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Methanol derivatives

4.2.1 Acetic acid

Acetic acid is a colorless liquid with a strong and pungent smell. It is also known as ethanoic acid or methanecarboxylic acid. Acetic acid can also be produced by bacterial fermentation but this route accounts for only about 10% of world production. Production of acetic acid employing biological processes has been known for over 10,000 years, as long as wine making has been practiced. Vinegar is an aqueous solution of acetic acid. Several aerobic and anaerobic processes have been practiced (Partin. 1993). For the synthetic production of acetic acid, there are three main methods: Acetaldehyde oxidation (Farming, 1993), hydrocarbon oxidation (hick, 1993). and methanol carbouylatiou (Zoeller, 1993). Of the three, due to favorable process economics, approximately 75% of the acetic acid is produced synthetically by carbonylation of methanol.

Paulik et al. (1968) at Monsanto disclosed a rhodium iodide catalyst system for methanol carbonylation that operates at a pressure of 30 to 60 atmospheres and temperature of 150-200 °C. This homogeneous liquid phase process employs an organometallic rhodium iodide complex as a catalyst. The process gives a selectivity of greater than 99% to acetic acid. The technology, known as the Monsanto Acetic Acid Process, has been the basis of all new acetic acid production worldwide. Several publications and patents describe the mechanism of the rhodium-catalyzed carbonylation reaction (Roth 1971), as well as a detailed process description, including a schematic plant design (Eby, 1983). Celanese practices a similar technology with some proprietary modifications. Monsanto granted rights to British Petroleum (BP). In 1996 BP introduced an iridium catalyst system for use in the BP Cativa Acetic Acid Process (Jones, 2000).

The main applications for acetic acid include the production of chemical compounds such as, vinyl acetate monomer (ЛАМ), purified terephthalic acid (PTA). acetate esters, acetic anhydride, and so on. Products of commercial importance made from acetic acid are latex emulsion resins for paints, adhesives, paper coatings, textile finishing agents, cellulose acetate fibers, cigarette filter tow, and cellulosic plastics.

The significant world acetic acid market growth is due to its extensive application in the production of vinyl acetate monomer (ЛАМ) and РТА. Л АМ, used in paints and adhesives, consumes approximately 40-45% of the world’s acetic acid production. PTA, on the other hand, uses acetic acid as a solvent and catalyst carrying agent in the oxidation of p-xylene to produce PTA. In the process some of the acetic acid is “burned” to CO, and H.O. The PTA is then used to manufacture polyethylene terephthalate (PET) fibers, resins and films, all of which have very high growth rates in consumer goods such as clothing, beverage containers and food packaging. Besides this, acetic acid is also used in the food industry and in household items as a preservative. Thus, the high demand for acetic acid in ЛАМ and PTA production, coupled with food industry applications, would bolster the acetic acid market growth. In terms of revenue in 2014, the global value of the acetic acid Market was calculated to be 9.1 billion U.S. dollars, and is projected to reach 13.8 billion U.S. dollars by 2022. In terms of volume, the market demand in 2014 for acetic acid was 12.1 million metric tons and is projected to reach 16.8 million tons by 2022. Companies such as DuPont, (BP), Celanese, and Eastman Chemicals dominate the market.

4.2.2 Formaldehyde

Formaldehyde is an intermediate, used in the manufacture of a wide range of products. More than 60% of it is used in the production of resins, such as urea-formaldehyde, phenol-formaldehyde, and melamine- formaldehyde. Other applications include 1,4-butanediol. and polyacetal resins. In 2004, formaldehyde was classified as a carcinogen to humans by the International Agency for Cancer Research and, as such, it is a highly regulated material. In 2011. in the USA, the National Toxicology Program (NTP) reclassified formaldehyde as carcinogenic to humans (NTP. 2011). Formaldehyde is highly soluble in water and is sold as a 37% solution in water, with up to 16% methanol. For higher concentrations, solution stabilizers are required. Formaldehyde is produced by partial oxidation and dehydrogenation of methanol using either silver catalysts (Reuss, 2002) or molybdenum oxide catalysts.

