Characteristics of hemicellulose, cellulose and lignin pyrolysis

Fast pyrolysis utilizes biomass to produce a product that is used both as an energy source and a feedstock for chemical production. Considerable efforts have been made to convert wood biomass to liquid fuels and chemicals since the oil crisis in mid-1970s. This review focuses on the recent developments in the wood pyrolysis and reports the characteristics of the resulting bio-oils, which are the main products of fast wood pyrolysis. Virtually any form of biomass can be considered for fast pyrolysis. Most work has been performed on wood, because of its consistency and comparability between tests. However, nearly 100 types of biomass have been tested, ranging from agricultural wastes such as straw, olive pits, and nut shells to energy crops such as miscanthus and sorghum. Forestry wastes such as bark and thinnings and other solid wastes, including sewage sludge and leather wastes, have also been studied. In this review, the main (although not exclusive) emphasis has been given to wood. The literature on woo...

Pyrolysis of Wood/Biomass for Bio-oil: A Critical Review

Sustainability is a key principle in natural resource management, and it involves operational efficiency, minimisation of environmental impact and socio-economic considerations; all of which are interdependent. It has become increasingly obvious that continued reliance on fossil fuel energy resources is unsustainable, owing to both depleting world reserves and the green house gas emissions associated with their use. Therefore, there are vigorous research initiatives aimed at developing alternative renewable and potentially carbon neutral solid, liquid and gaseous biofuels as alternative energy resources. However, alternate energy resources akin to first generation biofuels derived from terrestrial crops such as sugarcane, sugar beet, maize and rapeseed place an enormous strain on world food markets, contribute to water shortages and precipitate the destruction of the world's forests. Second generation biofuels derived from lignocellulosic agriculture and forest residues and from non-food crop feedstocks address some of the above problems; however there is concern over competing land use or required land use changes. Therefore, based on current knowledge and technology projections, third generation biofuels specifically derived from microalgae are considered to be a technically viable alternative energy resource that is devoid of the major drawbacks associated with first and second generation biofuels. Microalgae are photosynthetic microorganisms with simple growing requirements (light, sugars, CO 2 , N, P, and K) that can produce lipids, proteins and carbohydrates in large amounts over short periods of time. These products can be processed into both biofuels and valuable co-products. This study reviewed the technologies underpinning microalgae-to-biofuels systems, focusing on the biomass production, harvesting, conversion technologies, and the extraction of useful co-products. It also reviewed the synergistic coupling of microalgae propagation with carbon sequestration and wastewater treatment potential for mitigation of environmental impacts associated with energy conversion and utilisation. It was found that, whereas there are outstanding issues related to photosynthetic efficiencies and biomass output, microalgae-derived biofuels could progressively substitute a significant proportion of the fossil fuels required to meet the growing energy demand.

/pdf/biofuels-from-microalgae-a-review-of-technologies-for-1t1wwr5e69.pdf

Biofuels from microalgae—A review of technologies for production, processing, and extractions of biofuels and co-products

Energy production from biomass. (Part 2): Conversion technologies

An overview of the chemical composition of biomass

https://faculty.washington.edu/stevehar/Biomass-Overview.pdf

Energy production from biomass (Part 1): Overview of biomass.

Energy production from biomass (Part 3): Gasification technologies.

Treating organic wastes using a combination of mechanical biological treatment (MBT) and anaerobic digestion (AD) is an established process in Europe. In 2010 the UK was considered under resourced with respect to its per capita AD capacity, suggesting a significant prospect for plants
 in the UK. The ratio of plants then treating municipal solid waste (MSW) compared to biowaste, has changed in the past 10-15 years from favouring biowaste plants to plants treating residual MSW (rMSW). Contractors need to be aware of the parameters that impact on the performance of an MBT
 AD plant. To identify the key parameters, a review of available information on plant operational performance was undertaken using a wide range of sources. Operational parameters for AD processes are well-documented and provide key process design factors when designing a plant. Consolidation
 of the information obtained was assessed and a list of problems/solutions compiled that could be reviewed when considering a potential EPC contract. The 2010 list of identified problems has been compared to the current literature discussing the operational performance of MBT AD plants, to
 see if the issues have been resolved, continue to be a problem, or new issues have arisen.

Peter McKendry

Papers

Energy production from biomass (Part 1): Overview of biomass.

Energy production from biomass. (Part 2): Conversion technologies

Energy production from biomass (Part 3): Gasification technologies.

MBT Organic Waste Treatment: Lessons Learnt