Bioenergy systems for the future 4 light olefins bio gasoline production from biomass

Bioenergy systems for the future 4 light olefins bio gasoline production from biomass Bioenergy systems for the future 4 light olefins bio gasoline production from biomass Bioenergy systems for the future 4 light olefins bio gasoline production from biomass Bioenergy systems for the future 4 light olefins bio gasoline production from biomass Bioenergy systems for the future 4 light olefins bio gasoline production from biomass

Light olefins/bio-gasoline production from biomass A Bakhtyari, M.A Makarem, M.R Rahimpour Shiraz University, Shiraz, Iran Symbols a, b, c, d, e BTG BTO CN DME FAO FCC GHG GTO H/C (H/C)eff HDO ICP MTO MTG SAPO UN WGS WHSV 4.1 stoichiometric constants in Eq (4.1) biomass/bio-oil to gasoline biomass/bio-oil to olefins carbon number dimethyl ether agriculture organization fluid catalytic cracking greenhouse gas glycerol to olefins hydrogen-to-carbon ratio effective hydrogen-to-carbon ratio hydrodeoxygenation integrated catalytic pyrolysis methanol to olefin methanol to gasoline silicoaluminophosphate United Nations water-gas shift weight hourly space velocity Introduction Global energy consumption is rising due to the increasing dependence of our lifestyle to energy and increasing world’s population Transportation section is one of the main energy consumers with 20% share of total energy consumption Discovery of crude oil opened new window for manufacturing energy carriers and chemicals However, declining fossil hydrocarbon sources and increasing demand for fuels and some downstream products are driving governments and industries toward exploring new sources for manufacturing fuels and associated chemicals In addition to this, emission of greenhouse gases (GHG) is still a major challenge of crude oil associated industries Bioenergy Systems for the Future http://dx.doi.org/10.1016/B978-0-08-101031-0.00004-1 © 2017 Elsevier Ltd All rights reserved 88 Bioenergy Systems for the Future Hence, proposing new routes for the production of energy carriers and chemicals that are more environmental friendly is currently state of the art (Balat, 2011; Huber et al., 2006; Mortensen et al., 2011; Nigam and Singh, 2011; Sorrell et al., 2010; van Ruijven and van Vuuren, 2009) 4.2 Gasoline and olefins Gasoline and olefins are of the main products obtained directly or indirectly from fossil fuels There are different routes for the production of gasoline and olefins Gasoline, which is the primary liquid fuel for the internal combustion engines, is conventionally produced from crude oil The composition of gasoline is various and depends on the initial crude oil source and the applied refinery process Gasoline is mainly a mixture of organic compounds such as straight chain, branched, and cyclic aliphatics, aromatics, and additives and blending agents A typical gasoline contains 4%–8% alkanes, 25%–40% isoalkanes, 2%–5% alkenes, 3%–7% cycloalkanes, l%–4% cycloalkenes, and 20%–50% aromatics (volume percent) Refineries that are responsible for gasoline manufacturing blend various refinery streams with different characteristics to produce gasoline Straight-run gasoline (naphtha) directly distilled from crude oil, reformate obtained by catalytic reformer with high aromatic and low alkene contents, catalytic cracked gasoline (catalytic cracked naphtha) obtained by catalytic cracking of naphtha with moderate aromatics and high alkene contents, and hydrocrackate obtained from hydrocracker, with moderate aromatic contents, are some refinery streams blended in different manner to produce different grades (with different octane number) of gasoline (Meyers, 2004; Parkash, 2003; Speight, 2015) It is possible to produce gasoline from methanol In this process, methanol is primarily converted to dimethyl ether (DME) followed by further conversion of DME to light and higher paraffins, aromatics, and naphthenes by applying zeolite catalysts (Keil, 1999; Olsbye et al., 2012; St€ ocker, 1999) Olefins (also named alkenes) are aliphatic hydrocarbon compounds with pairs of carbon atoms connected by double