Economic tradeoff between biochar and bio-oil production via pyrolysis

This paper examines some of the economic tradeoffs in the joint production of biochar and bio-oil from cellulosic biomass. The pyrolysis process can be performed at different final temperatures, and with different heating rates. While most carbonization technologies operating at low heating rates (large biomass particles) result in higher yields of charcoal, fast pyrolysis (which processes small biomass particles) is the preferred technology to produce bio-oils. Varying operational and design parameters can change the relative quantity and quality of biochar and bio-oil produced for a given feedstock. These changes in quantity and quality of both products affect the potential revenue from their production and sale. We estimate quadratic production functions for biochar and bio-oil. The results are then used to calculate a product transformation curve that characterizes the yields of bio-oil and biochar that can be produced for a given amount of feedstock, movement along the curve corresponds to changes in temperatures, and it can be used to infer optimal pyrolysis temperature settings for a given ratio of biochar and bio-oil prices.     

Assessment of potential biomass energy production in China towards 2030 and 2050

The objective of this paper is to provide a more detailed picture of potential biomass energy production in the Chinese energy system towards 2030 and 2050. Biomass for bioenergy feedstocks comes from five sources, which are agricultural crop residues, forest residues and industrial wood waste, energy crops and woody crops, animal manure, and municipal solid waste. The potential biomass production is predicted based on the resource availability. In the process of identifying biomass resources production, assumptions are made regarding arable land, marginal land, crops yields, forest growth rate, and meat consumption and waste production. Four scenarios were designed to describe the potential biomass energy production to elaborate the role of biomass energy in the Chinese energy system in 2030. The assessment shows that under certain restrictions on land availability, the maximum potential biomass energy productions are estimated to be 18,833 and 24,901?PJ in 2030 and 2050.     

Waste and residue availability for advanced biofuel production in EU Member States

The EU is adopting policy measures to promote the use of advanced biofuels for transport made from sustainable sources including wastes and residues. As Member States prepare to implement these policy changes, they will need to understand if they have sufficient resource to meet an advanced biofuel target. This study assesses the availability of agricultural residues, forestry residues, and biogenic wastes that could potentially be used for advanced biofuel production in EU Member States at the present and projected to 2020 and 2030. This analysis incorporates specific information on agricultural, forestry, and waste production, management practices, and environmental risks in each Member State in order to model the amounts of residues needed to preserve soil quality and that are utilized in other industries; we exclude these quantities in order to determine the sustainable biomass potential that can be achieved without significant adverse impacts on the environment or biomass markets. We find that most EU Member States are likely to have more than enough sustainably available feedstock to meet the advanced biofuel requirement, and a majority may have more than 10 times the necessary amount. While this study does not assess economic viability of advanced biofuel production, from a resource perspective, the target appears to be achievable in most Member States. Some countries, including Austria, Cyprus, Denmark, Estonia, Ireland, Luxembourg, Malta, and Slovenia, may need to import either feedstock or advanced biofuel from neighboring countries to meet the target.     

Biogas as a potential renewable energy source: A Ghanaian case study

The associated harmful environmental, health and social effects with the use of traditional biomass and fossil fuel has enhanced the growing interest in the search for alternate cleaner source of energy globally. Ghana, a developing country depends heavy on woodfuel as a source of fuel contributing about 72% of the primary energy supply with crude oil and hydro making up the rest. Biogas generation has simply been seen as a by-product of anaerobic digestion of organic waste. Having proven to be a practicable and promising technology, it has been very successful and a very reliable and clean source of energy when proper management programmes are followed. There are vast biomass resources including organic waste in Ghana that have the potential for use as feedstock for biogas production to reduce the over reliance of woodfuel and fossil fuel, and to help reduce the it would reduce greenhouse gas emissions which may be affecting climate change. Ghana having the technical potential of constructing about 278,000 biogas plants, only a little over 100 biogas plants has so far been established. This paper presents the energy situation and the status of the biogas technology and utilization in Ghana. It also presents the potential benefits, prospects and challenges of the biogas technology.     

