фонд поддержки науки

  • Увеличить размер шрифта
  • Размер шрифта по умолчанию
  • Уменьшить размер шрифта

CATALYTIC TECHNOLOGIES, FROM THE DAWN OF THE IDEA TO THE INDUSTRIAL IMPLEMENTATION

Extracted from Fauser Award Lecture – Palermo, September 18, 2010

Contents

Drivers of Catalysis for development

1. Through catalysis to the society needs

1.1. Role of Catalysis in Oil Refining

1.2. Role of Catalysis in Petrochemistry and Chemi cals production

1.3. Role of Catalysis in Environment Preservation

2. Catalytic processes development: the long journey of an idea

3.1. The explorative and definition phase

3.2. The intensive and development phase

3.3. Projects survival and success rate

3.4. Multidisciplinarity mandates integration

Conclusions

Summary

Catalysis has reached a noteworthy degree of maturity in the industrial applications and continues to produce innovation that is reflected in a significant contribution to the development of the modern society. This goal is achieved thanks to the closest synergy of the scientific understanding of catalytic phenomena and the scale-up of the gained knowledge into commercial applications. The role of catalysis in oil refining, in petrochemicals production, and in environmental protection is outlined.

The scale up of an idea through the discovery, definition, and development phases is described.

For exemplifying typical scale up routes, a series of case histories is presented, narrating a chain of connected technologies development, illustrating their commercial and scientific motivations and the methodologies followed. The birth and growth of some technologies like MTBE synthesis and other etherifications, paraffins and ethylbenzene dehydrogenation is shown.

Drivers of Catalysis for development

Since ancient times, catalytic processes were applied in order to improve humankind lifestyle. Fermentation (and therefore bio-catalysis) allowed Noah to produce his wine [1] or the Sumerian husbandmen to brew their beer [2]. Primordial catalysts were used for preparing pigments, inks, soaps that have allowed the civilization progress and the human culture growth.

The social benefits of chemical transformations are related indeed to their technological implementation. The studies finalized to develop and scale-up catalytic processes are, by definition, application oriented: as a consequence the target of industrial catalysis is to make concrete innovations in better processes resulting in better economics, better utilization of raw materials and energy as well in improving the environmental impact.

Chemical Catalysis is an essential tool for chemicals and materials production, for fuel and other energy conversion systems, for combustion devices, for fuel cells, and for pollution control systems. Often it is the key to making an entirely new technology or transmitting new life into obsolete or mature technologies. Additionally to the traditional need for productivity improvements, environmental drivers, energy saving, and industrial safety bring new aspects to the importance of catalytic innovation [3]. More than 90% of all molecules of current transportation fuels at some point during their manufacture have passed over at least one catalyst, some 80% of all chemical products are manufactured with the aid of catalysis and more than 20% of all industrial products rely on catalytic reaction technology [4, 5].

The term “catalyst” has also migrated from the world of science to everyday spoken language. It is noteworthy that this term is always used with a positive meaning. “Catalyst” from the Thesaurus of The American Heritage Dictionary is something that incites or rouses to action: stimulus, fillip, goad, incitement, instigation, motivation, prod, push, spur, stimulant, provocation, activator, energizer, excitant.

Catalytic processes require the existence of a very particular industry for catalyst manufacture. This sector is a highly specialized and diversified business. About 100 companies worldwide, less than 20 are the major ones, have some degree of capability in the production of catalysts on their own technologies or as toll manufacturers. The worldwide market value for catalysts was reported to be over $16 billion in 2009. Table 1 shows the value of the global catalyst market and the relevant Average Growth Rate (AGR) in the main fields and processes of current catalyst applications [6]. Since the cost of catalyst ranges typically from 0.1% (petroleum refining) to 0.22% (petrochemicals) of the product value [7], it can be estimated that catalysts induce a market of manufactured goods exceeding $7,500 billion yearly.

Table 1. Global Catalyst Market Value 2003-2009 (Mil $)


2003

2006

2009

AGR 2003-09

Refining

2,464

2,682

2,946

3,3%

Petrochemicals

2,195

2,340

2,491

2,2%

Polymers

2,568

2,999

3,425

5,6%

Fine Chem.& Interm and Others

1,276

1,621

1,965

9,0%

Environmental

3,581

5,028

5,704

9,9%

Total

12,084

14,670

16,531

6,1%

1 Through catalysis to the society needs

“Energy is the primary force and the tool needed to build the Human Culture” [8].

In our world, populated by over 6 billion of human beings, energy and goods are necessary for their survival. The human culture, developed in thousands of years, has been a tool and will continue to provide the tools for satisfying all needs (even if with some concerns on the sustainability of the current means and development rate) from the primary ones of food supply up to the electronic gadgets of a modern society.

In the long view of human history, as for ancient Rome as in the following centuries, the decrease of the more accessible energy sources, such as wood, moved to exploit other sources, even considering the change of supply as a bother or a burden. Around 1880s, coal surpassed wood’s usage. Coal was, in turn, overtaken by petroleum in the first half of the 20th century. Natural gas, too, experienced rapid development into the second half of the 20th century. The higher complexity of the use of new less accessible resources (requiring new logistics and more complicated techniques of utilization/transformation) has not limited their exploitation.

Fossil resources, mainly Oil & Gas, additionally do represent the raw materials of choice for all synthetic material.

Basically the fossil sources are characterized by different H/C ratios ranging from 4 for Natural Gas to less than 1 for coal. The competition of raw materials traditionally based on their cost is shifting more and more on their availability (global and local distribution) and on the environmental impact in the entire production chain (LCA, Life Cycle Analysis). In this respect, industrial catalysis is assuming a determining impact as well for the selectivity to the desired product as well for the energy preservation during the producing cycle, reducing eventually also the CO2 emissions.

As an average about 90% of the fossil hydrocarbons are destined to the energy production both in stationary power generation and transportation. Some 10% of hydrocarbons constitute the feed for the production of chemicals.