bonds Compared with equivalent saturated paraffins (i.e., paraffins with the same carbon number (CN)), unsaturated molecules of olefins contain two less hydrogen atoms Hence, olefins tendency to reaction is more than paraffins Their more reactivity than paraffins is due to the presence of pi-type carbon-carbon bonds or allylic CH centers (McMurry, 1996; Wade, 2006) Similar to paraffins, olefins are colorless, nonpolar, inflammable, and almost odorless compounds Solubility of olefins in water is low At conventional pressures and temperatures, olefins with CN up to four are in gas state, and those with more CN are in liquid state Because of participating in a wide range of reactions (e.g., hydration to alcohols, polymerization, and alkylation), olefins play a crucial role in petrochemical industry Olefins are feedstocks for the production of a large variety of industrial chemicals such as polymers, adhesives, detergents, and solvents Ethylene and propylene are building blocks in manufacturing plastic products Higher olefins such as polyolefins and alpha-olefins are used as lubricants and comonomers, respectively (Bender, 2014; Rahimi and Karimzadeh, 2011; Sadrameli, 2016; Xieqing et al., 2006; Zakaria et al., 2013) Two major types of synthetic polymers produced from olefins are polyethylene and Light olefins/bio-gasoline production from biomass 89 polypropylene Polyethylene, which has a linear structure, is primarily utilized in the production of utility fabric, rope, and twine Polypropylene with a tridimensional structure has a wide variety of applications such as textiles, packaging, plastic parts, and recyclable containers (Kadolph, 2012; Zakaria et al., 2013) Generally, there exist monoolefins, diolefins, and triolefins in which there are, respectively, one, two, and three double bonds in their structures Acyclic monoolefins with general formula of CnH2n (in which n is an integer) are rarely found in the nature In fact, they are produced in large scales in petrochemical plants Pioneer technologies have been applying cracking of petroleum oils for large production of olefins, especially monoolefins (Zakaria et al., 2013) Thermal cracking, fluid catalytic cracking (FCC), and hydrocracking are commercial processes by which larger hydrocarbon molecules are broken down to smaller ones such as olefins (Bender, 2014; Rahimi and Karimzadeh, 2011; Sadrameli, 2016; Xieqing et al., 2006) However, olefin production from waste material sources is currently state of the art (Pyl et al., 2011) In fact, declining sources of fossil fuel and environmental regulations are motivations for exploring new routes to produce olefins (Fogassy et al., 2010; Hew et al., 2010; Kwon et al., 2011; Perego and Bosetti, 2011; Rezaei et al., 2014; Serrano-Ruiz and Dumesic, 2011) 4.3 Why bio-gasoline and bio-olefin? Noticeable worldwide increase in the production of olefins is observed in the recent years Fig 4.1 shows the trend of ethylene capacity growth from different areas up to 2011 (Zakaria et al., 2013) In spite of this, based on a global study over the outlook of ethylene and propylene market, there is a concern for the increasing production cost of light olefins Such an increase may be due to the raising cost of raw material (Zakaria et al., 2013) Hence, technologies utilizing material with lower cost could potentially lead to lower cost of olefin production Besides, the production of olefins from hydrocarbon sources such as naphtha may lead to GHG emissions (Rahimi and Karimzadeh, 2011; Rezaei et al., 2014) Many environmental issues such as change in climate pattern, global warming, and biodiversity defects are caused by increasing GHG emissions Hence, applying new routes that employs cheaper raw material and produces less GHG emissions is of a great interest (Nigam and Singh, 2011) There is a similar statement for gasoline Although fossil fuels are the main source of liquid fuels such as gasoline and downstream petrochemical products, their nonrenewable and nonsustainable nature and subsequent environmental defects are motivations to search for new alternatives with low carbon dioxide emissions