A review of agricultural crop residue supply in Canada for cellulosic ethanol production

This paper estimates the availability of agricultural crop residue feedstocks in Canada for cellulosic ethanol production. Canada's major field crops generate 100.6 million dry mega grams (Mg) of crops per year while non-forage crops produce 67 million dry Mg, leaving abundant agricultural residues for use as second generation feedstock for cellulosic ethanol production. This study used crop production and livestock data from Statistics Canada for a 10-year period (2001–2010), as well as tillage data from Statistics Canada census years 2001 and 2006, to estimate crop residue availability by province and soil zone. Total residue yield from crops is calculated by incorporating straw to grain ratios. Total agricultural residues available for ethanol production are computed by deducting soil conservation and livestock uses. An average of 48 million dry Mg of agricultural residues is available per year, with a minimum of 24.5 million dry Mg in drought year 2002. This implies an average yearly potential ethanol production of 13 billion litres from crop residues over the 2001–2010 period, with a minimum of 6.6 billion litres in 2002. Ontario, Manitoba, Saskatchewan, and Quebec have enough agricultural residue supply to set up ethanol plants using agricultural crop residues as primary lignocellulosic feedstocks. There is great variability in agricultural residue production between the provinces and by soil zone. Understanding variability in feedstock supply is important for the economics and operational planning of a cellulosic ethanol biorefinery. Factors such as residue yield per hectare and soil zone will influence cellulosic ethanol plant establishment in order to exploit the abundance of lignocellulosic biomass for an ethanol plant.     

我国生物质热解特性及工艺研究进展

我国秸秆和畜禽粪便等生物质原料的产量非常丰富,用这些量大而来源广泛的生物质原料热解制取生物炭,可用于燃料,替代化石能源,还可用作吸附剂以及土壤改良剂,用途广泛。本文从原料的种类,热解技术,工艺过程,以及影响因素等四方面,对生物质热解特性以及制取生物炭工艺研究现状进行梳理、分析与研究。依据现阶段的研究结果,阐明未来应在秸秆原料基础特性、秸秆热解特性、优化不同地域间的秸秆热解工艺以及畜禽粪便热解制炭等方面着手进行深入研究。     

Bioenergy in Australia: An improved approach for estimating spatial availability of biomass resources in the agricultural production zones

Bioenergy production from crops and agricultural residues has a greenhouse gas mitigation potential. However, there is considerable debate about the size of this potential. This is partly due to difficulties in estimating the feedstock resource base accurately and with good spatial resolution. Here we provide two techniques for spatially estimating crop-based bioenergy feedstocks in Australia using regional agricultural statistics and national land use maps. The approach accommodates temporal variability by estimating ranges of feedstock availability and the shifting nature of zones of the highest spatial concentration of feedstocks. The techniques are applicable to biomass production from forestry, agricultural residues or oilseeds, all of which have been proposed as biofuel feedstocks.     

Analysis of biomass residues potential for electrical energy generation in Albania

This paper presents the status of research of biomass potential for producing electrical energy in Albania. Biomass potential can be generated by different sources. Three types of biomass energy sources are included: dedicated bioenergy crops, agricultural and forestry residues and waste. The technical electrical energy considered in this study was calculated with two converting techniques: (1) combustion of the feedstock directly in an incinerator and then driving a steam generator for producing electrical energy and (2) production of biogas from an anaerobic digester and running a turbine for electrical energy generation. Analysis of the potential biomass resource quantity was computed according to statistical reports, literature review and personal investigations. From the biomass residue potential was calculated in terms of the theoretical energy content (total heating value) of every type of feedstock and the technical energy content for every Albanian prefecture according to different burning processes and different operation efficiencies. Results show that Albania was producing around of 4.8 million tons of dry biomass in year 2005. The theoretical energy content of biomass in Albania was 11.6 million MWh/a, and the technical electrical energy production was 3 million MWh/a. The electrical energy produced is equivalent to 45.8% of total Albania Country annual electrical consumption. In Albania Country, residues from agriculture, forest and urban waste represent a large biomass potential. By actual conversion techniques it is possible to generate one third of the theoretical heat energy into technical electrical energy. The use of heat from cogeneration plants depends on local heat provision conditions. It is another big energy potential but excluded in this study, so the rest of energy is considered as heat losses.     

