Applications in the metallurgical industries
Since the background of this month’s magazine is non-ferrous metals, I want to start this piece with a review of CO2 usage in the metals industries at large. Globally, CO2 is over 20 million tpy in usage. If we look at the US specifically, of the approximate 8 million short tpy in usage, no more than 30% of this value would be found in all industrial applications for the product, including metallurgical in full. Industrial is intended to represent CO2 usage as an acid, agricultural usage, dry ice applications, usage in the chemical industries, to include usage in the metals industries. CO2 usage surrounding applications in metallurgical settings would include welding applications, that being CO2 in a gas mixture, CO2 usage has been found in large steel mills, as CO2 stirring application of metals in a molten state. This has also been the same application via the use of other gases. Some of the selection is a function of metallurgical composition and technical approaches; and of course CO2 pricing compared to LIN (liquid nitrogen) for example, as an alternate agent. One application for CO2 many years ago, now down considerably in foundry applications, was the use for hardening silicate based molds.

Therefore today, the lion’s share of CO2 (when dedicated to metals at large) this would be found in welding gas mixes in a wide range of metal fabrication industries, again, use in large steel mills as a ‘stirring agent’; and the application of dry ice in shrink fitting, during certain assembly processes. Next, a growing and ever ‘environmentally-friendly’ application and some of which was reviewed in the March edition of gasworld, is the application of very fine dry ice pellets (usually referred to as dry ice ‘rice’) for blast cleaning. Under high pressure, and via utilisation of the 1/8” dry ice product, metal surfaces are cleaned and/or prepared for finishing. The metal fab industries will always have some use of CO2, but of all the metal related industries, CO2 in blast cleaning is probably the most rapidly growing sector of the business. Availability and price drive certain applications in all that is mentioned above, with respect to the metals industries and carbon dioxide use.

CO2 from ethanol sourcing – Growing as a merchant and captive sourcing alternative
Ethanol is a high-octane fuel which is used primarily as a gasoline additive and extender. CO2 is a by-product of fermentation processes; hence the growth in this industry at large is of major interest for all carbon dioxide markets and environmental projects. The reduction of MTBE due to its environmental problems and the surging prices for petroleum-based fuels are dramatically increasing the demand for ethanol. This demand is strong in the US, Latin America, Europe, and regions of Asia, to name major consuming markets. In terms of the 2007 global production of ethanol, this was about 35 billion gallons per year. Corn-based ethanol accounts for 97% of the market in the US, while Latin America produces ethanol primarily from sugarcane and molasses. Ambitious plans for ethanol now exist in the Philippines, with mandated blends on the rise. Four feedstocks, including sugarcane which should be the feedstock for the growing ethanol mandated usage and production on mainly four islands in the Philippines.

Over the last few years, literally hundreds upon hundreds, if not a thousand or more ethanol projects have been announced globally. As for this sector, the merchant markets can be well served if strategic availability should fit the markets served. In the US for example, about 30% of the CO2 plants for merchant service are sourced from by-product of ethanol.

If we consider the usual corn-based (sometimes wheat) in the US for example, the new plants are based upon continuous fermentation, dry mill operations. The scale of ethanol economics and plant size has grown to a usual 50-100 million gallons per year, which represent over 400-800 tpd in CO2 raw gas. The CO2 is low pressure when vented from the ethanol plant and the CO2 facilities can now range, with storage, civil work, building storage, and scales; turn key basis, $11m for the 400 tpd plan and $17m for the 800 tpd plant. Numerous new CO2 plants of the larger world scale size are slated for the US today; and more to come, all from ethanol. Please see table for CO2 plant related data.

The fastest growing sector for the merchant trade has been CO2 sourcing from ethanol by-product, while a few sources develop now and then from natural wells and reformer operations generally speaking; with ammonia as a US by-product source on the decline. Therefore, developments relative to ethanol projects, both from the traditional corn and wheat based (first generation) fermentation; and to come over the next few years, as technologies are refined, and efficiencies are improved upon the cellulostic ethanol sources, such as switchgrass, wood chips, and other organic matter. When CO2 has been discussed as a source from landfill operations, there is no realistic merchant market for this product, other than oil and gas, and perhaps coal bed methane projects; all due to the perception when such a product is in the greater merchant gas system, much of which is dedicated to the food and beverage markets. The consumer is absolutely turned off when the term ‘waste’ is used in feedstock definitions, as well as the ISBT and the major food and beverage firms (despite chemical purity) when sampling CO2. On the cellulose based front, proprietary technologies include concentrated acid hydrolysis, enzyme conversion technologies, and syngas processes claimed to yield an affordable and commercially sized ethanol process and fuel grade product.