Looking to the value chain of hydrocarbons from source to market, particularly to the one of oil and gas derivatives (Figure 1), it is easy to appreciate the important contribution given by the industrial catalysis in the major part of the transformation technologies: it is possible to identify in the figure the main steps of the chain from extraction, to the production, transportation and chemical transformation to the products required by the different market sectors.

Figure 1. Value chain of Oil & Gas hydrocarbons

Crude oil, after stabilization and transportation to the user sites via pipelines or ocean shipping, is refined to fuels and feeds for the petrochemistry. NG from gas fields or associated with crude oil is transported to the markets via pipelines as CNG (Compressed Natural Gas) or shipped as LNG (Liquefied Natural Gas) to be regasified in the user countries. A minor part of NG is chemically converted to fundamental commodities like fertilizers and chemicals through catalytic processes. Traditionally used as LPG, NGLs (Natural Gas Liquids), the wet fraction of NG, are kindling more and more interest for their chemical conversion to high value products and also in this case, catalytic technologies are already existing or under development.

The catalyst market is usually defined by the type of market served or by the type of catalyst product. From a sales perspective, the market is usually broken down into oil refining, chemical processing, and emission control.

1.1. Role of Catalysis in Oil Refining

The fundamental drivers determining the refinery mission are:

• Ensure the energetic security, covering the demand of energetic vectors and fuels.

• Reduce the environmental impact: although vehicle emissions have impressively decreased in the last 40 years (emissions of a Euro 5 car are 1-2% of the ones emitted by a 1970s same performance model), the road mobility and the fossil fuel use still are between the main causes of atmospheric pollution. Legislation becomes increasingly severe mandating better fuel quality to reduce the fuel impact at local/regional and global levels.

• Ensure operation economics creating value for shareholders despite the reduction of margins due to the higher products quality mandated by law and to the deteriorating quality of oil crudes in terms of sulfur content and API gravity.

Over 80 million barrel of crude oil are consumed daily worldwide and refined in about 700 refineries. Looking better to the box “Refinery” of Figure 1, in Figure 2 it is reported an example of a complex refinery scheme. A refinery is an integrated sequence of technologies able to separate various hydrocarbon fractions, transform them in molecules suitable for the final use, and remove unwanted impurities (heteroatoms mainly S, N, O, metals). Unit operations for separation and final blending of streams produce the pool of products going to the market.

 

Figure 2. Example of a complex refinery scheme

Indeed straight run products from main fractionation are not suitable for the market. Most part must be further processed for removing impurities, inducing chemical transformations and give them the requested quality. As an example gasoline from topping is not only insufficient for the market need, but it is also of very poor quality. As a consequence several catalytic technologies able to transform intermediate streams into finished high quality, high value products have been developed and are currently commercialized. The target is to utilize any “part” of crude oil using technologies environmentally friendly both during operation and during the use of the final product.

Reaction technology for petroleum refining consists almost entirely of catalytic processes designed to modify the components of the fractions in three ways:

• Breaking big molecules in smaller ones (cracking)

• Combining small molecules in larger ones (condensations)

• Rearranging “parts” of molecules for getting more appropriate “structures” (isomerization)

Major sectors of the petroleum refining catalyst market are catalytic cracking, hydrotreating, hydrocracking, reforming, and alkylation. The first four of these sectors employ zeolitic or metallic-based heterogeneous catalyst systems, whereas alkylation employs either sulfuric or hydrofluoric acid two-phase liquid catalyst systems [5]. The need for a more effective operation of the tailpipe catalytic converters mandates a better or total desulfurization of fuels since sulfur depresses the noble metals activity in catalytic muffler. Better knowledge of sulfur containing molecules and above all new catalysts and optimized reactor design in hydrotreating are able to bring sulfur in gasoline and diesel oil to less than 5 ppm.

A very important global aspect of the technological pattern is that crude oil has a ratio H/C lower than the one of the commercial products (gasoline, jet, gasoil, LPG). As a consequence it is necessary or to “add hydrogen” or “reject carbon”.

Since hydrogen is a chemical to be produced on purpose from the raw materials available in refinery, the hydrogen balance is a key factor for the refinery economics.

Important social and economic drivers for new catalytic technologies in the refining sector are emerging:

• The increasing severity of the legislation mandating lighter and almost sulfur-free fuels despite the deterioration of the quality in terms of sulfur content and °API of crude oils available to the refineries.

• The use of the bottom-of-the-barrel, due to the declining fuel oil demand and use

• The need/opportunity to bring to the market unconventional heavy crudes, like the Venezuelan Orinoco crudes and Canadian bitumen or tar sands preserving the high quality of the products.

The new opportunity for biofuels from renewable resources like ethanol (blended as such or ETBE), Biodiesel (methyl-esters of fatty acids), or Green Diesel (hydrocarbon derivative from vegetal oils) [9] are fostered by industrial catalysis.

1.2. Role of Catalysis in Petrochemistry and Chemicals production

Starting from a relatively low number of carbon and hydrogen sources, petrochemistry covers the production of over 70,000 intermediates and end-users products in all sectors of the modern societies. Figure 3 shows the main cycles of petrochemistry involving the first generation intermediates, the second generation ones up to the final products families for the end user. Industry of “big intermediates” and of the petrochemical downstream is mainly based on olefins and aromatics derived generally from C2-C4 paraffins in NG and refinery fractions via steam cracking (non-catalytic, even if catalysis is expected to play a future role) and catalytic reforming.

Figure 3. Main production cycles in Petrochemistry value chain

Chemical Industry can be seen as a value chain: products from one technology become the feed of a subsequent one. At each step the value of the products increases “creating value”. Industrial Catalysis accounts for large part of the total sales ($1,720 billion in 2002, global) of the Chemical Industry main sectors as in Table 2 [10].

