Bio‐oil,solid and gaseous biofuels from biomass pyrolysis processes—An overview

As the global demand for energy rapidly increases and fossil fuels will be soon exhausted, bio‐energy has become one of the key options for shorter and medium term substitution for fossil fuels and the mitigation of greenhouse gas emissions. Biomass currently supplies 14% of the world's energy needs. Biomass pyrolysis has a long history and substantial future potential—driven by increased interest in renewable energy. This article presents the state‐of‐the‐art of biomass pyrolysis systems, which have been—or are expected to be—commercialized. Performance levels, technological status, market penetration of new technologies and the costs of modern forms of biomass energy are discussed. Advanced methods have been developed in the last two decades for the direct thermal conversion of biomass to liquid fuels, charcoals and various chemicals in higher yields than those obtained by traditional pyrolysis processes. The most important reactor configurations are fluidized beds, rotating cones, vacuum and ablative pyrolysis reactors. Fluidized beds and rotating cones are easier for scaling and possibly more cost effective. Slow pyrolysis is being used for the production of charcoal, which can also be gasified to obtain hydrogen‐rich gas. The short residence time pyrolysis of biomass (flash pyrolysis), at moderate temperatures, is being used to obtain a high yield of liquid products (up to 70% wt), particularly interesting as energetic vectors. Bio‐oil can substitute for fuel oil—or diesel fuel—in many static applications including boilers, furnaces, engines and turbines for electricity generation. While commercial biocrudes can easily substitute for heavy fuel oils, it is necessary to improve the quality in order to consider biocrudes as a replacement for light fuel oils. For transportation fuels, high severity chemical/catalytic processes are needed. An attractive future transportation fuel can be hydrogen, produced by steam reforming of the whole oil, or its carbohydrate‐derived fraction. Pyrolysis gas—containing significant amount of carbon dioxide, along with methane—might be used as a fuel for industrial combustion. Presently, heat applications are most economically competitive, followed by combined heat and power applications; electric applications are generally not competitive. Copyright © 2011 John Wiley & Sons, Ltd.     

Life cycle assessment of electricity generation using fast pyrolysis bio-oil

Biomass is expected to become an important energy source in U.S. electricity generation under state-lead renewable portfolio standards. This paper investigated the greenhouse gas (GHG) emissions for energy generated from forest resources through pyrolysis-based processing. The GHG emissions of producing pyrolysis bio-oil (pyrolysis oil) from different forest resources were first investigated; logging residues collected from natural regeneration mixed hardwood stands, hybrid poplar cultivated and harvested from abandoned agricultural lands, short rotation forestry (SRF) willow plantations and waste wood available at the site of the pyrolysis plant. Effects of biomass transportation were investigated through a range of distances to a central pyrolysis facility through road transport by semi-truck. Pyrolysis oil is assumed to be converted to electrical power through co-combustion in conventional fossil fuels power plants, gas turbine combined cycle (GTCC) and diesel generators. Life cycle GHG emissions were compared with power generated using fossil fuels and power generated using biomass direct combustion in a conventional Rankine power plant. Life cycle GHG savings of 77%–99% were estimated for power generation from pyrolysis oil combustion relative to fossil fuels combustion, depending on the biomass feedstock and combustion technologies used. Several scenario analyses were conducted to determine effects of pyrolysis oil transportation distance, N-fertilizer inputs to energy crop plantations, and assumed electricity mixes for pyrolysis oil production.     

The Canadian synthetic fuel industry—a major user of hydrogen

Oil sands and coal will be the dominant future sources of synthetic fuels in Canada. Proved recoverable reserves of oil sands are equivalent to 54 y of supply at current petroleum production rates; established recoverable coal reserves could meet both Canada's petroleum and coal requirements (at current production rates) for 58 y. It is expected that advances in technology will extend these figures by many hundreds of years.Current production from oil sands is equivalent to roughly 10% of Canada's petroleum energy demand. The hydrogen requirement for the existing oil sand plants is 160 million scf per day, and this figure is expected to increase to at least 1000 million scf per day before the year 2005. Natural gas is the current source of hydrogen but coke gasification and electrolysis of water are potential future sources of supply. A combination of coke gasification and electrolysis, with the oxygen generated from the latter being used for the gasification reaction, shows promise.No commercial coal conversion plants exist in Canada, but extensive laboratory and bench unit testing of both pyrolysis and liquefaction processes are underway. Two-staged liquefaction processing has been shown to give higher liquid yields with lower hydrogen consumption and warrants further research and development. Due to the lower hydrogen content of coal, the hydrogen requirements for coal liquefaction plants will be more than double that of oil sand plants of equivalent output.     

