Political,economic and environmental impacts of biomass-based hydrogen

The purpose of this study is to assess the political, economic and environmental impacts of producing hydrogen from biomass. Hydrogen is a promising renewable fuel for transportation and domestic applications. Hydrogen is a secondary form of energy that has to be manufactured like electricity. The promise of hydrogen as an energy carrier that can provide pollution-free, carbon-free power and fuels for buildings, industry, and transport makes it a potentially critical player in our energy future. Currently, most hydrogen is derived from non-renewable resources by steam reforming in which fossil fuels, primarily natural gas, but could in principle be generated from renewable resources such as biomass by gasification. Hydrogen production from fossil fuels is not renewable and produces at least the same amount of CO₂ as the direct combustion of the fossil fuel. The production of hydrogen from biomass has several advantages compared to that of fossil fuels. The major problem in utilization of hydrogen gas as a fuel is its unavailability in nature and the need for inexpensive production methods. Hydrogen production using steam reforming methane is the most economical method among the current commercial processes. These processes use non-renewable energy sources to produce hydrogen and are not sustainable. It is believed that in the future biomass can become an important sustainable source of hydrogen. Several studies have shown that the cost of producing hydrogen from biomass is strongly dependent on the cost of the feedstock. Biomass, in particular, could be a low-cost option for some countries. Therefore, a cost-effective energy-production process could be achieved in which agricultural wastes and various other biomasses are recycled to produce hydrogen economically. Policy interest in moving towards a hydrogen-based economy is rising, largely because converting hydrogen into useable energy can be more efficient than fossil fuels and has the virtue of only producing water as the by-product of the process. Achieving large-scale changes to develop a sustained hydrogen economy requires a large amount of planning and cooperation at national and international alike levels.     

Biomass energy perspective in Pakistan based on chemical looping gasification for hydrogen production and power generation

Biomass has appeared as one of the most encouraging renewable energy sources for the replacement of fossil fuels. An extensive study about the prospective of biomass to produce renewable energy in Pakistan has been exhibited in this article, which takes into account Pakistan's current energy and future potential. A new generation of transformative energy conversion technologies has been developed, including chemical looping. This technique has the potential to control air pollution and clean fuel production, all of which have been major global challenges of this century. Through recent research, the study aims to aid in understanding of biomass-based chemical looping gasification and its development. CHP and CCHP systems are developed processes that produce power, heat, and cooling. Systems using fuel cells have greater efficiency, between 60 and 70%. Additionally, the SOFC-based power generating techniques are associated with the best electrical efficiency (67%).     

生物质能的应用前景分析

生物质能是可再生能源的重要组成部分，生物质能的高效利用，对解决能源和生态环境问题将起到十分积极的作用。概述了目前生物质能的主要转换方式。化学转变中的液化、气化和热解技术是目前主要研究方向。通过液化、热解可以直接得到一些化工产品；通过气化可以得到合成气，可以用来合成氨或者甲醇。总之，通过这些转变不但可以得到一些化工产品，而且可以缓解化石能源桔竭带来的能源危机。     

Lignocellulosic biomass gasification technology in China

With the critical worldwide energy shortage and global environment concern, lignocellulosic biomass is regarded as one of the potential renewable energy resources to substitute conventional fossil fuels. Among various thermo-chemical conversion technologies, gasification is now regarded as an advanced and efficient method. Based on the mechanism of biomass gasification, this paper outlines different types of gasifiers that have been developed in China. Air gasification technology has been employed in the rural areas or forestry/agricultural processing entities. Obviously, the product gas for cooking and heating can significantly upgrade the living standard of rural residents. The product gas for heating boiler and generating electricity benefits the forest or agricultural processing enterprises. For China’s sustainable development of energy and environment, multi-cogeneration of heat, electricity and liquid fuels together with chemical feedstock will be a potential direction for efficiently utilizing product gas from lignocellulosic biomass. This means oxygen (including oxygen-enriched air) gasification and steam gasification should be taken into more consideration.     

Sustainable rural bioenergy production for developing countries

Bioenergy is a renewable energy source made from biomass, which are organic materials such as plants and animals. Until enough biomass resources to ensure energy demand in the world is available, the bioenergy obtained from biomass, there may be used for heat, electrical and transport. Main biomass thermo-chemical conversion technologies are pyrolysis, gasification, and liquefaction. Biomass can be burned to produce heat and electricity, changed to gas-like fuels such as methane, hydrogen, and carbon monoxide, or changed to a liquid fuel. Modern biomass can be used for the generation of electricity and heat using modern conversion technologies. Technological advances have made modern biomass cogeneration plants cleaner, more efficient, and, under certain conditions, cost-effective as compared to public utility grids and fossil-fuel boilers or generators. Biomass can be converted to liquid biofuels: bioethanol and biodiesel. Two biofuels are becoming more and more attractive and competitive as complementary to or substitutions for petroleum basic products, due to their economic and environmental benefits.     