There are several formaldehyde technology licensors. Some licensors prefer to operate at 75-85% methanol conversion with recovery and recycle of unconverted methanol. Others operate near 92-95% conversion with no methanol recycle. BASF is one of the largest producers of formaldehyde with silver catalysts, but it does not offer the technology for license. The following companies are known to license formaldehyde technology based on silver catalysts: Dyuo Industries of Norway, Karl Fischer and Josef Meissner of Germany, Mitsubishi Gas of Japan, ENI (Montedison) of Italy and DB Western and Monsanto of United States.

Another technology for formaldehyde production is based on the vapor phase oxidation of methanol using metal oxide catalysts: Iron/molybdenum oxide with small amount of cobalt, phosphorus, chromium, vanadium and copper oxides (Klissurski, 1991). These technologies are licensed by Axeus (France), Dyno Industries (Norway), Haldor Topsoe (Denmark), Nippon Kasie (Japan), Lummus-CBI (United States), and Joseph Meissner and Karl Fischer (Germany) (PERJP, 1996).

Despite the health concerns, the demand for formaldehyde is continuously rising due to its increasing use in the production of various resins for manufacturing piuposes. Formaldehyde is also being used in the production of home building products and is known for its preservative and anti-bacterial properties. Hence, medical laboratories and some consumer products use formaldehyde as a preservative. The global consumption of formaldehyde is increasing as it is being used on a large scale for construction and remodeling activity and furniture production. Due to the excellent thermal and chemical resistance, formaldehyde-based resins are being used in manufacturing airplane and automobile parts. Formaldehyde is also being used in manufacturing anti-infective drugs, hard-gel capsules, and vaccines.

Some of the leading companies in the global formaldehyde market are Johnson Matthey Process Technologies, Foremark Performance Chemicals, Huntsman International LLC, Momentive Specialty Chemical Inc., Dyuea AS, Alder S.p.A, Georgia-Pacific Chemicals LLC, Perstorp Orgnr, Celanese AG, and BASF SE. The global formaldehyde market is also expected to reach 36.6 million tons towards the end of 2026. The global formaldehyde market has been segmented into applications. Urea Formaldehyde (UF) resins and concentrates are likely to witness the highest growth in terms of volume throughout the forecast period from 2017 to 2026. Asia Pacific Excluding Japan (APEJ) is expected to dominate the global formaldehyde market. Emerging economies, such as China and India, are witnessing a rapid increase in the demand for formaldehyde for use in various industries. Formaldehyde is the most commercially important aldehyde. Production of urea, phenol-, and melamine-formaldehyde resins (UF, PF, and MF resins) accounted for nearly 70% of world consumption of formaldehyde in 2017; other large applications include polyacetal resins, peutaerythritol, methylenebis(4-phenyl isocyanate) (MDI), 1,4-butauediol (BDO), and hexamethylenetetramine (HMTA).

4.2.3 Olefins

Conversion of methanol to olefins could potentially play a large role in increasing methanol demand. Figure 7 shows China’s 10-year plan for the use of coal for chemicals, presented by Yajim from National Institute of Clean-and-low-carbon Energy, Beijing in 2012 at Woodrow Wilson International Centre for Scholars. In 2010, of the total 670 million tons (MT) of coal consumed, 12% was used for the production of FT-liquids, olefins, ammonia, and methanol/DME. By 2020. coal consumption is expected to increase to 1,600 million tons, and about 28% of it will go toward the products mentioned above. The bulk of the increase is in the utilization of coal for the production of FT Liquids (5.1%), for the production of olefins (7.3%) and for DME 5.1%. In addition, 11.3% will go to the production of SNG. During the same period, the share of conventional electric power and industrial use will decline from 79.6% to 51.2%. Coal is emerging as a feedstock for new large scale methanol plants in China, and some of these plants are linked to the production of ethylene and propylene (Gregor, 2012; Hang, 2012).