In reality, much of this is in the pilot or demo phase; but at least one such cellulostic plant is slated for Georgia, with per Range Fuels in Colorado. DOE grants will supply $50m for the first 20MM GPY phase of the plant and the second phase will receive a $26m grant as well. It is said to be operational in 2008; however by scale, at least the first phase as 20MM GPY in capacity, is too small in scale for a viable CO2 plant, by most standards. The plant however, is said to expand in phases, then by definition of commercial CO2 viability.

The US claims to be the largest producer of ethanol globally; rivalled by International Producers; primarily Latin America. Merchant feasibility in these international regions is a problem since with sugarcane, even a better feedstock than corn, it is not readily stored as corn is and the growing season or seasons represent only a partial year for a continuous supply of raw feedstock for the merchant plants. Sugarcane compared with corn is a better feedstock since, as with corn, the conversion step to a sugar is not necessary for sugarcane, as with corn and wheat for example.

These days, with the capital crunch underway in the US, some of the financing of ethanol projects has slowed down; but I firmly believe the industry is in a strong long-term growth mode driven by the world and US hunger for fuels, the ever-smaller oil discoveries and reserves and driven further by high petroleum prices. On the flip side, grain products and reserves are creating some rather heated arguments with respect to ethanol’s viability.

Grain shortages coupled with high prices globally, have led to criticism concerning manufacturing ethanol from edible grains; which has placed further pressures on the manufacture of ethanol from these substances. High prices of grain have caused riots in many developing world markets due to unaffordable basic foodstuffs, as well as historically high pricing in developed markets for every day groceries. As second generation ethanol projects develop and refine their process and economic requirements, and such projects become successful in their industrial-sized facilities; this will take the pressure off the grain for food versus grain for fuel arguments.

On the other hand, in various global markets substances beyond corn are available as alternatives of a more affordable nature, such as sugarcane, for merchant CO2 production. With respect to some of the emerging ethanol producers outside of the US and Europe, their primary ethanol markets are of a fuel-grade nature. In the developed world, such as North America and Europe, the growing ethanol trade is to be dedicated to fuel grade product, compared to beverage grade distillation and pharmaceutical/specialty chemical usage. Those grades or classes of ethanol outside the fuel grade markets account for a small percentage of the grand total of ethanol to be produced globally.

Summary
Metals related applications for CO2
Utilisation of CO2 in the metals industry is a small percentage of total usage in both the developed and developing world markets. This accounts for perhaps 10% of many world market applications; whether this is via cylinder or bulk storage supplies in developing or developed world markets. On the other hand, if cold temperatures are sought in metallurgical applications, and other agents such as nitrogen are not available, then CO2 could be considered in some applications. One growth market today with CO2 would be via dry ice ‘blast’ cleaning. This application is a growing sector of the business, and if sublimation of dry ice and strategically produced product is available, a tidy profit can be achieved. I strongly recognise all segments of the industry, including the generally smaller ‘industrial’ sector, of which metals related applications are important to the overall profits and performance of all CO2 markets. The generalised ‘metals related’ sector of CO2 is often quite profitable, when comparing this with the more commodity style pricing to the world class food and beverage producers; therefore, the industrial sector of the market is ever-important in the industry and often more profitable.

Ethanol Related CO2 Sourcing
On the subject of ethanol, given all of the above stated concerning growth, feedstock type, emissions issues, grain shortages for food versus feedstock for fuels, and second generation ethanol; the subject is ever more vitally important to the CO2 industry and will continue to be as such. In terms of growing, current, and planned ethanol projects, and government mandates as a fuel additive or replacement; CO2 by-product should be recognised as a source of revenue. Despite the method of designing this form of CO2 revenues from ethanol projects, it should become more important as we strive to source (due to high transportation costs) closer to the markets; as well as recognising developments of emissions mandates. It is essential to understand CO2 markets, production costs, competition and sourcing developments, plus strategic sourcing; in order to best define and receive the benefits for properly developing the CO2 from ethanol projects. All by-product revenues are essential for long term health of the ethanol industry; and can be the key to best sourcing from a strategic and economic point of view the CO2 industry’s need.