FEED AND OXYGEN COMBUST. THE CATALYST BED BRINGS THE STEAM REFORMING AND SHIFT CONVERSION REACTIONS TO EQUILIBRIUM IN THE SYNTHESIS GAS. BY ADJUSTING LOW STEAM TO CARBON RATIOS, ATR PLANTS CAN RUN SIMILAR TO A TWO-STEP REFORMING PLANT BUT WITH A SINGLE INCOMING STREAM Figure 3. Autothermal Reformer (Aasberg-Petersen) Figure 2: Methanol production by ATR. (Aasberg-Petersen)

SYNTHESIS OF METHANOL CO 2 + 3 H 2 → CH 3 OH + H 2 O CO + 2 H 2 → CH 3 OH (-ΔH 298 K, 50 BAR = 40. 9 KJ/MOL) (-ΔH 298 K, 50 BAR = 90. 7 KJ/MOL) • QUENCH REACTOR: CONSISTS OF A NUMBER OF ADIABATC CATALYST BEDS INSTALLED IN A SERIES IN ONE PRESSURE SHELL. UP TO FIVE CATALYST BEDS HAVE BEEN USED. THE REACTOR IS SPLIT INTO SEVERAL FRACTIONS AND DISTRIBUTED TO THE SYNTHESIS REACTOR BETWEEN THE INDIVIDUAL CATALYST BEDS. THE QUENCH REACTOR DESIGN TODAY IS CONSIDERED OBSOLETE AND NOT SUITABLE FOR LARGE CAPACITY PLANTS. • ADIABATIC REACTORS: NORMALLY COMPRISES OF FIXED BED REACTORS PLACED IN SERIES WITH COOLING BETWEEN THE REACTORS. THE ADIABATIC REACTOR SYSTEM FEATURES GOOD ECONOMY OF SCALE. MECHANICAL SIMPLICITY CONTRIBUTES TO LOW INVESTMENT COST. • BOILING WATER REACTORS: IN PRINCIPLE IS A SHELL AND TUBE HEAT EXCHANGER WITH CATALYST ON THE TUBE SIDE. THE ISOTHERMAL NATURE OF THE BWR GIVES A HIGH CONVERSION COMPARED TO THE AMOUNT OF CATALYST INSTALLED. TO ENSURE A PROPER REACTION RATE THE REACTOR WILL OPERATE AT INTERMEDIATE TEMPERATURES. COMPLEX MECHANICAL DESIGN OF THE BWR RESULTS IN RELATIVELY HIGH INVESTMENT COST AND LIMITS THE MAXIMUM SIZE OF THE REACTORS. • THE METHANOL SYNTHESIS IS EXOTHERMIC AND THE MAXIMUM CONVERSION IS OBTAINED AT LOW TEMPERATURE AND HIGH PRESSURE. A SELECTIVITY OF 99. 9% IS NOT UNCOMMON WHEN THE RIGHT TEMPERATURE, PRESSURE, AND CATALYST ARE USED. (AASBERG-PETERSEN)

USES OF METHANOL • PRIMARILY USED AS FEEDSTOCK • FORMALDEYDE • MTBE METYL TERT-BUTYL ETHER • ACETIC ACID • DME DIMETHYL ETHER • OLEFINS • VERY “GREEN” AND INEXPENSIVE ENERGY SOURCE • OCTANE RATING OF 108. 7 (EYIDOGAN, 2010) • WATER DENITRIFICATION • TRANSESTERIFICATION PROCESS IN MAKING BIODIESEL FUEL

Fig. 4 Methanol Institute 2011

GLOBAL MENTHOL DEMAND GROWTH Demand=55. 4 million metric tons Fig. 5 Johnson 2012 Demand=92. 3 million metric tons

Fig. 6 Methanol Institute 2011 Fig. 8. Johnson 2012 Fig. 7 Johnson 2012

SOURCES CITED • AASBERG-PETERSEN, K. (N. D. ). LARGE SCALE METHANOL PRODUCTION FROM NATURAL GAS. RETRIEVED FROM HTTP: //WWW. TOPSOE. COM/BUSINESS_AREAS/METHANOL/~/MEDIA/PDFFILES/METHANOL/TOPSOE_LAR GE_SCALE_METHANOL_PROD_PAPER. ASHX • THE CHEMICAL COMPANY. (2013). METHANOL OVERVIEW. RETRIEVED FROM HTTP: //WWW. THECHEMCO. COM/CHEMICAL/METHANOL/ • JOHNSON, D. (2012). GLOBAL METHANOL MARKET REVIEW. UNPUBLISHED MANUSCRIPT, RETRIEVED FROM HTTP: //WWW. PTQ. PEMEX. COM/PRODUCTOSYSERVICIOS/EVENTOSDESCARGAS/DOCUMENTS/FORO PEMEX PETROQUÍMICA/2012/PEMEX_DJOHNSON. PDF • EYIDOGAN, M. (2010). IMPACT OF ALCOHOL–GASOLINE FUEL BLENDS ON THE PERFORMANCE AND COMBUSTION CHARACTERISTICS OF AN SI ENGINE. FUEL, 89(10), • LIU, X. (2003). RECENT ADVANCES IN CATALYSTS FOR METHANOL SYNTHESIS VIA. IND. ENG. CHEM. RES. , 42, 65186530. RETRIEVED FROM HTTP: //PUBS. ACS. ORG/DOI/PDF/10. 1021/IE 020979 S • METHANEX. (2012). METHANEX-THE GLOBAL LEADER IN METHANOL PRODUCTION AND MARKETING. RETRIEVED FROMWWW. METHANEX. COM • METHANOL INSTITUTE. (2011). METHANOL INSTITUTE. RETRIEVED FROM WWW. METHANOL. ORG