Hydrogen from biomass – Present scenario and future prospects

Hydrogen is considered in many countries to be an important alternative energy vector and a bridge to a sustainable energy future. Hydrogen is not an energy source. It is not primary energy existing freely in nature. Hydrogen is a secondary form of energy that has to be manufactured like electricity. It is an energy carrier. Hydrogen can be produced from a wide variety of primary energy sources and different production technologies. About half of all the hydrogen as currently produced is obtained from thermo catalytic and gasification processes using natural gas as a starting material, heavy oils and naphtha make up the next largest source, followed by coal. Currently, much research has been focused on sustainable and environmental friendly energy from biomass to replace conventional fossil fuels. Biomass can be considered as the best option and has the largest potential, which meets energy requirements and could insure fuel supply in the future. Biomass and biomass-derived fuels can be used to produce hydrogen sustainably. Biomass gasification offers the earliest and most economical route for the production of renewable hydrogen.     

生物质热化学液化技术研究进展

随着化石燃料可开采量的减少和人类对全球性环境问题的关注，生物质作为一种可再生能源，由于资源丰富，分布广泛，燃烧过程对环境的低污染性，CO2的净零排放等特性日益成为国内外众多学者研究的热点课题之一。生物质转化技术可分为生物法和热化学转化法，后者主要有气化、热解、高压液化及与煤共处理等工艺。其中生物质热化学液化由于比气化能得到更有价值的液体产物，操作温度比热解低，因而作为一项资源高效利用的新工艺日益受到重视。综述了近五年来生物质热化学液化技术方面的最新进展，提出了今后的研究动态与发展方向，并针对我国现状提出应采取的对策。     

Biomass: A modern and environmentally acceptable fuel

The energy of the sun and carbon dioxide from the atmosphere are captured by plants during photosynthesis. Plant biomass can be used to absorb carbon dioxide emissions from fossil fuels, or it can be converted into modern energy carriers such as electricity, and liquid and gaseous fuels. Biomass supplies 13% of the world's energy consumption (55 EJ, 1990), and in some developing countries it accounts for over 90% of energy use. There is considerable potential for the modernisation of biomass fuels through improved utilisation of existing resources, higher plant productivities and efficient conversion processes using advanced technologies. The interest in bioenergy is increasing rapidly, and it is widely considered as one of the main renewable energy resources of the future due to its large potential, economic viability, and various social and environmental benefits. In particular, biomass energy is among the most favourable options for reducing carbon dioxide emissions. Most of the perceived problems such as land availability, environmental impact, economic viability, and efficiency can be overcome with good management. The constraints to achieving environmentally-acceptable biomass production are not insurmountable, but should rather be seen as scientific and entrepreneurial opportunities which will yield numerous advantages at local, national and international levels in the long term.     

Biomass thermochemical conversion: A review on tar elimination from biomass catalytic gasification

Biomass is promising renewable energy because of the possibility of value-added fuels production from biomass thermochemical conversion. Among the thermochemical conversion technology, gasification could produce the H₂-rich syngas then into value-added chemicals via F-T (Fischer-Tropsch) synthesis. However, a variety of difficulties, such as tar formation, reactors impediment, complex tar cracked mechanism, etc. make it difficult to develop for further application. This paper sheds light on the developments of biomass thermochemical conversion, tar classifications, tar formation, and elimination methods. Secondly, we provide a comprehensive the state-of-the-art technologies for tar elimination, and we introduce some advanced high activity catalysts. Furthermore, many represent tar models were employed for explanation of the tar-cracked pathway, and real tar-cracked mechanism was proposed. Following this, some operational conditions and effective gasified models were concluded to give an instruction for biomass catalytic gasification.     

Systems analysis of integrating biomass gasification with pulp and paper production - Effects on economic performance, CO2 emissions and energy use

This paper evaluates system aspects of biorefineries based on biomass gasification integrated with pulp and paper production. As a case the Billerud Karlsborg mill is used. Two biomass gasification concepts are considered: BIGDME (biomass integrated gasification dimethyl ether production) and BIGCC (biomass integrated gasification combined cycle). The systems analysis is made with respect to economic performance, global CO₂ emissions and primary energy use. As reference cases, BIGDME and BIGCC integrated with district heating are considered. Biomass gasification is shown to be potentially profitable for the mill. The results are highly dependent on assumed energy market parameters, particularly policy support. With strong policies promoting biofuels or renewable electricity, the calculated opportunity to invest in a gasification-based biorefinery exceeds investment cost estimates from the literature. When integrated with district heating the BIGDME case performs better than the BIGCC case, which shows high sensitivity to heat price and annual operating time. The BIGCC cases show potential to contribute to decreased global CO₂ emissions and energy use, which the BIGDME cases do not, mainly due to high biomass demand. As biomass is a limited resource, increased biomass use due to investments in gasification plants will lead to increased use of fossil fuels elsewhere in the system.     