Ethylene and propylene derivatives are the basis of the chemical industry commodities and C4–C5 olefins are transformed into high quality fuel components [11]. Unfortunately olefins production requires sophisticated technologies and is extremely costly in terms of both Capex (Capital Expenditure) and Opex (Operating Expenditure).

The chemical processing catalyst market includes oxidation, hydrogenation, dehydrogenation, ammoxidation, oxychlorination, organic synthesis, etherification, esterification, ammonia, hydrogen, methanol synthesis and polymerization. The use of metal and metal oxide catalysts predominates in the non-polymerization categories of this segment. Zeolites are also used in commercial petrochemical operations such as the isomerization of xylenes, the disproportionation of toluene, and the production of various para-substituted aromatic compounds [12].

Table 2. Percent distribution of chemical sales on global scale in 2002.

%

%

Commodities

51

Petrochemicals

42

Inorganic Chemicals

9

Specialties

49

Performance Chemicals

22

Life Science Chemicals

27

Classical polymers such as polyethylene, polypropylene, and polystyrene are of great interest for science and industry. Catalysts used in polymerization depend on the type of general reaction technology (catalytic or free radical) employed. Catalysis is the soul of the polymerization of olefins, dienes and styrene conferring onto the polymer the desired properties. Polymers are the most extensively used plastics, and they show an above-average growth rate as materials. This increase is caused largely by new catalysts which are able to tailor the polymer structure and, by this, the physical properties. Catalytic olefin polymerization has made great steps forward over last few years. New metallocene or late-transition complexes have contributed enormously to the increase in catalytic activity and to the formation of new polymers with tailored microstructures. Through organometallic catalysts increasing amounts of plastic materials are produced. Catalysts such as metallocenes, half-sandwich, nickel and iron complexes, are able to tailor the microstructure of the polymer chain inferring new properties to the materials [13].

One major challenge to the process industry is the utilization of remote Natural Gas and particularly methane as alternative raw material for the manufacture of big intermediates of the chemical industry and fuels. The chemical conversion of methane and of C2, C3 and C4 alkanes present as wet fraction in many NG giant fields are a first step of a potential shift from “petro-” to “gas-” chemistry [14]. A cheaper and available feed has been always a driver for innovation in the chemical industry.

Attention paid to all the NG components from methane to butanes and pentanes as additional/alternative feed for chemicals and fuels comes not only from their large availability, and from their geographical distribution, that includes countries potentially in condition to develop a gas based chemistry, but also from the possibility of simplifying production processes through innovative catalytic technologies reducing costs and environmental impact.

Starting from methane in NG two complementary potential routes are possible: indirect conversions in which methane is first converted into syngas in presence of water, CO2, or oxygen (followed by already existing technologies or by the development of a chain of pacing technologies from methanol or other intermediates) and the direct functionalization of methane in the presence of oxygen or Cl2, HCl or ammonia [15]. The syngas based chemistry is already well established: cheaper technology for the manufacture of syngas is a key for improving the process economics of Gas-To-Liquid plants. Syngas-based routes to petrochemicals and synfuels are characterized by high carbon efficiency, which can hardly be met by direct conversion routes [16, 17]. Apart from a few examples, very little happened in the methane conversion processes since the initial efforts of a few decades ago under the oil crises, because of a questionable economic feasibility [18], but the situation may change in the mid term. Firstly, the environmental requirements may add a premium value to the sulphur-free synfuels and secondly, the large availability of stranded natural gas in fields where transportation is a major problem. Furthermore it has become a requirement that associated gas is not being flared. The major competition to the methane chemical conversion in the exploitation of huge stranded NG reserves remains LNG (Liquefied Natural Gas) that is becoming more and more convenient for the gas fields owners and investors because of the increasingly favorable economic margins helped by a steeply decreasing learning curve developed through the technology implementation in the last years.

Another field of growing interest for heterogeneous catalysis is the opportunity for better production processes for more complex agrochemicals and pharmaceuticals in the fine chemical sector [19]. An important contribution to catalytic processes is given by homogeneous catalysis: it estimated that in the chemical catalytic processes, a ratio of applications of heterogeneous to homogeneous catalysis of approximately 75:25. Homogeneous catalysis processes such as hydroformylation, carbonylation, oxidation, hydrogenation, metathesis, and hydrocyanation contribute, with millions of tons, considerably to the inventory of bulk chemicals. Today, we know much about how homogeneous catalysts are assembled, how they work, and how they can be improved: thanks to research in organometallic chemistry and its techniques and methods in experimental and theoretical concerns, and thanks to progress in chemical reaction engineering in processes using homogeneous catalysts [20].

1.3. Role of Catalysis in Environment Preservation

Environmental catalysis refers to catalytic technologies for reducing polluting emissions. This branch of catalysis finds application not only in traditional refinery and chemical technologies, but also for the treatment of emissions in several types of manufacturing industries (power generation, electronic, agro/food, paper, leather, metal cleaning, etc.), household or indoor applications, and in emissions control from road, sea and air transportation [21].

The environmental sector has the highest AGR of the catalysts market. Its share is passing from less than 1/4 in 2003 to over 1/3 in 2009 [6]. Environmental catalysis has continuously grown in importance over the last decades not only in economic terms, but also contributing to catalysis science with new knowledge, tools, and technologies. The development of innovative “environmental” catalysts is also the crucial factor towards the objective of developing an industrial chemistry sustainable and acceptable by stakeholders.

Three environment preservation strategies are available for reducing the impact of chemicals:

• waste minimization, finalized to the design and development of products and processes approaching the utopian goal of “zero emissions”

• emission abatement, by trapping harmful effluents or converting them to harmless substances (includes automotive and industrial end uses) and

• remediation, used to restore polluted sites to their natural state.