Assessing the potentials of agricultural residues for energy: What the CDM experience of India tells us about their availability

The potential of agricultural residues has been assessed worldwide and at different scales. Interpreting results so as to determine the possible role of this biomass feedstock in energy supplies, requires a clearer understanding of the conditions in which residues can effectively be mobilized for energy production. The experience of India with hundreds of projects where agricultural residues are transformed to heat and power partially sold to the grid, is analyzed and checked against the residue potentials that have been assessed in this country. We find that, in the absence of technological improvements in biomass conversion, the apparent success of Indian bioenergy projects is not sustainable in the long run due to rapid exhaustion effects on residue availability, coupled with the increasing costs that would be difficult to compensate by higher electricity tariffs. We also identify there is a serious agricultural issue which needs to be addressed in regard to degraded soils; this could lead to the reallocation of all primary residues, as well as part of secondary residues to soil and livestock needs. Such perspectives are considered within three contrasted scenario storylines.     

Woody biomass availability for bioethanol conversion in Mississippi

This study evaluated woody biomass from logging residues, small-diameter trees, mill residues, and urban waste as a feedstock for cellulosic ethanol conversion in Mississippi. The focus on Mississippi was to assess in-state regional variations and provide specific information of biomass estimates for those facilities interested in locating in Mississippi. Supply and cost of four woody biomass sources were derived from Forest Inventory Analysis (FIA) information, a recent forest inventory conducted by the Mississippi Institute for Forest Inventory, and primary production costs. According to our analysis, about 4.0 million dry tons of woody biomass are available for production of up to 1.2 billion liters of ethanol each year in Mississippi. The feedstock consists of 69% logging residues, 21% small-diameter trees, 7% urban waste, and 3% mill residues. Of the total, 3.1 million dry tons (930 million liters of ethanol) can be produced for $34 dry ton^?1 or less. Woody biomass from small-diameter trees is more expensive than other sources of biomass. Transportation costs accounted for the majority of total production costs. A sensitivity analysis indicates that the largest impacts in production costs of ethanol come from stumpage price of woody biomass and technological efficiency. These results provide a valuable decision support tool for resource managers and industries in identifying parameters that affect resource magnitude, type, and location of woody biomass feedstocks in Mississippi.     

Potentialities of energy generation from waste and feedstock produced by the agricultural sector in Brazil: The case of the State of Paraná

The State of Paraná contributes significantly for the Brazilian production of sugar cane, ethanol, soybeans and pigs. In addition to the current production of ethanol, the State has a huge potential for electricity, biodiesel and biogas production. This paper presents an overview of the current situation regarding energy generation from the agricultural sector in the State, an assessment of the potentialities of energy generation from sugar cane residues and pig agricultural chains, as well as an analysis of the socioeconomic factors underlying the availability of feedstock for biodiesel production. This study has shown that it is possible to expand the energy supply in the State using residual biomass from the sugar cane and pig production. On the other side, the biodiesel production increase in the State will depend on the expansion in the consumption of products that use the cake as raw material; the increase in the feedstock availability other than canola, castor beans and sunflower; the increase of the number of family farmers as feedstock providers, so as to ensure access for biodiesel producers to the Social Fuel Stamp.     