A review of hydrogen production via biomass gasification and its prospect in Bangladesh

Hydrogen has been using as one of the green fuel along with conventional fossil fuels which has enormous prospect. A new dimension of hydrogen energy technology can reduce the dependency on non-renewable energy sources due to the rapid depletion of fossil fuels. Hydrogen production via Biomass (Municipal solid waste, Agricultural waste and forest residue) gasification is one of the promising and economic technologies. The study highlights the hydrogen production potential from biomass through gasification technology and review the parameters effect of hydrogen production such as temperature, pressure, biomass and agent ratio, equivalence ratios, bed material, gasifying agents and catalysts effect. The study also covers the all associated steps of hydrogen separation and purification, WGS reaction, cleaning and drying, membrane separation and pressure swing adsorption (PSA). To meet the huge and rising energy demand, many countries made a multidimensional power development plan by adding different renewable, nuclear and fossil fuel sources. A large amount of biomass (total biomass production in Bangladesh is 47.71 million ton coal equivalent where 37.16, 3.49 and 7.04 MTCE are agricultural, MSW and forest residue based biomass respectively by 2016) is produced from daily uses by a big number of populations in a country. It also includes total feature of biomass gasification plant in Bangladesh.     

Upgrading of Candelilla biocrude to hydrocarbon fuels by fluid catalytic cracking

Biomass has been recognized as a major world renewable energy source to supplement declining fossil fuel sources of energy. Biomass derived transportation fuels have not only the potential to replace conventional fuels but can also be utilized as blending components for improving the quality of these fuels. The biocrude obtained from Euphorbia antisyphilitica, identified as the most potential petrocrop was investigated as a potential source for liquid fuels. The feed was studied for yield conversion data under different catalyst to feed ratio at various temperatures. Maximum middle distillates selectivity was observed at catalyst/oil ratio 4 and 6 and reaction temperature 500 °C. The main constituents of the gaseous products are C₃, C₄ and C₅. The liquid fuels are highly aromatic with low olefinic content.     

Improving the technical, environmental and social performance of wind energy systems using biomass-based energy storage

A completely renewable baseload electricity generation system is proposed by combining wind energy, compressed air energy storage, and biomass gasification. This system can eliminate problems associated with wind intermittency and provide a source of electrical energy functionally equivalent to a large fossil or nuclear power plant. Compressed air energy storage (CAES) can be economically deployed in the Midwestern US, an area with significant low-cost wind resources. CAES systems require a combustible fuel, typically natural gas, which results in fuel price risk and greenhouse gas emissions. Replacing natural gas with synfuel derived from biomass gasification eliminates the use of fossil fuels, virtually eliminating net CO₂ emissions from the system. In addition, by deriving energy completely from farm sources, this type of system may reduce some opposition to long distance transmission lines in rural areas, which may be an obstacle to large-scale wind deployment.     

Banana biomass as potential renewable energy resource: A Malaysian case study

The world has been relying on fossil fuels as its primary source of energy. This unsustainable energy source is not going to last long and thus, gradual shift towards green renewable energy should be practiced. In Malaysia, even though fossil fuel dominates the energy production, renewable energies such as hydropower and biomass are gaining popularity due to the implementation of energy policies and greater understanding on the importance of green energy. Malaysia has been well endowed with natural resources in areas such as agriculture and forestry. Thus, with the availability of feedstock, biomass energy is practical to be conducted and oil palm topped the ranking as biomass source here because of its high production. However, new sources should be sought after as to avoid the over dependency on a single source. Hence, other agriculture biomass should be considered such as banana plant biomass. This paper will discuss on its potential as a new biomass source in Malaysia. Banana plant is chosen as the subject due to its availability, high growth rates, carbon neutrality and the fact that it bears fruit only once a lifetime. Conversion of the biomass to energy can be done via combustion, supercritical water gasification and digestion to produce thermal energy and biogas. The theoretical potential power generation calculated reached maximum of 950 MW meeting more than half of the renewable energy requirement in the Fifth Fuel Policy (Eighth Malaysia Plan 2001–2005). Thus, banana biomass is feasible as a source of renewable energy in Malaysia and also other similar tropical countries in the world.     