Catalysts play a crucial role in controlling emissions of gaseous pollutants to the atmosphere, mainly from mobility and power generation plants. In 1989, for the first time, the market for emission control catalysts (largely for automotive emissions) exceeded the market for petroleum refining catalysts. The market for stationary emission control catalysts (especially from power plants) is also expected to grow rapidly, after a period of teething, as a result of the legislation worldwide. SCR without ammonia slip may make friendlier to the utilities industry the DeNOx technologies.

2. Catalytic processes development: the long journey of an idea

Social benefits from research become real through the development of an idea from its generation up to the industrial implementation, in respect of deontological codes of conduct. Industrial research is finalized to getting innovation and creating value for the state owned or private entrusting institution. Technological innovation in an industrial context is a fundamental tool for the development and the competitive positioning of a company. Innovation arises when a new idea is generated, evaluated, demonstrated and transformed at increasing scale (scale-up) into a successful operating reality. Innovation is not a brilliant proposal, but according to the Confederation of British Industries “Innovation is the successful exploitation of new ideas”.

An innovative process begins with an idea that is generated in the somebody’s mind. In the idea generation phase, individual creativity plays a fundamental role.

Discovery consists in seeing what everyone else has seen and thinking what no one else has thought (Albert Szent-Gyorgi).

Giorgio Vasari, historian and artist of Renaissance tells (in Le Vite) that Michelangelo in a piece of marble, available to anyone, “saw” the “figure” to be extracted from the stone and Newton certainly was not the first spectator of a dropping apple, but he could “think” through it to the universal law of gravity! The Newton case is an example of creativity in the scientific “discovery”.

Additionally to the creativity there is the “inventiveness”, that implies an application of discoveries. Human progress has been always based on creativity and inventiveness that reflects the dualism Science-Technology, two different but interconnected cultural worlds. Scale-up is the conjunction between them. Scale up allows the passage of an initial idea into innovation, through a long (and dangerous) journey. And there are only few ideas that will cover the entire way!

It is believed that creativity is innate and latent in any child and the life increasingly discourages it, above all with education and job which intrinsically impose to share and see what anyone knows and sees. As a consequence between the duties of R&D managers there is the need of liberating all creative potentialities in every researcher. There are structured methodologies for improving the level of the creativity of individuals, but I don’t know any effective system (even if someone claims it!) for generating ex-novo new break-through ideas. On purpose companies and consultants, associations of industries, academic courses pay attention to the mechanisms and methodologies for stimulating (or restoring) individual creativity. Methods and practices for helping motivated persons and teams to build from known elements a new innovative route certainly do exist. In the literature, the so-called “brain storming” in well organized sessions is reported as the most effective method for improving creativity [22]. Extremely effective is the “analysis” of all available information, but the following step of “synthesis” in non traditional ways requires to switch on a lamp allowed only by the personal characteristics. There are also commercial softwares working on the “synapses principle”.

Individuals’ motivation is key factor of creativity. Initial idea derives generally from the inborn tendency towards exploration together with the perception of the existence of a problem-to-be-solved. The feeling of having identified an unprecedented solution with a new product (product innovation) or with a more effective-economic way of producing a known product (process innovation) produces the new idea. Certainly also in catalysis necessity of solving a problem is a powerful motivation. It is always true that “necessity is mother of invention”: the need for a more powerful gasoline pushed the race driver and mechanical engineer Eugene Houdry to develop the catalytic cracking process; strong motivations arise in the war times: the Chilean nitrates embargo to Germany boosted the Haber and Bosch studies for the fixation of atmospheric nitrogen in catalytic ammonia synthesis; catalytic reforming and alkylation allowed the RAF pilots to have available a high-octane fuel to win the battle of Britain.

More generally the strategic lines (typically market driven) and the cultural background of research teams and of companies, the attention paid to the worldwide scientific advancement, including to the “weak signals”, stimulate the fantasy towards a way of producing a completely new material, or to a simpler and less capital-intensive route of producing an existing product, or to the use of lower cost feedstocks (or waste by-products). Social concerns and evolving legislation are additional drivers pushing efforts for improved technologies. It is my opinion that the achievement of a technological success, even involving innovative catalysts, is more probable when the initial idea is already process “pulled” (e.g. the possibility of transforming “A to B”, and I do not know what catalyst could work), in respect to the catalyst “pushed” research (e.g. the availability of a “wonderful catalyst”, and I do not know for what reaction). Indeed the connections between R&D and business have evolved from a “first generation” characterized by offering of skills from R&D to a reluctant business to a second generation of specific short term requests by the business to a “third generation” of integrated vision and match of needs and skills [23]. The most recent approach enlarges the concept to the integration of resources/know how outsourced wherever available.

Researchers have different attitude in respect to innovation: like for children in front of a new toy, three typical questions characterize the personal attitude of researchers: i) what’s the purpose? “to Invent”; ii) how it works? “to optimize”; iii) how it is inside? “to deepen”. These are also the steps for making real an innovative catalytic process.

The development of a commercially successful process is in any case a scientific as well a technical triumph. The journey of an idea, from its birth at the level of discovery up to the start-up of a commercial prototype, is a sequence of steps of increasing difficulty to be overcome, that can assume different names, like discovery, explorative phase, intensive phase, pre-development, development and, eventually, venture and commercial application [24, 25, 26].

Even in a continuum, the R&D activities, can be grouped into two basic periods, the “explorative and definition phase” and the “intensive and development phase”, being the former already oriented, but still looking for a general definition of the process, and the latter strictly finalized to achievement of the complete technology know-how.

2.1. The explorative and definition phase

Beyond the role of fundamental research of providing the tools for any knowledge advancement, all finalized industrial R&D projects face the “explorative and definition phase”, that includes all actions aimed at assessing:

• the technical feasibility of the innovation: thermodynamic constraints control, reaction scheme sequence, potential catalyst hypothesizing, preparing, characterizing and screening, process conditions exploration, level of novelty evaluation (how many wheels have been reinvented!) are the most typical activities,

• the economical potential which implies mass and heat balances, some conceptual process design hypothesis, and a rough prediction of production cost and some economical indexes, and

• the “social” feasibility which will verify the environmental impact of the process, of the products of intermediates etc.