Oil consumption and CO2 emissions in China's road transport: current status,future trends,and policy implications

With the rapid economic growth in China, the Chinese road transport system is becoming one of the largest and most rapidly growing oil consumers in China. This paper attempts to present the current status and forecast the future trends of oil demand and CO₂ emissions from the Chinese road transport sector and to explore possible policy measures to contain the explosive growth of Chinese transport oil consumption. A bottom-up model was developed to estimate the historical oil consumption and CO₂ emissions from China's road transport sector between 1997 and 2002 and to forecast future trends in oil consumption and CO₂ emissions up to 2030. To explore the importance of policy options of containing the dramatic growth in Chinese transport oil demand, three scenarios regarding motor vehicle fuel economy improvements were designed in predicting future oil use and CO₂ emissions. We conclude that China's road transportation will gradually become the largest oil consumer in China in the next two decades but that improvements in vehicle fuel economy have potentially large oil-saving benefits. In particular, if no control measures are implemented, the annual oil demand by China's road vehicles will reach 363 million tons by 2030. On the other hand, under the low- and high-fuel economy improvement scenarios, 55 and 85 million tons of oil will be saved in 2030, respectively. The scenario analysis suggests that China needs to implement vehicle fuel economy improvement measures immediately in order to contain the dramatic growth in transport oil consumption. The imminent implementation is required because (1) China is now in a period of very rapid growth in motor vehicle sales; (2) Chinese vehicles currently in the market are relatively inefficient; and (3) the turnover of a fleet of inefficient motor vehicles will take a long time.     

Use of pyrolysis oil in a test diesel engine to study the feasibility of a diesel power plant concept

The economic viability of power production in a diesel power plant utilizing flash pyrolysis oil produced from sawmill wastes in Finland has been investigated. A combination of biomass feedstock costs, pyrolysis oil fuel properties (ignition quality, lubricating properties, combustion speed and duration, emissions, etc.) and their effect on power plant investments and maintenance will ultimately determine electricity busbar costs and the economic competitiveness of the concept. Pyrolysis oil is not a suitable fuel for a conventional diesel engine as such. The preliminary tests with additive treated pyrolysis oil demonstrated, however, that once ignition has taken place, pyrolysis oil burns rapidly. Pyrolysis oil may be a suitable primary fuel for a diesel engine with a pilot injection system, which secures the ignition of the main fuel.     

Combustion engine applications of waste tyre pyrolytic oil

There is abundant worldwide research into combustion engine applications for tyre pyrolysis oil (TPO). However, many of these studies demonstrate conflicting or ambiguous results, so although the huge number of used tyres promises good availability for TPO, its role as fuel for transport applications is still uncertain. This review´s goal is to clarify the case for TPO as transport fuel by means of a critical, wide-ranging and updated review of TPO's engine applications. The work gathers, collates and analyses the results of over 200 influential original research papers, aiming to answer the governing research questions related to TPO production and quality, post-processing and quality improvement and its final end-use engine validation. The work re-evaluates the environmental aspects of TPO technology, setting it against the latest backdrop of growing climate change concern and the urgency to find alternative fuels. The hard economics of TPO are also addressed, for example, assessing other end-of-life tyre management routes and competing fuel alternatives.The critical discussion on the key issues, including the most relevant drivers and boundaries, points towards TPO's use as a fuel component in marine, off-road and heavy-duty road applications. The results indicate that state-of-the-art production methods yield fuel that could be used directly in bunkering chains for marine transport as low-sulphur fuel oil. Discussion reveals that automotive applications are limited to blends not exceeding 10% tyre pyrolytic oil: sulphur and polyaromatic hydrocarbons contents and particulate emissions are the main constraints. Pyrolysis process efficiency is high and feedstock for TPO is both available and flexible. Waste tyre-derived pyrolytic oils could function as a supplementary solution to biofuels, blended to take advantage of their complementary properties.The particular added value of this review is that it bridges the latest knowledge from several domains related to TPO fuel: industrial management, process chemistry, fuel science and combustion/engine research. The resultant analysis is expressed in terms that are accessible to all those domains. It underlines how studies from an individual domain perspective fail to produce the holistic view. The review creates a route towards modern multidisciplinary research supporting TPO´s role in global transition to circular economy.     