Before we discuss ethylene and propylene production from methanol, we must understand the current technologies and the market. Ethylene and propylene are the two largest volume chemicals produced for the petrochemical industry, with 2018 production at 160 and 92 million metric tons, respectively. This represents an annual product value of about USS250 billion. Light olefin demand is primarily driven by polyolefin production, but other olefin derivatives, such as ethylene oxide, ethylene dichloride, propylene oxide, acrylonitrile and others, consume about 40% of the light olefins produced today. The majority of the light olefins used for petrochemical applications are produced by the steam cracking of ethane, naphtha or other gas liquids, as shown in Table 10 (Vora, 2015).

China coal utilization planning. Table 10. 2012 Light olefin production sources

Figure 7. China coal utilization planning. Table 10. 2012 Light olefin production sources.

Production sources

Ethylene

Propylene

Ethane Cracking

35%

Propane Cracking

9%

58%

Butane Cracking

4%

Naphtha Cracking

47%

Fuel Oil Cracking

3%

Refineries (recovered fi'om FCC units)

32%

Propane Dehydrogenation (PDH)

5%

Others

2%

5%

Tlie main factor in olefin production economics is the cost of feedstock, so locations for new capacity are strongly influenced by the availability of cost-advantaged feedstocks. This is evident in the large capacity build-up of ethane-based ethylene production in the Middle East since 1990. Prices for ethane in the Middle East are especially low because there are large amounts of ethane produced in association with crude oil production and countries provide incentives for ethane utilization. Availability of ethane has also increased with the discovery and production of shale gas in North America. It is seen from the data in Table 11 that the use of naphtha as a feedstock for ethylene production as a percent of total production is declining with some gains in use of LPG, ethane and the new entry of coal to olefins (CTO) or methanol to olefins (MTO). As of 2019, all CTO/MTO-based ethylene and propylene production takes place in China. The ethane growth rate is very significant.

During the 1960s, ethylene was also produced by dehydrating ethanol, but with advances in steam cracking and the availability of naphtha and light hydrocarbons, this route is economically no longer favored. Economic analyses done by consulting films have shown that Middle East ethane crackers and the remote gas MTO have the lowest cash cost of ethylene production, followed by North American ethane crackers, based on ethane recovered from shale gas. Figure 8 shows the cash cost of ethylene production according to Chemical Market Resources, Inc (CMR, 2013). The cash cost of production is

Table 11. Ethylene production sources; rnniMTA (% of total).

Feed source

2000

2010

2015

2020 estimate

Naphtha

52 (58)

58 (51)

60 (43)

68 (40)

Ethane

28 (31)

40 (34.)

50 (36)

65 (38)

LPG

10 (11)

17 (15)

21 (15)

22(13)

MTO/CTO

0

0 (0)

9 (6)

15 (9)

Total

90 (100)

117 (100)

140(100)

170(100)

Cost of ethylene production, $/MT

Figure 8. Cost of ethylene production, $/MT.

Cash cost of ethylene, S/MT

Figure 9. Cash cost of ethylene, S/MT.

similar for China’s coal and naphtha cracker-based ethylene production. It is also seen that the production of ethylene from sugarcane or com-derived ethanol in Brazil and the USA is not economical. A similar analysis done by IHS-CMAI for the cash cost of production of existing capacity on a geographic basis is shown in Figure 9. It is seen that ethylene produced from lower cost ethane gives the Middle East a significant advantage in cash costs, followed by North America, due to shale gas discoveries that have lowered the ethane and LPG prices.

When it comes to propylene, in addition to naphtha crackers, where propylene is produced in significant quantities along with ethylene, the refinery FCC units also play an important role, supplying nearly 30% of the demand in 2012. Because of the increasing use of ethane in place of naphtha for the production of ethylene, the combined production of propylene from naphtha crackers and FCC imits falls short of meeting the propylene demand. Therefore, since 1990, alternate sources for propylene, such as propane dehydrogenation and metathesis, have emerged to meet the propylene supply gap (Vora, 2012).

 
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