Biochar as a viable carbon sequestration option: Global and Canadian perspective

Biochar production and mixing in soil are seen as the best options for atmospheric carbon sequestration, providing simultaneous benefits to soil and opportunities for distributed energy generation. The proximity of biomass source and biochar dispersal greatly reduces the energy and emissions footprint of the whole process. The viability of the whole biochar process is examined from two boundary points: is there enough biomass around to have significant impact on the atmospheric CO₂ levels and is there enough soil area for biochar dispersal. The answers are soundly positive, both for the world as a whole and for Canada, for which a more detailed analysis was done. However, the massive adoption of biochar solution is critically dependent on proper recognition of its carbon sequestration impact its soil improvement potentials. To that extent the International Biochar Initiative, together with national chapters, including recently formed Canadian Biochar Initiative, are actively promoting biochar related research and policy framework. This paper addresses the questions of availability of sources and sites that would benefit from its dispersal.     

Gasification biochar as a valuable by-product for carbon sequestration and soil amendment

Thermal gasification of various biomass residues is a promising technology for combining bioenergy production with soil fertility management through the application of the resulting biochar as soil amendment. In this study, we investigated gasification biochar (GB) materials originating from two major global biomass fuels: straw gasification biochar (SGB) and wood gasification biochar (WGB), produced by a Low Temperature Circulating Fluidized Bed gasifier (LT-CFB) and a TwoStage gasifier, respectively, optimized for energy conversion. Stability of carbon in GB against microbial degradation was assessed in a short-term soil incubation study and compared to the traditional practice of direct incorporation of cereal straw. The GBs were chemically and physically characterized to evaluate their potential to improve soil quality parameters. After 110 days of incubation, about 3% of the added GB carbon was respired as CO₂, compared to 80% of the straw carbon added. The stability of GB was also confirmed by low H/C and O/C atomic ratios with lowest values for WGB (H/C 0.12 and O/C 0.10). The soil application of GBs exhibited a liming effect increasing the soil pH from ca 8 to 9. Results from scanning electron microscopy and BET analyses showed high porosity and specific surface area of both GBs, indicating a high potential to increase important soil quality parameters such as soil structure, nutrient and water retention, especially for WGB. These results seem promising regarding the possibility to combine an efficient bioenergy production with various soil aspects such as carbon sequestration and soil quality improvements.     

A review on biomass‐based hydrogen production for renewable energy supply

This article gives an overview of the state‐of‐the‐art biomass‐based hydrogen production technologies. Various biological and thermochemical processes of biomass are taken into consideration to find the most economical method of hydrogen production. Biohydrogen generated by biophotolysis method, photo‐fermentation and dark fermentation is studied with respect to various feedstocks in Malaysia. The fermentation approaches of biohydrogen production have shown great potential to be a future substitute of fossil fuels. Dark fermentation method is a simple biological hydrogen production method that uses a variety of substrate and does not require any light as a source of energy. A promising future for biohydrogen production is anticipated by this process both industrially and commercially. Feasibility of hydrogen production from pyrolysis and water gasification of various biomass feedstock confirm that supercritical water gasification (SCWG) of biomass is the most cost‐effective thermochemical process. Highly moisturized biomass could be employed directly in SCWG without any high‐cost drying process. Indeed, a small amount of energy is required to pressurize hydrogen in the storage tank because of highly pressurized SCWG process. The cost of hydrogen produced by SCWG of biomass is about US$3/GJ (US$0.35/kg), which is extremely lower than biomass pyrolysis method (in the range of US$8.86/GJ to US$15.52/GJ) and wind‐electrolysis systems and PV‐electrolysis systems (US$20.2/GJ and US$41.8/GJ, respectively). The best feedstock for biomass‐based hydrogen production is identified based on the availability, location of the sources, processes required for the preparation of the feedstock and the total cost of acquiring the feedstock. The cheapest and most abundantly available biomass source in Malaysia is the waste of palm industry. Hydrogen production from palm oil mill effluent and palm solid residue could play a crucial role in the energy mix of Malaysia. Malaysia has this great capability to supply about 40% of its annual energy demand by hydrogen production from SCWG of palm solid waste. Copyright © 2015 John Wiley & Sons, Ltd.     