Determinants of China's energy imports: An empirical analysis

Sustained economic growth in China has triggered a surge of energy imports, especially oil imports. This paper investigates the determinants of China's energy import demand by using cointegraiton and VECM techniques. The findings suggest that, in the long run, growth of industrial production and expansion of transport sectors affect China's oil imports, while domestic energy output has a substitution effect. Thus, as the Chinese economy industrializes and the automotive sector expands, China's oil imports are likely to increase. Though China's domestic oil production has a substitution effect on imports, its growth is limited due to scarce domestic reserve and high exploration costs. It is anticipated that China will be more dependent on overseas oil supply regardless of the world oil price.     

Microwave-induced pyrolysis of waste truck tyres with carbonaceous susceptor for the production of diesel-like fuel

Microwave-induced pyrolysis technique was utilised to pyrolyse waste truck tyres (TT) into useful pyrolysis oil with the aid of activated carbon. The effect of temperature was studied to determine the truck-tyre pyrolysis oil (TTPO) yield, hydrocarbon fractions, chemicals composition, energy yield and fuel properties. The activated carbon functions as microwave absorber to elevate the pyrolysis temperature for enhancing production of pyrolysis oil. The optimal pyrolysis temperature of 500 °C produces highest TTPO yield of 38.12 wt% with calorific value of 42.39 MJkg^?1 and energy yield of 40.55 wt%. Detailed analysis shows the TTPO contained large amount of aromatic hydrocarbons and limonene (14.29%) compared to pyrolysis oil from personal car tyre. Among the important chemical compounds also discovered in TTPO are benzene, toluene, xylene (BTX). The relative yields of toluene obtained at 400 °C is 14.85%, whereas the relative yields of benzene and xylene at 450 °C were 0.85 and 7.60%, respectively. The physiochemical properties of TTPO500 are rather similar to conventional diesel, except the slightly lower flash point and calorific value for the former. This work shows that microwave-induced pyrolysis is a promising technique to recover diesel-like fuel for use as supplemental alternative fuel.     

Giant oil field decline rates and their influence on world oil production

The most important contributors to the world's total oil production are the giant oil fields. Using a comprehensive database of giant oil field production, the average decline rates of the world's giant oil fields are estimated. Separating subclasses was necessary, since there are large differences between land and offshore fields, as well as between non-OPEC and OPEC fields. The evolution of decline rates over past decades includes the impact of new technologies and production techniques and clearly shows that the average decline rate for individual giant fields is increasing with time. These factors have significant implications for the future, since the most important world oil production base – giant fields – will decline more rapidly in the future, according to our findings. Our conclusion is that the world faces an increasing oil supply challenge, as the decline in existing production is not only high now but will be increasing in the future.     

Will restrictions on CO2 emissions require reductions in transport demand?

In this paper, the potential for the transportation sector to develop in a way that is consistent with long-term climate targets will be discussed. An important question is whether technical measures will be sufficient for reaching long-term climate targets. Although there is a large potential to significantly increase the use of bioenergy from today's level, there will be severe restrictions to its use within the transportation sector. Other renewable energy sources such as wind and solar are much more abundant and could provide the majority of the necessary transportation fuel in the long run. Although potentially much more expensive than current fuels they could, in combination with strong efficiency improvements, provide transport services at costs that could be acceptable in a growing economy. Transport levels as high as today or even higher could be consistent from a climate perspective if such fuels and technologies are utilised. Relying only on technical measures would, however, be risky, as there is no guarantee that the technology will develop at a sufficient rate. Furthermore, the existence of other negative environmental effects would argue for the implementation of measures affecting transport demand as well.     