Even if there are not technical short-stoppers, before entering the following and expensive intensive and development phase, it is necessary to verify the new process expected economics. If the new process does not appear convenient (even assuming “dream” performances), only a very strong strategic motivation (of a company or a government through the research financing institutions) can leave alive the project. A recent example of this type is the intense current activity on hydrogen, on which an economical return is expected well beyond the pure financial requirements, but it is pursuing a strategic perspective of enormous impact. In the past the Fischer-Tropsch synthesis allowed South African government the production of fuels and chemicals from coal during the “apartheid” embargo.

The early definition of some “Criteria of Success” and the control on the achievement of intermediate milestones is fundamental in order to select the best projects. The techno-economical evaluation of the process must be anticipated as much as possible and repeated in any case of important “good or bad news” from Research. Bad projects’ killing is absolutely necessary for strengthening the good ones, but remains a very difficult task!

In this phase of development of catalytic processes the critical step is the identification/availability of a suitable catalyst. Catalysis was practiced long before it was recognized as a scientific discipline, but today “on-purpose” catalyst design is scientifically supported by the development of sophisticated and effective physico-chemical investigations at micro and macro level of the catalyst characteristics, old and new in situ-operando powerful techniques, microkinetics and mechanistic simulations, catalyst modeling. Electronic structure methods based on density functional theory (DFT) have reached a level of sophistication where they can be used to describe complete catalytic reactions on transition metals giving an unprecedented insight into molecular catalysis, and allowing looking better to the origin of the catalytic activity of a metal in terms of its electronic structure [27].

The objective remains the synergy of three vertexes of the triangle: how the catalyst has been prepared (Material Science); how it actually “looks” (Physico-chemical Characterization and Surface Science); how it performs (Catalyst testing).

As concerns equipment, the explorative phase is certainly carried out at “laboratory level” in bench scale units. The experimental check in laboratory of the feasibility is generally limited to verifying the chemical feasibility of the process, i.e. only the chemical factors (such as reactivity, yields, selection of the catalyst active components, etc.) are examined, independently from the size and therefore directly scalable, if phenomena dependant upon size were not present. In a first phase all “physical” factors (those connected with fluid motion, material and energy transport limitations etc) are frequently disregarded, but never forgotten. This very initial phase of experiments gives a preliminary indication on how to address the research in the future. Experimentally typical operation relies on small reactors (glass, quartz, or even metallic) with few cc or even hundreds of milligrams of catalyst generally in powder and granulates, not in the final shape. In this phase the set up of reliable analytical methods remains fundamental, as well for having satisfactory material balances (in this phase the error on balances and reproducibility might not exceed 3-5%) as well for identifying main byproducts: the devil is in the details!

Recently new “high throughput” techniques have been developed and it is possible to operate in parallel several reaction chambers and testing in short time several catalyst formulations or various operating conditions (temperature, space velocity, concentrations). Of course to a high availability of information must be associated a high capacity of handling them, and not only with computers!

For liquid phase systems, autoclaves (generally in batch) are the most used equipment.

2.2. The intensive and development phase

In order to be exploited at industrial level, findings of the explorative phase have to be tested and applied in larger dimensions. This work process is called scale-up.

Scale-up is defined as an increase in size, quantity, or activity according to a fixed scale or proportion.

The intensive and development phase is finalized to the acquisition of the technology complete know-how. The development of a catalytic industrial process is a complex interdisciplinary activity finalized to transform an idea into innovation getting and integrating all theoretical and experimental information on the catalyst, on the reaction, on the reactor, and on the entire process.

The keyword in this phase of development is “optimization” of: the catalyst formulation, its performances, and operating conditions, of the best reactor configuration, products purification, and eventually of the process flowsheet including energy and raw materials consumption, investment costs, safety, environmental constraints and impact, and controllability among other aspects.

The industrial development of a catalytic process is based on experimental studies. Haber and Bosch received the Nobel Prize for their basic studies on the ammonia synthesis, but the production process was based on over 20,000 catalytic tests carried out by Mittasch. Indeed the basis of intensive research is the collection of absolutely reliable experimental data.

As concerns equipment, the intensive-development phase is carried out on bench scale plants at laboratory level, on pilot plants, on process demonstration units (PDU); typically reactor size increases from grams to kilos and tons of catalyst.

Scale-up prepares the following commercial phase, which means the translation to a commercial scale of the experience gained since the lab experiments. Scale-up, therefore, beyond the technical approach, covers several aspects of the coming commercial activity, including product development and market studies.

In the intensive research phase, even at laboratory level, experiments and equipment must be designed bearing already in mind the full scale plant: the first step of scale-up is therefore scale-down the hypothesized problems of commercial unit bringing them to the small lab scale where all information needed can be collected and modeled effectively. Scale-up from small scale studies based on making “the toy bigger”, could be a very misleading concept.

The breakdown into simpler subsystems has some limits, since it increases the risk of missing some key factor in the investigation or of attributing to the system some effects due to the small scale.

Oversimplifying, three experimental approaches are possible: i) bench scale, where the mechanisms that are independent of size (thermodynamics, kinetics, chemical mechanisms) are studied, ii) mock-up (cold models), in order to analyze separately the physical mechanisms sensitive to size (fluid dynamics), and iii) finally pilot plants or even demonstration units which permit a simultaneous analysis of physical and chemical mechanisms, and of their interaction.

The process design and optimization is as much important as the catalyst optimization. The reactor conceptual choice and design together with the chemical reaction engineering and the design of all unit operations of the process (including feed and product separation-purification) makes real the possibility of developing a new catalytic technology.