Biomass availability, energy consumption and biochar production in rural households of Western Kenya

Pyrolytic cook stoves in smallholder farms may require different biomass supply than traditional bioenergy approaches. Therefore, we carried out an on-farm assessment of the energy consumption for food preparation, the biomass availability relevant to conventional and pyrolytic cook stoves, and the potential biochar generation in rural households of western Kenya. Biomass availability for pyrolysis varied widely from 0.7 to 12.4 Mg ha⁻¹ y⁻¹ with an average of 4.3 Mg ha⁻¹ y⁻¹, across all 50 studied farms. Farms with high soil fertility that were recently converted to agriculture from forest had the highest variability (CV = 83%), which was a result of the wide range of farm sizes and feedstock types in the farms. Biomass variability was two times lower for farms with low than high soil fertility (CV = 37%). The reduction in variability is a direct consequence of the soil quality, coupled with farm size and feedstock type. The total wood energy available in the farms (5.3 GJ capita⁻¹ y⁻¹) was not sufficient to meet the current cooking energy needs using conventional combustion stoves, but may be sufficient for improved combustion stoves depending on their energy efficiency. However, the biomass that is usable in pyrolytic cook stoves including crop residues, shrub and tree litter can provide 17.2 GJ capita⁻¹ y⁻¹ of energy for cooking, which is well above the current average cooking energy consumption of 10.5 GJ capita⁻¹ y⁻¹. The introduction of a first-generation pyrolytic cook stove reduced wood energy consumption by 27% while producing an average of 0.46 Mg ha⁻¹ y⁻¹ of biochar.     

Prospective life cycle carbon abatement for pyrolysis biochar systems in the UK

Life cycle assessment (LCA) of slow pyrolysis biochar systems (PBS) in the UK for small, medium and large scale process chains and ten feedstocks was performed, assessing carbon abatement and electricity production. Pyrolysis biochar systems appear to offer greater carbon abatement than other bioenergy systems. Carbon abatement of 0.7–1.3 t CO₂ equivalent per oven dry tonne of feedstock processed was found. In terms of delivered energy, medium to large scale PBS abates 1.4–1.9 t CO₂e/MWh, which compares to average carbon emissions of 0.05–0.30 t CO₂e/MWh for other bioenergy systems. The largest contribution to PBS carbon abatement is from the feedstock carbon stabilised in biochar (40–50%), followed by the less certain indirect effects of biochar in the soil (25–40%)—mainly due to increase in soil organic carbon levels. Change in soil organic carbon levels was found to be a key sensitivity. Electricity production off-setting emissions from fossil fuels accounted for 10–25% of carbon abatement. The LCA suggests that provided 43% of the carbon in the biochar remains stable, PBS will out-perform direct combustion of biomass at 33% efficiency in terms of carbon abatement, even if there is no beneficial effect upon soil organic carbon levels from biochar application.     

The role of biomass in California's hydrogen economy

This paper presents the results of a model of hydrogen production from waste biomass in California. We develop a profit-maximizing model of a biomass hydrogen industry from field to vehicle tank. This model is used to estimate the economic potential for hydrogen production from two waste biomass resources in Northern California—wheat straw and rice straw—taking into account the on the ground geographic dimensions of both biomass supply and hydrogen demand. The systems analysis approach allows for explicit consideration of the interactions between feedstock collection, hydrogen production, and hydrogen distribution in finding the optimal system design. This case study approach provides insight into both the real-world potential and the real-world cost of producing hydrogen from waste biomass. Additional context is provided through the estimation of California's total waste biomass hydrogen potential. We find that enough biomass is available from waste sources to provide up to 40% of the current California passenger car fuel demand as hydrogen. Optimized supply chains result in delivered hydrogen costing between $3/kg and $5.50/kg with one-tenth of the well-to-wheels greenhouse gas emissions of conventional gasoline-fueled vehicles.     