Impact of oil price change on airline's stock price and volatility: Evidence from China and South Korea

Generally, the influence of crude oil price on the industries (enterprises) varies because they have different levels of reliance on crude oil. For airlines, the expenditure on fuel accounts for a considerable proportion of their gross costs; thus, airlines are unusually sensitive to changes in the crude oil price. The discussion on the relationship between crude oil price and airlines will help the airlines improve their ability to cope with the crude oil price risk. In addition, the responses of South Korean and Chinese airlines in the event of a price shock, that take, are also very important as the airplane is a basic form of transportation in many countries. This study investigates the impact of three crude oil price (WTI, Brent, Dubai) change on the stock price and volatility of four airlines (Korean Air, Asiana Airlines, Air China, and China Eastern Airlines) using VAR-GARCH-BEKK model. The main findings are as follows. There is return and volatility spillover effect between crude oil price and the stock prices of airlines. The volatility spillover effect between the crude oil price and airlines' stock price is more significant than the return spillover effect. Compared with the transportation industry, the stock prices of smaller airlines of South Korea and China are relatively more sensitive to the change in oil price. In addition, compared with Korea's airlines, China's airlines are influenced more by the oil price change, implying that spillover effects owing to oil price are closely related to the different characteristics of the air transport markets of the two countries.     

Fast pyrolysis processes for biomass

Fast pyrolysis for production of liquids has developed considerably since the first experiments in the late 1970s. Many reactors and processes have been investigated and developed to the point where fast pyrolysis is now an accepted feasible and viable route to renewable liquid fuels, chemicals and derived products. It is also now clear that liquid products offer significant advantages in storage and transport over gas and heat. These advantages have caused greater attention to be paid to fast pyrolysis, leading to significant advances in process development.The technology of fast pyrolysis for liquids is noteworthy for the wide range of reactor configurations that have been developed to meet the stringent requirements for high yields of useful liquids, for use as a fuel in boilers, engines and turbines and as a source of chemical commodities. This review summarises the key features of fast pyrolysis and the resultant liquid product and describes the major reaction systems and processes that have been developed over the last 20 years.     

Identification of key oil refining technologies for China National Petroleum Co. (CNPC)

This paper summarizes the results from the project “Vision of the Key Petroleum Refining Technologies for China National Petroleum Co. (CNPC) in the Early 21st Century” undertaken by the Department of R&D Administration, CNPC, and its affiliate key laboratory, The Key Laboratory of Catalysis operated by China University of Petroleum, Beijing. The objective of the project was to identify the challenges and opportunities of CNPC's petroleum refining business given increasing economy globalization and stricter environmental regulations. Using the modified Delphi method, four key technologies for CNPC's oil refining industry were identified. They are: integrated fluid catalytic cracking (FCC), hydroprocessing, residue hydrocracking, and high-grade lubricant production. The most significant technology will be the integrated FCC technology that can economically increase the yield of light fractions as well as upgrade transportation fuels. In China, FCC units produce about 80% and 30% commercial gasoline and diesel, respectively. To ensure compliance with future environmental legislation, hydroprocessing technologies, including those related to petroleum product hydrorefining and distillate hydrocracking, should be developed. By combining residue hydrocracking and FCC technologies, poorer quality residua can be processed. Supplying high-grade lube oils is one of the main tasks for CNPC's oil refining industry. Development of hydrodewaxing technologies to manufacture API group II/III base oil is the main direction for CNPC's lubricant production business.     

Greenhouse impact assessment of peat-based Fischer–Tropsch diesel life-cycle

New raw materials for transportation fuels need to be introduced, in order to fight against climate change and also to cope with increasing risks of availability and price of oil. Peat has been recognised suitable raw material option for diesel produced by gasification and Fischer–Tropsch (FT) synthesis. The energy content of Finnish peat reserves is remarkable. In this study, the greenhouse impact of peat-based FT diesel production and utilisation in Finland was assessed from the life-cycle point of view. In 100 year's time horizon the greenhouse impact of peat-based FT diesel is likely larger than the impact of fossil diesel. The impact can somewhat be lowered by producing peat from the agricultural peatland (strong greenhouse gas emissions from the decaying peatlayer are avoided) with new peat production technique, and utilising the produced biomass from the after-treatment area for diesel also. If diesel production is integrated with pulp and paper mill to achieve energy efficiency benefits and if the electricity demand can be covered by zero emission electricity, the greenhouse impact of peat-based FT diesel reduces to the level of fossil diesel when agricultural peatland is used, and is somewhat higher when forestry-drained peatland is used as raw material source.     