and compatible and comparable energy efficiency (Huber and Corma, 2007; Huber et al., 2006; Mortensen et al., 2011) Biomass is an abundant source of carbon In this regard, green olefin or bio-olefin (i.e., olefin produced from biomass) and biogasoline could be considered as rivals for conventional olefins and gasoline produced from hydrocarbon sources Renewability and sustainability are the advantages of bio-olefins and biogasoline production over conventional routes, which may cause them to have a premium market in the near future (Huber and Corma, 2007; Huber et al., 2006; Nigam and Singh, 2011; Zakaria et al., 2013) 90 Bioenergy Systems for the Future 40 35 Million tones 30 25 20 15 Middle East 10 North America Northest Asia West Europe 12 20 1 20 20 20 20 20 20 20 20 20 20 20 0 20 9 19 19 19 19 19 19 19 19 19 19 19 Year Fig 4.1 Trends of ethylene capacity growth from different areas up to 2011 Data from Zakaria, Z.Y., Amin, N.A.S., Linnekoski, J., 2013 A perspective on catalytic conversion of glycerol to olefins Biomass Bioenergy, 55, 370–385 4.4 Feedstocks obtained from biomass Exploring cheap and available biomass feedstock is the first step in further bioproduct manufacturing In this regard, biomass feedstocks could be obtained from the following sources (Huber and Corma, 2007): l l l l Waste materials such as urban residues, residues of crop, wood, and agricultural wastes Woodland products such as trees, shrubs, wood, and residues of logging Energy crops and starch crops such as corn, wheat, barley, sugar crops, grasses, and vegetable oils Aquatic sources such as water weed, water hyacinth, and algae According to the sources of biomass feedstocks, cellulosic biomass, starch/sugar biomass, and triglyceride biomass are three major categories (Huber and Corma, 2007) In a general point of view and regardless of local regulations, cellulosic biomass has the less cost However, the technology of cellulosic biomass conversion imposes extra charges On the other hand, cellulosic biomass is the cheapest, the most available, and the most challenging one to convert into bioproducts due to its solid stated and low energy density (Huber and Corma, 2007; Huber et al., 2006) Due to the effect of biomass feedstock on the composition of subsequent bioproducts and yield of olefins or Light olefins/bio-gasoline production from biomass 91 gasoline production, characteristics of different biomass feedstocks are of a great importance Hence, they are discussed in this section Cellulosic biomass includes cellulose, hemicellulose, and lignin as three major groups in which cellulose and hemicellulose are abundant more than lignin In fact, up to 90% of biomass obtained from earth (i.e., terrestrial biomass) is made of cellulose and hemicellulose More details of their structure could be found elsewhere (Huber and Corma, 2007; Lynd et al., 1991; Wyman et al., 2005b) Processing cellulosic biomass is still a challenge due to difficulties in converting solid-state biomass to fluid (Kamm et al., 2006; Lynd et al., 1999; Mosier et al., 2005; Wyman et al., 2005a,b) Cellulosic biomass is processed and converted to fluid products using the following processes (Huber and Corma, 2007; Huber et al., 2006): l l l Hydrolysis in which aqueous sugar solutions are produced Pyrolysis and liquefaction in which bio-oils are produced Gasification in which liquid fuels are produced More details of the aforementioned processes for cellulosic biomass processing will be discussed in the following sections Starch/sugar biomass (also called edible biomass) is almost obtained from vegetables Due to the amorphous structure, starch/sugar biomass could be converted to sugars or fuels in a procedure easier than cellulosic biomass Hence, it is utilized as a valuable feedstock for bioalcohol production Bioethanol is produced by the fermentation of fermentable sugars initially obtained from biomass (Huber et al., 2006) Triglycerides (also known as fats) are obtained from vegetable oils, animal fats, and aquatic biomass such as algae and could be converted into glycerol and fatty acids Besides, they could be upgraded to a