Production and characterization of bio-oil and biochar from rapeseed cake

New and renewable fuels are the major alternatives to conventional fossil fuels. Biomass in the form of agricultural residues is becoming popular among new renewable energy sources, especially given its wide potential and abundant usage. Pyrolysis is the most important process among the thermal conversion processes of biomass. In this study, the production of bio-oil and biochar from rapeseed cake obtained by cold extraction pressing was investigated and the various characteristics of biochar and bio-oil acquired under static atmospheric conditions were identified. The biochar obtained are carbon rich, with high heating value and relatively pollution-free potential solid biofuel. The bio-oil product was presented as an environmentally friendly green biofuel candidate.     

Biomass availability for lignocellulosic ethanol production

The ethanol industry in North America uses starch derived from corn as its primary feedstock. In order to better understand the geographical distribution of advanced ethanol production, potential sources of lignocellulosic biomass for the process are considered. It is shown that the corn-producing regions of North America already support significant amounts of ethanol production, and that few unexploited sources of corn remain for the industry to utilize. Accessing other sources of sugar, including other types of biomass such as lignocellulosic materials, will become necessary for the industry as it expands, quite apart from the need to meet government mandates. The ability of bioconversion and thermochemical conversion to generate biofuels from lignocellulosic biomass is reviewed. The availability of lignocellulosic residues from agricultural and forestry operations is described, and the potential biofuel production associated with these residues is described. A residue-based process could greatly extend the potential of the ethanol industry to become a substantial contributor to the fuel and energy requirements of North America. It is estimated that ethanol production from residues could provide up to 13.7% of Canada’s 2009 transportation fuel demand, and up to 5.2% of the United States’ 2010 fuel demand. Utilizing lignocellulosic biomass will extend the geographic range of the biofuel industry, and increase the stability and security of this sector by reducing the impact of localized disruptions in supply. Development of a residue-based industry will help create the technologies needed to process energy crops as North America moves towards greater transportation fuel independence.     

Co-pyrolysis of waste plastic and solid biomass for synergistic production of biofuels and chemicals-A review

The amount of plastics disposed from modern lifestyles have increased sharply in recent years. Solid biomass is an abundant energy resource that exists worldwide. Transformation of these waste plastics and solid biomass feedstock mixtures via co-pyrolysis can provide synergistic product enhancement for fuels and value-added products. The produced products can be used as chemicals and pollutant sorbents to foster eco-friendly pathways for waste management and sustainability. Progress into this avenue of waste disposal and energy production is the focus of this review. Properties of characteristic solid feedstock mixtures are discussed with focus on elemental composition, proximate analysis, and heating value. Effective H to C ratio of the different feedstocks is evaluated for asserting the quality of petrochemical equivalent products produced from co-pyrolysis of plastic wastes and biomass. The characteristics of polyethylene terephthalate (PET), high density and low-density polyethylene (HDPE & LDPE), polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS) and other major plastic waste components are discussed with focus on synergistic effects attainable by co-pyrolyzing them with biomass. State-of-the-art experimental methods for co-pyrolysis investigation are reviewed in detail using TGA, pyrolyzer, fixed bed reactor, fluidized bed reactor, microwave, and multi-step reactors using GC, MS, and FTIR diagnostics. In addition, different catalytic co-pyrolysis reactors are compared and discussed at different ratios of feedstock to catalyst, reactor temperature, and other operational parameters along with an in-depth understanding of several catalytic processing (ZSM-5 based catalyst, transition metal-based catalyst, multipurpose catalysts and ex-situ catalyst) for favorable products yield. Co-pyrolysis of waste plastic and solid biomass mixtures are reviewed for insights into liquid products for fuels and chemicals, as well as yield and composition of gases and solid residues evolved along with surface characteristics of the solid residues obtained from the selected configurations. The challenges and opportunities envisioned for the development in co-pyrolysis of several solid organic waste and plastic feedstock mixtures are also discussed. The goal was to provide favorable feasible pathways for clean and efficient disposal of plastic wastes with the incorporation of waste biomass for enhanced synergistic effects in waste disposal along with the recovery of energy and value-added products.