Catalytic hydrodeoxygenation of dehydrated liquid phase pyrolysis oil

Biomass has been considered as promising energy source that should be able to suffice the increasing energy demand in the future. Therefore, new biomass utilization technologies and concepts are highly desirable. This paper contributes to the understanding of liquid phase pyrolysis oil upgrading that differs from the intensively investigated fast pyrolysis oil. Two new approaches, which were never reported in literature before, where investigated in this paper. At first, the liquid phase pyrolysis oil was dehydrated to lower transportation costs and increase energy density and efficiency of further upgrading steps. At second, a catalyst screening for hydrodeoxygenation (HDO) of dehydrated liquid phase pyrolysis oil was conducted in a batch reactor. Neither the dehydration nor the HDO of dehydrated liquid phase pyrolysis oil were reported in literature by now. The activity of the HDO catalysts Ru/C, Pt/C, and Pd/C as well as a Ni‐based catalyst was compared. HDO was investigated at 250 °C and 100 bar and at 300 °C and 150 bar. HDO of dehydrated liquid phase pyrolysis oil was observed with all catalysts. The Pt/C catalyst was found to be most promising with respect to the oil yield (56 wt.%), the deoxygenation ratio (65%), and hydrogen content (8.6 wt.%). Copyright © 2014 John Wiley & Sons, Ltd.     

Energy and exergy efficiencies in Turkish transportation sector, 1988–2004

This study aims at examining energy and exergy efficiencies in Turkish transportation sector. Unlike the previous studies, historical data is used to investigate the development of efficiencies of 17 years period from 1988 to 2004. The energy consumption values in tons-of-oil equivalent for eight transport modes of four transportation subsectors of the Turkish transportation sector, including hard coal, lignite, oil, and electricity for railways, oil for seaways and airways, and oil and natural gas for highways, are used. The weighted mean energy and exergy efficiencies are calculated for each mode of transport by multiplying weighting factors with efficiency values of that mode. They are then summed up to calculate the weighted mean overall efficiencies for a particular year. Although the energy and exergy efficiencies in Turkish transport sector are slightly improved from 1988 to 2004, the historical pattern is cyclic. The energy efficieny is found to range from 22.16% (2002) to 22.62% (1998 and 2004) with a mean of 22.42±0.14% and exergy efficiency to range from 22.39% (2002) to 22.85% (1998 and 2004) with a mean of 22.65±0.15%. Overall energy and exergy efficiencies of the transport sector consist mostly of energy and exergy efficiencies of the highways subsector in percentages varying from 81.5% in 2004 to 91.7% in 2002. The rest of them are consisted of other subsectors such as railways, seaways, and airways. The overall efficiency patterns are basically controlled by the fuel consumption in airways in spite of this subsector's consisting only a small fraction of total. The major reasons for this are that airways efficiencies and the rate of change in fuel consumption in airways are greater than those of the others. This study shows that airway transportation should be increased to improve the energy and exergy efficiencies of the Turkish transport sectors. However, it should also be noted that no innovations and other advances in transport technologies are included in the calculations. The future studies including such details will certainly help energy analysts and policy makers more than our study.     