Chemical reaction engineering (CRE) is concerned with the rational design and/or analysis of performance of chemical reactors, the heart of any chemical process [28, 29]. Design of chemical reactors is also at the forefront of new chemical technologies. Improvements in the reactor usually have enormous impact on upstream and downstream separation processes. The process engineers will have to translate discoveries and knowledge of the reaction, transferred by the researchers, into a new process and must supply everything else is needed to define the Process Design Package.

Assumptions must be made about which types of process units should be used, how those process units will be interconnected and what temperatures, pressures and process flow rates will be required: this activity is named “conceptual design”. Conceptual design can be approached at different levels during the development of a chemical process. The main key to the successful design of a new process is the continuous transfer of information between researchers and engineers, particularly the feedback of engineers to researchers, identifying critical points and addressing further research to clarify them. At the moment in which process development begins, the reaction has been tested in laboratory reactors, a catalyst is available, even if it will not be the final one, possible by-products and a plausible stoichiometry have been determined. A range of possible operating variables (temperature, pressure, space velocity) and the reaction phase have been determined, too.

The engineering of catalytic reactors has benefited from this increased understanding of reaction mechanisms; mass and heat transfer phenomena in catalyst pores, pellets, and beads; and mathematical modeling of catalytic processes and flow motion through computational fluid dynamics (CFD). New catalysts with tailor-made molecular designs are already playing important roles in advancing industrial technologies. At the same time, new ideas emerging from research promise breakthroughs that may make industry more efficient, safer, and more environmentally friendly.

Techno-economical evaluations [30, 31] for the assessment of the feasibility of commercial opportunities for the new catalytic process are fundamental in this phase and drive many technological choices. Favorable economics will give the green light to the continuation of the project.

Even in the phase of advanced development the search for new solutions and breakthroughs has to continue: experience says that sometime the exploration of parameters and variable outside the ranges assumed as optimal may open the doors to a breakthrough.

Scale up from laboratory scale to industrial scale in one step is rarely feasible. Pilot plants or even PDU allow to study the entire process, including the purification sections, and to get large amount of product for evaluation by potential clients (internal or external). At this demonstration scale there is also the experimental check of by-products that sometime changing from once-through systems (like in laboratory) to recycle systems may unexpectedly build up.

The accepted calculated risk determines the extent of homology and then the scale up ratio (the relationship between the size of the foreseen next scale unit and the size of the current experimental one) that is required in the intermediate step. Due to the high cost of pilot plants, there is great interest in moving in one step from bench scale to, at least, a process demonstration unit (PDU) to be used as a reference for larger future installations. There are no general rules for scale up ratios. Typical values based on experience are reported in the Table 3. Higher scale up ratios, at an acceptable level of risk, can be achieved only when marginal modifications to an existing technology (incremental research) are planned or extensive experience exists on similar systems or when a fundamental approach is possible to both chemical and engineering problems. There are examples of successful scale up ratios from bench scale to PDU or semi-commercial scale plants exceeding 100,000 or even 500,000 or difficulties met with a factor of only 5.

Table 3. Typical scaling-up ratios from lab to industrial plants

Systems

Lab to pilot

Pilot to ind.

gaseous

500-1000

200-1000

reag. gas-prod.liq.

200-500

100-500

Reag. liq./gas-prod.liq

100-500

100-200

A very important aspect of the development of catalytic processes is the scale-up of the catalyst production from the few grams typical of lab preparation to the tons needed by commercial units. Catalyst production is a real, complex chemical process handling generally solids that requires the same attention as that paid to the reaction.

2.3. Projects survival and success rate

The idyllic picture appearing up to now is not always or entirely true.

Commercializing a new catalytic process is capital-intensive, and as long as 10 to 15 years may be required from the discovery of a viable catalyst for a new process to commercial plant start-up. Most new processes are complex and large-scale pilot plants or PDU are required to collect the data needed to design and build safe, clean, and efficient commercial plants. Development can easily cost tens of millions of dollars, and the new commercial plant may cost hundreds of millions of dollars. Thus developing breakthrough catalyst systems is risky, time-consuming and costly [32].

Experience indicates that only a small number of innovative ideas complete their journey up to commercial implementation. First of all, it is not an easy task to overcome all the technical difficulties and achieve superior products/processes. Furthermore in almost all cases the initial scheme will require additional treatments, purifications, recycles and so on not included in the original design.

But even in the case of technical success, other hurdles make a selection among R&D projects: during the several years required by the process development, the economic scenario can change substantially (in the last 30 years the oil price has been subjected to sudden ups and downs) or the company strategy can change, the results can arrive too early (market not yet mature) or too late (someone else has arrived first) and, in any case, how big should be the contemplated advantage of choosing the new technology at the eyes of the investor or financing bank for prevailing over a referenced competing product/process? 10% or 20% or 30% or even higher? What is the breakeven between potential benefits and risk? One of the key factors will be the attitude of the companies regard to innovation.

As a consequence R&D projects undergo very considerable “attrition”, like entering in a virtual funnel from which just a few come out. According to some industrial experience, about 80% of the projects at the discovery phase reach the definition phase, less than 50% initiate the development phase, and only 20% of them survive up to the serious evaluation for a venture phase. A different picture is given by another source [33] according to which 1 to 3% of ideas for a new process at the early research stage reaches commercialization. Projects at the development stage have a probability of about 10 to 25%, and at the pilot plant stage of 40 to 60%. Of course, the success rate for marginal modifications of existing technologies will be higher than that of completely new processes.

2.4. Multidisciplinarity mandates integration

“No organ of the human body can claim the right to consider itself more important than the other ones and refuse to cooperate with them, otherwise the entire body will die.” (Menenius Agrippa, 494 b.c.).

As we have seen, the handling of the complexity of the phenomena involved in catalysis, in catalyst and catalytic processes development, involves skills coming from many complementary, each one developing independently its own progress and advancing towards a very sophisticated level of specialization.

