Pyrolysis of waste animal fats in a fixed-bed reactor: Production and characterization of bio-oil and bio-char

Abstract: The use of renewable energy sources is becoming increasingly necessary. Biomass is considered to have potential to be used as an alternative energy source. The bio-oil obtained of biomass pyrolysis is used as fuels and chemicals products. The yield and composition of pyrolysis oil depend on biomass composition and operating parameters of the process. This review was written with a focus on parameters that influence the process, such as temperature, reaction time, heating rate, gas flow rate, feed rate, particle size and biomass composition and discusses the effect of these parameters on the yield and quality of bio-oil. Besides that, a database with different types of biomass analyzed under different operating conditions that interfere with the pyrolysis process was obtained from 206 research on the pyrolysis process found in the literature. This database can be used for a better understanding of how the composition of the biomass and the parameters of the pyrolysis process interfere with the composition and yield of the obtained products.

Abstract: The authors acknowledges the financial support by Ministry of Science, Technology, and Innovation Malaysia (MOSTI), Ministry of Higher Education Malaysia (MOHE), and Universiti Malaysia Terengganu for the conduct of the research under the E-Science fund (UMT/RMC/SF/13/52072(5), Vot no.: 52072), the Fundamental Research Grant Scheme (Project no.: FRGS/1/2013/TK05/UMT/02/2, Vot no.: 59296), and the Research Acculturation Grant Scheme (Project no.: RAGS/2012/UMT/TK07/3, Vot no.: 57085).

Abstract: Non-edible feedstocks such as animal fat wastes (AFWs) have recently increased in popularity as alternatives to vegetable oils in the production of biodiesel. They are low cost, mitigate environmental damage and increase the quality of the resultant biodiesel fuel (low NOx emissions, high Cetane number and oxidative stability). Therefore, AFWs are an excellent feedstock for biodiesel production. Here we provide a comprehensive review trends and techniques in biodiesel production from AFWs. A critical overview of homogeneous and heterogeneous (one- or two-step) catalytic transesterification of AFWs is presented. Similarly, enzyme-catalyzed transesterification and the application of supercritical fluids conversion techniques in the production of biodiesel from AFWs are thoroughly assessed. Finally, cutting edge advances in assisted transesterification processes for biodiesel production are critically reviewed.

Abstract: This paper discusses about the importance of animal fats for power generation particularly from waste chicken fat, advantages of using chicken fat for biodiesel production, different ways of oil extraction from chicken fat and various biodiesel production techniques. A detailed review has been done on the use of novel heterogeneous catalysts for transesterification process such as metal based catalysts and organic catalysts. The factors influencing transesterification parameters like molar ratio, catalyst weight percentage, reaction time and temperature has been collected from several research articles were presented in detail. In addition, the transesterification reaction is studied at different co solvents employed to increase the methyl ester conversion. Also, analyses of relative optimization techniques implementing for transesterification process parameters have been discussed thoroughly. The physico-chemical properties of chicken fat methyl ester such as kinematic viscosity, density, pour, cloud, flash and cold filter plugging point, calorific value and fatty acid compositions of chicken fat methyl ester were compared with different animal fat methyl esters. The study reveals that biodiesel produced from waste chicken fat would be a suitable replacement of edible vegetable oils due to its low cost, ease of availability and the properties of chicken fat methyl ester were within the limits of ASTM D 6751 biodiesel standards. Furthermore, the research work has to be carried out for the improvement of cycles of catalyst reusability, biodiesel purity and cost-effectiveness of biodiesel production process in future.

Abstract: Waste generated from anthropogenic activities contributes toward stresses on our natural systems through impacts associated with both production and disposal. Sustainable waste management necessitates that industries shift from the current linear model to a circular based economy, utilizing wastes as raw materials for the production of new products, eg. fuels and chemicals. Biomass and associated waste materials can be converted into value-added products using thermochemical processes. The pyrolysis process is a convenient thermochemical method, whereby biomass is efficiently converted into biofuels, biochars and BBQ briquettes; and further processing yields additional value added products, such as activated carbons, carbon black and printing ink. This paper reviews current development work and evaluates potential opportunities for food waste pyrolysis focusing on the conversion of food waste to biochar products. Overall, it was found that the constituents of the food waste together with the process conditions play a major role in the yield and composition of the produced chars. Moreover, more research work needs to be conducted on food waste to biochar and on mixed food blends in particular.

Abstract: 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...

Abstract: Biodiesel (fatty acid methyl esters), which is derived from triglycerides by transesterification with methanol, has attracted considerable attention during the past decade as a renewable, biodegradable, and nontoxic fuel. Several processes for biodiesel fuel production have been developed, among which transesterification using alkali-catalysis gives high levels of conversion of triglycerides to their corresponding methyl esters in short reaction times. This process has therefore been widely utilized for biodiesel fuel production in a number of countries. Recently, enzymatic transesterification using lipase has become more attractive for biodiesel fuel production, since the glycerol produced as a by-product can easily be recovered and the purification of fatty methyl esters is simple to accomplish. The main hurdle to the commercialization of this system is the cost of lipase production. As a means of reducing the cost, the use of whole cell biocatalysts immobilized within biomass support particles is significantly advantageous since immobilization can be achieved spontaneously during batch cultivation, and in addition, no purification is necessary. The lipase production cost can be further lowered using genetic engineering technology, such as by developing lipases with high levels of expression and/or stability towards methanol. Hence, whole cell biocatalysts appear to have great potential for industrial application.

Abstract: Efforts are under way in many countries, including India, to search for suitable alternative diesel fuels that are environment friendly. The need to search for these fuels arises mainly from the standpoint of preserving the global environment and the concern about long-term supplies of conventional hydrocarbon-based diesel fuels. Among the different possible sources, diesel fuels derived from triglycerides (vegetable oils/animal fats) present a promising alternative to substitute diesel fuels. Although triglycerides can fuel diesel engines, their high viscosities, low volatilities and poor cold flow properties have led to the investigation of various derivatives. Fatty acid methyl esters, known as biodiesel, derived from triglycerides by transesterification with methanol have received the most attention. The main advantages of using biodiesel are its renewability, better-quality exhaust gas emissions, its biodegradability and given that all the organic carbon present is photosynthetic in origin, it does not contribute to a rise in the level of carbon dioxide in the atmosphere and consequently to the greenhouse effect.

Abstract: Bio-energy is now accepted as having the potential to provide the major part of the projected renewable energy provisions of the future. There are three main routes to providing these bio-fuels—biological conversion, physical conversion and thermal conversion—all of which employ a range of chemical reactors configurations and designs. This review concentrates on thermal conversion processes and particularly the reactors that have been developed to provide the necessary conditions to optimise performance. A number of primary and secondary products can be derived as gas, liquid and solid fuels and electricity as well as a considerable number of chemicals. The basic conversion processes are summarised with their products and the main technical and non-technical barriers to implementation are identified.

Abstract: 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 summarizes 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.