Main routes for the thermo-conversion of biomass into fuels and chemicals. Part 1: Pyrolysis systems

Since the energy crises of the 1970s, many countries have become interest in biomass as a fuel source to expand the development of domestic and renewable energy sources and reduce the environmental impacts of energy production. Biomass is used to meet a variety of energy needs, including generating electricity, heating homes, fueling vehicles and providing process heat for industrial facilities. The methods available for energy production from biomass can be divided into two main categories: thermo-chemical and biological conversion routes. There are several thermo-chemical routes for biomass-based energy production, such as direct combustion, liquefaction, pyrolysis, supercritical water extraction, gasification, air–steam gasification and so on. The pyrolysis is thermal degradation of biomass by heat in the absence of oxygen, which results in the production of charcoal (solid), bio-oil (liquid), and fuel gas products. Pyrolysis liquid is referred to in the literature by terms such as pyrolysis oil, bio-oil, bio-crude oil, bio-fuel oil, wood liquid, wood oil, liquid smoke, wood distillates, pyroligneous tar, and pyroligneous acid. Bio-oil can be used as a fuel in boilers, diesel engines or gas turbines for heat and electricity generation.     

Energy analysis of batteries in photovoltaic systems. Part I: Performance and energy requirements

The technical performance and energy requirements for production and transportation of a stand alone photovoltaic (PV)-battery system at different operating conditions are presented. Eight battery technologies are evaluated: lithium-ion (Li-ion), sodium–sulphur (NaS), nickel–cadmium (NiCd), nickel–metal hydride (NiMH), lead–acid (PbA), vanadium-redox (VRB), zinc–bromine (ZnBr) and polysulfide-bromide (PSB). In the reference case, the energy requirements for production and transport of PV-battery systems that use the different battery technologies differ by up to a factor of three. Production and transport of batteries contribute 24–70% to the energy requirements, and the PV array contributes 26–68%. The contribution from other system components is less than 10%. The contribution of transport to energy requirements is 1–9% for transportation by truck, but may be up to 73% for air transportation. The energy requirement for battery production and transport is dominant for systems based on NiCd, NiMH and PbA batteries. The energy requirements for these systems are, therefore, sensitive to changes in battery service life and gravimetric energy density. For systems with batteries with relatively low energy requirement for production and transportation (Li-ion, NaS, VRB, ZnBr, PSB), the battery charge–discharge efficiency has a larger impact. In Part II, the data presented here are used to calculate energy payback times and overall battery efficiencies of the PV-battery systems.     

Reduction potentials of energy demand and GHG emissions in China's road transport sector

Rapid growth of road vehicles, private vehicles in particular, has resulted in continuing growth in China's oil demand and imports, which has been widely accepted as a major factor effecting future oil availability and prices, and a major contributor to China's GHG emission increase. This paper is intended to analyze the future trends of energy demand and GHG emissions in China's road transport sector and to assess the effectiveness of possible reduction measures. A detailed model has been developed to derive a reliable historical trend of energy demand and GHG emissions in China's road transport sector between 2000 and 2005 and to project future trends. Two scenarios have been designed to describe the future strategies relating to the development of China's road transport sector. The ‘Business as Usual’ scenario is used as a baseline reference scenario, in which the government is assumed to do nothing to influence the long-term trends of road transport energy demand. The ‘Best Case’ scenario is considered to be the most optimized case where a series of available reduction measures such as private vehicle control, fuel economy regulation, promoting diesel and gas vehicles, fuel tax and biofuel promotion, are assumed to be implemented. Energy demand and GHG emissions in China's road transport sector up to 2030 are estimated in these two scenarios. The total reduction potentials in the ‘Best Case’ scenario and the relative reduction potentials of each measure have been estimated.     

Environmental cost of energy consumption and biodiesel as a solution (case study: Iran)

ABSTRACT

More than 8.5 million people live in Tehran, the capital of Iran, with 111 pollutant days during 2016. Based on Iranian 2016 energy balance sheet, more than 76% of SPM was emitted by gas oil combustion. To determine the main pollutant fuel-consuming sector, the amount of gas oil consumption and SPM production are investigated. Therefore, the transportation and power plant sectors are determined as the main gas oil users with 51.1% and 30.5% of its total consumption. Next, the reduced external cost of implementing biodiesel instead of gas oil for mobile and fixed sources is deliberated. Finally, by comparing the external cost of gas oil consumption and Iran's gross domestic production in 2016, it is revealed that by replacing gas oil with biofuels, 3.935 billion dollars (0.95% of gross domestic production of Iran in 2016) can be reduced.