suitable fuel by transesterification into biodiesel (i.e., alkyl fatty esters) and glycerol (Huber et al., 2006) Conversion of the obtained glycerol into olefins is currently state of the art (Corma et al., 2008; Murata et al., 2008; Zakaria et al., 2013) The main challenge with the triglycerides biomass feedstocks (such as vegetable oils) is their higher processing cost comparing that of cellulosic biomass (Huber et al., 2006; Zakaria et al., 2013) The type of biomass feedstocks used to obtain bio-oil and their physical and chemical properties (such as elemental composition, chemical composition, water content, density, viscosity, acid value, calorific value, and high heating value) were comprehensively summarized by Stedile et al (2015) 4.5 Routes to bio-olefin and bio-gasoline There are various routes to produce olefins and gasoline from biomass A graphic representation of the possible routes to produce olefins and gasoline from biomass is shown in Fig 4.2 The most probable route to produce olefins and gasoline from biomass is conversion of cellulosic biomass into bio-oil followed by a second process such as catalytic upgrading (Huber and Dumesic, 2006; Huber et al., 2006) Bio-oil, which is a mixture of more than 400 various compounds, is predominantly obtained from cellulosic biomass by either pyrolysis (Bridgwater, 2012; Huber and 92 Bioenergy Systems for the Future Syngas (CO + H2) ion Fischer-Tropsch Alkanes Methane Methanol Water-gas shift Hydrogen MTO or MTG Olefins gasoline at ic sif Ga Hydrodeoxygenation (HDO) Cellulosic biomass Pyrolysis or liquefaction Liquid fuels Bio-oil Catalytic upgrading Liquid fuels olefins gasoline Ethanol Dehydration Aromatics Aqueous phase processing Liquid alkanes hydrogen Lignin upgrading Etherified gasoline is s oly dr Hy Fermentation Aqueous sugars Lignin Fig 4.2 Possible routes to produce olefins and gasoline from cellulosic biomass Data from Huber, G.W., Iborra, S., Corma, A., 2006 Synthesis of transportation fuels from biomass: chemistry, catalysts, and engineering Chem Rev 106(9), 4044–4098 Corma, 2007; Huber et al., 2006; Isahak et al., 2012; Mohan et al., 2006; Papari and Hawboldt, 2015; Sharma et al., 2015) or liquefaction (Behrendt et al., 2008; Elliott et al., 1991; Toor et al., 2011) Hence, a vast variety of biomass feedstocks such as wood and agricultural and forest wastes could be utilized for the production of biooil However, bio-oil production from algae is currently state of the art (Saber et al., 2016) Depending on the biomass feedstock, method of bio-oil production, and operating conditions, various compounds such as aromatics, phenols, aldehydes, alcohols, esters, ketones, and acids could exist in the obtained bio-oil (Elliott et al., 1991; Huber et al., 2006) Pyrolysis is a process in which the biomass feedstock is warmed up to high temperature (i.e., 375°C–525°C) in a finite time and in the absence of air Consequently, a gaseous product is obtained, which is then condensed to liquid (Bridgwater, 2012; Huber and Corma, 2007; Huber et al., 2006; Isahak et al., 2012; Mohan et al., 2006; Papari and Hawboldt, 2015; Sharma et al., 2015) Liquefaction is a process at high pressures (up to 200 atm) and lower temperatures (i.e., 250°C–325°C) High pressure is a means of controlling reaction rate and mechanism in order to generate liquid bio-oil (Behrendt et al., 2008; Elliott et al., 1991; Huber et al., 2006; Toor et al., 2011) Production of bio-oil by pyrolysis process requires lower cost However, the bio-oil obtained by pyrolysis has higher oxygen content comparing that of liquefaction process (Huber et al., 2006) Light olefins/bio-gasoline production from biomass Table 4.1 93 State of products in different pyrolysis processes Process Conventional carbonization Pressurized carbonization Conventional pyrolysis Conventional pyrolysis Fast pyrolysis Flash pyrolysis Flash pyrolysis Vacuum pyrolysis Pressurized hydropyrolysis Residence time Temperature (°C) Heating rate State of product Hours-days 300–500 Very low Solid 15 min–2 h 450 Medium Solid Hours 400–600 Low 5–30 700–900 Medium Solid, liquid, gas Solid, gas 0.1–2 s