The pollutant discharge improvement by introducing HHO gas into biomass boiler

Biomass fuel has been widely concerned because its net CO₂ emission is close to zero. Biomass boilers are known to have lower pollutant emissions than fossil fuel boilers, but in some applications, they also release high-level CO and NO. We developed a medium-sized hydrogen and oxygen (HHO) generator, with high energy conversion rate and adjustable output gas. The HHO gas was then introduced into a biomass hot air generator for mixed combustion. The experimental results showed that based on the electricity consumption of gas production and biomass fuel price, the total cost during preheating reduced. In addition, the average concentrations of CO, NO and smoke decreased by 93.0%, 22.5% and 80%, respectively. Integration of biomass fuel and HHO gas can effectively reduce pollutant emissions and save fuel, especially in areas rich in renewable energy.     

农村生物质再生资源利用的构思

生物质作为一种可再生的洁净能源,已经受到人们的高度重视,它不仅解决了能源的可持续性,而且对环境的改善起到了重要的作用.利用生物质,通过不同的转化处理体系可生产出有价值的燃料和上百种的化学物质.我国农村的生物质能源十分丰富,通过气化、快速热解和厌氧发酵技术的合理开发利用,不仅可以改善农民的生活状况,增加就业机会,而且能改善生态环境,促进农村经济可持续发展.     

Biomass energy and the environmental impacts associated with its production and utilization

Biomass is the first-ever fuel used by humankind and is also the fuel which was the mainstay of the global fuel economy till the middle of the 18th century. Then fossil fuels took over because fossil fuels were not only more abundant and denser in their energy content, but also generated less pollution when burnt, in comparison to biomass. In recent years there is a resurgence of interest in biomass energy because biomass is perceived as a carbon-neutral source of energy unlike net carbon-emitting fossil fuels of which copious use has led to global warming and ocean acidification.The paper takes stock of the various sources of biomass and the possible ways in which it can be utilized for generating energy. It then examines the environmental impacts, including impact vis a vis greenhouse gas emissions, of different biomass energy generation–utilization options.     

Hydrogen and syngas production from sewage sludge via steam gasification

High temperature steam gasification is an attractive alternative technology which can allow one to obtain high percentage of hydrogen in the syngas from low-grade fuels. Gasification is considered a clean technology for energy conversion without environmental impact using biomass and solid wastes as feedstock. Sewage sludge is considered a renewable fuel because it is sustainable and has good potential for energy recovery. In this investigation, sewage sludge samples were gasified at various temperatures to determine the evolutionary behavior of syngas characteristics and other properties of the syngas produced. The syngas characteristics were evaluated in terms of syngas yield, hydrogen production, syngas chemical analysis, and efficiency of energy conversion. In addition to gasification experiments, pyrolysis experiments were conducted for evaluating the performance of gasification over pyrolysis. The increase in reactor temperature resulted in increased generation of hydrogen. Hydrogen yield at 1000 °C was found to be 0.076 g_gas g_sample⁻¹. Steam as the gasifying agent increased the hydrogen yield three times as compared to air gasification. Sewage sludge gasification results were compared with other samples, such as, paper, food wastes and plastics. The time duration for sewage sludge gasification was longer as compared to other samples. On the other hand sewage sludge yielded more hydrogen than that from paper and food wastes.     

Progress and recent trends in biofuels

In this paper, the modern biomass-based transportation fuels such as fuels from Fischer–Tropsch synthesis, bioethanol, fatty acid (m)ethylester, biomethanol, and biohydrogen are briefly reviewed. Here, the term biofuel is referred to as liquid or gaseous fuels for the transport sector that are predominantly produced from biomass. There are several reasons for bio-fuels to be considered as relevant technologies by both developing and industrialized countries. They include energy security reasons, environmental concerns, foreign exchange savings, and socioeconomic issues related to the rural sector. The term modern biomass is generally used to describe the traditional biomass use through the efficient and clean combustion technologies and sustained supply of biomass resources, environmentally sound and competitive fuels, heat and electricity using modern conversion technologies. Modern biomass can be used for the generation of electricity and heat. Bioethanol and biodiesel as well as diesel produced from biomass by Fischer–Tropsch synthesis are the most modern biomass-based transportation fuels. Bio-ethanol is a petrol additive/substitute. It is possible that wood, straw and even household wastes may be economically converted to bio-ethanol. Bio-ethanol is derived from alcoholic fermentation of sucrose or simple sugars, which are produced from biomass by hydrolysis process. Currently crops generating starch, sugar or oil are the basis for transport fuel production. There has been renewed interest in the use of vegetable oils for making biodiesel due to its less polluting and renewable nature as against the conventional petroleum diesel fuel. Biodiesel is a renewable replacement to petroleum-based diesel. Biomass energy conversion facilities are important for obtaining bio-oil. Pyrolysis is the most important process among the thermal conversion processes of biomass. Brief summaries of the basic concepts involved in the thermochemical conversions of biomass fuels are presented. The percentage share of biomass was 62.1% of the total renewable energy sources in 1995. The reduction of greenhouse gases pollution is the main advantage of utilizing biomass energy.     

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.