Catalysis needs integration and “bridging the gaps” [34]: gaps between catalyst preparation and performances, between model catalyst and working catalyst, between laboratory and industrial conditions, between reactor engineering and catalyst formulation, between electronic structure calculations at molecular level and experimental results, and not to be forgotten, between business and science. Successful catalytic processes development requires bringing in a common culture members from different disciplines such as materials and surface science, solid state physics and chemistry, organometallic chemistry, chemical kinetics, reaction and reactor engineering.

Integration is achieved bearing in mind that the development activity is not a relay race and the project has not to pass from one competence to the next like the baton from one racer to the other, but all skills have to work together synergistically from the lab level up to the start-up of the commercial unit, with a continuous feedback of information. Integration is an unavoidable necessity that should not be felt by the individuals as an ethical duty or a management imposition, but as an intrinsic cultural attitude.

Management has the responsibility of the correct involvement of the broad spectrum of specialist skills and of making available the complete view of the total problem under study.

A form of integration is also the collaborations of industrial research with universities and scientific institutes that promotes new roads for future technology developments. These collaborations not only enlarge the cultural basis of the projects, but educate synergistically industrial researchers to apply new scientific concepts in their “real-world” and academic researchers to introduce “real problems” in their world.

It is fundamental the integration inside the company between the organization functions in order to preserve the warm attention of the business to R&D projects in order to accelerate the time to market.

Commercial R&D in industrial catalysis, as in other fields, is typically a high-risk investment with a deferred payoff. Any R&D project has to pass through a period of negative cash-flow (the so-called Valley of Death) before the income starts to recover the expenses. It is wrong to view R&D projects as a cost since, as with other high-risk investments, returns can be extremely attractive. Joint development and joint ventures with other companies to share risk, and select and evaluate high-quality methods offers a higher chance of success. The value-creating potential for investment in industrial catalysis depends on technical opportunity and commercial opportunity. When both are aligned within the company, prospects are excellent for coming true the sentence “Science to Dollars” [H. Topsøe in 34]. By experience, a strong internal sponsorship and commitment is a necessary catalyst for success!

Conclusions

The process industry faces challenges requiring innovative efforts. Catalysis and the related disciplines are continuously evolving from the point of view of both the proposition of new technological topics and the availability of new scientific methodologies that, through a deeper understanding of elementary steps, allow a conceptual design of the catalyst at molecular level and its engineering systems. Technological challenges for industrial catalysis are the keys for creating new opportunities for knowledge progress.

Catalysis allows better utilization of fossil resources through selectivity control: in the future, selectivity to form the desired product without the formation of byproducts will be one of the major research challenges. Our understanding of the molecular ingredients of selectivity needs to be improved. New synthetic methods of catalyst preparation are needed for precise control of size, structure, location of additives and location of catalyst particles on supports. Characterization of the catalysts under reaction conditions is essential as the catalyst restructures in the presence of the reactant mixture [63].

During the coming decades, oil will still be the main source of energy [64] and will supply a large share of the fuel required by industry and virtually all the fuel required for transport. Catalytic technologies are expected to allow the “white refineries” with complete conversion of the bottom of the barrel and the exploitation of unconventional heavy oils such as Venezuelan and Canadian resources.

During the last decade, proven world gas reserves increased considerably, exceeding oil reserves in barrel of oil equivalent. Furthermore enormous methane reserves are trapped as hydrates at the oceans rims. Additionally to the use for primary energy generation, Natural Gas is expected to be more and more exploited through its conversion in catalytic industrial processes to produce liquid transportation fuels and intermediates for the chemical industry. There is a growing interest for the use of NGL, the wet fraction of NG, as clean feedstock for high quality fuel components and for chemicals.

Hydrogen is candidate to become a major vector of energy in the future, but it must be associayted with the use of renewable energy sources or the CO2 sequestration if it is produced from fossil fuels Biomass has the potential for contributing to provide alternative feed for producing energetic vectors via catalytic processes, but it has to be considered the competition with the food for human beings.

Catalytic processes intensification through integration of unit operations in reactor engineering and advanced catalysis like in membrane reactors [65], catalytic distillation [66, 67], micro-channel reactors [68] etc. offers potential breakthrough benefits increasing product yields and selectivities, energy efficiency by improving heat and mass transfer performance, shrinking processing equipment cost-effective creation of new products by enabling optimal processing conditions not possible with conventional hardware.

Given the combined challenges of achieving environmental protection at all stages of production, use, and disposal of chemicals and of using at improved efficiency new sources of raw material feedstocks, industry needs efforts from fundamental and practical approach to catalysis. As to individuals, a major challenge is to smooth the barrier between science and technology. Without the Fundamental Science, all technological progresses are marginal, as well without the technological implementation, cultural and financial efforts in scientific progress become meaningless for the social benefits. Chemistry and Catalysis play a key role in this aspect and the relevant technologies impregnate all our daily actions.

Charles Darwin said “In the long history of humankind (and animal kingdom too), those who learned to collaborate and improvise most effectively prevailed”.

It is a very good suggestion.

Acknowledgements

I wish to express my appreciation to the many colleagues that with their creativity, inventiveness and firm will, have spent their best efforts to generate and develop the ideas I described here.

References

1 Bible, Genesis 9, 20

2 Arnold J-P. (2005) Origin and History of Beer and Brewing: From Prehistoric Times to the Beginning of Brewing Science and Technology. ISBN 0-9662084-1-2

3 Dautzenberg F. M., Angevine P. J. (2004). Encouraging innovation in catalysis Cat. Today, 93-95, 3-16

4 SRI (Stanford Research Institute) (1996) Catalysts Process Economics Program Report 153A. A multiclient study on catalyst market

5 Marcilly C. (2003), Present status and future trends in catalysis for refining and petrochemicals, J. Cat. 216, 1-2, 47-62

6 TCGR (The Catalyst Group Resources) (2004): Intelligence Report - Business shifts in Global Catalytic Process Industries 2003-2009

7 Rabo J.A. (1993) New Frontiers in Catalysis - Proc. 10th Int. Cong. on Catalysis, Budapest 19-24 July 1992 Ed. Guczi, et al... Elsevier

8 Rifkin J. (2002) The Hydrogen Economy Penguin Putnam Inc.

9 Holmgren J. et al. (2007) A New Development in Renewable Fuels: Green Diesel NPRA Annual Meeting March 18-20, 2007 San Antonio, TX Paper AM-07-10

10 Federchimica (2004) Chemical Industry in numbers. Responsible Care Program

11 Sanfilippo D., Miracca I., DiGirolamo M. (2005) Engineering alkanes to olefins and higher value chemicals in Sustainable Strategies for up-grading Natural Gas: Fundamentals, Challenges and Opportunities. Derouane E. et al. Eds. NATO ASI Math., Phys. and Chem. 191, 217-247 (Springer)

12 Rabo J.A., Schoonover M.W. (2001) Early discoveries in zeolite chemistry and catalysis at Union Carbide, and follow-up in industrial catalysis. Appl. Cat. A Gen. 222, 1-2, 261-275

13 Kaminsky W. (2000) Polymerization catalysis, Cat. Today 62, 1, 23-34 doi:10.1016/S0920-5861(00)00406-5

14 Sanfilippo D., Miracca I. (2006) Dehydrogenation of paraffins: synergies between catalyst design and reactor engineering Cat. Today 111, 1-2, 133-139

15 Guczi L., Van Santen R-A., Sarma K-V. (1996) Low-Temperature Coupling of Methane Catal. Rev.-Sci. Eng. 38, 249

16 Rostrup-Nielsen J. (2005) Natural Gas: Fuel or Feedstock in Sustainable Strategies for up-grading Natural Gas: Fundamentals, Challenges and Opportunities. Derouane et al. Eds. NATO ASI Mathematics, Physics and Chemistry, 191, 3-24 (Springer)

17 Rostrup-Nielsen J., Alstrup I. (1999) Innovation and science in the process industry Steam reforming and hydrogenolysis Cat. Today 53, 3, 311-316

18 Lange J-P. (2005) Economics of alkane conversion: Economic guidelines and techno-economical evaluation of alkane conversion processes. In Sustainable Strategies for up-grading Natural Gas: Fundamentals, Challenges and Opportunities. Derouane et al. Eds. NATO ASI Mathematics, Physics and Chemistry 191, 51-83 (Springer)

19 Blaser H-U. (2000) Heterogeneous catalysis for fine chemicals production Cat. Today 60, 3-4 161-165

20 Cornils B., Herrmann W-A. (2003) Concepts in homogeneous catalysis: the industrial view J. Cat. 216, 1-2, 23-31

21 Centi G., Ciambelli P., Perathoner S., Russo P. (2002) Environmental catalysis: trends and outlook. Cat. Today 75, 1-4, 3-15

22 EIRMA (European Industrial Research Management Association) (1998) Creativity and Innovativeness. Workshop Report IX EIRMA 34, Rue de Bassano Paris

23 Sanfilippo D. (1997) The catalytic process from laboratory to the industrial plant, CatToday 34, 1-2, 259-557

24 Roussel P-A., Saad K-N., Erikson T-J. (1991) Third Generation R&D, Arthur D. Little Inc. Harvard Business School Press, Boston

25 Hoyle W. (1997), Pilot Plants and Scale-up of Chemical Processes Special Publication No. 195. The Royal Society of Chemistry

26 Nauman B-E. (2002), Chemical Reactor Design, Optimization, and Scaleup, McGraw-Hill,

27 Nørskov J-K., Hammer B. (2000) Theoretical surface science and catalysis, calculations and concepts Adv. Cat. 45, 71-129

28 Schmidt L-D. (1998) The engineering of chemical reactions. Oxford University Press New York Oxford

29 Missen R-W., Mims C-A., Saville B-A. (1999) Introduction To Chemical Reaction Engineering And Kinetics, John Wiley & Sons, Inc.

30 Newnan D-G. (2004) Engineering Economic Analysis. Oxford University Press, Inc. - New York (USA)

31 Behrens W., Hawranek P-M. (1995). Manual for the Preparation of Industrial Feasibility Studies UNIDO, Vienna ISBN 92-1-106269-1;

32 Boer F-P. (2005) Research is an investment, not an expense Appl. Cat. A: Gen. 280, 1, 3-15

33 Douglas J-M. (1988) Conceptual design of Chemical Processes. McGraw-Hill

34 Clausen B. (2006) Frontiers in Catalysis: A Molecular View of Industrial Catalysis CatToday 111, 1-2

35 Somorjai G-A., McCrea K. (2001) Roadmap for catalysis science in the 21st century: a personal view of building the future on past and present accomplishments Appl. Cat. A: Gen., 222, 1-2, 3-18

36 EIA U.S. DOE, Annual Energy Outlook 2010, Washington, DC 20585 ,www.eia.doe.gov/oiaf/aeo/, April 2010

37 Dalmon J-A. et al. (2007) Oxidation in catalytic membrane reactors Appl. Cat. A: Gen. 325, 2, 198-204

38 Harmsen G.J., (2007) Reactive distillation: The front-runner of industrial process intensification A full review of commercial applications, research, scale-up, design and operation, Chem. Eng. Proc. 46, 9, 774-780

39 Miracca I., Judzis A. Jr., Sahayi N., Sanfilippo D. (2008) Catalytic Distillation in Heterog. Cat. Handbook, 2nd Ed.Vol. 4- 10.6, 2188-2198 - G. Ertl, H. Knotzinger, F. Schueth, J. Weitkamp Ed. Wiley-VCH

40 Mazanec T. (2007) High Intensity Olefin Production in Microchannel Reactors AIChE Meeting, Houston, TX April